SQLite

compat

compat/*

OPT_FEATURE_FLAGS = @OPT_FEATURE_FLAGS@

TCC += $(OPT_FEATURE_FLAGS)

# Add in any optional parameters specified on the make commane line
# ie.  make "OPTS=-DSQLITE_ENABLE_FOO=1 -DSQLITE_OMIT_FOO=1".
TCC += $(OPTS)

# Add in compile-time options for some libraries used by extensions
TCC += @HAVE_ZLIB@

# Version numbers and release number for the SQLite being compiled.
#
VERSION = @VERSION@
VERSION_NUMBER = @VERSION_NUMBER@
RELEASE = @RELEASE@

  $(TOP)/ext/fts3/fts3_test.c  \
  $(TOP)/ext/session/test_session.c \
  $(TOP)/ext/rbu/test_rbu.c 

# Statically linked extensions
#
TESTSRC += \
  $(TOP)/ext/expert/sqlite3expert.c \
  $(TOP)/ext/expert/test_expert.c \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/carray.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/csv.c \
  $(TOP)/ext/misc/eval.c \
  $(TOP)/ext/misc/fileio.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/fts5/fts5_tcl.c \
  $(TOP)/ext/fts5/fts5_test_mi.c \
  $(TOP)/ext/fts5/fts5_test_tok.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/mmapwarm.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/normalize.c \
  $(TOP)/ext/misc/percentile.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/remember.c \
  $(TOP)/ext/misc/series.c \
  $(TOP)/ext/misc/spellfix.c \
  $(TOP)/ext/misc/totype.c \
  $(TOP)/ext/misc/unionvtab.c \
  $(TOP)/ext/misc/wholenumber.c \
  $(TOP)/ext/misc/zipfile.c

# Source code to the library files needed by the test fixture
#
TESTSRC2 = \
  $(TOP)/src/attach.c \
  $(TOP)/src/backup.c \
  $(TOP)/src/bitvec.c \

# executables needed for testing
#
TESTPROGS = \
  testfixture$(TEXE) \
  sqlite3$(TEXE) \
  sqlite3_analyzer$(TEXE) \
  sqldiff$(TEXE) \
  dbhash$(TEXE) \
  sqltclsh$(TEXE)

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)/test/fuzzdata1.db \
  $(TOP)/test/fuzzdata2.db \
  $(TOP)/test/fuzzdata3.db \
  $(TOP)/test/fuzzdata4.db \
  $(TOP)/test/fuzzdata5.db

# Standard options to testfixture
#
TESTOPTS = --verbose=file --output=test-out.txt

# Extra compiler options for various shell tools
#
SHELL_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS4
#SHELL_OPT += -DSQLITE_ENABLE_FTS5
SHELL_OPT += -DSQLITE_ENABLE_RTREE
SHELL_OPT += -DSQLITE_ENABLE_EXPLAIN_COMMENTS
SHELL_OPT += -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
SHELL_OPT += -DSQLITE_ENABLE_STMTVTAB
SHELL_OPT += -DSQLITE_ENABLE_DBPAGE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
SHELL_OPT += -DSQLITE_ENABLE_OFFSET_SQL_FUNC
SHELL_OPT += -DSQLITE_INTROSPECTION_PRAGMAS
FUZZERSHELL_OPT = -DSQLITE_ENABLE_JSON1
FUZZCHECK_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ
FUZZCHECK_OPT += -DSQLITE_MAX_MEMORY=50000000
FUZZCHECK_OPT += -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_SRC = $(TOP)/test/fuzzcheck.c $(TOP)/test/ossfuzz.c
DBFUZZ_OPT = 

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	sqlite3.h libsqlite3.la sqlite3$(TEXE) $(HAVE_TCL:1=libtclsqlite3.la)

keywordhash.h:	$(TOP)/tool/mkkeywordhash.c
	$(BCC) -o mkkeywordhash$(BEXE) $(OPT_FEATURE_FLAGS) $(OPTS) $(TOP)/tool/mkkeywordhash.c
	./mkkeywordhash$(BEXE) >keywordhash.h

# Source files that go into making shell.c
SHELL_SRC = \
	$(TOP)/src/shell.c.in \
        $(TOP)/ext/misc/appendvfs.c \
	$(TOP)/ext/misc/shathree.c \
	$(TOP)/ext/misc/fileio.c \
	$(TOP)/ext/misc/completion.c \
	$(TOP)/ext/misc/sqlar.c \
	$(TOP)/ext/expert/sqlite3expert.c \
	$(TOP)/ext/expert/sqlite3expert.h \
	$(TOP)/ext/misc/zipfile.c \
        $(TOP)/src/test_windirent.c

shell.c:	$(SHELL_SRC) $(TOP)/tool/mkshellc.tcl
	$(TCLSH_CMD) $(TOP)/tool/mkshellc.tcl >shell.c

	./testfixture$(TEXE) $(TOP)/test/main.test $(TESTOPTS)

sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(TEXE): sqlite3_analyzer.c
	$(LTLINK) sqlite3_analyzer.c -o $@ $(LIBTCL) $(TLIBS)

sqltclsh.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/sqltclsh.tcl $(TOP)/ext/misc/appendvfs.c $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqltclsh.c.in	
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqltclsh.c.in >sqltclsh.c

sqltclsh$(TEXE): sqltclsh.c
	$(LTLINK) sqltclsh.c -o $@ $(LIBTCL) $(TLIBS)

sqlite3_expert$(TEXE): $(TOP)/ext/expert/sqlite3expert.h $(TOP)/ext/expert/sqlite3expert.c $(TOP)/ext/expert/expert.c sqlite3.c
	$(LTLINK)	$(TOP)/ext/expert/sqlite3expert.h $(TOP)/ext/expert/sqlite3expert.c $(TOP)/ext/expert/expert.c sqlite3.c -o sqlite3_expert $(TLIBS)

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \

# be used for debugging with Visual Studio.
#
!IFNDEF SPLIT_AMALGAMATION
SPLIT_AMALGAMATION = 0
!ENDIF

# <<mark>>
# Set this non-0 to have this makefile assume the Tcl shell executable
# (tclsh*.exe) is available in the PATH.  By default, this is disabled
# for compatibility with older build environments.  This setting only
# applies if TCLSH_CMD is not set manually.
#
!IFNDEF USE_TCLSH_IN_PATH
USE_TCLSH_IN_PATH = 0
!ENDIF

# Set this non-0 to use zlib, possibly compiling it from source code.
#
!IFNDEF USE_ZLIB
USE_ZLIB = 0
!ENDIF

# Set this non-0 to build zlib from source code.  This is enabled by
# default and in that case it will be assumed that the ZLIBDIR macro
# points to the top-level source code directory for zlib.
#
!IFNDEF BUILD_ZLIB
BUILD_ZLIB = 1
!ENDIF

# Set this non-0 to use the International Components for Unicode (ICU).
#
!IFNDEF USE_ICU
USE_ICU = 0
!ENDIF
# <</mark>>

!IF $(DYNAMIC_SHELL)!=0 || $(FOR_WIN10)!=0
SHELL_CORE_DEP = $(SQLITE3DLL)
!ELSE
SHELL_CORE_DEP =
!ENDIF
!ENDIF

# <<mark>>
# If zlib support is enabled, add the dependencies for it.
#
!IF $(USE_ZLIB)!=0 && $(BUILD_ZLIB)!=0
SHELL_CORE_DEP = zlib $(SHELL_CORE_DEP)
TESTFIXTURE_DEP = zlib $(TESTFIXTURE_DEP)
!ENDIF
# <</mark>>

# This is the core library that the shell executable should link with.
#
!IFNDEF SHELL_CORE_LIB
!IF $(DYNAMIC_SHELL)!=0 || $(FOR_WIN10)!=0
SHELL_CORE_LIB = $(SQLITE3LIB)
!ELSE
SHELL_CORE_LIB =

# <<mark>>
# The locations of the Tcl header and library files.  Also, the library that
# non-stubs enabled programs using Tcl must link against.  These variables
# (TCLINCDIR, TCLLIBDIR, and LIBTCL) may be overridden via the environment
# prior to running nmake in order to match the actual installed location and
# version on this machine.
#
!IFNDEF TCLDIR
TCLDIR = $(TOP)\compat\tcl
!ENDIF

!IFNDEF TCLINCDIR
TCLINCDIR = $(TCLDIR)\include
!ENDIF

!IFNDEF TCLLIBDIR
TCLLIBDIR = $(TCLDIR)\lib
!ENDIF

!IFNDEF LIBTCL
LIBTCL = tcl86.lib
!ENDIF

!IFNDEF LIBTCLSTUB
LIBTCLSTUB = tclstub86.lib
!ENDIF

!IFNDEF LIBTCLPATH
LIBTCLPATH = $(TCLDIR)\bin
!ENDIF

# The locations of the zlib header and library files.  These variables
# (ZLIBINCDIR, ZLIBLIBDIR, and ZLIBLIB) may be overridden via the environment
# prior to running nmake in order to match the actual installed (or source
# code) location on this machine.
#
!IFNDEF ZLIBDIR
ZLIBDIR = $(TOP)\compat\zlib
!ENDIF

!IFNDEF ZLIBINCDIR
ZLIBINCDIR = $(ZLIBDIR)
!ENDIF

!IFNDEF ZLIBLIBDIR
ZLIBLIBDIR = $(ZLIBDIR)
!ENDIF

!IFNDEF ZLIBLIB
!IF $(DYNAMIC_SHELL)!=0
ZLIBLIB = zdll.lib
!ELSE
ZLIBLIB = zlib.lib
!ENDIF
!ENDIF

# The locations of the ICU header and library files.  These variables
# (ICUINCDIR, ICULIBDIR, and LIBICU) may be overridden via the environment
# prior to running nmake in order to match the actual installed location on
# this machine.
#
!IFNDEF ICUDIR
ICUDIR = $(TOP)\compat\icu
!ENDIF

!IFNDEF ICUINCDIR
ICUINCDIR = $(ICUDIR)\include
!ENDIF

!IFNDEF ICULIBDIR
ICULIBDIR = $(ICUDIR)\lib
!ENDIF

!IFNDEF LIBICU
LIBICU = icuuc.lib icuin.lib
!ENDIF

# This is the command to use for tclsh - normally just "tclsh", but we may
# know the specific version we want to use.  This variable (TCLSH_CMD) may be
# overridden via the environment prior to running nmake in order to select a
# specific Tcl shell to use.
#
!IFNDEF TCLSH_CMD
!IF $(USE_TCLSH_IN_PATH)!=0 || !EXIST("$(TCLDIR)\bin\tclsh.exe")
TCLSH_CMD = tclsh
!ELSE
TCLSH_CMD = $(TCLDIR)\bin\tclsh.exe
!ENDIF
!ENDIF
# <</mark>>

# Compiler options needed for programs that use the readline() library.
#
!IFNDEF READLINE_FLAGS
READLINE_FLAGS = -DHAVE_READLINE=0

#
!IF $(DEBUG)>1 || $(SYMBOLS)!=0
TCC = $(TCC) -Zi
BCC = $(BCC) -Zi
!ENDIF

# <<mark>>
# If zlib support is enabled, add the compiler options for it.
#
!IF $(USE_ZLIB)!=0
TCC = $(TCC) -DSQLITE_HAVE_ZLIB=1
RCC = $(RCC) -DSQLITE_HAVE_ZLIB=1
TCC = $(TCC) -I$(ZLIBINCDIR)
RCC = $(RCC) -I$(ZLIBINCDIR)
!ENDIF

# If ICU support is enabled, add the compiler options for it.
#
!IF $(USE_ICU)!=0
TCC = $(TCC) -DSQLITE_ENABLE_ICU=1
RCC = $(RCC) -DSQLITE_ENABLE_ICU=1
TCC = $(TCC) -I$(TOP)\ext\icu
RCC = $(RCC) -I$(TOP)\ext\icu

LTRCOMPILE = $(RCC) -r
LTLIB = lib.exe
LTLINK = $(TCC) -Fe$@

# If requested, link to the RPCRT4 library.
#
!IF $(USE_RPCRT4_LIB)!=0
LTLIBS = $(LTLIBS) rpcrt4.lib
!ENDIF

# If a platform was set, force the linker to target that.
# Note that the vcvars*.bat family of batch files typically
# set this for you.  Otherwise, the linker will attempt
# to deduce the binary type based on the object files.
!IFDEF PLATFORM

LDFLAGS = $(LDOPTS)
!ENDIF

# <<mark>>
# Start with the Tcl related linker options.
#
!IF $(NO_TCL)==0
TCLLIBPATHS = $(TCLLIBPATHS) /LIBPATH:$(TCLLIBDIR)
TCLLIBS = $(TCLLIBS) $(LIBTCL)
!ENDIF

# If zlib support is enabled, add the linker options for it.
#
!IF $(USE_ZLIB)!=0
LTLIBPATHS = $(LTLIBPATHS) /LIBPATH:$(ZLIBLIBDIR)
LTLIBS = $(LTLIBS) $(ZLIBLIB)
!ENDIF

# If ICU support is enabled, add the linker options for it.
#
!IF $(USE_ICU)!=0
LTLIBPATHS = $(LTLIBPATHS) /LIBPATH:$(ICULIBDIR)
LTLIBS = $(LTLIBS) $(LIBICU)

  $(TOP)\ext\fts3\fts3_test.c \
  $(TOP)\ext\rbu\test_rbu.c \
  $(TOP)\ext\session\test_session.c

# Statically linked extensions.
#
TESTEXT = \
  $(TOP)\ext\expert\sqlite3expert.c \
  $(TOP)\ext\expert\test_expert.c \
  $(TOP)\ext\misc\amatch.c \
  $(TOP)\ext\misc\carray.c \
  $(TOP)\ext\misc\closure.c \
  $(TOP)\ext\misc\csv.c \
  $(TOP)\ext\misc\eval.c \
  $(TOP)\ext\misc\fileio.c \
  $(TOP)\ext\misc\fuzzer.c \
  $(TOP)\ext\fts5\fts5_tcl.c \
  $(TOP)\ext\fts5\fts5_test_mi.c \
  $(TOP)\ext\fts5\fts5_test_tok.c \
  $(TOP)\ext\misc\ieee754.c \
  $(TOP)\ext\misc\mmapwarm.c \
  $(TOP)\ext\misc\nextchar.c \
  $(TOP)\ext\misc\normalize.c \
  $(TOP)\ext\misc\percentile.c \
  $(TOP)\ext\misc\regexp.c \
  $(TOP)\ext\misc\remember.c \
  $(TOP)\ext\misc\series.c \
  $(TOP)\ext\misc\spellfix.c \
  $(TOP)\ext\misc\totype.c \
  $(TOP)\ext\misc\unionvtab.c \
  $(TOP)\ext\misc\wholenumber.c

# If use of zlib is enabled, add the "zipfile.c" source file.
#
!IF $(USE_ZLIB)!=0
TESTEXT = $(TESTEXT) $(TOP)\ext\misc\zipfile.c
!ENDIF

# Source code to the library files needed by the test fixture
# (non-amalgamation)
#
TESTSRC2 = \
  $(SRC00) \
  $(SRC01) \

#
TESTPROGS = \
  testfixture.exe \
  $(SQLITE3EXE) \
  sqlite3_analyzer.exe \
  sqlite3_checker.exe \
  sqldiff.exe \
  dbhash.exe \
  sqltclsh.exe

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)\test\fuzzdata1.db \
  $(TOP)\test\fuzzdata2.db \
  $(TOP)\test\fuzzdata3.db \
  $(TOP)\test\fuzzdata4.db \
  $(TOP)\test\fuzzdata5.db
# <</mark>>

# Additional compiler options for the shell.  These are only effective
# when the shell is not being dynamically linked.
#
!IF $(DYNAMIC_SHELL)==0 && $(FOR_WIN10)==0
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_EXPLAIN_COMMENTS -DSQLITE_ENABLE_STMTVTAB
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_DBPAGE_VTAB -DSQLITE_ENABLE_DBSTAT_VTAB
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_OFFSET_SQL_FUNC -DSQLITE_INTROSPECTION_PRAGMAS
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_RTREE
!ENDIF

# <<mark>>
# Extra compiler options for various test tools.
#
MPTESTER_COMPILE_OPTS = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS5
FUZZERSHELL_COMPILE_OPTS = -DSQLITE_ENABLE_JSON1
FUZZCHECK_COMPILE_OPTS = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ -DSQLITE_MAX_MEMORY=50000000 -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_SRC = $(TOP)\test\fuzzcheck.c $(TOP)\test\ossfuzz.c
OSSSHELL_SRC = $(TOP)\test\ossshell.c $(TOP)\test\ossfuzz.c
DBFUZZ_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION
KV_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_DIRECT_OVERFLOW_READ
DBSELFTEST_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -DSQLITE_ENABLE_RTREE -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_FTS5
ST_COMPILE_OPTS = -DSQLITE_THREADSAFE=0

ALL_TCL_TARGETS =
!ENDIF
# <</mark>>

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
core:	dll libsqlite3.lib shell

# Targets that require the Tcl library.
#
tcl:	$(ALL_TCL_TARGETS)

# This Makefile target builds all of the standard binaries.
#
all:	core tcl

# Dynamic link library section.
#
dll:	$(SQLITE3DLL)

# Shell executable.
#

tclsqlite.lo:	$(TOP)\src\tclsqlite.c $(HDR) $(SQLITE_TCL_DEP)
	$(LTCOMPILE) $(NO_WARN) -DUSE_TCL_STUBS=1 -DBUILD_sqlite -I$(TCLINCDIR) -c $(TOP)\src\tclsqlite.c

tclsqlite-shell.lo:	$(TOP)\src\tclsqlite.c $(HDR) $(SQLITE_TCL_DEP)
	$(LTCOMPILE) $(NO_WARN) -DTCLSH -DBUILD_sqlite -I$(TCLINCDIR) -c $(TOP)\src\tclsqlite.c

tclsqlite3.exe:	tclsqlite-shell.lo $(SQLITE3C) $(SQLITE3H) $(LIBRESOBJS)
	$(LTLINK) $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS) $(TCLLIBPATHS) $(LTLIBPATHS) /OUT:$@ tclsqlite-shell.lo $(LIBRESOBJS) $(TCLLIBS) $(LTLIBS) $(TLIBS)

# Rules to build opcodes.c and opcodes.h
#
opcodes.c:	opcodes.h $(TOP)\tool\mkopcodec.tcl
	$(TCLSH_CMD) $(TOP)\tool\mkopcodec.tcl opcodes.h > opcodes.c

opcodes.h:	parse.h $(TOP)\src\vdbe.c $(TOP)\tool\mkopcodeh.tcl

keywordhash.h:	$(TOP)\tool\mkkeywordhash.c mkkeywordhash.exe
	.\mkkeywordhash.exe > keywordhash.h

# Source files that go into making shell.c
SHELL_SRC = \
	$(TOP)\src\shell.c.in \
        $(TOP)\ext\misc\appendvfs.c \
	$(TOP)\ext\misc\shathree.c \
	$(TOP)\ext\misc\fileio.c \
	$(TOP)\ext\misc\completion.c \
	$(TOP)\ext\expert\sqlite3expert.c \
	$(TOP)\ext\expert\sqlite3expert.h \
	$(TOP)\src\test_windirent.c

# If use of zlib is enabled, add the "zipfile.c" source file.
#
!IF $(USE_ZLIB)!=0
SHELL_SRC = $(SHELL_SRC) $(TOP)\ext\misc\sqlar.c
SHELL_SRC = $(SHELL_SRC) $(TOP)\ext\misc\zipfile.c
!ENDIF

shell.c:	$(SHELL_SRC) $(TOP)\tool\mkshellc.tcl
	$(TCLSH_CMD) $(TOP)\tool\mkshellc.tcl > shell.c

zlib:
	pushd $(ZLIBDIR) && $(MAKE) /f win32\Makefile.msc clean $(ZLIBLIB) && popd

# Rules to build the extension objects.
#
icu.lo:	$(TOP)\ext\icu\icu.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) $(NO_WARN) -DSQLITE_CORE -c $(TOP)\ext\icu\icu.c

fts2.lo:	$(TOP)\ext\fts2\fts2.c $(HDR) $(EXTHDR)

   fts5parse.c fts5parse.h \
   $(TOP)\ext\fts5\fts5_storage.c \
   $(TOP)\ext\fts5\fts5_tokenize.c \
   $(TOP)\ext\fts5\fts5_unicode2.c \
   $(TOP)\ext\fts5\fts5_varint.c \
   $(TOP)\ext\fts5\fts5_vocab.c

LSM1_SRC = \
   $(TOP)\ext\lsm1\lsm.h \
   $(TOP)\ext\lsm1\lsmInt.h \
   $(TOP)\ext\lsm1\lsm_ckpt.c \
   $(TOP)\ext\lsm1\lsm_file.c \
   $(TOP)\ext\lsm1\lsm_log.c \
   $(TOP)\ext\lsm1\lsm_main.c \
   $(TOP)\ext\lsm1\lsm_mem.c \
   $(TOP)\ext\lsm1\lsm_mutex.c \
   $(TOP)\ext\lsm1\lsm_shared.c \
   $(TOP)\ext\lsm1\lsm_sorted.c \
   $(TOP)\ext\lsm1\lsm_str.c \
   $(TOP)\ext\lsm1\lsm_tree.c \
   $(TOP)\ext\lsm1\lsm_unix.c \
   $(TOP)\ext\lsm1\lsm_varint.c \
   $(TOP)\ext\lsm1\lsm_vtab.c \
   $(TOP)\ext\lsm1\lsm_win32.c

fts5parse.c:	$(TOP)\ext\fts5\fts5parse.y lemon.exe
	copy $(TOP)\ext\fts5\fts5parse.y .
	del /Q fts5parse.h 2>NUL
	.\lemon.exe $(REQ_FEATURE_FLAGS) $(OPT_FEATURE_FLAGS) $(EXT_FEATURE_FLAGS) $(OPTS) fts5parse.y

fts5parse.h:	fts5parse.c

fts5.c:	$(FTS5_SRC)
	$(TCLSH_CMD) $(TOP)\ext\fts5\tool\mkfts5c.tcl
	copy $(TOP)\ext\fts5\fts5.h .

lsm1.c:	$(LSM1_SRC)
	$(TCLSH_CMD) $(TOP)\ext\lsm1\tool\mklsm1c.tcl
	copy $(TOP)\ext\lsm1\lsm.h .

fts5.lo:	fts5.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) $(NO_WARN) -DSQLITE_CORE -c fts5.c

fts5_ext.lo:	fts5.c $(HDR) $(EXTHDR)
	$(LTCOMPILE) $(NO_WARN) -c fts5.c

fts5.dll:	fts5_ext.lo

TESTFIXTURE_FLAGS = -DTCLSH_INIT_PROC=sqlite3TestInit -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERVER=1 -DSQLITE_PRIVATE=""
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_CORE $(NO_WARN)
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERIES_CONSTRAINT_VERIFY=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_DEFAULT_PAGE_SIZE=1024
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_STMTVTAB
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_DBPAGE_VTAB
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_JSON1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) $(TEST_CCONV_OPTS)

TESTFIXTURE_SRC0 = $(TESTEXT) $(TESTSRC2)
TESTFIXTURE_SRC1 = $(TESTEXT) $(SQLITE3C)
!IF $(USE_AMALGAMATION)==0
TESTFIXTURE_SRC = $(TESTSRC) $(TOP)\src\tclsqlite.c $(TESTFIXTURE_SRC0)
!ELSE

	type "$(TCLINCDIR)\tcl.h" | $(TCLSH_CMD) $(TOP)\tool\replace.tcl exact tclDecls.h sqlite_tclDecls.h \
		| $(TCLSH_CMD) $(TOP)\tool\replace.tcl regsub "typedef (.*?)\(Tcl_" "typedef \1 (SQLITE_TCLAPI Tcl_" \
		| $(TCLSH_CMD) $(TOP)\tool\replace.tcl exact "void (*freeProc)" "void (SQLITE_TCLAPI *freeProc)" \
		| $(TCLSH_CMD) $(TOP)\tool\replace.tcl exact "Tcl_HashEntry *(*findProc)" "Tcl_HashEntry *(SQLITE_TCLAPI *findProc)" \
		| $(TCLSH_CMD) $(TOP)\tool\replace.tcl exact "Tcl_HashEntry *(*createProc)" "Tcl_HashEntry *(SQLITE_TCLAPI *createProc)" >> $(SQLITETCLH)
!ENDIF

testfixture.exe:	$(TESTFIXTURE_SRC) $(TESTFIXTURE_DEP) $(SQLITE3H) $(LIBRESOBJS) $(HDR) $(SQLITE_TCL_DEP)
	$(LTLINK) -DSQLITE_NO_SYNC=1 $(TESTFIXTURE_FLAGS) \
		-DBUILD_sqlite -I$(TCLINCDIR) \
		$(TESTFIXTURE_SRC) \
		/link $(LDFLAGS) $(LTLINKOPTS) $(TCLLIBPATHS) $(LTLIBPATHS) $(LIBRESOBJS) $(TCLLIBS) $(LTLIBS) $(TLIBS)

extensiontest:	testfixture.exe testloadext.dll
	@set PATH=$(LIBTCLPATH);$(PATH)
	.\testfixture.exe $(TOP)\test\loadext.test $(TESTOPTS)

fulltest:	$(TESTPROGS) fuzztest
	@set PATH=$(LIBTCLPATH);$(PATH)

	.\testfixture.exe $(TOP)\test\main.test $(TESTOPTS)

sqlite3_analyzer.c:	$(SQLITE3C) $(SQLITE3H) $(TOP)\src\tclsqlite.c $(TOP)\tool\spaceanal.tcl $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in $(SQLITE_TCL_DEP)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in > $@

sqlite3_analyzer.exe:	sqlite3_analyzer.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_analyzer.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(TCLLIBPATHS) $(LTLIBPATHS) $(LIBRESOBJS) $(TCLLIBS) $(LTLIBS) $(TLIBS)

sqltclsh.c: sqlite3.c $(TOP)\src\tclsqlite.c $(TOP)\tool\sqltclsh.tcl $(TOP)\ext\misc\appendvfs.c $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqltclsh.c.in
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqltclsh.c.in >sqltclsh.c

sqltclsh.exe: sqltclsh.c  $(SHELL_CORE_DEP) $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqltclsh.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(TCLLIBPATHS) $(LTLIBPATHS) $(LIBRESOBJS) $(TCLLIBS) $(LTLIBS) $(TLIBS)

sqlite3_expert.exe: $(SQLITE3C) $(TOP)\ext\expert\sqlite3expert.h $(TOP)\ext\expert\sqlite3expert.c $(TOP)\ext\expert\expert.c
	$(LTLINK) $(NO_WARN)	$(TOP)\ext\expert\sqlite3expert.c $(TOP)\ext\expert\expert.c $(SQLITE3C) $(TLIBS)

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\ext\repair\sqlite3_checker.c.in > $@

sqlite3_checker.exe:	sqlite3_checker.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_checker.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(TCLLIBPATHS) $(LTLIBPATHS) $(LIBRESOBJS) $(TCLLIBS) $(LTLIBS) $(TLIBS)

dbdump.exe:	$(TOP)\ext\misc\dbdump.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DDBDUMP_STANDALONE $(TOP)\ext\misc\dbdump.c $(SQLITE3C) \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS)

testloadext.lo:	$(TOP)\src\test_loadext.c
	$(LTCOMPILE) $(NO_WARN) -c $(TOP)\src\test_loadext.c

	del /Q mptester.exe wordcount.exe rbu.exe srcck1.exe 2>NUL
	del /Q sqlite3.c sqlite3-*.c 2>NUL
	del /Q sqlite3rc.h 2>NUL
	del /Q shell.c sqlite3ext.h sqlite3session.h 2>NUL
	del /Q sqlite3_analyzer.exe sqlite3_analyzer.c 2>NUL
	del /Q sqlite-*-output.vsix 2>NUL
	del /Q fuzzershell.exe fuzzcheck.exe sqldiff.exe dbhash.exe 2>NUL
	del /Q sqltclsh.exe 2>NUL
	del /Q fts5.* fts5parse.* 2>NUL
	del /Q lsm.h lsm1.c 2>NUL
# <</mark>>

<h1 align="center">SQLite Source Repository</h1>

This repository contains the complete source code for the SQLite database
engine.  Some test scripts are also included.  However, many other test scripts
and most of the documentation are managed separately.

If you are reading this on a Git mirror someplace, you are doing it wrong.
The [official repository](https://www.sqlite.org/src/) is better.  Go there
now.

## Obtaining The Code

SQLite sources are managed using the
[Fossil](https://www.fossil-scm.org/), a distributed version control system
that was specifically designed to support SQLite development.
If you do not want to use Fossil, you can download tarballs or ZIP
archives or [SQLite archives](https://sqlite.org/cli.html#sqlar) as follows:

  *  Lastest trunk check-in as
     [Tarball](https://www.sqlite.org/src/tarball/sqlite.tar.gz),
     [ZIP-archive](https://www.sqlite.org/src/zip/sqlite.zip), or
     [SQLite-archive](https://www.sqlite.org/src/sqlar/sqlite.sqlar).

  *  Latest release as
     [Tarball](https://www.sqlite.org/src/tarball/sqlite.tar.gz?r=release),
     [ZIP-archive](https://www.sqlite.org/src/zip/sqlite.zip?r=release), or
     [SQLite-archive](https://www.sqlite.org/src/sqlar/sqlite.sqlar?r=release).

  *  For other check-ins, substitute an appropriate branch name or
     tag or hash prefix for "release" in the URLs of the previous
     bullet.  Or browse the [timeline](https://www.sqlite.org/src/timeline)
     to locate the check-in desired, click on its information page link,
     then click on the "Tarball" or "ZIP Archive" links on the information
     page.

to the "sqlite3.dll" command line above.  When debugging into the SQLite
code, adding the "DEBUG=1" argument to one of the above command lines is
recommended.

SQLite does not require [Tcl](http://www.tcl.tk/) to run, but a Tcl installation
is required by the makefiles (including those for MSVC).  SQLite contains
a lot of generated code and Tcl is used to do much of that code generation.


## Source Code Tour

Most of the core source files are in the **src/** subdirectory.  The
**src/** folder also contains files used to build the "testfixture" test
harness. The names of the source files used by "testfixture" all begin
with "test".
The **src/** also contains the "shell.c" file
which is the main program for the "sqlite3.exe"
[command-line shell](https://sqlite.org/cli.html) and
the "tclsqlite.c" file which implements the
[Tcl bindings](https://sqlite.org/tclsqlite.html) for SQLite.
(Historical note:  SQLite began as a Tcl
extension and only later escaped to the wild as an independent library.)

Test scripts and programs are found in the **test/** subdirectory.
Addtional test code is found in other source repositories.
See [How SQLite Is Tested](http://www.sqlite.org/testing.html) for
additional information.

the src/parse.y file.  The conversion of "parse.y" into "parse.c" is done
by the [lemon](./doc/lemon.html) LALR(1) parser generator.  The source code
for lemon is at tool/lemon.c.  Lemon uses the tool/lempar.c file as a
template for generating its parser.

Lemon also generates the **parse.h** header file, at the same time it
generates parse.c. But the parse.h header file is
modified further (to add additional symbols) using the ./addopcodes.tcl
Tcl script.

The **opcodes.h** header file contains macros that define the numbers
corresponding to opcodes in the "VDBE" virtual machine.  The opcodes.h
file is generated by the scanning the src/vdbe.c source file.  The
Tcl script at ./mkopcodeh.tcl does this scan and generates opcodes.h.
A second Tcl script, ./mkopcodec.tcl, then scans opcodes.h to generate
the **opcodes.c** source file, which contains a reverse mapping from
opcode-number to opcode-name that is used for EXPLAIN output.

The **keywordhash.h** header file contains the definition of a hash table
that maps SQL language keywords (ex: "CREATE", "SELECT", "INDEX", etc.) into
the numeric codes used by the parse.c parser.  The keywordhash.h file is
generated by a C-language program at tool mkkeywordhash.c.

tool/mksqlite3c.tcl script is run to copy them all together in just the
right order while resolving internal "#include" references.

The amalgamation source file is more than 200K lines long.  Some symbolic
debuggers (most notably MSVC) are unable to deal with files longer than 64K
lines.  To work around this, a separate Tcl script, tool/split-sqlite3c.tcl,
can be run on the amalgamation to break it up into a single small C file
called **sqlite3-all.c** that does #include on about seven other files
named **sqlite3-1.c**, **sqlite3-2.c**, ..., **sqlite3-7.c**.  In this way,
all of the source code is contained within a single translation unit so
that the compiler can do extra cross-procedure optimization, but no
individual source file exceeds 32K lines in length.

## How It All Fits Together

SQLite is modular in design.

Key files:

  *  **sqlite.h.in** - This file defines the public interface to the SQLite
     library.  Readers will need to be familiar with this interface before
     trying to understand how the library works internally.

  *  **sqliteInt.h** - this header file defines many of the data objects
     used internally by SQLite.  In addition to "sqliteInt.h", some
     subsystems have their own header files.

  *  **parse.y** - This file describes the LALR(1) grammar that SQLite uses
     to parse SQL statements, and the actions that are taken at each step
     in the parsing process.

  *  **vdbe.c** - This file implements the virtual machine that runs
     prepared statements.  There are various helper files whose names
     begin with "vdbe".  The VDBE has access to the vdbeInt.h header file
     which defines internal data objects.  The rest of SQLite interacts
     with the VDBE through an interface defined by vdbe.h.

  *  **where.c** - This file (together with its helper files named
     by "where*.c") analyzes the WHERE clause and generates
     virtual machine code to run queries efficiently.  This file is
     sometimes called the "query optimizer".  It has its own private
     header file, whereInt.h, that defines data objects used internally.

  *  **btree.c** - This file contains the implementation of the B-Tree
     storage engine used by SQLite.  The interface to the rest of the system
     is defined by "btree.h".  The "btreeInt.h" header defines objects
     used internally by btree.c and not published to the rest of the system.

  *  **pager.c** - This file contains the "pager" implementation, the
     module that implements transactions.  The "pager.h" header file
     defines the interface between pager.c and the rest of the system.

  *  **os_unix.c** and **os_win.c** - These two files implement the interface
     between SQLite and the underlying operating system using the run-time
     pluggable VFS interface.

  *  **shell.c.in** - This file is not part of the core SQLite library.  This
     is the file that, when linked against sqlite3.a, generates the
     "sqlite3.exe" command-line shell.  The "shell.c.in" file is transformed
     into "shell.c" as part of the build process.

  *  **tclsqlite.c** - This file implements the Tcl bindings for SQLite.  It
     is not part of the core SQLite library.  But as most of the tests in this
     repository are written in Tcl, the Tcl language bindings are important.

  *  **test*.c** - Files in the src/ folder that begin with "test" go into
     building the "testfixture.exe" program.  The testfixture.exe program is
     an enhanced Tcl shell.  The testfixture.exe program runs scripts in the
     test/ folder to validate the core SQLite code.  The testfixture program
     (and some other test programs too) is build and run when you type
     "make test".

  *  **ext/misc/json1.c** - This file implements the various JSON functions
     that are build into SQLite.

There are many other source files.  Each has a succinct header comment that
describes its purpose and role within the larger system.


## Contacts

The main SQLite webpage is [http://www.sqlite.org/](http://www.sqlite.org/)
with geographically distributed backups at
[http://www2.sqlite.org/](http://www2.sqlite.org) and
[http://www3.sqlite.org/](http://www3.sqlite.org).

3.23.0

AM_CFLAGS = @THREADSAFE_FLAGS@ @DYNAMIC_EXTENSION_FLAGS@ @FTS5_FLAGS@ @JSON1_FLAGS@ @ZLIB_FLAGS@ @SESSION_FLAGS@ -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE

lib_LTLIBRARIES = libsqlite3.la
libsqlite3_la_SOURCES = sqlite3.c
libsqlite3_la_LDFLAGS = -no-undefined -version-info 8:6:8

bin_PROGRAMS = sqlite3
sqlite3_SOURCES = shell.c sqlite3.h
EXTRA_sqlite3_SOURCES = sqlite3.c
sqlite3_LDADD = @EXTRA_SHELL_OBJ@ @READLINE_LIBS@
sqlite3_DEPENDENCIES = @EXTRA_SHELL_OBJ@
sqlite3_CFLAGS = $(AM_CFLAGS) -DSQLITE_ENABLE_EXPLAIN_COMMENTS -DSQLITE_ENABLE_DBPAGE_VTAB -DSQLITE_ENABLE_STMTVTAB -DSQLITE_ENABLE_DBSTAT_VTAB $(SHELL_CFLAGS)

include_HEADERS = sqlite3.h sqlite3ext.h

EXTRA_DIST = sqlite3.1 tea Makefile.msc sqlite3.rc README.txt Replace.cs
pkgconfigdir = ${libdir}/pkgconfig
pkgconfig_DATA = sqlite3.pc

!IFNDEF SHELL_CORE_DEP
!IF $(DYNAMIC_SHELL)!=0 || $(FOR_WIN10)!=0
SHELL_CORE_DEP = $(SQLITE3DLL)
!ELSE
SHELL_CORE_DEP =
!ENDIF
!ENDIF


# This is the core library that the shell executable should link with.
#
!IFNDEF SHELL_CORE_LIB
!IF $(DYNAMIC_SHELL)!=0 || $(FOR_WIN10)!=0
SHELL_CORE_LIB = $(SQLITE3LIB)
!ELSE

LTRCOMPILE = $(RCC) -r
LTLIB = lib.exe
LTLINK = $(TCC) -Fe$@

# If requested, link to the RPCRT4 library.
#
!IF $(USE_RPCRT4_LIB)!=0
LTLIBS = $(LTLIBS) rpcrt4.lib
!ENDIF

# If a platform was set, force the linker to target that.
# Note that the vcvars*.bat family of batch files typically
# set this for you.  Otherwise, the linker will attempt
# to deduce the binary type based on the object files.
!IFDEF PLATFORM

# Additional compiler options for the shell.  These are only effective
# when the shell is not being dynamically linked.
#
!IF $(DYNAMIC_SHELL)==0 && $(FOR_WIN10)==0
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_EXPLAIN_COMMENTS -DSQLITE_ENABLE_STMTVTAB
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_DBPAGE_VTAB -DSQLITE_ENABLE_DBSTAT_VTAB
SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_OFFSET_SQL_FUNC -DSQLITE_INTROSPECTION_PRAGMAS
!ENDIF


# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
core:	dll shell

# Targets that require the Tcl library.
#
tcl:	$(ALL_TCL_TARGETS)

# This Makefile target builds all of the standard binaries.
#
all:	core tcl

# Dynamic link library section.
#
dll:	$(SQLITE3DLL)

# Shell executable.
#

else
  EXTRA_SHELL_OBJ=libsqlite3.la
fi
AC_SUBST(EXTRA_SHELL_OBJ)
#-----------------------------------------------------------------------

AC_CHECK_FUNCS(posix_fallocate)
AC_CHECK_HEADERS(zlib.h,[
  AC_SEARCH_LIBS(deflate,z,[ZLIB_FLAGS="-DSQLITE_HAVE_ZLIB"])
])
AC_SUBST(ZLIB_FLAGS)

AC_SEARCH_LIBS(system,,,[SHELL_CFLAGS="-DSQLITE_NOHAVE_SYSTEM"])
AC_SUBST(SHELL_CFLAGS)

#-----------------------------------------------------------------------
# UPDATE: Maybe it's better if users just set CFLAGS before invoking
# configure. This option doesn't really add much...
#
#   --enable-tempstore
#

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.69 for sqlite 3.23.0.
#
#
# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
#
#
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.

subdirs=
MFLAGS=
MAKEFLAGS=

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.23.0'
PACKAGE_STRING='sqlite 3.23.0'
PACKAGE_BUGREPORT=''
PACKAGE_URL=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H

#endif"

ac_subst_vars='LTLIBOBJS
LIBOBJS
BUILD_CFLAGS
USE_GCOV
OPT_FEATURE_FLAGS
HAVE_ZLIB
USE_AMALGAMATION
TARGET_DEBUG
TARGET_HAVE_EDITLINE
TARGET_HAVE_READLINE
TARGET_READLINE_INC
TARGET_READLINE_LIBS
HAVE_TCL

#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.23.0 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.23.0:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]

    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.23.0
generated by GNU Autoconf 2.69

Copyright (C) 2012 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit

  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno

} # ac_fn_c_check_header_mongrel
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.23.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking the name lister ($NM) interface" >&5
$as_echo_n "checking the name lister ($NM) interface... " >&6; }
if ${lt_cv_nm_interface+:} false; then :
  $as_echo_n "(cached) " >&6
else
  lt_cv_nm_interface="BSD nm"
  echo "int some_variable = 0;" > conftest.$ac_ext
  (eval echo "\"\$as_me:3935: $ac_compile\"" >&5)
  (eval "$ac_compile" 2>conftest.err)
  cat conftest.err >&5
  (eval echo "\"\$as_me:3938: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
  (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
  cat conftest.err >&5
  (eval echo "\"\$as_me:3941: output\"" >&5)
  cat conftest.out >&5
  if $GREP 'External.*some_variable' conftest.out > /dev/null; then
    lt_cv_nm_interface="MS dumpbin"
  fi
  rm -f conftest*
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $lt_cv_nm_interface" >&5

	;;
    esac
  fi
  rm -rf conftest*
  ;;
*-*-irix6*)
  # Find out which ABI we are using.
  echo '#line 5147 "configure"' > conftest.$ac_ext
  if { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_compile\""; } >&5
  (eval $ac_compile) 2>&5
  ac_status=$?
  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
  test $ac_status = 0; }; then
    if test "$lt_cv_prog_gnu_ld" = yes; then
      case `/usr/bin/file conftest.$ac_objext` in

   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   # The option is referenced via a variable to avoid confusing sed.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:6672: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
   echo "$as_me:6676: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings other than the usual output.
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' >conftest.exp
     $SED '/^$/d; /^ *+/d' conftest.err >conftest.er2
     if test ! -s conftest.er2 || diff conftest.exp conftest.er2 >/dev/null; then
       lt_cv_prog_compiler_rtti_exceptions=yes

   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   # The option is referenced via a variable to avoid confusing sed.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:7011: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
   echo "$as_me:7015: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings other than the usual output.
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' >conftest.exp
     $SED '/^$/d; /^ *+/d' conftest.err >conftest.er2
     if test ! -s conftest.er2 || diff conftest.exp conftest.er2 >/dev/null; then
       lt_cv_prog_compiler_pic_works=yes

   # (2) before a word containing "conftest.", or (3) at the end.
   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:7116: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
   echo "$as_me:7120: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' > out/conftest.exp
     $SED '/^$/d; /^ *+/d' out/conftest.err >out/conftest.er2
     if test ! -s out/conftest.er2 || diff out/conftest.exp out/conftest.er2 >/dev/null; then

   # (2) before a word containing "conftest.", or (3) at the end.
   # Note that $ac_compile itself does not contain backslashes and begins
   # with a dollar sign (not a hyphen), so the echo should work correctly.
   lt_compile=`echo "$ac_compile" | $SED \
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
   (eval echo "\"\$as_me:7171: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
   echo "$as_me:7175: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings
     $ECHO "X$_lt_compiler_boilerplate" | $Xsed -e '/^$/d' > out/conftest.exp
     $SED '/^$/d; /^ *+/d' out/conftest.err >out/conftest.er2
     if test ! -s out/conftest.er2 || diff out/conftest.exp out/conftest.er2 >/dev/null; then

else
  	  if test "$cross_compiling" = yes; then :
  lt_cv_dlopen_self=cross
else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<_LT_EOF
#line 9551 "configure"
#include "confdefs.h"

#if HAVE_DLFCN_H
#include <dlfcn.h>
#endif

#include <stdio.h>

else
  	  if test "$cross_compiling" = yes; then :
  lt_cv_dlopen_self_static=cross
else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<_LT_EOF
#line 9647 "configure"
#include "confdefs.h"

#if HAVE_DLFCN_H
#include <dlfcn.h>
#endif

#include <stdio.h>

  use_amalgamation=yes
fi

if test "${use_amalgamation}" != "yes" ; then
  USE_AMALGAMATION=0
fi


#########
# Look for zlib.  Only needed by extensions and by the sqlite3.exe shell
for ac_header in zlib.h
do :
  ac_fn_c_check_header_mongrel "$LINENO" "zlib.h" "ac_cv_header_zlib_h" "$ac_includes_default"
if test "x$ac_cv_header_zlib_h" = xyes; then :
  cat >>confdefs.h <<_ACEOF
#define HAVE_ZLIB_H 1
_ACEOF

fi

done

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing deflate" >&5
$as_echo_n "checking for library containing deflate... " >&6; }
if ${ac_cv_search_deflate+:} false; then :
  $as_echo_n "(cached) " >&6
else
  ac_func_search_save_LIBS=$LIBS
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h.  */

/* Override any GCC internal prototype to avoid an error.
   Use char because int might match the return type of a GCC
   builtin and then its argument prototype would still apply.  */
#ifdef __cplusplus
extern "C"
#endif
char deflate ();
int
main ()
{
return deflate ();
  ;
  return 0;
}
_ACEOF
for ac_lib in '' z; do
  if test -z "$ac_lib"; then
    ac_res="none required"
  else
    ac_res=-l$ac_lib
    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
  fi
  if ac_fn_c_try_link "$LINENO"; then :
  ac_cv_search_deflate=$ac_res
fi
rm -f core conftest.err conftest.$ac_objext \
    conftest$ac_exeext
  if ${ac_cv_search_deflate+:} false; then :
  break
fi
done
if ${ac_cv_search_deflate+:} false; then :

else
  ac_cv_search_deflate=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_deflate" >&5
$as_echo "$ac_cv_search_deflate" >&6; }
ac_res=$ac_cv_search_deflate
if test "$ac_res" != no; then :
  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
  HAVE_ZLIB="-DSQLITE_HAVE_ZLIB=1"
else
  HAVE_ZLIB=""
fi



#########
# See whether we should allow loadable extensions
# Check whether --enable-load-extension was given.
if test "${enable_load_extension+set}" = set; then :
  enableval=$enable_load_extension; use_loadextension=$enableval
else

test $as_write_fail = 0 && chmod +x $CONFIG_STATUS || ac_write_fail=1

cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
# Save the log message, to keep $0 and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.23.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@

Report bugs to the package provider."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
ac_cs_version="\\
sqlite config.status 3.23.0
configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

Copyright (C) 2012 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

      [Disable the amalgamation and instead build all files separately]),
      [use_amalgamation=$enableval],[use_amalgamation=yes])
if test "${use_amalgamation}" != "yes" ; then
  USE_AMALGAMATION=0
fi
AC_SUBST(USE_AMALGAMATION)

#########
# Look for zlib.  Only needed by extensions and by the sqlite3.exe shell
AC_CHECK_HEADERS(zlib.h)
AC_SEARCH_LIBS(deflate, z, [HAVE_ZLIB="-DSQLITE_HAVE_ZLIB=1"], [HAVE_ZLIB=""])
AC_SUBST(HAVE_ZLIB)

#########
# See whether we should allow loadable extensions
AC_ARG_ENABLE(load-extension, AC_HELP_STRING([--disable-load-extension],
      [Disable loading of external extensions]),
      [use_loadextension=$enableval],[use_loadextension=yes])
if test "${use_loadextension}" = "yes" ; then
  OPT_FEATURE_FLAGS=""

## SQLite Expert Extension

This folder contains code for a simple system to propose useful indexes
given a database and a set of SQL queries. It works as follows:

  1. The user database schema is copied to a temporary database.

  1. All SQL queries are prepared against the temporary database.
     Information regarding the WHERE and ORDER BY clauses, and other query
     features that affect index selection are recorded.

  1. The information gathered in step 2 is used to create candidate 
     indexes - indexes that the planner might have made use of in the previous
     step, had they been available.

  1. A subset of the data in the user database is used to generate statistics
     for all existing indexes and the candidate indexes generated in step 3
     above.

  1. The SQL queries are prepared a second time. If the planner uses any
     of the indexes created in step 3, they are recommended to the user.

# C API

The SQLite expert C API is defined in sqlite3expert.h. Most uses will proceed
as follows:

  1. An sqlite3expert object is created by calling **sqlite3\_expert\_new()**.
     A database handle opened by the user is passed as an argument.

  1. The sqlite3expert object is configured with one or more SQL statements
     by making one or more calls to **sqlite3\_expert\_sql()**. Each call may
     specify a single SQL statement, or multiple statements separated by
     semi-colons.
  
  1. Optionally, the **sqlite3\_expert\_config()** API may be used to 
     configure the size of the data subset used to generate index statistics.
     Using a smaller subset of the data can speed up the analysis.

  1. **sqlite3\_expert\_analyze()** is called to run the analysis.

  1. One or more calls are made to **sqlite3\_expert\_report()** to extract
     components of the results of the analysis.

  1. **sqlite3\_expert\_destroy()** is called to free all resources.

Refer to comments in sqlite3expert.h for further details.

# sqlite3_expert application

The file "expert.c" contains the code for a command line application that
uses the API described above. It can be compiled with (for example):

<pre>
  gcc -O2 sqlite3.c expert.c sqlite3expert.c -o sqlite3_expert
</pre>

Assuming the database is named "test.db", it can then be run to analyze a
single query:

<pre>
  ./sqlite3_expert -sql &lt;sql-query&gt; test.db
</pre>

Or an entire text file worth of queries with:

<pre>
  ./sqlite3_expert -file &lt;text-file&gt; test.db
</pre>

By default, sqlite3\_expert generates index statistics using all the data in
the user database. For a large database, this may be prohibitively time
consuming. The "-sample" option may be used to configure sqlite3\_expert to
generate statistics based on an integer percentage of the user database as
follows:

<pre>
  # Generate statistics based on 25% of the user database rows:
  ./sqlite3_expert -sample 25 -sql &lt;sql-query&gt; test.db

  # Do not generate any statistics at all:
  ./sqlite3_expert -sample 0 -sql &lt;sql-query&gt; test.db
</pre>

/*
** 2017 April 07
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/


#include <sqlite3.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "sqlite3expert.h"


static void option_requires_argument(const char *zOpt){
  fprintf(stderr, "Option requires an argument: %s\n", zOpt);
  exit(-3);
}

static int option_integer_arg(const char *zVal){
  return atoi(zVal);
}

static void usage(char **argv){
  fprintf(stderr, "\n");
  fprintf(stderr, "Usage %s ?OPTIONS? DATABASE\n", argv[0]);
  fprintf(stderr, "\n");
  fprintf(stderr, "Options are:\n");
  fprintf(stderr, "  -sql SQL   (analyze SQL statements passed as argument)\n");
  fprintf(stderr, "  -file FILE (read SQL statements from file FILE)\n");
  fprintf(stderr, "  -verbose LEVEL (integer verbosity level. default 1)\n");
  fprintf(stderr, "  -sample PERCENT (percent of db to sample. default 100)\n");
  exit(-1);
}

static int readSqlFromFile(sqlite3expert *p, const char *zFile, char **pzErr){
  FILE *in = fopen(zFile, "rb");
  long nIn;
  size_t nRead;
  char *pBuf;
  int rc;
  if( in==0 ){
    *pzErr = sqlite3_mprintf("failed to open file %s\n", zFile);
    return SQLITE_ERROR;
  }
  fseek(in, 0, SEEK_END);
  nIn = ftell(in);
  rewind(in);
  pBuf = sqlite3_malloc64( nIn+1 );
  nRead = fread(pBuf, nIn, 1, in);
  fclose(in);
  if( nRead!=1 ){
    sqlite3_free(pBuf);
    *pzErr = sqlite3_mprintf("failed to read file %s\n", zFile);
    return SQLITE_ERROR;
  }
  pBuf[nIn] = 0;
  rc = sqlite3_expert_sql(p, pBuf, pzErr);
  sqlite3_free(pBuf);
  return rc;
}

int main(int argc, char **argv){
  const char *zDb;
  int rc = 0;
  char *zErr = 0;
  int i;
  int iVerbose = 1;               /* -verbose option */

  sqlite3 *db = 0;
  sqlite3expert *p = 0;

  if( argc<2 ) usage(argv);
  zDb = argv[argc-1];
  if( zDb[0]=='-' ) usage(argv);
  rc = sqlite3_open(zDb, &db);
  if( rc!=SQLITE_OK ){
    fprintf(stderr, "Cannot open db file: %s - %s\n", zDb, sqlite3_errmsg(db));
    exit(-2);
  }

  p = sqlite3_expert_new(db, &zErr);
  if( p==0 ){
    fprintf(stderr, "Cannot run analysis: %s\n", zErr);
    rc = 1;
  }else{
    for(i=1; i<(argc-1); i++){
      char *zArg = argv[i];
      if( zArg[0]=='-' && zArg[1]=='-' && zArg[2]!=0 ) zArg++;
      int nArg = (int)strlen(zArg);
      if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-file", nArg) ){
        if( ++i==(argc-1) ) option_requires_argument("-file");
        rc = readSqlFromFile(p, argv[i], &zErr);
      }

      else if( nArg>=3 && 0==sqlite3_strnicmp(zArg, "-sql", nArg) ){
        if( ++i==(argc-1) ) option_requires_argument("-sql");
        rc = sqlite3_expert_sql(p, argv[i], &zErr);
      }

      else if( nArg>=3 && 0==sqlite3_strnicmp(zArg, "-sample", nArg) ){
        int iSample;
        if( ++i==(argc-1) ) option_requires_argument("-sample");
        iSample = option_integer_arg(argv[i]);
        sqlite3_expert_config(p, EXPERT_CONFIG_SAMPLE, iSample);
      }

      else if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-verbose", nArg) ){
        if( ++i==(argc-1) ) option_requires_argument("-verbose");
        iVerbose = option_integer_arg(argv[i]);
      }

      else{
        usage(argv);
      }
    }
  }

  if( rc==SQLITE_OK ){
    rc = sqlite3_expert_analyze(p, &zErr);
  }

  if( rc==SQLITE_OK ){
    int nQuery = sqlite3_expert_count(p);
    if( iVerbose>0 ){
      const char *zCand = sqlite3_expert_report(p,0,EXPERT_REPORT_CANDIDATES);
      fprintf(stdout, "-- Candidates -------------------------------\n");
      fprintf(stdout, "%s\n", zCand);
    }
    for(i=0; i<nQuery; i++){
      const char *zSql = sqlite3_expert_report(p, i, EXPERT_REPORT_SQL);
      const char *zIdx = sqlite3_expert_report(p, i, EXPERT_REPORT_INDEXES);
      const char *zEQP = sqlite3_expert_report(p, i, EXPERT_REPORT_PLAN);
      if( zIdx==0 ) zIdx = "(no new indexes)\n";
      if( iVerbose>0 ){
        fprintf(stdout, "-- Query %d ----------------------------------\n",i+1);
        fprintf(stdout, "%s\n\n", zSql);
      }
      fprintf(stdout, "%s\n%s\n", zIdx, zEQP);
    }
  }else{
    fprintf(stderr, "Error: %s\n", zErr ? zErr : "?");
  }

  sqlite3_expert_destroy(p);
  sqlite3_free(zErr);
  return rc;
}

# 2009 Nov 11
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# The focus of this file is testing the CLI shell tool. Specifically,
# the ".recommend" command.
#
#

# Test plan:
#
#
if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
}
source $testdir/tester.tcl
set testprefix expert1

if {[info commands sqlite3_expert_new]==""} {
  finish_test
  return
}

set CLI [test_binary_name sqlite3]
set CMD [test_binary_name sqlite3_expert]

proc squish {txt} {
  regsub -all {[[:space:]]+} $txt { }
}

proc do_setup_rec_test {tn setup sql res} {
  reset_db
  db eval $setup
  uplevel [list do_rec_test $tn $sql $res]
}

foreach {tn setup} {
  1 {
    if {![file executable $CMD]} { continue }

    proc do_rec_test {tn sql res} {
      set res [squish [string trim $res]]
      set tst [subst -nocommands { 
        squish [string trim [exec $::CMD -verbose 0 -sql {$sql;} test.db]]
      }]
      uplevel [list do_test $tn $tst $res]
    }
  }
  2 {
    if {[info commands sqlite3_expert_new]==""} { continue }

    proc do_rec_test {tn sql res} {
      set expert [sqlite3_expert_new db]
      $expert sql $sql
      $expert analyze

      set result [list]
      for {set i 0} {$i < [$expert count]} {incr i} {
        set idx [string trim [$expert report $i indexes]]
        if {$idx==""} {set idx "(no new indexes)"}
        lappend result $idx
        lappend result [string trim [$expert report $i plan]]
      }

      $expert destroy

      set tst [subst -nocommands {set {} [squish [join {$result}]]}]
      uplevel [list do_test $tn $tst [string trim [squish $res]]]
    }
  }
  3 {
    if {![file executable $CLI]} { continue }

    proc do_rec_test {tn sql res} {
      set res [squish [string trim $res]]
      set tst [subst -nocommands { 
        squish [string trim [exec $::CLI test.db ".expert" {$sql;}]]
      }]
      uplevel [list do_test $tn $tst $res]
    }
  }
} {

  eval $setup


do_setup_rec_test $tn.1 { CREATE TABLE t1(a, b, c) } {
  SELECT * FROM t1
} {
  (no new indexes)
  0|0|0|SCAN TABLE t1
}

do_setup_rec_test $tn.2 {
  CREATE TABLE t1(a, b, c);
} {
  SELECT * FROM t1 WHERE b>?;
} {
  CREATE INDEX t1_idx_00000062 ON t1(b);
  0|0|0|SEARCH TABLE t1 USING INDEX t1_idx_00000062 (b>?)
}

do_setup_rec_test $tn.3 {
  CREATE TABLE t1(a, b, c);
} {
  SELECT * FROM t1 WHERE b COLLATE nocase BETWEEN ? AND ?
} {
  CREATE INDEX t1_idx_3e094c27 ON t1(b COLLATE NOCASE);
  0|0|0|SEARCH TABLE t1 USING INDEX t1_idx_3e094c27 (b>? AND b<?)
}

do_setup_rec_test $tn.4 {
  CREATE TABLE t1(a, b, c);
} {
  SELECT a FROM t1 ORDER BY b;
} {
  CREATE INDEX t1_idx_00000062 ON t1(b);
  0|0|0|SCAN TABLE t1 USING INDEX t1_idx_00000062
}

do_setup_rec_test $tn.5 {
  CREATE TABLE t1(a, b, c);
} {
  SELECT a FROM t1 WHERE a=? ORDER BY b;
} {
  CREATE INDEX t1_idx_000123a7 ON t1(a, b);
  0|0|0|SEARCH TABLE t1 USING COVERING INDEX t1_idx_000123a7 (a=?)
}

do_setup_rec_test $tn.6 {
  CREATE TABLE t1(a, b, c);
} {
  SELECT min(a) FROM t1
} {
  CREATE INDEX t1_idx_00000061 ON t1(a);
  0|0|0|SEARCH TABLE t1 USING COVERING INDEX t1_idx_00000061
}

do_setup_rec_test $tn.7 {
  CREATE TABLE t1(a, b, c);
} {
  SELECT * FROM t1 ORDER BY a, b, c;
} {
  CREATE INDEX t1_idx_033e95fe ON t1(a, b, c);
  0|0|0|SCAN TABLE t1 USING COVERING INDEX t1_idx_033e95fe
}

#do_setup_rec_test $tn.1.8 {
#  CREATE TABLE t1(a, b, c);
#} {
#  SELECT * FROM t1 ORDER BY a ASC, b COLLATE nocase DESC, c ASC;
#} {
#  CREATE INDEX t1_idx_5be6e222 ON t1(a, b COLLATE NOCASE DESC, c);
#  0|0|0|SCAN TABLE t1 USING COVERING INDEX t1_idx_5be6e222
#}

do_setup_rec_test $tn.8.1 {
  CREATE TABLE t1(a COLLATE NOCase, b, c);
} {
  SELECT * FROM t1 WHERE a=?
} {
  CREATE INDEX t1_idx_00000061 ON t1(a);
  0|0|0|SEARCH TABLE t1 USING INDEX t1_idx_00000061 (a=?)
}
do_setup_rec_test $tn.8.2 {
  CREATE TABLE t1(a, b COLLATE nocase, c);
} {
  SELECT * FROM t1 ORDER BY a ASC, b DESC, c ASC;
} {
  CREATE INDEX t1_idx_5cb97285 ON t1(a, b DESC, c);
  0|0|0|SCAN TABLE t1 USING COVERING INDEX t1_idx_5cb97285
}


# Tables with names that require quotes.
#
do_setup_rec_test $tn.9.1 {
  CREATE TABLE "t t"(a, b, c);
} {
  SELECT * FROM "t t" WHERE a=?
} {
  CREATE INDEX 't t_idx_00000061' ON 't t'(a);
  0|0|0|SEARCH TABLE t t USING INDEX t t_idx_00000061 (a=?) 
}

do_setup_rec_test $tn.9.2 {
  CREATE TABLE "t t"(a, b, c);
} {
  SELECT * FROM "t t" WHERE b BETWEEN ? AND ?
} {
  CREATE INDEX 't t_idx_00000062' ON 't t'(b);
  0|0|0|SEARCH TABLE t t USING INDEX t t_idx_00000062 (b>? AND b<?)
}

# Columns with names that require quotes.
#
do_setup_rec_test $tn.10.1 {
  CREATE TABLE t3(a, "b b", c);
} {
  SELECT * FROM t3 WHERE "b b" = ?
} {
  CREATE INDEX t3_idx_00050c52 ON t3('b b');
  0|0|0|SEARCH TABLE t3 USING INDEX t3_idx_00050c52 (b b=?)
}

do_setup_rec_test $tn.10.2 {
  CREATE TABLE t3(a, "b b", c);
} {
  SELECT * FROM t3 ORDER BY "b b"
} {
  CREATE INDEX t3_idx_00050c52 ON t3('b b');
  0|0|0|SCAN TABLE t3 USING INDEX t3_idx_00050c52
}

# Transitive constraints
#
do_setup_rec_test $tn.11.1 {
  CREATE TABLE t5(a, b);
  CREATE TABLE t6(c, d);
} {
  SELECT * FROM t5, t6 WHERE a=? AND b=c AND c=?
} {
  CREATE INDEX t5_idx_000123a7 ON t5(a, b);
  CREATE INDEX t6_idx_00000063 ON t6(c);
  0|0|1|SEARCH TABLE t6 USING INDEX t6_idx_00000063 (c=?) 
  0|1|0|SEARCH TABLE t5 USING COVERING INDEX t5_idx_000123a7 (a=? AND b=?)
}

# OR terms.
#
do_setup_rec_test $tn.12.1 {
  CREATE TABLE t7(a, b);
} {
  SELECT * FROM t7 WHERE a=? OR b=?
} {
  CREATE INDEX t7_idx_00000062 ON t7(b);
  CREATE INDEX t7_idx_00000061 ON t7(a);
  0|0|0|SEARCH TABLE t7 USING INDEX t7_idx_00000061 (a=?) 
  0|0|0|SEARCH TABLE t7 USING INDEX t7_idx_00000062 (b=?)
}

# rowid terms.
#
do_setup_rec_test $tn.13.1 {
  CREATE TABLE t8(a, b);
} {
  SELECT * FROM t8 WHERE rowid=?
} {
  (no new indexes)
  0|0|0|SEARCH TABLE t8 USING INTEGER PRIMARY KEY (rowid=?)
}
do_setup_rec_test $tn.13.2 {
  CREATE TABLE t8(a, b);
} {
  SELECT * FROM t8 ORDER BY rowid
} {
  (no new indexes)
  0|0|0|SCAN TABLE t8
}
do_setup_rec_test $tn.13.3 {
  CREATE TABLE t8(a, b);
} {
  SELECT * FROM t8 WHERE a=? ORDER BY rowid
} {
  CREATE INDEX t8_idx_00000061 ON t8(a); 
  0|0|0|SEARCH TABLE t8 USING INDEX t8_idx_00000061 (a=?)
}

# Triggers
#
do_setup_rec_test $tn.14 {
  CREATE TABLE t9(a, b, c);
  CREATE TABLE t10(a, b, c);
  CREATE TRIGGER t9t AFTER INSERT ON t9 BEGIN
    UPDATE t10 SET a=new.a WHERE b = new.b;
  END;
} {
  INSERT INTO t9 VALUES(?, ?, ?);
} {
  CREATE INDEX t10_idx_00000062 ON t10(b); 
  0|0|0|SEARCH TABLE t10 USING INDEX t10_idx_00000062 (b=?)
}

do_setup_rec_test $tn.15 {
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d);

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
  INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
  INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
} {
  SELECT * FROM t2, t1 WHERE b=? AND d=? AND t2.rowid=t1.rowid
} {
  CREATE INDEX t2_idx_00000064 ON t2(d);
  0|0|0|SEARCH TABLE t2 USING INDEX t2_idx_00000064 (d=?) 
  0|1|1|SEARCH TABLE t1 USING INTEGER PRIMARY KEY (rowid=?)
}

do_setup_rec_test $tn.16 {
  CREATE TABLE t1(a, b);
} {
  SELECT * FROM t1 WHERE b IS NOT NULL;
} {
  (no new indexes)
  0|0|0|SCAN TABLE t1
}

}

proc do_candidates_test {tn sql res} {
  set res [squish [string trim $res]]

  set expert [sqlite3_expert_new db]
  $expert sql $sql
  $expert analyze

  set candidates [squish [string trim [$expert report 0 candidates]]]
  $expert destroy

  uplevel [list do_test $tn [list set {} $candidates] $res]
}


reset_db
do_execsql_test 3.0 {
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d);

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
  INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
  INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
}
do_candidates_test 3.1 {
  SELECT * FROM t1,t2 WHERE (b=? OR a=?) AND (c=? OR d=?)
} {
  CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20 
  CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50 
  CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20 
  CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
}

do_candidates_test 3.2 {
  SELECT * FROM t1,t2 WHERE a=? AND b=? AND c=? AND d=?
} {
  CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 17
  CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5
}

do_execsql_test 3.2 {
  CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50 
  CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20 
  CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 16

  CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20 
  CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
  CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5

  ANALYZE;
  SELECT * FROM sqlite_stat1 ORDER BY 1, 2;
} {
  t1 t1_idx_00000061 {100 50} 
  t1 t1_idx_00000062 {100 20}
  t1 t1_idx_000123a7 {100 50 17}
  t2 t2_idx_00000063 {100 20} 
  t2 t2_idx_00000064 {100 5} 
  t2 t2_idx_0001295b {100 20 5}
}


finish_test

/*
** 2017 April 09
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/
#include "sqlite3expert.h"
#include <assert.h>
#include <string.h>
#include <stdio.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE 

typedef sqlite3_int64 i64;
typedef sqlite3_uint64 u64;

typedef struct IdxColumn IdxColumn;
typedef struct IdxConstraint IdxConstraint;
typedef struct IdxScan IdxScan;
typedef struct IdxStatement IdxStatement;
typedef struct IdxTable IdxTable;
typedef struct IdxWrite IdxWrite;

#define STRLEN  (int)strlen

/*
** A temp table name that we assume no user database will actually use.
** If this assumption proves incorrect triggers on the table with the
** conflicting name will be ignored.
*/
#define UNIQUE_TABLE_NAME "t592690916721053953805701627921227776"

/*
** A single constraint. Equivalent to either "col = ?" or "col < ?" (or
** any other type of single-ended range constraint on a column).
**
** pLink:
**   Used to temporarily link IdxConstraint objects into lists while
**   creating candidate indexes.
*/
struct IdxConstraint {
  char *zColl;                    /* Collation sequence */
  int bRange;                     /* True for range, false for eq */
  int iCol;                       /* Constrained table column */
  int bFlag;                      /* Used by idxFindCompatible() */
  int bDesc;                      /* True if ORDER BY <expr> DESC */
  IdxConstraint *pNext;           /* Next constraint in pEq or pRange list */
  IdxConstraint *pLink;           /* See above */
};

/*
** A single scan of a single table.
*/
struct IdxScan {
  IdxTable *pTab;                 /* Associated table object */
  int iDb;                        /* Database containing table zTable */
  i64 covering;                   /* Mask of columns required for cov. index */
  IdxConstraint *pOrder;          /* ORDER BY columns */
  IdxConstraint *pEq;             /* List of == constraints */
  IdxConstraint *pRange;          /* List of < constraints */
  IdxScan *pNextScan;             /* Next IdxScan object for same analysis */
};

/*
** Information regarding a single database table. Extracted from 
** "PRAGMA table_info" by function idxGetTableInfo().
*/
struct IdxColumn {
  char *zName;
  char *zColl;
  int iPk;
};
struct IdxTable {
  int nCol;
  char *zName;                    /* Table name */
  IdxColumn *aCol;
  IdxTable *pNext;                /* Next table in linked list of all tables */
};

/*
** An object of the following type is created for each unique table/write-op
** seen. The objects are stored in a singly-linked list beginning at
** sqlite3expert.pWrite.
*/
struct IdxWrite {
  IdxTable *pTab;
  int eOp;                        /* SQLITE_UPDATE, DELETE or INSERT */
  IdxWrite *pNext;
};

/*
** Each statement being analyzed is represented by an instance of this
** structure.
*/
struct IdxStatement {
  int iId;                        /* Statement number */
  char *zSql;                     /* SQL statement */
  char *zIdx;                     /* Indexes */
  char *zEQP;                     /* Plan */
  IdxStatement *pNext;
};


/*
** A hash table for storing strings. With space for a payload string
** with each entry. Methods are:
**
**   idxHashInit()
**   idxHashClear()
**   idxHashAdd()
**   idxHashSearch()
*/
#define IDX_HASH_SIZE 1023
typedef struct IdxHashEntry IdxHashEntry;
typedef struct IdxHash IdxHash;
struct IdxHashEntry {
  char *zKey;                     /* nul-terminated key */
  char *zVal;                     /* nul-terminated value string */
  char *zVal2;                    /* nul-terminated value string 2 */
  IdxHashEntry *pHashNext;        /* Next entry in same hash bucket */
  IdxHashEntry *pNext;            /* Next entry in hash */
};
struct IdxHash {
  IdxHashEntry *pFirst;
  IdxHashEntry *aHash[IDX_HASH_SIZE];
};

/*
** sqlite3expert object.
*/
struct sqlite3expert {
  int iSample;                    /* Percentage of tables to sample for stat1 */
  sqlite3 *db;                    /* User database */
  sqlite3 *dbm;                   /* In-memory db for this analysis */
  sqlite3 *dbv;                   /* Vtab schema for this analysis */
  IdxTable *pTable;               /* List of all IdxTable objects */
  IdxScan *pScan;                 /* List of scan objects */
  IdxWrite *pWrite;               /* List of write objects */
  IdxStatement *pStatement;       /* List of IdxStatement objects */
  int bRun;                       /* True once analysis has run */
  char **pzErrmsg;
  int rc;                         /* Error code from whereinfo hook */
  IdxHash hIdx;                   /* Hash containing all candidate indexes */
  char *zCandidates;              /* For EXPERT_REPORT_CANDIDATES */
};


/*
** Allocate and return nByte bytes of zeroed memory using sqlite3_malloc(). 
** If the allocation fails, set *pRc to SQLITE_NOMEM and return NULL.
*/
static void *idxMalloc(int *pRc, int nByte){
  void *pRet;
  assert( *pRc==SQLITE_OK );
  assert( nByte>0 );
  pRet = sqlite3_malloc(nByte);
  if( pRet ){
    memset(pRet, 0, nByte);
  }else{
    *pRc = SQLITE_NOMEM;
  }
  return pRet;
}

/*
** Initialize an IdxHash hash table.
*/
static void idxHashInit(IdxHash *pHash){
  memset(pHash, 0, sizeof(IdxHash));
}

/*
** Reset an IdxHash hash table.
*/
static void idxHashClear(IdxHash *pHash){
  int i;
  for(i=0; i<IDX_HASH_SIZE; i++){
    IdxHashEntry *pEntry;
    IdxHashEntry *pNext;
    for(pEntry=pHash->aHash[i]; pEntry; pEntry=pNext){
      pNext = pEntry->pHashNext;
      sqlite3_free(pEntry->zVal2);
      sqlite3_free(pEntry);
    }
  }
  memset(pHash, 0, sizeof(IdxHash));
}

/*
** Return the index of the hash bucket that the string specified by the
** arguments to this function belongs.
*/
static int idxHashString(const char *z, int n){
  unsigned int ret = 0;
  int i;
  for(i=0; i<n; i++){
    ret += (ret<<3) + (unsigned char)(z[i]);
  }
  return (int)(ret % IDX_HASH_SIZE);
}

/*
** If zKey is already present in the hash table, return non-zero and do
** nothing. Otherwise, add an entry with key zKey and payload string zVal to
** the hash table passed as the second argument. 
*/
static int idxHashAdd(
  int *pRc, 
  IdxHash *pHash, 
  const char *zKey,
  const char *zVal
){
  int nKey = STRLEN(zKey);
  int iHash = idxHashString(zKey, nKey);
  int nVal = (zVal ? STRLEN(zVal) : 0);
  IdxHashEntry *pEntry;
  assert( iHash>=0 );
  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
      return 1;
    }
  }
  pEntry = idxMalloc(pRc, sizeof(IdxHashEntry) + nKey+1 + nVal+1);
  if( pEntry ){
    pEntry->zKey = (char*)&pEntry[1];
    memcpy(pEntry->zKey, zKey, nKey);
    if( zVal ){
      pEntry->zVal = &pEntry->zKey[nKey+1];
      memcpy(pEntry->zVal, zVal, nVal);
    }
    pEntry->pHashNext = pHash->aHash[iHash];
    pHash->aHash[iHash] = pEntry;

    pEntry->pNext = pHash->pFirst;
    pHash->pFirst = pEntry;
  }
  return 0;
}

/*
** If zKey/nKey is present in the hash table, return a pointer to the 
** hash-entry object.
*/
static IdxHashEntry *idxHashFind(IdxHash *pHash, const char *zKey, int nKey){
  int iHash;
  IdxHashEntry *pEntry;
  if( nKey<0 ) nKey = STRLEN(zKey);
  iHash = idxHashString(zKey, nKey);
  assert( iHash>=0 );
  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
      return pEntry;
    }
  }
  return 0;
}

/*
** If the hash table contains an entry with a key equal to the string
** passed as the final two arguments to this function, return a pointer
** to the payload string. Otherwise, if zKey/nKey is not present in the
** hash table, return NULL.
*/
static const char *idxHashSearch(IdxHash *pHash, const char *zKey, int nKey){
  IdxHashEntry *pEntry = idxHashFind(pHash, zKey, nKey);
  if( pEntry ) return pEntry->zVal;
  return 0;
}

/*
** Allocate and return a new IdxConstraint object. Set the IdxConstraint.zColl
** variable to point to a copy of nul-terminated string zColl.
*/
static IdxConstraint *idxNewConstraint(int *pRc, const char *zColl){
  IdxConstraint *pNew;
  int nColl = STRLEN(zColl);

  assert( *pRc==SQLITE_OK );
  pNew = (IdxConstraint*)idxMalloc(pRc, sizeof(IdxConstraint) * nColl + 1);
  if( pNew ){
    pNew->zColl = (char*)&pNew[1];
    memcpy(pNew->zColl, zColl, nColl+1);
  }
  return pNew;
}

/*
** An error associated with database handle db has just occurred. Pass
** the error message to callback function xOut.
*/
static void idxDatabaseError(
  sqlite3 *db,                    /* Database handle */
  char **pzErrmsg                 /* Write error here */
){
  *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
}

/*
** Prepare an SQL statement.
*/
static int idxPrepareStmt(
  sqlite3 *db,                    /* Database handle to compile against */
  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
  const char *zSql                /* SQL statement to compile */
){
  int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
  if( rc!=SQLITE_OK ){
    *ppStmt = 0;
    idxDatabaseError(db, pzErrmsg);
  }
  return rc;
}

/*
** Prepare an SQL statement using the results of a printf() formatting.
*/
static int idxPrintfPrepareStmt(
  sqlite3 *db,                    /* Database handle to compile against */
  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
  const char *zFmt,               /* printf() format of SQL statement */
  ...                             /* Trailing printf() arguments */
){
  va_list ap;
  int rc;
  char *zSql;
  va_start(ap, zFmt);
  zSql = sqlite3_vmprintf(zFmt, ap);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = idxPrepareStmt(db, ppStmt, pzErrmsg, zSql);
    sqlite3_free(zSql);
  }
  va_end(ap);
  return rc;
}


/*************************************************************************
** Beginning of virtual table implementation.
*/
typedef struct ExpertVtab ExpertVtab;
struct ExpertVtab {
  sqlite3_vtab base;
  IdxTable *pTab;
  sqlite3expert *pExpert;
};

typedef struct ExpertCsr ExpertCsr;
struct ExpertCsr {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pData;
};

static char *expertDequote(const char *zIn){
  int n = STRLEN(zIn);
  char *zRet = sqlite3_malloc(n);

  assert( zIn[0]=='\'' );
  assert( zIn[n-1]=='\'' );

  if( zRet ){
    int iOut = 0;
    int iIn = 0;
    for(iIn=1; iIn<(n-1); iIn++){
      if( zIn[iIn]=='\'' ){
        assert( zIn[iIn+1]=='\'' );
        iIn++;
      }
      zRet[iOut++] = zIn[iIn];
    }
    zRet[iOut] = '\0';
  }

  return zRet;
}

/* 
** This function is the implementation of both the xConnect and xCreate
** methods of the r-tree virtual table.
**
**   argv[0]   -> module name
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> column names...
*/
static int expertConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  sqlite3expert *pExpert = (sqlite3expert*)pAux;
  ExpertVtab *p = 0;
  int rc;

  if( argc!=4 ){
    *pzErr = sqlite3_mprintf("internal error!");
    rc = SQLITE_ERROR;
  }else{
    char *zCreateTable = expertDequote(argv[3]);
    if( zCreateTable ){
      rc = sqlite3_declare_vtab(db, zCreateTable);
      if( rc==SQLITE_OK ){
        p = idxMalloc(&rc, sizeof(ExpertVtab));
      }
      if( rc==SQLITE_OK ){
        p->pExpert = pExpert;
        p->pTab = pExpert->pTable;
        assert( sqlite3_stricmp(p->pTab->zName, argv[2])==0 );
      }
      sqlite3_free(zCreateTable);
    }else{
      rc = SQLITE_NOMEM;
    }
  }

  *ppVtab = (sqlite3_vtab*)p;
  return rc;
}

static int expertDisconnect(sqlite3_vtab *pVtab){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  sqlite3_free(p);
  return SQLITE_OK;
}

static int expertBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  int rc = SQLITE_OK;
  int n = 0;
  IdxScan *pScan;
  const int opmask = 
    SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_GT |
    SQLITE_INDEX_CONSTRAINT_LT | SQLITE_INDEX_CONSTRAINT_GE |
    SQLITE_INDEX_CONSTRAINT_LE;

  pScan = idxMalloc(&rc, sizeof(IdxScan));
  if( pScan ){
    int i;

    /* Link the new scan object into the list */
    pScan->pTab = p->pTab;
    pScan->pNextScan = p->pExpert->pScan;
    p->pExpert->pScan = pScan;

    /* Add the constraints to the IdxScan object */
    for(i=0; i<pIdxInfo->nConstraint; i++){
      struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
      if( pCons->usable 
       && pCons->iColumn>=0 
       && p->pTab->aCol[pCons->iColumn].iPk==0
       && (pCons->op & opmask) 
      ){
        IdxConstraint *pNew;
        const char *zColl = sqlite3_vtab_collation(pIdxInfo, i);
        pNew = idxNewConstraint(&rc, zColl);
        if( pNew ){
          pNew->iCol = pCons->iColumn;
          if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
            pNew->pNext = pScan->pEq;
            pScan->pEq = pNew;
          }else{
            pNew->bRange = 1;
            pNew->pNext = pScan->pRange;
            pScan->pRange = pNew;
          }
        }
        n++;
        pIdxInfo->aConstraintUsage[i].argvIndex = n;
      }
    }

    /* Add the ORDER BY to the IdxScan object */
    for(i=pIdxInfo->nOrderBy-1; i>=0; i--){
      int iCol = pIdxInfo->aOrderBy[i].iColumn;
      if( iCol>=0 ){
        IdxConstraint *pNew = idxNewConstraint(&rc, p->pTab->aCol[iCol].zColl);
        if( pNew ){
          pNew->iCol = iCol;
          pNew->bDesc = pIdxInfo->aOrderBy[i].desc;
          pNew->pNext = pScan->pOrder;
          pNew->pLink = pScan->pOrder;
          pScan->pOrder = pNew;
          n++;
        }
      }
    }
  }

  pIdxInfo->estimatedCost = 1000000.0 / (n+1);
  return rc;
}

static int expertUpdate(
  sqlite3_vtab *pVtab, 
  int nData, 
  sqlite3_value **azData, 
  sqlite_int64 *pRowid
){
  (void)pVtab;
  (void)nData;
  (void)azData;
  (void)pRowid;
  return SQLITE_OK;
}

/* 
** Virtual table module xOpen method.
*/
static int expertOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  int rc = SQLITE_OK;
  ExpertCsr *pCsr;
  (void)pVTab;
  pCsr = idxMalloc(&rc, sizeof(ExpertCsr));
  *ppCursor = (sqlite3_vtab_cursor*)pCsr;
  return rc;
}

/* 
** Virtual table module xClose method.
*/
static int expertClose(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  sqlite3_finalize(pCsr->pData);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Virtual table module xEof method.
**
** Return non-zero if the cursor does not currently point to a valid 
** record (i.e if the scan has finished), or zero otherwise.
*/
static int expertEof(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  return pCsr->pData==0;
}

/* 
** Virtual table module xNext method.
*/
static int expertNext(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  int rc = SQLITE_OK;

  assert( pCsr->pData );
  rc = sqlite3_step(pCsr->pData);
  if( rc!=SQLITE_ROW ){
    rc = sqlite3_finalize(pCsr->pData);
    pCsr->pData = 0;
  }else{
    rc = SQLITE_OK;
  }

  return rc;
}

/* 
** Virtual table module xRowid method.
*/
static int expertRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  (void)cur;
  *pRowid = 0;
  return SQLITE_OK;
}

/* 
** Virtual table module xColumn method.
*/
static int expertColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  sqlite3_value *pVal;
  pVal = sqlite3_column_value(pCsr->pData, i);
  if( pVal ){
    sqlite3_result_value(ctx, pVal);
  }
  return SQLITE_OK;
}

/* 
** Virtual table module xFilter method.
*/
static int expertFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  ExpertVtab *pVtab = (ExpertVtab*)(cur->pVtab);
  sqlite3expert *pExpert = pVtab->pExpert;
  int rc;

  (void)idxNum;
  (void)idxStr;
  (void)argc;
  (void)argv;
  rc = sqlite3_finalize(pCsr->pData);
  pCsr->pData = 0;
  if( rc==SQLITE_OK ){
    rc = idxPrintfPrepareStmt(pExpert->db, &pCsr->pData, &pVtab->base.zErrMsg,
        "SELECT * FROM main.%Q WHERE sample()", pVtab->pTab->zName
    );
  }

  if( rc==SQLITE_OK ){
    rc = expertNext(cur);
  }
  return rc;
}

static int idxRegisterVtab(sqlite3expert *p){
  static sqlite3_module expertModule = {
    2,                            /* iVersion */
    expertConnect,                /* xCreate - create a table */
    expertConnect,                /* xConnect - connect to an existing table */
    expertBestIndex,              /* xBestIndex - Determine search strategy */
    expertDisconnect,             /* xDisconnect - Disconnect from a table */
    expertDisconnect,             /* xDestroy - Drop a table */
    expertOpen,                   /* xOpen - open a cursor */
    expertClose,                  /* xClose - close a cursor */
    expertFilter,                 /* xFilter - configure scan constraints */
    expertNext,                   /* xNext - advance a cursor */
    expertEof,                    /* xEof */
    expertColumn,                 /* xColumn - read data */
    expertRowid,                  /* xRowid - read data */
    expertUpdate,                 /* xUpdate - write data */
    0,                            /* xBegin - begin transaction */
    0,                            /* xSync - sync transaction */
    0,                            /* xCommit - commit transaction */
    0,                            /* xRollback - rollback transaction */
    0,                            /* xFindFunction - function overloading */
    0,                            /* xRename - rename the table */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
  };

  return sqlite3_create_module(p->dbv, "expert", &expertModule, (void*)p);
}
/*
** End of virtual table implementation.
*************************************************************************/
/*
** Finalize SQL statement pStmt. If (*pRc) is SQLITE_OK when this function
** is called, set it to the return value of sqlite3_finalize() before
** returning. Otherwise, discard the sqlite3_finalize() return value.
*/
static void idxFinalize(int *pRc, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

/*
** Attempt to allocate an IdxTable structure corresponding to table zTab
** in the main database of connection db. If successful, set (*ppOut) to
** point to the new object and return SQLITE_OK. Otherwise, return an
** SQLite error code and set (*ppOut) to NULL. In this case *pzErrmsg may be
** set to point to an error string.
**
** It is the responsibility of the caller to eventually free either the
** IdxTable object or error message using sqlite3_free().
*/
static int idxGetTableInfo(
  sqlite3 *db,                    /* Database connection to read details from */
  const char *zTab,               /* Table name */
  IdxTable **ppOut,               /* OUT: New object (if successful) */
  char **pzErrmsg                 /* OUT: Error message (if not) */
){
  sqlite3_stmt *p1 = 0;
  int nCol = 0;
  int nTab = STRLEN(zTab);
  int nByte = sizeof(IdxTable) + nTab + 1;
  IdxTable *pNew = 0;
  int rc, rc2;
  char *pCsr = 0;

  rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_info=%Q", zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    nByte += 1 + STRLEN(zCol);
    rc = sqlite3_table_column_metadata(
        db, "main", zTab, zCol, 0, &zCol, 0, 0, 0
    );
    nByte += 1 + STRLEN(zCol);
    nCol++;
  }
  rc2 = sqlite3_reset(p1);
  if( rc==SQLITE_OK ) rc = rc2;

  nByte += sizeof(IdxColumn) * nCol;
  if( rc==SQLITE_OK ){
    pNew = idxMalloc(&rc, nByte);
  }
  if( rc==SQLITE_OK ){
    pNew->aCol = (IdxColumn*)&pNew[1];
    pNew->nCol = nCol;
    pCsr = (char*)&pNew->aCol[nCol];
  }

  nCol = 0;
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    int nCopy = STRLEN(zCol) + 1;
    pNew->aCol[nCol].zName = pCsr;
    pNew->aCol[nCol].iPk = sqlite3_column_int(p1, 5);
    memcpy(pCsr, zCol, nCopy);
    pCsr += nCopy;

    rc = sqlite3_table_column_metadata(
        db, "main", zTab, zCol, 0, &zCol, 0, 0, 0
    );
    if( rc==SQLITE_OK ){
      nCopy = STRLEN(zCol) + 1;
      pNew->aCol[nCol].zColl = pCsr;
      memcpy(pCsr, zCol, nCopy);
      pCsr += nCopy;
    }

    nCol++;
  }
  idxFinalize(&rc, p1);

  if( rc!=SQLITE_OK ){
    sqlite3_free(pNew);
    pNew = 0;
  }else{
    pNew->zName = pCsr;
    memcpy(pNew->zName, zTab, nTab+1);
  }

  *ppOut = pNew;
  return rc;
}

/*
** This function is a no-op if *pRc is set to anything other than 
** SQLITE_OK when it is called.
**
** If *pRc is initially set to SQLITE_OK, then the text specified by
** the printf() style arguments is appended to zIn and the result returned
** in a buffer allocated by sqlite3_malloc(). sqlite3_free() is called on
** zIn before returning.
*/
static char *idxAppendText(int *pRc, char *zIn, const char *zFmt, ...){
  va_list ap;
  char *zAppend = 0;
  char *zRet = 0;
  int nIn = zIn ? STRLEN(zIn) : 0;
  int nAppend = 0;
  va_start(ap, zFmt);
  if( *pRc==SQLITE_OK ){
    zAppend = sqlite3_vmprintf(zFmt, ap);
    if( zAppend ){
      nAppend = STRLEN(zAppend);
      zRet = (char*)sqlite3_malloc(nIn + nAppend + 1);
    }
    if( zAppend && zRet ){
      if( nIn ) memcpy(zRet, zIn, nIn);
      memcpy(&zRet[nIn], zAppend, nAppend+1);
    }else{
      sqlite3_free(zRet);
      zRet = 0;
      *pRc = SQLITE_NOMEM;
    }
    sqlite3_free(zAppend);
    sqlite3_free(zIn);
  }
  va_end(ap);
  return zRet;
}

/*
** Return true if zId must be quoted in order to use it as an SQL
** identifier, or false otherwise.
*/
static int idxIdentifierRequiresQuotes(const char *zId){
  int i;
  for(i=0; zId[i]; i++){
    if( !(zId[i]=='_')
     && !(zId[i]>='0' && zId[i]<='9')
     && !(zId[i]>='a' && zId[i]<='z')
     && !(zId[i]>='A' && zId[i]<='Z')
    ){
      return 1;
    }
  }
  return 0;
}

/*
** This function appends an index column definition suitable for constraint
** pCons to the string passed as zIn and returns the result.
*/
static char *idxAppendColDefn(
  int *pRc,                       /* IN/OUT: Error code */
  char *zIn,                      /* Column defn accumulated so far */
  IdxTable *pTab,                 /* Table index will be created on */
  IdxConstraint *pCons
){
  char *zRet = zIn;
  IdxColumn *p = &pTab->aCol[pCons->iCol];
  if( zRet ) zRet = idxAppendText(pRc, zRet, ", ");

  if( idxIdentifierRequiresQuotes(p->zName) ){
    zRet = idxAppendText(pRc, zRet, "%Q", p->zName);
  }else{
    zRet = idxAppendText(pRc, zRet, "%s", p->zName);
  }

  if( sqlite3_stricmp(p->zColl, pCons->zColl) ){
    if( idxIdentifierRequiresQuotes(pCons->zColl) ){
      zRet = idxAppendText(pRc, zRet, " COLLATE %Q", pCons->zColl);
    }else{
      zRet = idxAppendText(pRc, zRet, " COLLATE %s", pCons->zColl);
    }
  }

  if( pCons->bDesc ){
    zRet = idxAppendText(pRc, zRet, " DESC");
  }
  return zRet;
}

/*
** Search database dbm for an index compatible with the one idxCreateFromCons()
** would create from arguments pScan, pEq and pTail. If no error occurs and 
** such an index is found, return non-zero. Or, if no such index is found,
** return zero.
**
** If an error occurs, set *pRc to an SQLite error code and return zero.
*/
static int idxFindCompatible(
  int *pRc,                       /* OUT: Error code */
  sqlite3* dbm,                   /* Database to search */
  IdxScan *pScan,                 /* Scan for table to search for index on */
  IdxConstraint *pEq,             /* List of == constraints */
  IdxConstraint *pTail            /* List of range constraints */
){
  const char *zTbl = pScan->pTab->zName;
  sqlite3_stmt *pIdxList = 0;
  IdxConstraint *pIter;
  int nEq = 0;                    /* Number of elements in pEq */
  int rc;

  /* Count the elements in list pEq */
  for(pIter=pEq; pIter; pIter=pIter->pLink) nEq++;

  rc = idxPrintfPrepareStmt(dbm, &pIdxList, 0, "PRAGMA index_list=%Q", zTbl);
  while( rc==SQLITE_OK && sqlite3_step(pIdxList)==SQLITE_ROW ){
    int bMatch = 1;
    IdxConstraint *pT = pTail;
    sqlite3_stmt *pInfo = 0;
    const char *zIdx = (const char*)sqlite3_column_text(pIdxList, 1);

    /* Zero the IdxConstraint.bFlag values in the pEq list */
    for(pIter=pEq; pIter; pIter=pIter->pLink) pIter->bFlag = 0;

    rc = idxPrintfPrepareStmt(dbm, &pInfo, 0, "PRAGMA index_xInfo=%Q", zIdx);
    while( rc==SQLITE_OK && sqlite3_step(pInfo)==SQLITE_ROW ){
      int iIdx = sqlite3_column_int(pInfo, 0);
      int iCol = sqlite3_column_int(pInfo, 1);
      const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);

      if( iIdx<nEq ){
        for(pIter=pEq; pIter; pIter=pIter->pLink){
          if( pIter->bFlag ) continue;
          if( pIter->iCol!=iCol ) continue;
          if( sqlite3_stricmp(pIter->zColl, zColl) ) continue;
          pIter->bFlag = 1;
          break;
        }
        if( pIter==0 ){
          bMatch = 0;
          break;
        }
      }else{
        if( pT ){
          if( pT->iCol!=iCol || sqlite3_stricmp(pT->zColl, zColl) ){
            bMatch = 0;
            break;
          }
          pT = pT->pLink;
        }
      }
    }
    idxFinalize(&rc, pInfo);

    if( rc==SQLITE_OK && bMatch ){
      sqlite3_finalize(pIdxList);
      return 1;
    }
  }
  idxFinalize(&rc, pIdxList);

  *pRc = rc;
  return 0;
}

static int idxCreateFromCons(
  sqlite3expert *p,
  IdxScan *pScan,
  IdxConstraint *pEq, 
  IdxConstraint *pTail
){
  sqlite3 *dbm = p->dbm;
  int rc = SQLITE_OK;
  if( (pEq || pTail) && 0==idxFindCompatible(&rc, dbm, pScan, pEq, pTail) ){
    IdxTable *pTab = pScan->pTab;
    char *zCols = 0;
    char *zIdx = 0;
    IdxConstraint *pCons;
    unsigned int h = 0;
    const char *zFmt;

    for(pCons=pEq; pCons; pCons=pCons->pLink){
      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
    }
    for(pCons=pTail; pCons; pCons=pCons->pLink){
      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
    }

    if( rc==SQLITE_OK ){
      /* Hash the list of columns to come up with a name for the index */
      const char *zTable = pScan->pTab->zName;
      char *zName;                /* Index name */
      int i;
      for(i=0; zCols[i]; i++){
        h += ((h<<3) + zCols[i]);
      }
      zName = sqlite3_mprintf("%s_idx_%08x", zTable, h);
      if( zName==0 ){ 
        rc = SQLITE_NOMEM;
      }else{
        if( idxIdentifierRequiresQuotes(zTable) ){
          zFmt = "CREATE INDEX '%q' ON %Q(%s)";
        }else{
          zFmt = "CREATE INDEX %s ON %s(%s)";
        }
        zIdx = sqlite3_mprintf(zFmt, zName, zTable, zCols);
        if( !zIdx ){
          rc = SQLITE_NOMEM;
        }else{
          rc = sqlite3_exec(dbm, zIdx, 0, 0, p->pzErrmsg);
          idxHashAdd(&rc, &p->hIdx, zName, zIdx);
        }
        sqlite3_free(zName);
        sqlite3_free(zIdx);
      }
    }

    sqlite3_free(zCols);
  }
  return rc;
}

/*
** Return true if list pList (linked by IdxConstraint.pLink) contains
** a constraint compatible with *p. Otherwise return false.
*/
static int idxFindConstraint(IdxConstraint *pList, IdxConstraint *p){
  IdxConstraint *pCmp;
  for(pCmp=pList; pCmp; pCmp=pCmp->pLink){
    if( p->iCol==pCmp->iCol ) return 1;
  }
  return 0;
}

static int idxCreateFromWhere(
  sqlite3expert *p, 
  IdxScan *pScan,                 /* Create indexes for this scan */
  IdxConstraint *pTail            /* range/ORDER BY constraints for inclusion */
){
  IdxConstraint *p1 = 0;
  IdxConstraint *pCon;
  int rc;

  /* Gather up all the == constraints. */
  for(pCon=pScan->pEq; pCon; pCon=pCon->pNext){
    if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
      pCon->pLink = p1;
      p1 = pCon;
    }
  }

  /* Create an index using the == constraints collected above. And the
  ** range constraint/ORDER BY terms passed in by the caller, if any. */
  rc = idxCreateFromCons(p, pScan, p1, pTail);

  /* If no range/ORDER BY passed by the caller, create a version of the
  ** index for each range constraint.  */
  if( pTail==0 ){
    for(pCon=pScan->pRange; rc==SQLITE_OK && pCon; pCon=pCon->pNext){
      assert( pCon->pLink==0 );
      if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
        rc = idxCreateFromCons(p, pScan, p1, pCon);
      }
    }
  }

  return rc;
}

/*
** Create candidate indexes in database [dbm] based on the data in 
** linked-list pScan.
*/
static int idxCreateCandidates(sqlite3expert *p){
  int rc = SQLITE_OK;
  IdxScan *pIter;

  for(pIter=p->pScan; pIter && rc==SQLITE_OK; pIter=pIter->pNextScan){
    rc = idxCreateFromWhere(p, pIter, 0);
    if( rc==SQLITE_OK && pIter->pOrder ){
      rc = idxCreateFromWhere(p, pIter, pIter->pOrder);
    }
  }

  return rc;
}

/*
** Free all elements of the linked list starting at pConstraint.
*/
static void idxConstraintFree(IdxConstraint *pConstraint){
  IdxConstraint *pNext;
  IdxConstraint *p;

  for(p=pConstraint; p; p=pNext){
    pNext = p->pNext;
    sqlite3_free(p);
  }
}

/*
** Free all elements of the linked list starting from pScan up until pLast
** (pLast is not freed).
*/
static void idxScanFree(IdxScan *pScan, IdxScan *pLast){
  IdxScan *p;
  IdxScan *pNext;
  for(p=pScan; p!=pLast; p=pNext){
    pNext = p->pNextScan;
    idxConstraintFree(p->pOrder);
    idxConstraintFree(p->pEq);
    idxConstraintFree(p->pRange);
    sqlite3_free(p);
  }
}

/*
** Free all elements of the linked list starting from pStatement up 
** until pLast (pLast is not freed).
*/
static void idxStatementFree(IdxStatement *pStatement, IdxStatement *pLast){
  IdxStatement *p;
  IdxStatement *pNext;
  for(p=pStatement; p!=pLast; p=pNext){
    pNext = p->pNext;
    sqlite3_free(p->zEQP);
    sqlite3_free(p->zIdx);
    sqlite3_free(p);
  }
}

/*
** Free the linked list of IdxTable objects starting at pTab.
*/
static void idxTableFree(IdxTable *pTab){
  IdxTable *pIter;
  IdxTable *pNext;
  for(pIter=pTab; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_free(pIter);
  }
}

/*
** Free the linked list of IdxWrite objects starting at pTab.
*/
static void idxWriteFree(IdxWrite *pTab){
  IdxWrite *pIter;
  IdxWrite *pNext;
  for(pIter=pTab; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_free(pIter);
  }
}



/*
** This function is called after candidate indexes have been created. It
** runs all the queries to see which indexes they prefer, and populates
** IdxStatement.zIdx and IdxStatement.zEQP with the results.
*/
int idxFindIndexes(
  sqlite3expert *p,
  char **pzErr                         /* OUT: Error message (sqlite3_malloc) */
){
  IdxStatement *pStmt;
  sqlite3 *dbm = p->dbm;
  int rc = SQLITE_OK;

  IdxHash hIdx;
  idxHashInit(&hIdx);

  for(pStmt=p->pStatement; rc==SQLITE_OK && pStmt; pStmt=pStmt->pNext){
    IdxHashEntry *pEntry;
    sqlite3_stmt *pExplain = 0;
    idxHashClear(&hIdx);
    rc = idxPrintfPrepareStmt(dbm, &pExplain, pzErr,
        "EXPLAIN QUERY PLAN %s", pStmt->zSql
    );
    while( rc==SQLITE_OK && sqlite3_step(pExplain)==SQLITE_ROW ){
      int iSelectid = sqlite3_column_int(pExplain, 0);
      int iOrder = sqlite3_column_int(pExplain, 1);
      int iFrom = sqlite3_column_int(pExplain, 2);
      const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
      int nDetail = STRLEN(zDetail);
      int i;

      for(i=0; i<nDetail; i++){
        const char *zIdx = 0;
        if( memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
          zIdx = &zDetail[i+13];
        }else if( memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 ){
          zIdx = &zDetail[i+22];
        }
        if( zIdx ){
          const char *zSql;
          int nIdx = 0;
          while( zIdx[nIdx]!='\0' && (zIdx[nIdx]!=' ' || zIdx[nIdx+1]!='(') ){
            nIdx++;
          }
          zSql = idxHashSearch(&p->hIdx, zIdx, nIdx);
          if( zSql ){
            idxHashAdd(&rc, &hIdx, zSql, 0);
            if( rc ) goto find_indexes_out;
          }
          break;
        }
      }

      pStmt->zEQP = idxAppendText(&rc, pStmt->zEQP, "%d|%d|%d|%s\n", 
          iSelectid, iOrder, iFrom, zDetail
      );
    }

    for(pEntry=hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
      pStmt->zIdx = idxAppendText(&rc, pStmt->zIdx, "%s;\n", pEntry->zKey);
    }

    idxFinalize(&rc, pExplain);
  }

 find_indexes_out:
  idxHashClear(&hIdx);
  return rc;
}

static int idxAuthCallback(
  void *pCtx,
  int eOp,
  const char *z3,
  const char *z4,
  const char *zDb,
  const char *zTrigger
){
  int rc = SQLITE_OK;
  (void)z4;
  (void)zTrigger;
  if( eOp==SQLITE_INSERT || eOp==SQLITE_UPDATE || eOp==SQLITE_DELETE ){
    if( sqlite3_stricmp(zDb, "main")==0 ){
      sqlite3expert *p = (sqlite3expert*)pCtx;
      IdxTable *pTab;
      for(pTab=p->pTable; pTab; pTab=pTab->pNext){
        if( 0==sqlite3_stricmp(z3, pTab->zName) ) break;
      }
      if( pTab ){
        IdxWrite *pWrite;
        for(pWrite=p->pWrite; pWrite; pWrite=pWrite->pNext){
          if( pWrite->pTab==pTab && pWrite->eOp==eOp ) break;
        }
        if( pWrite==0 ){
          pWrite = idxMalloc(&rc, sizeof(IdxWrite));
          if( rc==SQLITE_OK ){
            pWrite->pTab = pTab;
            pWrite->eOp = eOp;
            pWrite->pNext = p->pWrite;
            p->pWrite = pWrite;
          }
        }
      }
    }
  }
  return rc;
}

static int idxProcessOneTrigger(
  sqlite3expert *p, 
  IdxWrite *pWrite, 
  char **pzErr
){
  static const char *zInt = UNIQUE_TABLE_NAME;
  static const char *zDrop = "DROP TABLE " UNIQUE_TABLE_NAME;
  IdxTable *pTab = pWrite->pTab;
  const char *zTab = pTab->zName;
  const char *zSql = 
    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_master "
    "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
    "ORDER BY type;";
  sqlite3_stmt *pSelect = 0;
  int rc = SQLITE_OK;
  char *zWrite = 0;

  /* Create the table and its triggers in the temp schema */
  rc = idxPrintfPrepareStmt(p->db, &pSelect, pzErr, zSql, zTab, zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSelect) ){
    const char *zCreate = (const char*)sqlite3_column_text(pSelect, 0);
    rc = sqlite3_exec(p->dbv, zCreate, 0, 0, pzErr);
  }
  idxFinalize(&rc, pSelect);

  /* Rename the table in the temp schema to zInt */
  if( rc==SQLITE_OK ){
    char *z = sqlite3_mprintf("ALTER TABLE temp.%Q RENAME TO %Q", zTab, zInt);
    if( z==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_exec(p->dbv, z, 0, 0, pzErr);
      sqlite3_free(z);
    }
  }

  switch( pWrite->eOp ){
    case SQLITE_INSERT: {
      int i;
      zWrite = idxAppendText(&rc, zWrite, "INSERT INTO %Q VALUES(", zInt);
      for(i=0; i<pTab->nCol; i++){
        zWrite = idxAppendText(&rc, zWrite, "%s?", i==0 ? "" : ", ");
      }
      zWrite = idxAppendText(&rc, zWrite, ")");
      break;
    }
    case SQLITE_UPDATE: {
      int i;
      zWrite = idxAppendText(&rc, zWrite, "UPDATE %Q SET ", zInt);
      for(i=0; i<pTab->nCol; i++){
        zWrite = idxAppendText(&rc, zWrite, "%s%Q=?", i==0 ? "" : ", ", 
            pTab->aCol[i].zName
        );
      }
      break;
    }
    default: {
      assert( pWrite->eOp==SQLITE_DELETE );
      if( rc==SQLITE_OK ){
        zWrite = sqlite3_mprintf("DELETE FROM %Q", zInt);
        if( zWrite==0 ) rc = SQLITE_NOMEM;
      }
    }
  }

  if( rc==SQLITE_OK ){
    sqlite3_stmt *pX = 0;
    rc = sqlite3_prepare_v2(p->dbv, zWrite, -1, &pX, 0);
    idxFinalize(&rc, pX);
    if( rc!=SQLITE_OK ){
      idxDatabaseError(p->dbv, pzErr);
    }
  }
  sqlite3_free(zWrite);

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbv, zDrop, 0, 0, pzErr);
  }

  return rc;
}

static int idxProcessTriggers(sqlite3expert *p, char **pzErr){
  int rc = SQLITE_OK;
  IdxWrite *pEnd = 0;
  IdxWrite *pFirst = p->pWrite;

  while( rc==SQLITE_OK && pFirst!=pEnd ){
    IdxWrite *pIter;
    for(pIter=pFirst; rc==SQLITE_OK && pIter!=pEnd; pIter=pIter->pNext){
      rc = idxProcessOneTrigger(p, pIter, pzErr);
    }
    pEnd = pFirst;
    pFirst = p->pWrite;
  }

  return rc;
}


static int idxCreateVtabSchema(sqlite3expert *p, char **pzErrmsg){
  int rc = idxRegisterVtab(p);
  sqlite3_stmt *pSchema = 0;

  /* For each table in the main db schema:
  **
  **   1) Add an entry to the p->pTable list, and
  **   2) Create the equivalent virtual table in dbv.
  */
  rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
      "SELECT type, name, sql, 1 FROM sqlite_master "
      "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%%' "
      " UNION ALL "
      "SELECT type, name, sql, 2 FROM sqlite_master "
      "WHERE type = 'trigger'"
      "  AND tbl_name IN(SELECT name FROM sqlite_master WHERE type = 'view') "
      "ORDER BY 4, 1"
  );
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
    const char *zType = (const char*)sqlite3_column_text(pSchema, 0);
    const char *zName = (const char*)sqlite3_column_text(pSchema, 1);
    const char *zSql = (const char*)sqlite3_column_text(pSchema, 2);

    if( zType[0]=='v' || zType[1]=='r' ){
      rc = sqlite3_exec(p->dbv, zSql, 0, 0, pzErrmsg);
    }else{
      IdxTable *pTab;
      rc = idxGetTableInfo(p->db, zName, &pTab, pzErrmsg);
      if( rc==SQLITE_OK ){
        int i;
        char *zInner = 0;
        char *zOuter = 0;
        pTab->pNext = p->pTable;
        p->pTable = pTab;

        /* The statement the vtab will pass to sqlite3_declare_vtab() */
        zInner = idxAppendText(&rc, 0, "CREATE TABLE x(");
        for(i=0; i<pTab->nCol; i++){
          zInner = idxAppendText(&rc, zInner, "%s%Q COLLATE %s", 
              (i==0 ? "" : ", "), pTab->aCol[i].zName, pTab->aCol[i].zColl
          );
        }
        zInner = idxAppendText(&rc, zInner, ")");

        /* The CVT statement to create the vtab */
        zOuter = idxAppendText(&rc, 0, 
            "CREATE VIRTUAL TABLE %Q USING expert(%Q)", zName, zInner
        );
        if( rc==SQLITE_OK ){
          rc = sqlite3_exec(p->dbv, zOuter, 0, 0, pzErrmsg);
        }
        sqlite3_free(zInner);
        sqlite3_free(zOuter);
      }
    }
  }
  idxFinalize(&rc, pSchema);
  return rc;
}

struct IdxSampleCtx {
  int iTarget;
  double target;                  /* Target nRet/nRow value */
  double nRow;                    /* Number of rows seen */
  double nRet;                    /* Number of rows returned */
};

static void idxSampleFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  struct IdxSampleCtx *p = (struct IdxSampleCtx*)sqlite3_user_data(pCtx);
  int bRet;

  (void)argv;
  assert( argc==0 );
  if( p->nRow==0.0 ){
    bRet = 1;
  }else{
    bRet = (p->nRet / p->nRow) <= p->target;
    if( bRet==0 ){
      unsigned short rnd;
      sqlite3_randomness(2, (void*)&rnd);
      bRet = ((int)rnd % 100) <= p->iTarget;
    }
  }

  sqlite3_result_int(pCtx, bRet);
  p->nRow += 1.0;
  p->nRet += (double)bRet;
}

struct IdxRemCtx {
  int nSlot;
  struct IdxRemSlot {
    int eType;                    /* SQLITE_NULL, INTEGER, REAL, TEXT, BLOB */
    i64 iVal;                     /* SQLITE_INTEGER value */
    double rVal;                  /* SQLITE_FLOAT value */
    int nByte;                    /* Bytes of space allocated at z */
    int n;                        /* Size of buffer z */
    char *z;                      /* SQLITE_TEXT/BLOB value */
  } aSlot[1];
};

/*
** Implementation of scalar function rem().
*/
static void idxRemFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  struct IdxRemCtx *p = (struct IdxRemCtx*)sqlite3_user_data(pCtx);
  struct IdxRemSlot *pSlot;
  int iSlot;
  assert( argc==2 );

  iSlot = sqlite3_value_int(argv[0]);
  assert( iSlot<=p->nSlot );
  pSlot = &p->aSlot[iSlot];

  switch( pSlot->eType ){
    case SQLITE_NULL:
      /* no-op */
      break;

    case SQLITE_INTEGER:
      sqlite3_result_int64(pCtx, pSlot->iVal);
      break;

    case SQLITE_FLOAT:
      sqlite3_result_double(pCtx, pSlot->rVal);
      break;

    case SQLITE_BLOB:
      sqlite3_result_blob(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
      break;

    case SQLITE_TEXT:
      sqlite3_result_text(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
      break;
  }

  pSlot->eType = sqlite3_value_type(argv[1]);
  switch( pSlot->eType ){
    case SQLITE_NULL:
      /* no-op */
      break;

    case SQLITE_INTEGER:
      pSlot->iVal = sqlite3_value_int64(argv[1]);
      break;

    case SQLITE_FLOAT:
      pSlot->rVal = sqlite3_value_double(argv[1]);
      break;

    case SQLITE_BLOB:
    case SQLITE_TEXT: {
      int nByte = sqlite3_value_bytes(argv[1]);
      if( nByte>pSlot->nByte ){
        char *zNew = (char*)sqlite3_realloc(pSlot->z, nByte*2);
        if( zNew==0 ){
          sqlite3_result_error_nomem(pCtx);
          return;
        }
        pSlot->nByte = nByte*2;
        pSlot->z = zNew;
      }
      pSlot->n = nByte;
      if( pSlot->eType==SQLITE_BLOB ){
        memcpy(pSlot->z, sqlite3_value_blob(argv[1]), nByte);
      }else{
        memcpy(pSlot->z, sqlite3_value_text(argv[1]), nByte);
      }
      break;
    }
  }
}

static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
  int rc = SQLITE_OK;
  const char *zMax = 
    "SELECT max(i.seqno) FROM "
    "  sqlite_master AS s, "
    "  pragma_index_list(s.name) AS l, "
    "  pragma_index_info(l.name) AS i "
    "WHERE s.type = 'table'";
  sqlite3_stmt *pMax = 0;

  *pnMax = 0;
  rc = idxPrepareStmt(db, &pMax, pzErr, zMax);
  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
    *pnMax = sqlite3_column_int(pMax, 0) + 1;
  }
  idxFinalize(&rc, pMax);

  return rc;
}

static int idxPopulateOneStat1(
  sqlite3expert *p,
  sqlite3_stmt *pIndexXInfo,
  sqlite3_stmt *pWriteStat,
  const char *zTab,
  const char *zIdx,
  char **pzErr
){
  char *zCols = 0;
  char *zOrder = 0;
  char *zQuery = 0;
  int nCol = 0;
  int i;
  sqlite3_stmt *pQuery = 0;
  int *aStat = 0;
  int rc = SQLITE_OK;

  assert( p->iSample>0 );

  /* Formulate the query text */
  sqlite3_bind_text(pIndexXInfo, 1, zIdx, -1, SQLITE_STATIC);
  while( SQLITE_OK==rc && SQLITE_ROW==sqlite3_step(pIndexXInfo) ){
    const char *zComma = zCols==0 ? "" : ", ";
    const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0);
    const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1);
    zCols = idxAppendText(&rc, zCols, 
        "%sx.%Q IS rem(%d, x.%Q) COLLATE %s", zComma, zName, nCol, zName, zColl
    );
    zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol);
  }
  sqlite3_reset(pIndexXInfo);
  if( rc==SQLITE_OK ){
    if( p->iSample==100 ){
      zQuery = sqlite3_mprintf(
          "SELECT %s FROM %Q x ORDER BY %s", zCols, zTab, zOrder
      );
    }else{
      zQuery = sqlite3_mprintf(
          "SELECT %s FROM temp."UNIQUE_TABLE_NAME" x ORDER BY %s", zCols, zOrder
      );
    }
  }
  sqlite3_free(zCols);
  sqlite3_free(zOrder);

  /* Formulate the query text */
  if( rc==SQLITE_OK ){
    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
    rc = idxPrepareStmt(dbrem, &pQuery, pzErr, zQuery);
  }
  sqlite3_free(zQuery);

  if( rc==SQLITE_OK ){
    aStat = (int*)idxMalloc(&rc, sizeof(int)*(nCol+1));
  }
  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
    IdxHashEntry *pEntry;
    char *zStat = 0;
    for(i=0; i<=nCol; i++) aStat[i] = 1;
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
      aStat[0]++;
      for(i=0; i<nCol; i++){
        if( sqlite3_column_int(pQuery, i)==0 ) break;
      }
      for(/*no-op*/; i<nCol; i++){
        aStat[i+1]++;
      }
    }

    if( rc==SQLITE_OK ){
      int s0 = aStat[0];
      zStat = sqlite3_mprintf("%d", s0);
      if( zStat==0 ) rc = SQLITE_NOMEM;
      for(i=1; rc==SQLITE_OK && i<=nCol; i++){
        zStat = idxAppendText(&rc, zStat, " %d", (s0+aStat[i]/2) / aStat[i]);
      }
    }

    if( rc==SQLITE_OK ){
      sqlite3_bind_text(pWriteStat, 1, zTab, -1, SQLITE_STATIC);
      sqlite3_bind_text(pWriteStat, 2, zIdx, -1, SQLITE_STATIC);
      sqlite3_bind_text(pWriteStat, 3, zStat, -1, SQLITE_STATIC);
      sqlite3_step(pWriteStat);
      rc = sqlite3_reset(pWriteStat);
    }

    pEntry = idxHashFind(&p->hIdx, zIdx, STRLEN(zIdx));
    if( pEntry ){
      assert( pEntry->zVal2==0 );
      pEntry->zVal2 = zStat;
    }else{
      sqlite3_free(zStat);
    }
  }
  sqlite3_free(aStat);
  idxFinalize(&rc, pQuery);

  return rc;
}

static int idxBuildSampleTable(sqlite3expert *p, const char *zTab){
  int rc;
  char *zSql;

  rc = sqlite3_exec(p->dbv,"DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  if( rc!=SQLITE_OK ) return rc;

  zSql = sqlite3_mprintf(
      "CREATE TABLE temp." UNIQUE_TABLE_NAME " AS SELECT * FROM %Q", zTab
  );
  if( zSql==0 ) return SQLITE_NOMEM;
  rc = sqlite3_exec(p->dbv, zSql, 0, 0, 0);
  sqlite3_free(zSql);

  return rc;
}

/*
** This function is called as part of sqlite3_expert_analyze(). Candidate
** indexes have already been created in database sqlite3expert.dbm, this
** function populates sqlite_stat1 table in the same database.
**
** The stat1 data is generated by querying the 
*/
static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
  int rc = SQLITE_OK;
  int nMax =0;
  struct IdxRemCtx *pCtx = 0;
  struct IdxSampleCtx samplectx; 
  int i;
  i64 iPrev = -100000;
  sqlite3_stmt *pAllIndex = 0;
  sqlite3_stmt *pIndexXInfo = 0;
  sqlite3_stmt *pWrite = 0;

  const char *zAllIndex =
    "SELECT s.rowid, s.name, l.name FROM "
    "  sqlite_master AS s, "
    "  pragma_index_list(s.name) AS l "
    "WHERE s.type = 'table'";
  const char *zIndexXInfo = 
    "SELECT name, coll FROM pragma_index_xinfo(?) WHERE key";
  const char *zWrite = "INSERT INTO sqlite_stat1 VALUES(?, ?, ?)";

  /* If iSample==0, no sqlite_stat1 data is required. */
  if( p->iSample==0 ) return SQLITE_OK;

  rc = idxLargestIndex(p->dbm, &nMax, pzErr);
  if( nMax<=0 || rc!=SQLITE_OK ) return rc;

  rc = sqlite3_exec(p->dbm, "ANALYZE; PRAGMA writable_schema=1", 0, 0, 0);

  if( rc==SQLITE_OK ){
    int nByte = sizeof(struct IdxRemCtx) + (sizeof(struct IdxRemSlot) * nMax);
    pCtx = (struct IdxRemCtx*)idxMalloc(&rc, nByte);
  }

  if( rc==SQLITE_OK ){
    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
    rc = sqlite3_create_function(
        dbrem, "rem", 2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
    );
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(
        p->db, "sample", 0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
    );
  }

  if( rc==SQLITE_OK ){
    pCtx->nSlot = nMax+1;
    rc = idxPrepareStmt(p->dbm, &pAllIndex, pzErr, zAllIndex);
  }
  if( rc==SQLITE_OK ){
    rc = idxPrepareStmt(p->dbm, &pIndexXInfo, pzErr, zIndexXInfo);
  }
  if( rc==SQLITE_OK ){
    rc = idxPrepareStmt(p->dbm, &pWrite, pzErr, zWrite);
  }

  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pAllIndex) ){
    i64 iRowid = sqlite3_column_int64(pAllIndex, 0);
    const char *zTab = (const char*)sqlite3_column_text(pAllIndex, 1);
    const char *zIdx = (const char*)sqlite3_column_text(pAllIndex, 2);
    if( p->iSample<100 && iPrev!=iRowid ){
      samplectx.target = (double)p->iSample / 100.0;
      samplectx.iTarget = p->iSample;
      samplectx.nRow = 0.0;
      samplectx.nRet = 0.0;
      rc = idxBuildSampleTable(p, zTab);
      if( rc!=SQLITE_OK ) break;
    }
    rc = idxPopulateOneStat1(p, pIndexXInfo, pWrite, zTab, zIdx, pzErr);
    iPrev = iRowid;
  }
  if( rc==SQLITE_OK && p->iSample<100 ){
    rc = sqlite3_exec(p->dbv, 
        "DROP TABLE IF EXISTS temp." UNIQUE_TABLE_NAME, 0,0,0
    );
  }

  idxFinalize(&rc, pAllIndex);
  idxFinalize(&rc, pIndexXInfo);
  idxFinalize(&rc, pWrite);

  for(i=0; i<pCtx->nSlot; i++){
    sqlite3_free(pCtx->aSlot[i].z);
  }
  sqlite3_free(pCtx);

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_master", 0, 0, 0);
  }

  sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  return rc;
}

/*
** Allocate a new sqlite3expert object.
*/
sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
  int rc = SQLITE_OK;
  sqlite3expert *pNew;

  pNew = (sqlite3expert*)idxMalloc(&rc, sizeof(sqlite3expert));

  /* Open two in-memory databases to work with. The "vtab database" (dbv)
  ** will contain a virtual table corresponding to each real table in
  ** the user database schema, and a copy of each view. It is used to
  ** collect information regarding the WHERE, ORDER BY and other clauses
  ** of the user's query.
  */
  if( rc==SQLITE_OK ){
    pNew->db = db;
    pNew->iSample = 100;
    rc = sqlite3_open(":memory:", &pNew->dbv);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_open(":memory:", &pNew->dbm);
    if( rc==SQLITE_OK ){
      sqlite3_db_config(pNew->dbm, SQLITE_DBCONFIG_TRIGGER_EQP, 1, (int*)0);
    }
  }
  

  /* Copy the entire schema of database [db] into [dbm]. */
  if( rc==SQLITE_OK ){
    sqlite3_stmt *pSql;
    rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg, 
        "SELECT sql FROM sqlite_master WHERE name NOT LIKE 'sqlite_%%'"
        " AND sql NOT LIKE 'CREATE VIRTUAL %%'"
    );
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
      const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
      rc = sqlite3_exec(pNew->dbm, zSql, 0, 0, pzErrmsg);
    }
    idxFinalize(&rc, pSql);
  }

  /* Create the vtab schema */
  if( rc==SQLITE_OK ){
    rc = idxCreateVtabSchema(pNew, pzErrmsg);
  }

  /* Register the auth callback with dbv */
  if( rc==SQLITE_OK ){
    sqlite3_set_authorizer(pNew->dbv, idxAuthCallback, (void*)pNew);
  }

  /* If an error has occurred, free the new object and reutrn NULL. Otherwise,
  ** return the new sqlite3expert handle.  */
  if( rc!=SQLITE_OK ){
    sqlite3_expert_destroy(pNew);
    pNew = 0;
  }
  return pNew;
}

/*
** Configure an sqlite3expert object.
*/
int sqlite3_expert_config(sqlite3expert *p, int op, ...){
  int rc = SQLITE_OK;
  va_list ap;
  va_start(ap, op);
  switch( op ){
    case EXPERT_CONFIG_SAMPLE: {
      int iVal = va_arg(ap, int);
      if( iVal<0 ) iVal = 0;
      if( iVal>100 ) iVal = 100;
      p->iSample = iVal;
      break;
    }
    default:
      rc = SQLITE_NOTFOUND;
      break;
  }

  va_end(ap);
  return rc;
}

/*
** Add an SQL statement to the analysis.
*/
int sqlite3_expert_sql(
  sqlite3expert *p,               /* From sqlite3_expert_new() */
  const char *zSql,               /* SQL statement to add */
  char **pzErr                    /* OUT: Error message (if any) */
){
  IdxScan *pScanOrig = p->pScan;
  IdxStatement *pStmtOrig = p->pStatement;
  int rc = SQLITE_OK;
  const char *zStmt = zSql;

  if( p->bRun ) return SQLITE_MISUSE;

  while( rc==SQLITE_OK && zStmt && zStmt[0] ){
    sqlite3_stmt *pStmt = 0;
    rc = sqlite3_prepare_v2(p->dbv, zStmt, -1, &pStmt, &zStmt);
    if( rc==SQLITE_OK ){
      if( pStmt ){
        IdxStatement *pNew;
        const char *z = sqlite3_sql(pStmt);
        int n = STRLEN(z);
        pNew = (IdxStatement*)idxMalloc(&rc, sizeof(IdxStatement) + n+1);
        if( rc==SQLITE_OK ){
          pNew->zSql = (char*)&pNew[1];
          memcpy(pNew->zSql, z, n+1);
          pNew->pNext = p->pStatement;
          if( p->pStatement ) pNew->iId = p->pStatement->iId+1;
          p->pStatement = pNew;
        }
        sqlite3_finalize(pStmt);
      }
    }else{
      idxDatabaseError(p->dbv, pzErr);
    }
  }

  if( rc!=SQLITE_OK ){
    idxScanFree(p->pScan, pScanOrig);
    idxStatementFree(p->pStatement, pStmtOrig);
    p->pScan = pScanOrig;
    p->pStatement = pStmtOrig;
  }

  return rc;
}

int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr){
  int rc;
  IdxHashEntry *pEntry;

  /* Do trigger processing to collect any extra IdxScan structures */
  rc = idxProcessTriggers(p, pzErr);

  /* Create candidate indexes within the in-memory database file */
  if( rc==SQLITE_OK ){
    rc = idxCreateCandidates(p);
  }

  /* Generate the stat1 data */
  if( rc==SQLITE_OK ){
    rc = idxPopulateStat1(p, pzErr);
  }

  /* Formulate the EXPERT_REPORT_CANDIDATES text */
  for(pEntry=p->hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
    p->zCandidates = idxAppendText(&rc, p->zCandidates, 
        "%s;%s%s\n", pEntry->zVal, 
        pEntry->zVal2 ? " -- stat1: " : "", pEntry->zVal2
    );
  }

  /* Figure out which of the candidate indexes are preferred by the query
  ** planner and report the results to the user.  */
  if( rc==SQLITE_OK ){
    rc = idxFindIndexes(p, pzErr);
  }

  if( rc==SQLITE_OK ){
    p->bRun = 1;
  }
  return rc;
}

/*
** Return the total number of statements that have been added to this
** sqlite3expert using sqlite3_expert_sql().
*/
int sqlite3_expert_count(sqlite3expert *p){
  int nRet = 0;
  if( p->pStatement ) nRet = p->pStatement->iId+1;
  return nRet;
}

/*
** Return a component of the report.
*/
const char *sqlite3_expert_report(sqlite3expert *p, int iStmt, int eReport){
  const char *zRet = 0;
  IdxStatement *pStmt;

  if( p->bRun==0 ) return 0;
  for(pStmt=p->pStatement; pStmt && pStmt->iId!=iStmt; pStmt=pStmt->pNext);
  switch( eReport ){
    case EXPERT_REPORT_SQL:
      if( pStmt ) zRet = pStmt->zSql;
      break;
    case EXPERT_REPORT_INDEXES:
      if( pStmt ) zRet = pStmt->zIdx;
      break;
    case EXPERT_REPORT_PLAN:
      if( pStmt ) zRet = pStmt->zEQP;
      break;
    case EXPERT_REPORT_CANDIDATES:
      zRet = p->zCandidates;
      break;
  }
  return zRet;
}

/*
** Free an sqlite3expert object.
*/
void sqlite3_expert_destroy(sqlite3expert *p){
  if( p ){
    sqlite3_close(p->dbm);
    sqlite3_close(p->dbv);
    idxScanFree(p->pScan, 0);
    idxStatementFree(p->pStatement, 0);
    idxTableFree(p->pTable);
    idxWriteFree(p->pWrite);
    idxHashClear(&p->hIdx);
    sqlite3_free(p->zCandidates);
    sqlite3_free(p);
  }
}

#endif /* ifndef SQLITE_OMIT_VIRTUAL_TABLE */

/*
** 2017 April 07
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/


#include "sqlite3.h"

typedef struct sqlite3expert sqlite3expert;

/*
** Create a new sqlite3expert object.
**
** If successful, a pointer to the new object is returned and (*pzErr) set
** to NULL. Or, if an error occurs, NULL is returned and (*pzErr) set to
** an English-language error message. In this case it is the responsibility
** of the caller to eventually free the error message buffer using
** sqlite3_free().
*/
sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErr);

/*
** Configure an sqlite3expert object.
**
** EXPERT_CONFIG_SAMPLE:
**   By default, sqlite3_expert_analyze() generates sqlite_stat1 data for
**   each candidate index. This involves scanning and sorting the entire
**   contents of each user database table once for each candidate index
**   associated with the table. For large databases, this can be 
**   prohibitively slow. This option allows the sqlite3expert object to
**   be configured so that sqlite_stat1 data is instead generated based on a
**   subset of each table, or so that no sqlite_stat1 data is used at all.
**
**   A single integer argument is passed to this option. If the value is less
**   than or equal to zero, then no sqlite_stat1 data is generated or used by
**   the analysis - indexes are recommended based on the database schema only.
**   Or, if the value is 100 or greater, complete sqlite_stat1 data is
**   generated for each candidate index (this is the default). Finally, if the
**   value falls between 0 and 100, then it represents the percentage of user
**   table rows that should be considered when generating sqlite_stat1 data.
**
**   Examples:
**
**     // Do not generate any sqlite_stat1 data
**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 0);
**
**     // Generate sqlite_stat1 data based on 10% of the rows in each table.
**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 10);
*/
int sqlite3_expert_config(sqlite3expert *p, int op, ...);

#define EXPERT_CONFIG_SAMPLE 1    /* int */

/*
** Specify zero or more SQL statements to be included in the analysis.
**
** Buffer zSql must contain zero or more complete SQL statements. This
** function parses all statements contained in the buffer and adds them
** to the internal list of statements to analyze. If successful, SQLITE_OK
** is returned and (*pzErr) set to NULL. Or, if an error occurs - for example
** due to a error in the SQL - an SQLite error code is returned and (*pzErr)
** may be set to point to an English language error message. In this case
** the caller is responsible for eventually freeing the error message buffer
** using sqlite3_free().
**
** If an error does occur while processing one of the statements in the
** buffer passed as the second argument, none of the statements in the
** buffer are added to the analysis.
**
** This function must be called before sqlite3_expert_analyze(). If a call
** to this function is made on an sqlite3expert object that has already
** been passed to sqlite3_expert_analyze() SQLITE_MISUSE is returned
** immediately and no statements are added to the analysis.
*/
int sqlite3_expert_sql(
  sqlite3expert *p,               /* From a successful sqlite3_expert_new() */
  const char *zSql,               /* SQL statement(s) to add */
  char **pzErr                    /* OUT: Error message (if any) */
);


/*
** This function is called after the sqlite3expert object has been configured
** with all SQL statements using sqlite3_expert_sql() to actually perform
** the analysis. Once this function has been called, it is not possible to
** add further SQL statements to the analysis.
**
** If successful, SQLITE_OK is returned and (*pzErr) is set to NULL. Or, if
** an error occurs, an SQLite error code is returned and (*pzErr) set to 
** point to a buffer containing an English language error message. In this
** case it is the responsibility of the caller to eventually free the buffer
** using sqlite3_free().
**
** If an error does occur within this function, the sqlite3expert object
** is no longer useful for any purpose. At that point it is no longer
** possible to add further SQL statements to the object or to re-attempt
** the analysis. The sqlite3expert object must still be freed using a call
** sqlite3_expert_destroy().
*/
int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr);

/*
** Return the total number of statements loaded using sqlite3_expert_sql().
** The total number of SQL statements may be different from the total number
** to calls to sqlite3_expert_sql().
*/
int sqlite3_expert_count(sqlite3expert*);

/*
** Return a component of the report.
**
** This function is called after sqlite3_expert_analyze() to extract the
** results of the analysis. Each call to this function returns either a
** NULL pointer or a pointer to a buffer containing a nul-terminated string.
** The value passed as the third argument must be one of the EXPERT_REPORT_*
** #define constants defined below.
**
** For some EXPERT_REPORT_* parameters, the buffer returned contains 
** information relating to a specific SQL statement. In these cases that
** SQL statement is identified by the value passed as the second argument.
** SQL statements are numbered from 0 in the order in which they are parsed.
** If an out-of-range value (less than zero or equal to or greater than the
** value returned by sqlite3_expert_count()) is passed as the second argument
** along with such an EXPERT_REPORT_* parameter, NULL is always returned.
**
** EXPERT_REPORT_SQL:
**   Return the text of SQL statement iStmt.
**
** EXPERT_REPORT_INDEXES:
**   Return a buffer containing the CREATE INDEX statements for all recommended
**   indexes for statement iStmt. If there are no new recommeded indexes, NULL 
**   is returned.
**
** EXPERT_REPORT_PLAN:
**   Return a buffer containing the EXPLAIN QUERY PLAN output for SQL query
**   iStmt after the proposed indexes have been added to the database schema.
**
** EXPERT_REPORT_CANDIDATES:
**   Return a pointer to a buffer containing the CREATE INDEX statements 
**   for all indexes that were tested (for all SQL statements). The iStmt
**   parameter is ignored for EXPERT_REPORT_CANDIDATES calls.
*/
const char *sqlite3_expert_report(sqlite3expert*, int iStmt, int eReport);

/*
** Values for the third argument passed to sqlite3_expert_report().
*/
#define EXPERT_REPORT_SQL        1
#define EXPERT_REPORT_INDEXES    2
#define EXPERT_REPORT_PLAN       3
#define EXPERT_REPORT_CANDIDATES 4

/*
** Free an (sqlite3expert*) handle and all associated resources. There 
** should be one call to this function for each successful call to 
** sqlite3-expert_new().
*/
void sqlite3_expert_destroy(sqlite3expert*);

/*
** 2017 April 07
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#if defined(SQLITE_TEST)

#include "sqlite3expert.h"
#include <assert.h>
#include <string.h>

#if defined(INCLUDE_SQLITE_TCL_H)
#  include "sqlite_tcl.h"
#else
#  include "tcl.h"
#  ifndef SQLITE_TCLAPI
#    define SQLITE_TCLAPI
#  endif
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Extract an sqlite3* db handle from the object passed as the second
** argument. If successful, set *pDb to point to the db handle and return
** TCL_OK. Otherwise, return TCL_ERROR.
*/
static int dbHandleFromObj(Tcl_Interp *interp, Tcl_Obj *pObj, sqlite3 **pDb){
  Tcl_CmdInfo info;
  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(pObj), &info) ){
    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(pObj), 0);
    return TCL_ERROR;
  }

  *pDb = *(sqlite3 **)info.objClientData;
  return TCL_OK;
}


/*
** Tclcmd:  $expert sql SQL
**          $expert analyze
**          $expert count
**          $expert report STMT EREPORT
**          $expert destroy
*/
static int SQLITE_TCLAPI testExpertCmd(
  void *clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3expert *pExpert = (sqlite3expert*)clientData;
  struct Subcmd {
    const char *zSub;
    int nArg;
    const char *zMsg;
  } aSub[] = {
    { "sql",       1, "TABLE",        }, /* 0 */
    { "analyze",   0, "",             }, /* 1 */
    { "count",     0, "",             }, /* 2 */
    { "report",    2, "STMT EREPORT", }, /* 3 */
    { "destroy",   0, "",             }, /* 4 */
    { 0 }
  };
  int iSub;
  int rc = TCL_OK;
  char *zErr = 0;

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
    return TCL_ERROR;
  }
  rc = Tcl_GetIndexFromObjStruct(interp, 
      objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iSub
  );
  if( rc!=TCL_OK ) return rc;
  if( objc!=2+aSub[iSub].nArg ){
    Tcl_WrongNumArgs(interp, 2, objv, aSub[iSub].zMsg);
    return TCL_ERROR;
  }

  switch( iSub ){
    case 0: {      /* sql */
      char *zArg = Tcl_GetString(objv[2]);
      rc = sqlite3_expert_sql(pExpert, zArg, &zErr);
      break;
    }

    case 1: {      /* analyze */
      rc = sqlite3_expert_analyze(pExpert, &zErr);
      break;
    }

    case 2: {      /* count */
      int n = sqlite3_expert_count(pExpert);
      Tcl_SetObjResult(interp, Tcl_NewIntObj(n));
      break;
    }

    case 3: {      /* report */
      const char *aEnum[] = {
        "sql", "indexes", "plan", "candidates", 0
      };
      int iEnum;
      int iStmt;
      const char *zReport;

      if( Tcl_GetIntFromObj(interp, objv[2], &iStmt) 
       || Tcl_GetIndexFromObj(interp, objv[3], aEnum, "report", 0, &iEnum)
      ){
        return TCL_ERROR;
      }

      assert( EXPERT_REPORT_SQL==1 );
      assert( EXPERT_REPORT_INDEXES==2 );
      assert( EXPERT_REPORT_PLAN==3 );
      assert( EXPERT_REPORT_CANDIDATES==4 );
      zReport = sqlite3_expert_report(pExpert, iStmt, 1+iEnum);
      Tcl_SetObjResult(interp, Tcl_NewStringObj(zReport, -1));
      break;
    }

    default:       /* destroy */
      assert( iSub==4 );     
      Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
      break;
  }

  if( rc!=TCL_OK ){
    if( zErr ){
      Tcl_SetObjResult(interp, Tcl_NewStringObj(zErr, -1));
    }else{
      extern const char *sqlite3ErrName(int);
      Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
    }
  }
  sqlite3_free(zErr);
  return rc;
}

static void SQLITE_TCLAPI testExpertDel(void *clientData){
  sqlite3expert *pExpert = (sqlite3expert*)clientData;
  sqlite3_expert_destroy(pExpert);
}

/*
** sqlite3_expert_new DB
*/
static int SQLITE_TCLAPI test_sqlite3_expert_new(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  static int iCmd = 0;
  sqlite3 *db;
  char *zCmd = 0;
  char *zErr = 0;
  sqlite3expert *pExpert;
  int rc = TCL_OK;

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( dbHandleFromObj(interp, objv[1], &db) ){
    return TCL_ERROR;
  }

  zCmd = sqlite3_mprintf("sqlite3expert%d", ++iCmd);
  if( zCmd==0 ){
    Tcl_AppendResult(interp, "out of memory", (char*)0);
    return TCL_ERROR;
  }

  pExpert = sqlite3_expert_new(db, &zErr);
  if( pExpert==0 ){
    Tcl_AppendResult(interp, zErr, (char*)0);
    rc = TCL_ERROR;
  }else{
    void *p = (void*)pExpert;
    Tcl_CreateObjCommand(interp, zCmd, testExpertCmd, p, testExpertDel);
    Tcl_SetObjResult(interp, Tcl_NewStringObj(zCmd, -1));
  }

  sqlite3_free(zCmd);
  sqlite3_free(zErr);
  return rc;
}

#endif  /* ifndef SQLITE_OMIT_VIRTUALTABLE */

int TestExpert_Init(Tcl_Interp *interp){
#ifndef SQLITE_OMIT_VIRTUALTABLE
  struct Cmd {
    const char *zCmd;
    Tcl_ObjCmdProc *xProc;
  } aCmd[] = {
    { "sqlite3_expert_new", test_sqlite3_expert_new },
  };
  int i;

  for(i=0; i<sizeof(aCmd)/sizeof(struct Cmd); i++){
    struct Cmd *p = &aCmd[i];
    Tcl_CreateObjCommand(interp, p->zCmd, p->xProc, 0, 0);
  }
#endif
  return TCL_OK;
}

#endif

  sqlite3_stmt *pStmt;
  int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int64(pStmt, 1, iBlock);
    sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC);
    sqlite3_step(pStmt);
    rc = sqlite3_reset(pStmt);
    sqlite3_bind_null(pStmt, 2);
  }
  return rc;
}

/*
** Find the largest relative level number in the table. If successful, set
** *pnMax to this value and return SQLITE_OK. Otherwise, if an error occurs,

      char *zEnd = sqlite3_mprintf("%lld %lld", iEndBlock, nLeafData);
      if( !zEnd ) return SQLITE_NOMEM;
      sqlite3_bind_text(pStmt, 5, zEnd, -1, sqlite3_free);
    }
    sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);
    sqlite3_step(pStmt);
    rc = sqlite3_reset(pStmt);
    sqlite3_bind_null(pStmt, 6);
  }
  return rc;
}

/*
** Return the size of the common prefix (if any) shared by zPrev and
** zNext, in bytes. For example, 

    *pRC = rc;
    return;
  }
  sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
  sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, SQLITE_STATIC);
  sqlite3_step(pStmt);
  *pRC = sqlite3_reset(pStmt);
  sqlite3_bind_null(pStmt, 2);
  sqlite3_free(a);
}

/*
** Merge the entire database so that there is one segment for each 
** iIndex/iLangid combination.
*/

    if( rc==SQLITE_OK ){
      sqlite3_bind_int64(pChomp, 1, iNewStart);
      sqlite3_bind_blob(pChomp, 2, root.a, root.n, SQLITE_STATIC);
      sqlite3_bind_int64(pChomp, 3, iAbsLevel);
      sqlite3_bind_int(pChomp, 4, iIdx);
      sqlite3_step(pChomp);
      rc = sqlite3_reset(pChomp);
      sqlite3_bind_null(pChomp, 2);
    }
  }

  sqlite3_free(root.a);
  sqlite3_free(block.a);
  return rc;
}

  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pReplace, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pReplace, 1, FTS_STAT_INCRMERGEHINT);
    sqlite3_bind_blob(pReplace, 2, pHint->a, pHint->n, SQLITE_STATIC);
    sqlite3_step(pReplace);
    rc = sqlite3_reset(pReplace);
    sqlite3_bind_null(pReplace, 2);
  }

  return rc;
}

/*
** Load an incr-merge hint from the database. The incr-merge hint, if one 

  sqlite3_vtab *pVtab,            /* FTS3 vtab object */
  int nArg,                       /* Size of argument array */
  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;             /* Return Code */

  u32 *aSzIns = 0;                /* Sizes of inserted documents */
  u32 *aSzDel = 0;                /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;

  /* At this point it must be known if the %_stat table exists or not.
  ** So bHasStat may not be 2.  */

    goto update_out;
  }

  /* If this is a DELETE or UPDATE operation, remove the old record. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER );
    rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel);

  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){
    int iLangid = sqlite3_value_int(apVal[2 + p->nColumn + 2]);
    if( bInsertDone==0 ){
      rc = fts3InsertData(p, apVal, pRowid);
      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
        rc = FTS_CORRUPT_VTAB;
      }
    }
    if( rc==SQLITE_OK ){
      rc = fts3PendingTermsDocid(p, 0, iLangid, *pRowid);
    }
    if( rc==SQLITE_OK ){
      assert( p->iPrevDocid==*pRowid );
      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
    }
    if( p->bHasDocsize ){

Fts5ExprPhrase *sqlite3Fts5ParseTerm(
  Fts5Parse *pParse, 
  Fts5ExprPhrase *pPhrase, 
  Fts5Token *pToken,
  int bPrefix
);

void sqlite3Fts5ParseSetCaret(Fts5ExprPhrase*);

Fts5ExprNearset *sqlite3Fts5ParseNearset(
  Fts5Parse*, 
  Fts5ExprNearset*,
  Fts5ExprPhrase* 
);

    if( (iAdj+nToken)>nDocsize ) iAdj = nDocsize - nToken;
    if( iAdj<0 ) iAdj = 0;
    *piPos = iAdj;
  }

  return rc;
}

/*
** Return the value in pVal interpreted as utf-8 text. Except, if pVal 
** contains a NULL value, return a pointer to a static string zero
** bytes in length instead of a NULL pointer.
*/
static const char *fts5ValueToText(sqlite3_value *pVal){
  const char *zRet = (const char*)sqlite3_value_text(pVal);
  return zRet ? zRet : "";
}

/*
** Implementation of snippet() function.
*/
static void fts5SnippetFunction(
  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
  Fts5Context *pFts,              /* First arg to pass to pApi functions */

    sqlite3_result_error(pCtx, zErr, -1);
    return;
  }

  nCol = pApi->xColumnCount(pFts);
  memset(&ctx, 0, sizeof(HighlightContext));
  iCol = sqlite3_value_int(apVal[0]);
  ctx.zOpen = fts5ValueToText(apVal[1]);
  ctx.zClose = fts5ValueToText(apVal[2]);
  zEllips = fts5ValueToText(apVal[3]);
  nToken = sqlite3_value_int(apVal[4]);

  iBestCol = (iCol>=0 ? iCol : 0);
  nPhrase = pApi->xPhraseCount(pFts);
  aSeen = sqlite3_malloc(nPhrase);
  if( aSeen==0 ){
    rc = SQLITE_NOMEM;

#define fts5ExprNodeNext(a,b,c,d) (b)->xNext((a), (b), (c), (d))

/*
** An instance of the following structure represents a single search term
** or term prefix.
*/
struct Fts5ExprTerm {
  u8 bPrefix;                     /* True for a prefix term */
  u8 bFirst;                      /* True if token must be first in column */
  char *zTerm;                    /* nul-terminated term */
  Fts5IndexIter *pIter;           /* Iterator for this term */
  Fts5ExprTerm *pSynonym;         /* Pointer to first in list of synonyms */
};

/*
** A phrase. One or more terms that must appear in a contiguous sequence

    case '{':  tok = FTS5_LCP;   break;
    case '}':  tok = FTS5_RCP;   break;
    case ':':  tok = FTS5_COLON; break;
    case ',':  tok = FTS5_COMMA; break;
    case '+':  tok = FTS5_PLUS;  break;
    case '*':  tok = FTS5_STAR;  break;
    case '-':  tok = FTS5_MINUS; break;
    case '^':  tok = FTS5_CARET; break;
    case '\0': tok = FTS5_EOF;   break;

    case '"': {
      const char *z2;
      tok = FTS5_STRING;

      for(z2=&z[1]; 1; z2++){

  int *pbMatch                    /* OUT: Set to true if really a match */
){
  Fts5PoslistWriter writer = {0};
  Fts5PoslistReader aStatic[4];
  Fts5PoslistReader *aIter = aStatic;
  int i;
  int rc = SQLITE_OK;
  int bFirst = pPhrase->aTerm[0].bFirst;
  
  fts5BufferZero(&pPhrase->poslist);

  /* If the aStatic[] array is not large enough, allocate a large array
  ** using sqlite3_malloc(). This approach could be improved upon. */
  if( pPhrase->nTerm>ArraySize(aStatic) ){
    int nByte = sizeof(Fts5PoslistReader) * pPhrase->nTerm;

          }
          if( pPos->iPos>iAdj ) iPos = pPos->iPos-i;
        }
      }
    }while( bMatch==0 );

    /* Append position iPos to the output */
    if( bFirst==0 || FTS5_POS2OFFSET(iPos)==0 ){
      rc = sqlite3Fts5PoslistWriterAppend(&pPhrase->poslist, &writer, iPos);
      if( rc!=SQLITE_OK ) goto ismatch_out;
    }

    for(i=0; i<pPhrase->nTerm; i++){
      if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) goto ismatch_out;
    }
  }

 ismatch_out:

    int i;

    /* Check that each phrase in the nearset matches the current row.
    ** Populate the pPhrase->poslist buffers at the same time. If any
    ** phrase is not a match, break out of the loop early.  */
    for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
      if( pPhrase->nTerm>1 || pPhrase->aTerm[0].pSynonym 
       || pNear->pColset || pPhrase->aTerm[0].bFirst
      ){
        int bMatch = 0;
        rc = fts5ExprPhraseIsMatch(pNode, pPhrase, &bMatch);
        if( bMatch==0 ) break;
      }else{
        Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;
        fts5BufferSet(&rc, &pPhrase->poslist, pIter->nData, pIter->pData);
      }

  int bMatch;                     /* True if all terms are at the same rowid */
  const int bDesc = pExpr->bDesc;

  /* Check that this node should not be FTS5_TERM */
  assert( pNear->nPhrase>1 
       || pNear->apPhrase[0]->nTerm>1 
       || pNear->apPhrase[0]->aTerm[0].pSynonym
       || pNear->apPhrase[0]->aTerm[0].bFirst
  );

  /* Initialize iLast, the "lastest" rowid any iterator points to. If the
  ** iterator skips through rowids in the default ascending order, this means
  ** the maximum rowid. Or, if the iterator is "ORDER BY rowid DESC", then it
  ** means the minimum rowid.  */
  if( pLeft->aTerm[0].pSynonym ){

        sqlite3_free(pSyn);
      }
    }
    if( pPhrase->poslist.nSpace>0 ) fts5BufferFree(&pPhrase->poslist);
    sqlite3_free(pPhrase);
  }
}

/*
** Set the "bFirst" flag on the first token of the phrase passed as the
** only argument.
*/
void sqlite3Fts5ParseSetCaret(Fts5ExprPhrase *pPhrase){
  if( pPhrase && pPhrase->nTerm ){
    pPhrase->aTerm[0].bFirst = 1;
  }
}

/*
** If argument pNear is NULL, then a new Fts5ExprNearset object is allocated
** and populated with pPhrase. Or, if pNear is not NULL, phrase pPhrase is
** appended to it and the results returned.
**
** If an OOM error occurs, both the pNear and pPhrase objects are freed and

        const char *zTerm = p->zTerm;
        rc = fts5ParseTokenize((void*)&sCtx, tflags, zTerm, (int)strlen(zTerm),
            0, 0);
        tflags = FTS5_TOKEN_COLOCATED;
      }
      if( rc==SQLITE_OK ){
        sCtx.pPhrase->aTerm[i].bPrefix = pOrig->aTerm[i].bPrefix;
        sCtx.pPhrase->aTerm[i].bFirst = pOrig->aTerm[i].bFirst;
      }
    }
  }else{
    /* This happens when parsing a token or quoted phrase that contains
    ** no token characters at all. (e.g ... MATCH '""'). */
    sCtx.pPhrase = sqlite3Fts5MallocZero(&rc, sizeof(Fts5ExprPhrase));
  }

  if( rc==SQLITE_OK ){
    /* All the allocations succeeded. Put the expression object together. */
    pNew->pIndex = pExpr->pIndex;
    pNew->pConfig = pExpr->pConfig;
    pNew->nPhrase = 1;
    pNew->apExprPhrase[0] = sCtx.pPhrase;
    pNew->pRoot->pNear->apPhrase[0] = sCtx.pPhrase;
    pNew->pRoot->pNear->nPhrase = 1;
    sCtx.pPhrase->pNode = pNew->pRoot;

    if( pOrig->nTerm==1 
     && pOrig->aTerm[0].pSynonym==0 
     && pOrig->aTerm[0].bFirst==0 
    ){
      pNew->pRoot->eType = FTS5_TERM;
      pNew->pRoot->xNext = fts5ExprNodeNext_TERM;
    }else{
      pNew->pRoot->eType = FTS5_STRING;
      pNew->pRoot->xNext = fts5ExprNodeNext_STRING;
    }
  }else{

static void fts5ExprAssignXNext(Fts5ExprNode *pNode){
  switch( pNode->eType ){
    case FTS5_STRING: {
      Fts5ExprNearset *pNear = pNode->pNear;
      if( pNear->nPhrase==1 && pNear->apPhrase[0]->nTerm==1 
       && pNear->apPhrase[0]->aTerm[0].pSynonym==0
       && pNear->apPhrase[0]->aTerm[0].bFirst==0
      ){
        pNode->eType = FTS5_TERM;
        pNode->xNext = fts5ExprNodeNext_TERM;
      }else{
        pNode->xNext = fts5ExprNodeNext_STRING;
      }
      break;

          pNear->apPhrase[iPhrase]->pNode = pRet;
          if( pNear->apPhrase[iPhrase]->nTerm==0 ){
            pRet->xNext = 0;
            pRet->eType = FTS5_EOF;
          }
        }

        if( pParse->pConfig->eDetail!=FTS5_DETAIL_FULL ){
          Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];
          if( pNear->nPhrase!=1 
           || pPhrase->nTerm>1
           || (pPhrase->nTerm>0 && pPhrase->aTerm[0].bFirst)
          ){
            assert( pParse->rc==SQLITE_OK );
            pParse->rc = SQLITE_ERROR;
            assert( pParse->zErr==0 );
            pParse->zErr = sqlite3_mprintf(
                "fts5: %s queries are not supported (detail!=full)", 
                pNear->nPhrase==1 ? "phrase": "NEAR"
                );
            sqlite3_free(pRet);
            pRet = 0;
          }
        }
      }else{
        fts5ExprAddChildren(pRet, pLeft);
        fts5ExprAddChildren(pRet, pRight);
      }
    }
  }

    if( p->rc ) return;
  }

  sqlite3_bind_int64(p->pWriter, 1, iRowid);
  sqlite3_bind_blob(p->pWriter, 2, pData, nData, SQLITE_STATIC);
  sqlite3_step(p->pWriter);
  p->rc = sqlite3_reset(p->pWriter);
  sqlite3_bind_null(p->pWriter, 2);
}

/*
** Execute the following SQL:
**
**     DELETE FROM %_data WHERE id BETWEEN $iFirst AND $iLast
*/

  sqlite3_bind_blob(pIdxSelect, 2, pTerm, nTerm, SQLITE_STATIC);
  if( SQLITE_ROW==sqlite3_step(pIdxSelect) ){
    i64 val = sqlite3_column_int(pIdxSelect, 0);
    iPg = (int)(val>>1);
    bDlidx = (val & 0x0001);
  }
  p->rc = sqlite3_reset(pIdxSelect);
  sqlite3_bind_null(pIdxSelect, 2);

  if( iPg<pSeg->pgnoFirst ){
    iPg = pSeg->pgnoFirst;
    bDlidx = 0;
  }

  pIter->iLeafPgno = iPg - 1;

        sqlite3_stmt *pIdxSelect = fts5IdxSelectStmt(p);
        if( p->rc==SQLITE_OK ){
          u8 aBlob[2] = {0xff, 0xff};
          sqlite3_bind_int(pIdxSelect, 1, iSegid);
          sqlite3_bind_blob(pIdxSelect, 2, aBlob, 2, SQLITE_STATIC);
          assert( sqlite3_step(pIdxSelect)!=SQLITE_ROW );
          p->rc = sqlite3_reset(pIdxSelect);
          sqlite3_bind_null(pIdxSelect, 2);
        }
      }
#endif
    }
  }

  return iSegid;

    const char *z = (pWriter->btterm.n>0?(const char*)pWriter->btterm.p:"");
    /* The following was already done in fts5WriteInit(): */
    /* sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid); */
    sqlite3_bind_blob(p->pIdxWriter, 2, z, pWriter->btterm.n, SQLITE_STATIC);
    sqlite3_bind_int64(p->pIdxWriter, 3, bFlag + ((i64)pWriter->iBtPage<<1));
    sqlite3_step(p->pIdxWriter);
    p->rc = sqlite3_reset(p->pIdxWriter);
    sqlite3_bind_null(p->pIdxWriter, 2);
  }
  pWriter->iBtPage = 0;
}

/*
** This is called once for each leaf page except the first that contains
** at least one term. Argument (nTerm/pTerm) is the split-key - a term that

  if( p2->n ){
    i64 iLastRowid = 0;
    Fts5DoclistIter i1;
    Fts5DoclistIter i2;
    Fts5Buffer out = {0, 0, 0};
    Fts5Buffer tmp = {0, 0, 0};

    /* The maximum size of the output is equal to the sum of the two 
    ** input sizes + 1 varint (9 bytes). The extra varint is because if the
    ** first rowid in one input is a large negative number, and the first in
    ** the other a non-negative number, the delta for the non-negative
    ** number will be larger on disk than the literal integer value
    ** was.  */
    if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n + 9) ) return;
    fts5DoclistIterInit(p1, &i1);
    fts5DoclistIterInit(p2, &i2);

    while( 1 ){
      if( i1.iRowid<i2.iRowid ){
        /* Copy entry from i1 */
        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);

      fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
      fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);
    }
    else if( i2.aPoslist ){
      fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
      fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);
    }
    assert( out.n<=(p1->n+p2->n+9) );

    fts5BufferSet(&p->rc, p1, out.n, out.p);
    fts5BufferFree(&tmp);
    fts5BufferFree(&out);
  }
}

    sqlite3_stmt *pReplace = 0;
    rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_DOCSIZE, &pReplace, 0);
    if( rc==SQLITE_OK ){
      sqlite3_bind_int64(pReplace, 1, iRowid);
      sqlite3_bind_blob(pReplace, 2, pBuf->p, pBuf->n, SQLITE_STATIC);
      sqlite3_step(pReplace);
      rc = sqlite3_reset(pReplace);
      sqlite3_bind_null(pReplace, 2);
    }
  }
  return rc;
}

/*
** Load the contents of the "averages" record from disk into the 

    if( pVal ){
      sqlite3_bind_value(pReplace, 2, pVal);
    }else{
      sqlite3_bind_int(pReplace, 2, iVal);
    }
    sqlite3_step(pReplace);
    rc = sqlite3_reset(pReplace);
    sqlite3_bind_null(pReplace, 1);
  }
  if( rc==SQLITE_OK && pVal ){
    int iNew = p->pConfig->iCookie + 1;
    rc = sqlite3Fts5IndexSetCookie(p->pIndex, iNew);
    if( rc==SQLITE_OK ){
      p->pConfig->iCookie = iNew;
    }
  }
  return rc;
}

      rc = p->pApi->xSetAuxdata(p->pFts, (void*)((char*)0 + iVal), 0);
      break;
    }
    CASE(15, "xGetAuxdataInt") {
      int iVal;
      int bClear;
      if( Tcl_GetBooleanFromObj(interp, objv[2], &bClear) ) return TCL_ERROR;
      iVal = (int)((char*)p->pApi->xGetAuxdata(p->pFts, bClear) - (char*)0);
      Tcl_SetObjResult(interp, Tcl_NewIntObj(iVal));
      break;
    }

    CASE(16, "xPhraseForeach") {
      int iPhrase;
      int iCol;

      Fts5PhraseIter iter;

      if( Tcl_GetIntFromObj(interp, objv[2], &iPhrase) ) return TCL_ERROR;
      zColvar = Tcl_GetString(objv[3]);

      rc = p->pApi->xPhraseFirstColumn(p->pFts, iPhrase, &iter, &iCol);
      if( rc!=SQLITE_OK ){
        Tcl_SetResult(interp, (char*)sqlite3ErrName(rc), TCL_VOLATILE);
        return TCL_ERROR;
      }
      for( ; iCol>=0; p->pApi->xPhraseNextColumn(p->pFts, &iter, &iCol)){
        Tcl_SetVar2Ex(interp, zColvar, 0, Tcl_NewIntObj(iCol), 0);
        rc = Tcl_EvalObjEx(interp, pScript, 0);
        if( rc==TCL_CONTINUE ) rc = TCL_OK;
        if( rc!=TCL_OK ){

        "sqlite3_fts5_token may only be used by tokenizer callback", 0
    );
    return TCL_ERROR;
  }

  rc = p->xToken(p->pCtx, tflags, zToken, nToken, iStart, iEnd);
  Tcl_SetResult(interp, (char*)sqlite3ErrName(rc), TCL_VOLATILE);
  return rc==SQLITE_OK ? TCL_OK : TCL_ERROR;

 usage:
  Tcl_WrongNumArgs(interp, 1, objv, "?-colocated? TEXT START END");
  return TCL_ERROR;
}

static void f5tDelTokenizer(void *pCtx){

%type nearset     {Fts5ExprNearset*}
%type nearphrases {Fts5ExprNearset*}
%destructor nearset { sqlite3Fts5ParseNearsetFree($$); }
%destructor nearphrases { sqlite3Fts5ParseNearsetFree($$); }

nearset(A) ::= phrase(Y). { A = sqlite3Fts5ParseNearset(pParse, 0, Y); }
nearset(A) ::= CARET phrase(Y). { 
  sqlite3Fts5ParseSetCaret(Y);
  A = sqlite3Fts5ParseNearset(pParse, 0, Y); 
}
nearset(A) ::= STRING(X) LP nearphrases(Y) neardist_opt(Z) RP. {
  sqlite3Fts5ParseNear(pParse, &X);
  sqlite3Fts5ParseSetDistance(pParse, Y, &Z);
  A = Y;
}

nearphrases(A) ::= phrase(X). { 

  A = sqlite3Fts5ParseTerm(pParse, 0, &Y, Z);
}

/*
** Optional "*" character.
*/
%type star_opt {int}

star_opt(A) ::= STAR. { A = 1; }
star_opt(A) ::= . { A = 0; }

do_execsql_test 22.1 {
  SELECT rowid FROM t9('a*')
} {1}

}

expand_all_sql db
finish_test

    'x a a a a a a a a a a',
    'a a a a a a a a a a a a a a a a a a a x'
  );
}
do_execsql_test 5.1 {
  SELECT snippet(p1, 0, '[', ']', '...', 6) FROM p1('x');
} {{[x] a a a a a...}}

do_execsql_test 5.2 {
  SELECT snippet(p1, 0, '[', ']', NULL, 6) FROM p1('x');
} {{[x] a a a a a}}
do_execsql_test 5.3 {
  SELECT snippet(p1, 0, NULL, ']', '...', 6) FROM p1('x');
} {{x] a a a a a...}}
do_execsql_test 5.4 {
  SELECT snippet(p1, 0, '[', NULL, '...', 6) FROM p1('x');
} {{[x a a a a a...}}

} ;# foreach_detail_mode 

finish_test

  sqlite3_fts5_register_matchinfo db
  db func mit mit
} -body {
  db eval { 
    SELECT rowid, mit(matchinfo(t1, 'x')) FROM t1 WHERE t1 MATCH 'a AND c'
  }
} -test {
  faultsim_test_result [list 0 $::res] {1 {SQL logic error}}
}

do_faultsim_test 5.3 -faults oom* -prep {
  faultsim_restore_and_reopen
  sqlite3_fts5_create_tokenizer db tcl tcl_create
} -body {
  db eval { 
    SELECT count(*) FROM t1 WHERE t1 MATCH 'd AND e AND f'
  }
} -test {
  faultsim_test_result {0 29} {1 {SQL logic error}}
}

do_faultsim_test 5.4 -faults oom* -prep {
  faultsim_restore_and_reopen
  sqlite3_fts5_create_tokenizer db tcl tcl_create
} -body {
  db eval { 
    SELECT count(*) FROM t1 WHERE t1 MATCH 'x + e'
  }
} -test {
  faultsim_test_result {0 1} {1 {SQL logic error}}
}

#-------------------------------------------------------------------------
catch { db close }
do_faultsim_test 6 -faults oom* -prep {
  sqlite_orig db test.db
  sqlite3_db_config_lookaside db 0 0 0

ifcapable !fts5 {
  finish_test
  return
}

foreach_detail_mode $testprefix {

if {"%DETAIL%" != "none"} continue

fts5_aux_test_functions db

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(a, b, detail=%DETAIL%);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  WITH seq(s) AS ( SELECT 1 UNION ALL SELECT s+1 FROM seq WHERE s<50)
  INSERT INTO t1 SELECT 'x x x y y y', 'a b c d e f' FROM seq;

  INSERT INTO t4 VALUES('c1 c2 c3', 'c4 c5 c6', 'c7 c8 c9');
}

do_faultsim_test 4.1 -faults oom-t* -body {
  execsql { SELECT rowid, fts5_test_collist(t4) FROM t4('2') }
} -test {
  faultsim_test_result \
      {0 {1 {0.0 0.1 0.2} 2 {0.0 0.1 0.2} 3 {0.0 0.1 0.2}}} \
      {1 SQLITE_NOMEM} {1 SQLITE_ERROR} {1 {SQL logic error}}
}

do_faultsim_test 4.2 -faults oom-t* -body {
  execsql { SELECT rowid, fts5_test_collist(t4) FROM t4('a5 OR b5 OR c5') }
} -test {
  faultsim_test_result \
      {0 {4 {0.0 0.1 0.2} 5 {1.0 1.1 1.2} 6 {2.0 2.1 2.2}}} \
      {1 SQLITE_NOMEM} {1 SQLITE_ERROR} {1 {SQL logic error}}
}


#-------------------------------------------------------------------------
# An OOM within an "ORDER BY rank" query.
#
db func rnddoc fts5_rnddoc 

}

do_faultsim_test 4.2 -faults oom* -body {
  execsql { SELECT rowid FROM t1('{a b c} : (a AND d)') }
} -test {
  faultsim_test_result {0 {2 3}}
}

#-------------------------------------------------------------------------
# Test OOM injection while parsing a CARET expression
#
reset_db
do_execsql_test 5.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(a);
  INSERT INTO t1 VALUES('a b c d');  -- 1
  INSERT INTO t1 VALUES('d a b c');  -- 2
  INSERT INTO t1 VALUES('c d a b');  -- 3
  INSERT INTO t1 VALUES('b c d a');  -- 4
}
do_faultsim_test 5.1 -faults oom* -body {
  execsql { SELECT rowid FROM t1('^a OR ^b') }
} -test {
  faultsim_test_result {0 {1 4}}
}


finish_test

# 2017 November 25
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5first

ifcapable !fts5 {
  finish_test
  return
}


do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE x1 USING fts5(a, b);
}

foreach {tn expr ok} {
  1 {^abc}           1
  2 {^abc + def}     1
  3 {^ "abc def"}    1
  4 {^"abc def"}     1
  5 {abc ^def}       1
  6 {abc + ^def}     0
  7 {abc ^+ def}     0
  8 {"^abc"}         1
  9 {NEAR(^abc def)} 0
} {
  set res(0) {/1 {fts5: syntax error near .*}/}
  set res(1) {0 {}}

  do_catchsql_test 1.$tn { SELECT * FROM x1($expr) } $res($ok)
}

#-------------------------------------------------------------------------
# 
do_execsql_test 2.0 {
  INSERT INTO x1 VALUES('a b c', 'b c a');
}

foreach {tn expr match} {
  1 {^a} 1
  2 {^b} 1
  3 {^c} 0
  4 {^a + b} 1
  5 {^b + c} 1
  6 {^c + a} 0
  7 {^"c a"} 0
  8 {a:^a} 1
  9 {a:^b} 0
  10 {a:^"a b"} 1
} {
  do_execsql_test 2.$tn { SELECT EXISTS (SELECT rowid FROM x1($expr)) } $match
}

#-------------------------------------------------------------------------
# 
do_execsql_test 3.0 {
  DELETE FROM x1;
  INSERT INTO x1 VALUES('b a', 'c a');
  INSERT INTO x1 VALUES('a a', 'c c');
  INSERT INTO x1 VALUES('a b', 'a a');
}
fts5_aux_test_functions db

foreach {tn expr expect} {
  1 {^a} {{2 1}}
  2 {^c AND ^b} {{0 2} {1 0}}
} {
  do_execsql_test 3.$tn {
    SELECT fts5_test_queryphrase(x1) FROM x1($expr) LIMIT 1
  } [list $expect]
}

#-------------------------------------------------------------------------
# 
do_execsql_test 3.1 {
  CREATE VIRTUAL TABLE x2 USING fts5(a, b, c, detail=column);
}

do_catchsql_test 3.2 {
  SELECT * FROM x2('a + b');
} {1 {fts5: phrase queries are not supported (detail!=full)}}

do_catchsql_test 3.3 {
  SELECT * FROM x2('^a');
} {1 {fts5: phrase queries are not supported (detail!=full)}}
finish_test

    foreach x [list bbb ddd fff hhh jjj lll nnn ppp rrr ttt] {
      set doc [string repeat "$x " 30]
      execsql { INSERT INTO t1 VALUES($doc) }
    }
    execsql COMMIT
  } {}

  do_execsql_test 2.$tn.2 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }

  set ret 1
  foreach x [list a c e g i k m o q s u] {
    do_execsql_test 2.$tn.3.$ret {
      SELECT rowid FROM t1 WHERE t1 MATCH $x || '*';
    } {}
    incr ret
  }
}

reset_db
do_execsql_test 3.0 {
  CREATE VIRTUAL TABLE x1 USING fts5(a);
  INSERT INTO x1(rowid, a) VALUES(-1000000000000, 'toyota');
  INSERT INTO x1(rowid, a) VALUES(1, 'tarago');
}
do_execsql_test 3.1 {
  SELECT rowid FROM x1('t*');
} {-1000000000000 1}


finish_test

**
**   * Integration of ICU and SQLite collation sequences.
**
**   * An implementation of the LIKE operator that uses ICU to 
**     provide case-independent matching.
*/

#if !defined(SQLITE_CORE)                  \
 || defined(SQLITE_ENABLE_ICU)             \
 || defined(SQLITE_ENABLE_ICU_COLLATIONS)

/* Include ICU headers */
#include <unicode/utypes.h>
#include <unicode/uregex.h>
#include <unicode/ustring.h>
#include <unicode/ucol.h>

#include <assert.h>

#ifndef SQLITE_CORE
  #include "sqlite3ext.h"
  SQLITE_EXTENSION_INIT1
#else
  #include "sqlite3.h"
#endif

/*
** This function is called when an ICU function called from within
** the implementation of an SQL scalar function returns an error.
**
** The scalar function context passed as the first argument is 
** loaded with an error message based on the following two args.
*/
static void icuFunctionError(
  sqlite3_context *pCtx,       /* SQLite scalar function context */
  const char *zName,           /* Name of ICU function that failed */
  UErrorCode e                 /* Error code returned by ICU function */
){
  char zBuf[128];
  sqlite3_snprintf(128, zBuf, "ICU error: %s(): %s", zName, u_errorName(e));
  zBuf[127] = '\0';
  sqlite3_result_error(pCtx, zBuf, -1);
}

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)

/*
** Maximum length (in bytes) of the pattern in a LIKE or GLOB
** operator.
*/
#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
#endif

  }

  if( zA && zB ){
    sqlite3_result_int(context, icuLikeCompare(zA, zB, uEsc));
  }
}



















/*
** Function to delete compiled regexp objects. Registered as
** a destructor function with sqlite3_set_auxdata().
*/
static void icuRegexpDelete(void *p){
  URegularExpression *pExpr = (URegularExpression *)p;
  uregex_close(pExpr);

      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
    }
    return;
  }
  assert( 0 );     /* Unreachable */
}

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU) */

/*
** Collation sequence destructor function. The pCtx argument points to
** a UCollator structure previously allocated using ucol_open().
*/
static void icuCollationDel(void *pCtx){
  UCollator *p = (UCollator *)pCtx;
  ucol_close(p);

    const char *zName;                        /* Function name */
    unsigned char nArg;                       /* Number of arguments */
    unsigned short enc;                       /* Optimal text encoding */
    unsigned char iContext;                   /* sqlite3_user_data() context */
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } scalars[] = {
    {"icu_load_collation",  2, SQLITE_UTF8,                1, icuLoadCollation},
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)
    {"regexp", 2, SQLITE_ANY|SQLITE_DETERMINISTIC,         0, icuRegexpFunc},
    {"lower",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
    {"lower",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"lower",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
    {"upper",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"upper",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
    {"like",   2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
    {"like",   3, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU) */
  };
  int rc = SQLITE_OK;
  int i;

  
  for(i=0; rc==SQLITE_OK && i<(int)(sizeof(scalars)/sizeof(scalars[0])); i++){
    const struct IcuScalar *p = &scalars[i];
    rc = sqlite3_create_function(
        db, p->zName, p->nArg, p->enc, 
        p->iContext ? (void*)db : (void*)0,
        p->xFunc, 0, 0

** Functions in wrapper3.c. This file contains the tdb wrapper for lsm.
** The wrapper for lsm is a bit more involved than the others, as it 
** includes code for a couple of different lsm configurations, and for
** various types of fault injection and robustness testing.
*/
int test_lsm_open(const char*, const char *zFile, int bClear, TestDb **ppDb);
int test_lsm_lomem_open(const char*, const char*, int bClear, TestDb **ppDb);
int test_lsm_lomem2_open(const char*, const char*, int bClear, TestDb **ppDb);
int test_lsm_zip_open(const char*, const char*, int bClear, TestDb **ppDb);
int test_lsm_small_open(const char*, const char*, int bClear, TestDb **ppDb);
int test_lsm_mt2(const char*, const char *zFile, int bClear, TestDb **ppDb);
int test_lsm_mt3(const char*, const char *zFile, int bClear, TestDb **ppDb);

int tdb_lsm_configure(lsm_db *, const char *);

  const char *zName;
  const char *zDefaultDb;
  int (*xOpen)(const char *, const char *zFilename, int bClear, TestDb **ppDb);
} aLib[] = {
  { "sqlite3",      "testdb.sqlite",    sql_open },
  { "lsm_small",    "testdb.lsm_small", test_lsm_small_open },
  { "lsm_lomem",    "testdb.lsm_lomem", test_lsm_lomem_open },
  { "lsm_lomem2",   "testdb.lsm_lomem2", test_lsm_lomem2_open },
#ifdef HAVE_ZLIB
  { "lsm_zip",      "testdb.lsm_zip",   test_lsm_zip_open },
#endif
  { "lsm",          "testdb.lsm",       test_lsm_open },
#ifdef LSM_MUTEX_PTHREADS
  { "lsm_mt2",      "testdb.lsm_mt2",   test_lsm_mt2 },
  { "lsm_mt3",      "testdb.lsm_mt3",   test_lsm_mt3 },

  const char *zCfg = 
    "page_size=256 block_size=64 autoflush=16 "
    "autocheckpoint=32"
    "mmap=0 "
  ;
  return testLsmOpen(zCfg, zFilename, bClear, ppDb);
}

int test_lsm_lomem2_open(
  const char *zSpec, 
  const char *zFilename, 
  int bClear, 
  TestDb **ppDb
){
    /* "max_freelist=4 autocheckpoint=32" */
  const char *zCfg = 
    "page_size=512 block_size=64 autoflush=0 mmap=0 "
  ;
  return testLsmOpen(zCfg, zFilename, bClear, ppDb);
}

int test_lsm_zip_open(
  const char *zSpec, 
  const char *zFilename, 
  int bClear, 
  TestDb **ppDb
){

typedef unsigned short int u16;
typedef unsigned int u32;
typedef lsm_i64 i64;
typedef unsigned long long int u64;
#endif

/* A page number is a 64-bit integer. */
typedef i64 LsmPgno;

#ifdef LSM_DEBUG
int lsmErrorBkpt(int);
#else
# define lsmErrorBkpt(x) (x)
#endif

  void **apShm;                   /* Shared memory chunks */
  ShmHeader *pShmhdr;             /* Live shared-memory header */
  TreeHeader treehdr;             /* Local copy of tree-header */
  u32 aSnapshot[LSM_META_PAGE_SIZE / sizeof(u32)];
};

struct Segment {
  LsmPgno iFirst;                  /* First page of this run */
  LsmPgno iLastPg;                 /* Last page of this run */
  LsmPgno iRoot;                   /* Root page number (if any) */
  int nSize;                       /* Size of this run in pages */

  Redirect *pRedirect;             /* Block redirects (or NULL) */
};

/*
** iSplitTopic/pSplitKey/nSplitKey:

** access to the associated Level struct.
**
** iOutputOff:
**   The byte offset to write to next within the last page of the 
**   output segment.
*/
struct MergeInput {
  LsmPgno iPg;                    /* Page on which next input is stored */
  int iCell;                      /* Cell containing next input to merge */
};
struct Merge {
  int nInput;                     /* Number of input runs being merged */
  MergeInput *aInput;             /* Array nInput entries in size */
  MergeInput splitkey;            /* Location in file of current splitkey */
  int nSkip;                      /* Number of separators entries to skip */
  int iOutputOff;                 /* Write offset on output page */
  LsmPgno iCurrentPtr;            /* Current pointer value */
};

/* 
** The first argument to this macro is a pointer to a Segment structure.
** Returns true if the structure instance indicates that the separators
** array is valid.
*/

  u32 iCmpId;                     /* Id of compression scheme */
  Level *pLevel;                  /* Pointer to level 0 of snapshot (or NULL) */
  i64 iId;                        /* Snapshot id */
  i64 iLogOff;                    /* Log file offset */
  Redirect redirect;              /* Block redirection array */

  /* Used by worker snapshots only */
  int nBlock;                        /* Number of blocks in database file */
  LsmPgno aiAppend[LSM_APPLIST_SZ];  /* Append point list */
  Freelist freelist;                 /* Free block list */
  u32 nWrite;                        /* Total number of pages written to disk */
};
#define LSM_INITIAL_SNAPSHOT_ID 11

/*
** Functions from file "lsm_ckpt.c".
*/
int lsmCheckpointWrite(lsm_db *, u32 *);

int lsmFsPageSize(FileSystem *);
void lsmFsSetPageSize(FileSystem *, int);

int lsmFsFileid(lsm_db *pDb, void **ppId, int *pnId);

/* Creating, populating, gobbling and deleting sorted runs. */
void lsmFsGobble(lsm_db *, Segment *, LsmPgno *, int);
int lsmFsSortedDelete(FileSystem *, Snapshot *, int, Segment *);
int lsmFsSortedFinish(FileSystem *, Segment *);
int lsmFsSortedAppend(FileSystem *, Snapshot *, Level *, int, Page **);
int lsmFsSortedPadding(FileSystem *, Snapshot *, Segment *);

/* Functions to retrieve the lsm_env pointer from a FileSystem or Page object */
lsm_env *lsmFsEnv(FileSystem *);
lsm_env *lsmPageEnv(Page *);
FileSystem *lsmPageFS(Page *);

int lsmFsSectorSize(FileSystem *);

void lsmSortedSplitkey(lsm_db *, Level *, int *);

/* Reading sorted run content. */
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg);
int lsmFsDbPageGet(FileSystem *, Segment *, LsmPgno, Page **);
int lsmFsDbPageNext(Segment *, Page *, int eDir, Page **);

u8 *lsmFsPageData(Page *, int *);
int lsmFsPageRelease(Page *);
int lsmFsPagePersist(Page *);
void lsmFsPageRef(Page *);
LsmPgno lsmFsPageNumber(Page *);

int lsmFsNRead(FileSystem *);
int lsmFsNWrite(FileSystem *);

int lsmFsMetaPageGet(FileSystem *, int, int, MetaPage **);
int lsmFsMetaPageRelease(MetaPage *);
u8 *lsmFsMetaPageData(MetaPage *, int *);

#ifdef LSM_DEBUG
int lsmFsDbPageIsLast(Segment *pSeg, Page *pPg);
int lsmFsIntegrityCheck(lsm_db *);
#endif

LsmPgno lsmFsRedirectPage(FileSystem *, Redirect *, LsmPgno);

int lsmFsPageWritable(Page *);

/* Functions to read, write and sync the log file. */
int lsmFsWriteLog(FileSystem *pFS, i64 iOff, LsmString *pStr);
int lsmFsSyncLog(FileSystem *pFS);
int lsmFsReadLog(FileSystem *pFS, i64 iOff, int nRead, LsmString *pStr);
int lsmFsTruncateLog(FileSystem *pFS, i64 nByte);
int lsmFsTruncateDb(FileSystem *pFS, i64 nByte);
int lsmFsCloseAndDeleteLog(FileSystem *pFS);

LsmFile *lsmFsDeferClose(FileSystem *pFS);

/* And to sync the db file */
int lsmFsSyncDb(FileSystem *, int);

void lsmFsFlushWaiting(FileSystem *, int *);

/* Used by lsm_info(ARRAY_STRUCTURE) and lsm_config(MMAP) */
int lsmInfoArrayStructure(lsm_db *pDb, int bBlock, LsmPgno iFirst, char **pz);
int lsmInfoArrayPages(lsm_db *pDb, LsmPgno iFirst, char **pzOut);
int lsmConfigMmap(lsm_db *pDb, int *piParam);

int lsmEnvOpen(lsm_env *, const char *, int, lsm_file **);
int lsmEnvClose(lsm_env *pEnv, lsm_file *pFile);
int lsmEnvLock(lsm_env *pEnv, lsm_file *pFile, int iLock, int eLock);
int lsmEnvTestLock(lsm_env *pEnv, lsm_file *pFile, int iLock, int nLock, int);

int lsmEnvShmMap(lsm_env *, lsm_file *, int, int, void **); 
void lsmEnvShmBarrier(lsm_env *);
void lsmEnvShmUnmap(lsm_env *, lsm_file *, int);

void lsmEnvSleep(lsm_env *, int);

int lsmFsReadSyncedId(lsm_db *db, int, i64 *piVal);

int lsmFsSegmentContainsPg(FileSystem *pFS, Segment *, LsmPgno, int *);

void lsmFsPurgeCache(FileSystem *);

/*
** End of functions from "lsm_file.c".
**************************************************************************/

/* 
** Functions from file "lsm_sorted.c".
*/
int lsmInfoPageDump(lsm_db *, LsmPgno, int, char **);
void lsmSortedCleanup(lsm_db *);
int lsmSortedAutoWork(lsm_db *, int nUnit);

int lsmSortedWalkFreelist(lsm_db *, int, int (*)(void *, int, i64), void *);

int lsmSaveWorker(lsm_db *, int);

static void ckptExportAppendlist(
  lsm_db *db,                     /* Database connection */
  CkptBuffer *p,                  /* Checkpoint buffer to write to */
  int *piOut,                     /* IN/OUT: Offset within checkpoint buffer */
  int *pRc                        /* IN/OUT: Error code */
){
  int i;
  LsmPgno *aiAppend = db->pWorker->aiAppend;

  for(i=0; i<LSM_APPLIST_SZ; i++){
    ckptAppend64(p, piOut, aiAppend[i], pRc);
  }
};

static int ckptExportSnapshot( 

**   The lsmFsSortedAppend() function sets the pSeg pointer to point to the
**   segment that the new page will be a part of. It is unset by
**   lsmFsPagePersist() after the page is written to disk.
*/
struct Page {
  u8 *aData;                      /* Buffer containing page data */
  int nData;                      /* Bytes of usable data at aData[] */
  LsmPgno iPg;                    /* Page number */
  int nRef;                       /* Number of outstanding references */
  int flags;                      /* Combination of PAGE_XXX flags */
  Page *pHashNext;                /* Next page in hash table slot */
  Page *pLruNext;                 /* Next page in LRU list */
  Page *pLruPrev;                 /* Previous page in LRU list */
  FileSystem *pFS;                /* File system that owns this page */

#else
# define IOERR_WRAPPER(rc) (rc)
#endif

#ifdef NDEBUG
# define assert_lists_are_ok(x)
#else
static Page *fsPageFindInHash(FileSystem *pFS, LsmPgno iPg, int *piHash);

static void assert_lists_are_ok(FileSystem *pFS){
#if 0
  Page *p;

  assert( pFS->nMapLimit>=0 );

  return LSM_OK;
}

/*
** Return true if page iReal of the database should be accessed using mmap.
** False otherwise.
*/
static int fsMmapPage(FileSystem *pFS, LsmPgno iReal){
  return ((i64)iReal*pFS->nPagesize <= pFS->nMapLimit);
}

/*
** Given that there are currently nHash slots in the hash table, return 
** the hash key for file iFile, page iPg.
*/
static int fsHashKey(int nHash, LsmPgno iPg){
  return (iPg % nHash);
}

/*
** This is a helper function for lsmFsOpen(). It opens a single file on
** disk (either the database or log file).
*/

** Return the page number of the first page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset immediately following the 4-byte
** "previous block" pointer at the start of each block.
*/
static LsmPgno fsFirstPageOnBlock(FileSystem *pFS, int iBlock){
  LsmPgno iPg;
  if( pFS->pCompress ){
    if( iBlock==1 ){
      iPg = pFS->nMetasize * 2 + 4;
    }else{
      iPg = pFS->nBlocksize * (LsmPgno)(iBlock-1) + 4;
    }
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    if( iBlock==1 ){
      iPg = 1 + ((pFS->nMetasize*2 + pFS->nPagesize - 1) / pFS->nPagesize);
    }else{
      iPg = 1 + (iBlock-1) * nPagePerBlock;
    }
  }
  return iPg;
}

/*
** Return the page number of the last page on block iBlock. Blocks are
** numbered starting from 1.
**
** For a compressed database, page numbers are byte offsets. The first
** page on each block is the byte offset of the byte immediately before 
** the 4-byte "next block" pointer at the end of each block.
*/
static LsmPgno fsLastPageOnBlock(FileSystem *pFS, int iBlock){
  if( pFS->pCompress ){
    return pFS->nBlocksize * (LsmPgno)iBlock - 1 - 4;
  }else{
    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    return iBlock * nPagePerBlock;
  }
}

/*
** Return the block number of the block that page iPg is located on. 
** Blocks are numbered starting from 1.
*/
static int fsPageToBlock(FileSystem *pFS, LsmPgno iPg){
  if( pFS->pCompress ){
    return (int)((iPg / pFS->nBlocksize) + 1);
  }else{
    return (int)(1 + ((iPg-1) / (pFS->nBlocksize / pFS->nPagesize)));
  }
}

/*
** Return true if page iPg is the last page on its block.
**
** This function is only called in non-compressed database mode.
*/
static int fsIsLast(FileSystem *pFS, LsmPgno iPg){
  const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
  assert( !pFS->pCompress );
  return ( iPg && (iPg % nPagePerBlock)==0 );
}

/*
** Return true if page iPg is the first page on its block.
**
** This function is only called in non-compressed database mode.
*/
static int fsIsFirst(FileSystem *pFS, LsmPgno iPg){
  const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
  assert( !pFS->pCompress );
  return ( (iPg % nPagePerBlock)==1
        || (iPg<nPagePerBlock && iPg==fsFirstPageOnBlock(pFS, 1))
  );
}

  }
  return pPage->aData;
}

/*
** Return the page number of a page.
*/
LsmPgno lsmFsPageNumber(Page *pPage){
  /* assert( (pPage->flags & PAGE_DIRTY)==0 ); */
  return pPage ? pPage->iPg : 0;
}

/*
** Page pPg is currently part of the LRU list belonging to pFS. Remove
** it from the list. pPg->pLruNext and pPg->pLruPrev are cleared by this

/*
** Search the hash-table for page iPg. If an entry is round, return a pointer
** to it. Otherwise, return NULL.
**
** Either way, if argument piHash is not NULL set *piHash to the hash slot
** number that page iPg would be stored in before returning.
*/
static Page *fsPageFindInHash(FileSystem *pFS, LsmPgno iPg, int *piHash){
  Page *p;                        /* Return value */
  int iHash = fsHashKey(pFS->nHash, iPg);

  if( piHash ) *piHash = iHash;
  for(p=pFS->apHash[iHash]; p; p=p->pHashNext){
    if( p->iPg==iPg) break;
  }

}

/*
** If page iPg has been redirected according to the redirections in the
** object passed as the second argument, return the destination page to
** which it is redirected. Otherwise, return a copy of iPg.
*/
LsmPgno lsmFsRedirectPage(FileSystem *pFS, Redirect *pRedir, LsmPgno iPg){
  LsmPgno iReal = iPg;

  if( pRedir ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    int iBlk = fsPageToBlock(pFS, iPg);
    int i;
    for(i=0; i<pRedir->n; i++){
      int iFrom = pRedir->a[i].iFrom;
      if( iFrom>iBlk ) break;
      if( iFrom==iBlk ){
        int iTo = pRedir->a[i].iTo;
        iReal = iPg - (LsmPgno)(iFrom - iTo) * nPagePerBlock;
        if( iTo==1 ){
          iReal += (fsFirstPageOnBlock(pFS, 1)-1);
        }
        break;
      }
    }
  }

  assert( iReal!=0 );
  return iReal;
}

/* Required by the circular fsBlockNext<->fsPageGet dependency. */
static int fsPageGet(FileSystem *, Segment *, LsmPgno, int, Page **, int *);

/*
** Parameter iBlock is a database file block. This function reads the value 
** stored in the blocks "next block" pointer and stores it in *piNext.
** LSM_OK is returned if everything is successful, or an LSM error code
** otherwise.
*/

  }
  return rc;
}

/*
** Return the page number of the last page on the same block as page iPg.
*/
LsmPgno fsLastPageOnPagesBlock(FileSystem *pFS, LsmPgno iPg){
  return fsLastPageOnBlock(pFS, fsPageToBlock(pFS, iPg));
}

/*
** Read nData bytes of data from offset iOff of the database file into
** buffer aData. If this means reading past the end of a block, follow
** the block pointer to the next block and continue reading.

** to the total number of free bytes before returning.
**
** If no error occurs, LSM_OK is returned. Otherwise, an lsm error code.
*/
static int fsPageGet(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Block redirection to use (or NULL) */
  LsmPgno iPg,                    /* Page id */
  int noContent,                  /* True to not load content from disk */
  Page **ppPg,                    /* OUT: New page handle */
  int *pnSpace                    /* OUT: Bytes of free space */
){
  Page *p;
  int iHash;
  int rc = LSM_OK;

  /* In most cases iReal is the same as iPg. Except, if pSeg->pRedirect is 
  ** not NULL, and the block containing iPg has been redirected, then iReal
  ** is the page number after redirection.  */
  LsmPgno iReal = lsmFsRedirectPage(pFS, (pSeg ? pSeg->pRedirect : 0), iPg);

  assert_lists_are_ok(pFS);
  assert( iPg>=fsFirstPageOnBlock(pFS, 1) );
  assert( iReal>=fsFirstPageOnBlock(pFS, 1) );
  *ppPg = 0;

  /* Search the hash-table for the page */

/*
** Return true if the first or last page of segment pRun falls between iFirst
** and iLast, inclusive, and pRun is not equal to pIgnore.
*/
static int fsRunEndsBetween(
  Segment *pRun, 
  Segment *pIgnore, 
  LsmPgno iFirst, 
  LsmPgno iLast
){
  return (pRun!=pIgnore && (
        (pRun->iFirst>=iFirst && pRun->iFirst<=iLast)
     || (pRun->iLastPg>=iFirst && pRun->iLastPg<=iLast)
  ));
}

/*
** Return true if level pLevel contains a segment other than pIgnore for
** which the first or last page is between iFirst and iLast, inclusive.
*/
static int fsLevelEndsBetween(
  Level *pLevel, 
  Segment *pIgnore, 
  LsmPgno iFirst, 
  LsmPgno iLast
){
  int i;

  if( fsRunEndsBetween(&pLevel->lhs, pIgnore, iFirst, iLast) ){
    return 1;
  }
  for(i=0; i<pLevel->nRight; i++){

static int fsFreeBlock(
  FileSystem *pFS,                /* File system object */
  Snapshot *pSnapshot,            /* Worker snapshot */
  Segment *pIgnore,               /* Ignore this run when searching */
  int iBlk                        /* Block number of block to free */
){
  int rc = LSM_OK;                /* Return code */
  LsmPgno iFirst;                 /* First page on block iBlk */
  LsmPgno iLast;                  /* Last page on block iBlk */
  Level *pLevel;                  /* Used to iterate through levels */

  int iIn;                        /* Used to iterate through append points */
  int iOut = 0;                   /* Used to output append points */
  LsmPgno *aApp = pSnapshot->aiAppend;

  iFirst = fsFirstPageOnBlock(pFS, iBlk);
  iLast = fsLastPageOnBlock(pFS, iBlk);

  /* Check if any other run in the snapshot has a start or end page 
  ** within this block. If there is such a run, return early. */
  for(pLevel=lsmDbSnapshotLevel(pSnapshot); pLevel; pLevel=pLevel->pNext){

}

/*
** aPgno is an array containing nPgno page numbers. Return the smallest page
** number from the array that falls on block iBlk. Or, if none of the pages
** in aPgno[] fall on block iBlk, return 0.
*/
static LsmPgno firstOnBlock(
  FileSystem *pFS, 
  int iBlk, 
  LsmPgno *aPgno, 
  int nPgno
){
  LsmPgno iRet = 0;
  int i;
  for(i=0; i<nPgno; i++){
    LsmPgno iPg = aPgno[i];
    if( fsPageToBlock(pFS, iPg)==iBlk && (iRet==0 || iPg<iRet) ){
      iRet = iPg;
    }
  }
  return iRet;
}

#ifndef NDEBUG
/*
** Return true if page iPg, which is a part of segment p, lies on
** a redirected block. 
*/
static int fsPageRedirects(FileSystem *pFS, Segment *p, LsmPgno iPg){
  return (iPg!=0 && iPg!=lsmFsRedirectPage(pFS, p->pRedirect, iPg));
}

/*
** Return true if the second argument is not NULL and any of the first
** last or root pages lie on a redirected block. 
*/

** the segment pRun. This function gobbles from the start of the run to the
** first page that appears in aPgno[] (i.e. so that the aPgno[] entry is
** the new first page of the run).
*/
void lsmFsGobble(
  lsm_db *pDb,
  Segment *pRun, 
  LsmPgno *aPgno,
  int nPgno
){
  int rc = LSM_OK;
  FileSystem *pFS = pDb->pFS;
  Snapshot *pSnapshot = pDb->pWorker;
  int iBlk;

  assert( pRun->nSize>0 );
  assert( 0==fsSegmentRedirects(pFS, pRun) );
  assert( nPgno>0 && 0==fsPageRedirects(pFS, pRun, aPgno[0]) );

  iBlk = fsPageToBlock(pFS, pRun->iFirst);
  pRun->nSize += (int)(pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));

  while( rc==LSM_OK ){
    int iNext = 0;
    LsmPgno iFirst = firstOnBlock(pFS, iBlk, aPgno, nPgno);
    if( iFirst ){
      pRun->iFirst = iFirst;
      break;
    }
    rc = fsBlockNext(pFS, pRun, iBlk, &iNext);
    if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, pRun, iBlk);
    pRun->nSize -= (int)(

**   *piNext = iPg + nByte;
**
** But take block overflow and redirection into account.
*/
static int fsNextPageOffset(
  FileSystem *pFS,                /* File system object */
  Segment *pSeg,                  /* Segment to move within */
  LsmPgno iPg,                    /* Offset of current page */
  int nByte,                      /* Size of current page including headers */
  LsmPgno *piNext                 /* OUT: Offset of next page. Or zero (EOF) */
){
  LsmPgno iNext;
  int rc;

  assert( pFS->pCompress );

  rc = fsAddOffset(pFS, pSeg, iPg, nByte-1, &iNext);
  if( pSeg && iNext==pSeg->iLastPg ){
    iNext = 0;

** LSM_OK is returned if no error occurs. Otherwise, an lsm error code.
** If any value other than LSM_OK is returned, then the final value of
** *piPrev is undefined.
*/
static int fsGetPageBefore(
  FileSystem *pFS, 
  Segment *pSeg, 
  LsmPgno iPg, 
  LsmPgno *piPrev
){
  u8 aSz[3];
  int rc;
  i64 iRead;

  assert( pFS->pCompress );

**
** Page references returned by this function should be released by the 
** caller using lsmFsPageRelease().
*/
int lsmFsDbPageNext(Segment *pRun, Page *pPg, int eDir, Page **ppNext){
  int rc = LSM_OK;
  FileSystem *pFS = pPg->pFS;
  LsmPgno iPg = pPg->iPg;

  assert( 0==fsSegmentRedirects(pFS, pRun) );
  if( pFS->pCompress ){
    int nSpace = pPg->nCompress + 2*3;

    do {
      if( eDir>0 ){

** already allocated block. If it is possible, the page number of the first
** page to use for the new segment is returned. Otherwise zero.
**
** If argument pLvl is not NULL, then this function will not attempt to
** start the new segment immediately following any segment that is part
** of the right-hand-side of pLvl.
*/
static LsmPgno findAppendPoint(FileSystem *pFS, Level *pLvl){
  int i;
  LsmPgno *aiAppend = pFS->pDb->pWorker->aiAppend;
  LsmPgno iRet = 0;

  for(i=LSM_APPLIST_SZ-1; iRet==0 && i>=0; i--){
    if( (iRet = aiAppend[i]) ){
      if( pLvl ){
        int iBlk = fsPageToBlock(pFS, iRet);
        int j;
        for(j=0; iRet && j<pLvl->nRight; j++){

  Snapshot *pSnapshot,
  Level *pLvl,
  int bDefer,
  Page **ppOut
){
  int rc = LSM_OK;
  Page *pPg = 0;
  LsmPgno iApp = 0;
  LsmPgno iNext = 0;
  Segment *p = &pLvl->lhs;
  LsmPgno iPrev = p->iLastPg;

  *ppOut = 0;
  assert( p->pRedirect==0 );

  if( pFS->pCompress || bDefer ){
    /* In compressed database mode the page is not assigned a page number
    ** or location in the database file at this point. This will be done

    ** Shift this extra block back to the free-block list. 
    **
    ** Otherwise, add the first free page in the last block used by the run
    ** to the lAppend list.
    */
    if( fsLastPageOnPagesBlock(pFS, p->iLastPg)!=p->iLastPg ){
      int i;
      LsmPgno *aiAppend = pFS->pDb->pWorker->aiAppend;
      for(i=0; i<LSM_APPLIST_SZ; i++){
        if( aiAppend[i]==0 ){
          aiAppend[i] = p->iLastPg+1;
          break;
        }
      }
    }else if( pFS->pCompress==0 ){

}

/*
** Obtain a reference to page number iPg.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageGet(FileSystem *pFS, Segment *pSeg, LsmPgno iPg, Page **ppPg){
  return fsPageGet(pFS, pSeg, iPg, 0, ppPg, 0);
}

/*
** Obtain a reference to the last page in the segment passed as the 
** second argument.
**
** Return LSM_OK if successful, or an lsm error code if an error occurs.
*/
int lsmFsDbPageLast(FileSystem *pFS, Segment *pSeg, Page **ppPg){
  int rc;
  LsmPgno iPg = pSeg->iLastPg;
  if( pFS->pCompress ){
    int nSpace;
    iPg++;
    do {
      nSpace = 0;
      rc = fsGetPageBefore(pFS, pSeg, iPg, &iPg);
      if( rc==LSM_OK ){

** number (*piPg) lies on block iFrom, then calculate the equivalent
** page on block iTo and set *piPg to this value before returning.
*/
static void fsMovePage(
  FileSystem *pFS,                /* File system object */
  int iTo,                        /* Destination block */
  int iFrom,                      /* Source block */
  LsmPgno *piPg                   /* IN/OUT: Page number */
){
  LsmPgno iPg = *piPg;
  if( iFrom==fsPageToBlock(pFS, iPg) ){
    const int nPagePerBlock = (
        pFS->pCompress ? pFS ->nBlocksize : (pFS->nBlocksize / pFS->nPagesize)
    );
    *piPg = iPg - (LsmPgno)(iFrom - iTo) * nPagePerBlock;
  }
}

/*
** Copy the contents of block iFrom to block iTo. 
**
** It is safe to assume that there are no outstanding references to pages 

/*
** Append raw data to a segment. Return the database file offset that the
** data is written to (this may be used as the page number if the data
** being appended is a new page record).
**
** This function is only used in compressed database mode.
*/
static LsmPgno fsAppendData(
  FileSystem *pFS,                /* File-system handle */
  Segment *pSeg,                  /* Segment to append to */
  const u8 *aData,                /* Buffer containing data to write */
  int nData,                      /* Size of buffer aData[] in bytes */
  int *pRc                        /* IN/OUT: Error code */
){
  LsmPgno iRet = 0;
  int rc = *pRc;
  assert( pFS->pCompress );
  if( rc==LSM_OK ){
    int nRem = 0;
    int nWrite = 0;
    LsmPgno iLastOnBlock;
    LsmPgno iApp = pSeg->iLastPg+1;

    /* If this is the first data written into the segment, find an append-point
    ** or allocate a new block.  */
    if( iApp==1 ){
      pSeg->iFirst = iApp = findAppendPoint(pFS, 0);
      if( iApp==0 ){
        int iBlk;

          assert( iApp==(fsPageToBlock(pFS, iApp)*pFS->nBlocksize)-4 );
          lsmPutU32(aPtr, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iApp, aPtr, sizeof(aPtr));
        }

        /* Set the "prev" pointer on the new block */
        if( rc==LSM_OK ){
          LsmPgno iWrite;
          lsmPutU32(aPtr, fsPageToBlock(pFS, iApp));
          iWrite = fsFirstPageOnBlock(pFS, iBlk);
          rc = lsmEnvWrite(pFS->pEnv, pFS->fdDb, iWrite-4, aPtr, sizeof(aPtr));
          if( nRem>0 ) iApp = iWrite;
        }
      }else{
        /* The next block is already allocated. */

** LSM_OK is returned if successful, or an lsm error code otherwise. If
** any value other than LSM_OK is returned, then the final value of all
** output variables is undefined.
*/
static int fsAppendPage(
  FileSystem *pFS, 
  Segment *pSeg,
  LsmPgno *piNew,
  int *piPrev,
  int *piNext
){
  LsmPgno iPrev = pSeg->iLastPg;
  int rc;
  assert( iPrev!=0 );

  *piPrev = 0;
  *piNext = 0;

  if( fsIsLast(pFS, iPrev) ){

  }
  *pRc = rc;
}

/*
** If there exists a hash-table entry associated with page iPg, remove it.
*/
static void fsRemoveHashEntry(FileSystem *pFS, LsmPgno iPg){
  Page *p;
  int iHash = fsHashKey(pFS->nHash, iPg);

  for(p=pFS->apHash[iHash]; p && p->iPg!=iPg; p=p->pHashNext);

  if( p ){
    assert( p->nRef==0 || (p->flags & PAGE_FREE)==0 );

int lsmFsSortedPadding(
  FileSystem *pFS, 
  Snapshot *pSnapshot,
  Segment *pSeg
){
  int rc = LSM_OK;
  if( pFS->pCompress && pSeg->iFirst ){
    LsmPgno iLast2;
    LsmPgno iLast = pSeg->iLastPg;  /* Current last page of segment */
    int nPad;                       /* Bytes of padding required */
    u8 aSz[3];

    iLast2 = (1 + iLast/pFS->szSector) * pFS->szSector - 1;
    assert( fsPageToBlock(pFS, iLast)==fsPageToBlock(pFS, iLast2) );
    nPad = (int)(iLast2 - iLast);

int lsmFsSectorSize(FileSystem *pFS){
  return pFS->szSector;
}

/*
** Helper function for lsmInfoArrayStructure().
*/
static Segment *startsWith(Segment *pRun, LsmPgno iFirst){
  return (iFirst==pRun->iFirst) ? pRun : 0;
}

/*
** Return the segment that starts with page iFirst, if any. If no such segment
** can be found, return NULL.
*/
static Segment *findSegment(Snapshot *pWorker, LsmPgno iFirst){
  Level *pLvl;                    /* Used to iterate through db levels */
  Segment *pSeg = 0;              /* Pointer to segment to return */

  for(pLvl=lsmDbSnapshotLevel(pWorker); pLvl && pSeg==0; pLvl=pLvl->pNext){
    if( 0==(pSeg = startsWith(&pLvl->lhs, iFirst)) ){
      int i;
      for(i=0; i<pLvl->nRight; i++){

** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayStructure(
  lsm_db *pDb, 
  int bBlock,                     /* True for block numbers only */
  LsmPgno iFirst,
  char **pzOut
){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pArray = 0;            /* Array to report on */
  int bUnlock = 0;

  }
  return rc;
}

int lsmFsSegmentContainsPg(
  FileSystem *pFS, 
  Segment *pSeg, 
  LsmPgno iPg, 
  int *pbRes
){
  Redirect *pRedir = pSeg->pRedirect;
  int rc = LSM_OK;
  int iBlk;
  int iLastBlk;
  int iPgBlock;                   /* Block containing page iPg */

** This function implements the lsm_info(LSM_INFO_ARRAY_PAGES) request.
** If successful, *pzOut is set to point to a nul-terminated string 
** containing the array structure and LSM_OK is returned. The caller should
** eventually free the string using lsmFree().
**
** If an error occurs, *pzOut is set to NULL and an LSM error code returned.
*/
int lsmInfoArrayPages(lsm_db *pDb, LsmPgno iFirst, char **pzOut){
  int rc = LSM_OK;
  Snapshot *pWorker;              /* Worker snapshot */
  Segment *pSeg = 0;              /* Array to report on */
  int bUnlock = 0;

  *pzOut = 0;
  if( iFirst==0 ) return LSM_ERROR;

#ifndef NDEBUG
/*
** Return true if pPg happens to be the last page in segment pSeg. Or false
** otherwise. This function is only invoked as part of assert() conditions.
*/
int lsmFsDbPageIsLast(Segment *pSeg, Page *pPg){
  if( pPg->pFS->pCompress ){
    LsmPgno iNext = 0;
    int rc;
    rc = fsNextPageOffset(pPg->pFS, pSeg, pPg->iPg, pPg->nCompress+6, &iNext);
    return (rc!=LSM_OK || iNext==0);
  }
  return (pPg->iPg==pSeg->iLastPg);
}
#endif

    case LSM_INFO_DB_STRUCTURE: {
      char **pzVal = va_arg(ap, char **);
      rc = lsmStructList(pDb, pzVal);
      break;
    }

    case LSM_INFO_ARRAY_STRUCTURE: {
      LsmPgno pgno = va_arg(ap, LsmPgno);
      char **pzVal = va_arg(ap, char **);
      rc = lsmInfoArrayStructure(pDb, 0, pgno, pzVal);
      break;
    }

    case LSM_INFO_ARRAY_PAGES: {
      LsmPgno pgno = va_arg(ap, LsmPgno);
      char **pzVal = va_arg(ap, char **);
      rc = lsmInfoArrayPages(pDb, pgno, pzVal);
      break;
    }

    case LSM_INFO_PAGE_HEX_DUMP:
    case LSM_INFO_PAGE_ASCII_DUMP: {
      LsmPgno pgno = va_arg(ap, LsmPgno);
      char **pzVal = va_arg(ap, char **);
      int bUnlock = 0;
      rc = infoGetWorker(pDb, 0, &bUnlock);
      if( rc==LSM_OK ){
        int bHex = (eParam==LSM_INFO_PAGE_HEX_DUMP);
        rc = lsmInfoPageDump(pDb, pgno, bHex, pzVal);
      }

    int pgsz = lsmFsPageSize(pDb->pFS);
    int nQuant = LSM_AUTOWORK_QUANT * pgsz;
    int nBefore;
    int nAfter;
    int nDiff;

    if( nQuant>pDb->nTreeLimit ){
      nQuant = LSM_MAX(pDb->nTreeLimit, pgsz);
    }

    nBefore = lsmTreeSize(pDb);
    if( bDeleteRange ){
      rc = lsmTreeDelete(pDb, (void *)pKey, nKey, (void *)pVal, nVal);
    }else{
      rc = lsmTreeInsert(pDb, (void *)pKey, nKey, (void *)pVal, nVal);

** The following macros are used to access a page footer.
*/
#define SEGMENT_NRECORD_OFFSET(pgsz)        ((pgsz) - 2)
#define SEGMENT_FLAGS_OFFSET(pgsz)          ((pgsz) - 2 - 2)
#define SEGMENT_POINTER_OFFSET(pgsz)        ((pgsz) - 2 - 2 - 8)
#define SEGMENT_CELLPTR_OFFSET(pgsz, iCell) ((pgsz) - 2 - 2 - 8 - 2 - (iCell)*2)

#define SEGMENT_EOF(pgsz, nEntry) SEGMENT_CELLPTR_OFFSET(pgsz, nEntry-1)

#define SEGMENT_BTREE_FLAG     0x0001
#define PGFTR_SKIP_NEXT_FLAG   0x0002
#define PGFTR_SKIP_THIS_FLAG   0x0004


#ifndef LSM_SEGMENTPTR_FREE_THRESHOLD
# define LSM_SEGMENTPTR_FREE_THRESHOLD 1024
#endif

typedef struct SegmentPtr SegmentPtr;
typedef struct LsmBlob LsmBlob;

struct LsmBlob {
  lsm_env *pEnv;
  void *pData;
  int nData;
  int nAlloc;
};

/*

  Level *pLevel;                /* Level object segment is part of */
  Segment *pSeg;                /* Segment to access */

  /* Current page. See segmentPtrLoadPage(). */
  Page *pPg;                    /* Current page */
  u16 flags;                    /* Copy of page flags field */
  int nCell;                    /* Number of cells on pPg */
  LsmPgno iPtr;                 /* Base cascade pointer */

  /* Current cell. See segmentPtrLoadCell() */
  int iCell;                    /* Current record within page pPg */
  int eType;                    /* Type of current record */
  LsmPgno iPgPtr;               /* Cascade pointer offset */
  void *pKey; int nKey;         /* Key associated with current record */
  void *pVal; int nVal;         /* Current record value (eType==WRITE only) */

  /* Blobs used to allocate buffers for pKey and pVal as required */
  LsmBlob blob1;
  LsmBlob blob2;
};

/*
** Used to iterate through the keys stored in a b-tree hierarchy from start
** to finish. Only First() and Next() operations are required.
**
**   btreeCursorNew()

  int iPg;                        /* Current entry in aPg[]. -1 -> EOF. */
  BtreePg *aPg;                   /* Pages from root to current location */

  /* Cache of current entry. pKey==0 for EOF. */
  void *pKey;
  int nKey;
  int eType;
  LsmPgno iPtr;

  /* Storage for key, if not local */
  LsmBlob blob;
};


/*
** A cursor used for merged searches or iterations through up to one
** Tree structure and any number of sorted files.
**

*/
struct MultiCursor {
  lsm_db *pDb;                    /* Connection that owns this cursor */
  MultiCursor *pNext;             /* Next cursor owned by connection pDb */
  int flags;                      /* Mask of CURSOR_XXX flags */

  int eType;                      /* Cache of current key type */
  LsmBlob key;                    /* Cache of current key (or NULL) */
  LsmBlob val;                    /* Cache of current value */

  /* All the component cursors: */
  TreeCursor *apTreeCsr[2];       /* Up to two tree cursors */
  int iFree;                      /* Next element of free-list (-ve for eof) */
  SegmentPtr *aPtr;               /* Array of segment pointers */
  int nPtr;                       /* Size of array aPtr[] */
  BtreeCursor *pBtCsr;            /* b-tree cursor (db writes only) */

  /* Comparison results */
  int nTree;                      /* Size of aTree[] array */
  int *aTree;                     /* Array of comparison results */

  /* Used by cursors flushing the in-memory tree only */
  void *pSystemVal;               /* Pointer to buffer to free */

  /* Used by worker cursors only */
  LsmPgno *pPrevMergePtr;
};

/*
** The following constants are used to assign integers to each component
** cursor of a multi-cursor.
*/
#define CURSOR_DATA_TREE0     0   /* Current tree cursor (apTreeCsr[0]) */

  lsm_db *pDb;                    /* Database handle */
  Level *pLevel;                  /* Worker snapshot Level being merged */
  MultiCursor *pCsr;              /* Cursor to read new segment contents from */
  int bFlush;                     /* True if this is an in-memory tree flush */
  Hierarchy hier;                 /* B-tree hierarchy under construction */
  Page *pPage;                    /* Current output page */
  int nWork;                      /* Number of calls to mergeWorkerNextPage() */
  LsmPgno *aGobble;               /* Gobble point for each input segment */

  LsmPgno iIndirect;
  struct SavedPgno {
    LsmPgno iPgno;
    int bStore;
  } aSave[2];
};

#ifdef LSM_DEBUG_EXPENSIVE
static int assertPointersOk(lsm_db *, Segment *, Segment *, int);
static int assertBtreeOk(lsm_db *, Segment *);

  aOut[3] = (u8)((nVal>>32) & 0xFF);
  aOut[4] = (u8)((nVal>>24) & 0xFF);
  aOut[5] = (u8)((nVal>>16) & 0xFF);
  aOut[6] = (u8)((nVal>> 8) & 0xFF);
  aOut[7] = (u8)((nVal    ) & 0xFF);
}

static int sortedBlobGrow(lsm_env *pEnv, LsmBlob *pBlob, int nData){
  assert( pBlob->pEnv==pEnv || (pBlob->pEnv==0 && pBlob->pData==0) );
  if( pBlob->nAlloc<nData ){
    pBlob->pData = lsmReallocOrFree(pEnv, pBlob->pData, nData);
    if( !pBlob->pData ) return LSM_NOMEM_BKPT;
    pBlob->nAlloc = nData;
    pBlob->pEnv = pEnv;
  }
  return LSM_OK;
}

static int sortedBlobSet(lsm_env *pEnv, LsmBlob *pBlob, void *pData, int nData){
  if( sortedBlobGrow(pEnv, pBlob, nData) ) return LSM_NOMEM;
  memcpy(pBlob->pData, pData, nData);
  pBlob->nData = nData;
  return LSM_OK;
}

#if 0
static int sortedBlobCopy(LsmBlob *pDest, LsmBlob *pSrc){
  return sortedBlobSet(pDest, pSrc->pData, pSrc->nData);
}
#endif

static void sortedBlobFree(LsmBlob *pBlob){
  assert( pBlob->pEnv || pBlob->pData==0 );
  if( pBlob->pData ) lsmFree(pBlob->pEnv, pBlob->pData);
  memset(pBlob, 0, sizeof(LsmBlob));
}

static int sortedReadData(
  Segment *pSeg,
  Page *pPg,
  int iOff,
  int nByte,
  void **ppData,
  LsmBlob *pBlob
){
  int rc = LSM_OK;
  int iEnd;
  int nData;
  int nCell;
  u8 *aData;

  return rc;
}

static int pageGetNRec(u8 *aData, int nData){
  return (int)lsmGetU16(&aData[SEGMENT_NRECORD_OFFSET(nData)]);
}

static LsmPgno pageGetPtr(u8 *aData, int nData){
  return (LsmPgno)lsmGetU64(&aData[SEGMENT_POINTER_OFFSET(nData)]);
}

static int pageGetFlags(u8 *aData, int nData){
  return (int)lsmGetU16(&aData[SEGMENT_FLAGS_OFFSET(nData)]);
}

static u8 *pageGetCell(u8 *aData, int nData, int iCell){

  return pageGetNRec(aData, nData);
}

/*
** Return the decoded (possibly relative) pointer value stored in cell 
** iCell from page aData/nData.
*/
static LsmPgno pageGetRecordPtr(u8 *aData, int nData, int iCell){
  LsmPgno iRet;                   /* Return value */
  u8 *aCell;                      /* Pointer to cell iCell */

  assert( iCell<pageGetNRec(aData, nData) && iCell>=0 );
  aCell = pageGetCell(aData, nData, iCell);
  lsmVarintGet64(&aCell[1], &iRet);
  return iRet;
}

static u8 *pageGetKey(
  Segment *pSeg,                  /* Segment pPg belongs to */
  Page *pPg,                      /* Page to read from */
  int iCell,                      /* Index of cell on page to read */
  int *piTopic,                   /* OUT: Topic associated with this key */
  int *pnKey,                     /* OUT: Size of key in bytes */
  LsmBlob *pBlob                  /* If required, use this for dynamic memory */
){
  u8 *pKey;
  int nDummy;
  int eType;
  u8 *aData;
  int nData;

static int pageGetKeyCopy(
  lsm_env *pEnv,                  /* Environment handle */
  Segment *pSeg,                  /* Segment pPg belongs to */
  Page *pPg,                      /* Page to read from */
  int iCell,                      /* Index of cell on page to read */
  int *piTopic,                   /* OUT: Topic associated with this key */
  LsmBlob *pBlob                  /* If required, use this for dynamic memory */
){
  int rc = LSM_OK;
  int nKey;
  u8 *aKey;

  aKey = pageGetKey(pSeg, pPg, iCell, piTopic, &nKey, pBlob);
  assert( (void *)aKey!=pBlob->pData || nKey==pBlob->nData );
  if( (void *)aKey!=pBlob->pData ){
    rc = sortedBlobSet(pEnv, pBlob, aKey, nKey);
  }

  return rc;
}

static LsmPgno pageGetBtreeRef(Page *pPg, int iKey){
  LsmPgno iRef;
  u8 *aData;
  int nData;
  u8 *aCell;

  aData = fsPageData(pPg, &nData);
  aCell = pageGetCell(aData, nData, iKey);
  assert( aCell[0]==0 );

#define GETVARINT64(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet64((a), &(i)))
#define GETVARINT32(a, i) (((i)=((u8*)(a))[0])<=240?1:lsmVarintGet32((a), &(i)))

static int pageGetBtreeKey(
  Segment *pSeg,                  /* Segment page pPg belongs to */
  Page *pPg,
  int iKey, 
  LsmPgno *piPtr, 
  int *piTopic, 
  void **ppKey,
  int *pnKey,
  LsmBlob *pBlob
){
  u8 *aData;
  int nData;
  u8 *aCell;
  int eType;

  aData = fsPageData(pPg, &nData);
  assert( SEGMENT_BTREE_FLAG & pageGetFlags(aData, nData) );
  assert( iKey>=0 && iKey<pageGetNRec(aData, nData) );

  aCell = pageGetCell(aData, nData, iKey);
  eType = *aCell++;
  aCell += GETVARINT64(aCell, *piPtr);

  if( eType==0 ){
    int rc;
    LsmPgno iRef;               /* Page number of referenced page */
    Page *pRef;
    aCell += GETVARINT64(aCell, iRef);
    rc = lsmFsDbPageGet(lsmPageFS(pPg), pSeg, iRef, &pRef);
    if( rc!=LSM_OK ) return rc;
    pageGetKeyCopy(lsmPageEnv(pPg), pSeg, pRef, 0, &eType, pBlob);
    lsmFsPageRelease(pRef);
    *ppKey = pBlob->pData;

static int btreeCursorLoadKey(BtreeCursor *pCsr){
  int rc = LSM_OK;
  if( pCsr->iPg<0 ){
    pCsr->pKey = 0;
    pCsr->nKey = 0;
    pCsr->eType = 0;
  }else{
    LsmPgno dummy;
    int iPg = pCsr->iPg;
    int iCell = pCsr->aPg[iPg].iCell;
    while( iCell<0 && (--iPg)>=0 ){
      iCell = pCsr->aPg[iPg].iCell-1;
    }
    if( iPg<0 || iCell<0 ) return LSM_CORRUPT_BKPT;

  assert( pCsr->iPg==pCsr->nDepth-1 );

  aData = fsPageData(pPg->pPage, &nData);
  nCell = pageGetNRec(aData, nData);
  assert( pPg->iCell<=nCell );
  pPg->iCell++;
  if( pPg->iCell==nCell ){
    LsmPgno iLoad;

    /* Up to parent. */
    lsmFsPageRelease(pPg->pPage);
    pPg->pPage = 0;
    pCsr->iPg--;
    while( pCsr->iPg>=0 ){
      pPg = &pCsr->aPg[pCsr->iPg];

  MergeInput *p
){
  int rc = LSM_OK;

  if( p->iPg ){
    lsm_env *pEnv = lsmFsEnv(pCsr->pFS);
    int iCell;                    /* Current cell number on leaf page */
    LsmPgno iLeaf;                /* Page number of current leaf page */
    int nDepth;                   /* Depth of b-tree structure */
    Segment *pSeg = pCsr->pSeg;

    /* Decode the MergeInput structure */
    iLeaf = p->iPg;
    nDepth = (p->iCell & 0x00FF);
    iCell = (p->iCell >> 8) - 1;

      pCsr->nDepth = nDepth;
      pCsr->aPg[pCsr->iPg].iCell = iCell;
      rc = lsmFsDbPageGet(pCsr->pFS, pSeg, iLeaf, pp);
    }

    /* Populate any other aPg[] array entries */
    if( rc==LSM_OK && nDepth>1 ){
      LsmBlob blob = {0,0,0};
      void *pSeek;
      int nSeek;
      int iTopicSeek;
      int iPg = 0;
      int iLoad = (int)pSeg->iRoot;
      Page *pPg = pCsr->aPg[nDepth-1].pPage;
 
      if( pageObjGetNRec(pPg)==0 ){
        /* This can happen when pPg is the right-most leaf in the b-tree.
        ** In this case, set the iTopicSeek/pSeek/nSeek key to a value
        ** greater than any real key.  */
        assert( iCell==-1 );
        iTopicSeek = 1000;
        pSeek = 0;
        nSeek = 0;
      }else{
        LsmPgno dummy;
        rc = pageGetBtreeKey(pSeg, pPg,
            0, &dummy, &iTopicSeek, &pSeek, &nSeek, &pCsr->blob
        );
      }

      do {
        Page *pPg2;

          iMax = iCell2-1;
          iMin = 0;

          while( iMax>=iMin ){
            int iTry = (iMin+iMax)/2;
            void *pKey; int nKey;         /* Key for cell iTry */
            int iTopic;                   /* Topic for key pKeyT/nKeyT */
            LsmPgno iPtr;                 /* Pointer for cell iTry */
            int res;                      /* (pSeek - pKeyT) */

            rc = pageGetBtreeKey(
                pSeg, pPg2, iTry, &iPtr, &iTopic, &pKey, &nKey, &blob
            );
            if( rc!=LSM_OK ) break;

      u8 *aData;
      int nData;

      pBtreePg = &pCsr->aPg[pCsr->iPg];
      aData = fsPageData(pBtreePg->pPage, &nData);
      pCsr->iPtr = btreeCursorPtr(aData, nData, pBtreePg->iCell+1);
      if( pBtreePg->iCell<0 ){
        LsmPgno dummy;
        int i;
        for(i=pCsr->iPg-1; i>=0; i--){
          if( pCsr->aPg[i].iCell>0 ) break;
        }
        assert( i>=0 );
        rc = pageGetBtreeKey(pSeg,
            pCsr->aPg[i].pPage, pCsr->aPg[i].iCell-1,

}

static int segmentPtrReadData(
  SegmentPtr *pPtr,
  int iOff,
  int nByte,
  void **ppData,
  LsmBlob *pBlob
){
  return sortedReadData(pPtr->pSeg, pPtr->pPg, iOff, nByte, ppData, pBlob);
}

static int segmentPtrNextPage(
  SegmentPtr *pPtr,              /* Load page into this SegmentPtr object */
  int eDir                       /* +1 for next(), -1 for prev() */

  pSeg = sortedSplitkeySegment(pLevel);
  if( rc==LSM_OK ){
    rc = lsmFsDbPageGet(pDb->pFS, pSeg, pMerge->splitkey.iPg, &pPg);
  }
  if( rc==LSM_OK ){
    int iTopic;
    LsmBlob blob = {0, 0, 0, 0};
    u8 *aData;
    int nData;
  
    aData = lsmFsPageData(pPg, &nData);
    if( pageGetFlags(aData, nData) & SEGMENT_BTREE_FLAG ){
      void *pKey;
      int nKey;
      LsmPgno dummy;
      rc = pageGetBtreeKey(pSeg,
          pPg, pMerge->splitkey.iCell, &dummy, &iTopic, &pKey, &nKey, &blob
      );
      if( rc==LSM_OK && blob.pData!=pKey ){
        rc = sortedBlobSet(pEnv, &blob, pKey, nKey);
      }
    }else{

*/
static int assertKeyLocation(
  MultiCursor *pCsr, 
  SegmentPtr *pPtr, 
  void *pKey, int nKey
){
  lsm_env *pEnv = lsmFsEnv(pCsr->pDb->pFS);
  LsmBlob blob = {0, 0, 0};
  int eDir;
  int iTopic = 0;                 /* TODO: Fix me */

  for(eDir=-1; eDir<=1; eDir+=2){
    Page *pTest = pPtr->pPg;

    lsmFsPageRef(pTest);

  return rc;
}

static int ptrFwdPointer(
  Page *pPage,
  int iCell,
  Segment *pSeg,
  LsmPgno *piPtr,
  int *pbFound
){
  Page *pPg = pPage;
  int iFirst = iCell;
  int rc = LSM_OK;

  do {

**   much better if the multi-cursor could do this lazily - only seek to the
**   level (N+1) page after the user has moved the cursor on level N passed
**   the big range-delete.
*/
static int segmentPtrFwdPointer(
  MultiCursor *pCsr,              /* Multi-cursor pPtr belongs to */
  SegmentPtr *pPtr,               /* Segment-pointer to extract FC ptr from */
  LsmPgno *piPtr                  /* OUT: FC pointer value */
){
  Level *pLvl = pPtr->pLevel;
  Level *pNext = pLvl->pNext;
  Page *pPg = pPtr->pPg;
  int rc;
  int bFound;
  LsmPgno iOut = 0;

  if( pPtr->pSeg==&pLvl->lhs || pPtr->pSeg==&pLvl->aRhs[pLvl->nRight-1] ){
    if( pNext==0 
        || (pNext->nRight==0 && pNext->lhs.iRoot)
        || (pNext->nRight!=0 && pNext->aRhs[0].iRoot)
      ){
      /* Do nothing. The pointer will not be used anyway. */