3.2.7

/*
** 2004 May 22
**
** 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.
**
******************************************************************************
**
** This file contains code that is specific to Unix systems. It is used
** for testing SQLite only.
*/
#if OS_TEST              /* This file is used for the test backend only */
#include "sqliteInt.h"
#include "os.h"          /* Must be first to enable large file support */

#define sqlite3OsOpenReadWrite     sqlite3RealOpenReadWrite
#define sqlite3OsOpenExclusive     sqlite3RealOpenExclusive
#define sqlite3OsOpenReadOnly      sqlite3RealOpenReadOnly
#define sqlite3OsOpenDirectory     sqlite3RealOpenDirectory
#define sqlite3OsClose             sqlite3RealClose
#define sqlite3OsRead              sqlite3RealRead
#define sqlite3OsWrite             sqlite3RealWrite
#define sqlite3OsSeek              sqlite3RealSeek
#define sqlite3OsSync              sqlite3RealSync
#define sqlite3OsTruncate          sqlite3RealTruncate
#define sqlite3OsFileSize          sqlite3RealFileSize
#define sqlite3OsLock              sqlite3RealLock
#define sqlite3OsUnlock            sqlite3RealUnlock
#define sqlite3OsCheckReservedLock sqlite3RealCheckReservedLock

#define OsFile OsRealFile
#define OS_UNIX 1
#include "os_unix.c"
#undef OS_UNIX
#undef OsFile

#undef sqlite3OsOpenReadWrite     
#undef sqlite3OsOpenExclusive     
#undef sqlite3OsOpenReadOnly      
#undef sqlite3OsOpenDirectory     
#undef sqlite3OsClose             
#undef sqlite3OsRead              
#undef sqlite3OsWrite             
#undef sqlite3OsSeek              
#undef sqlite3OsSync              
#undef sqlite3OsTruncate          
#undef sqlite3OsFileSize          
#undef sqlite3OsLock              
#undef sqlite3OsUnlock            
#undef sqlite3OsCheckReservedLock 

#define BLOCKSIZE 512
#define BLOCK_OFFSET(x) ((x) * BLOCKSIZE)


/*
** The following variables control when a simulated crash occurs.
**
** If iCrashDelay is non-zero, then zCrashFile contains (full path) name of
** a file that SQLite will call sqlite3OsSync() on. Each time this happens
** iCrashDelay is decremented. If iCrashDelay is zero after being
** decremented, a "crash" occurs during the sync() operation.
**
** In other words, a crash occurs the iCrashDelay'th time zCrashFile is
** synced.
*/
static int iCrashDelay = 0;
char zCrashFile[256];

/*
** Set the value of the two crash parameters.
*/
void sqlite3SetCrashParams(int iDelay, char const *zFile){
  sqlite3OsEnterMutex();
  assert( strlen(zFile)<256 );
  strcpy(zCrashFile, zFile);
  iCrashDelay = iDelay;
  sqlite3OsLeaveMutex();
}

/*
** File zPath is being sync()ed. Return non-zero if this should
** cause a crash.
*/
static int crashRequired(char const *zPath){
  int r;
  int n;
  sqlite3OsEnterMutex();
  n = strlen(zCrashFile);
  if( zCrashFile[n-1]=='*' ){
    n--;
  }else if( strlen(zPath)>n ){
    n = strlen(zPath);
  }
  r = 0;
  if( iCrashDelay>0 && strncmp(zPath, zCrashFile, n)==0 ){
    iCrashDelay--;
    if( iCrashDelay<=0 ){
      r = 1;
    }
  }
  sqlite3OsLeaveMutex();
  return r;
}


static OsTestFile *pAllFiles = 0;

/*
** Initialise the os_test.c specific fields of pFile.
*/
static void initFile(OsFile *id, char const *zName){
  OsTestFile *pFile = (OsTestFile *)
      sqliteMalloc(sizeof(OsTestFile) + strlen(zName)+1);
  pFile->nMaxWrite = 0; 
  pFile->nBlk = 0; 
  pFile->apBlk = 0; 
  pFile->zName = (char *)(&pFile[1]);
  strcpy(pFile->zName, zName);
  *id = pFile;
  pFile->pNext = pAllFiles;
  pAllFiles = pFile;
}

/*
** Undo the work done by initFile. Delete the OsTestFile structure
** and unlink the structure from the pAllFiles list.
*/
static void closeFile(OsFile *id){
  OsTestFile *pFile = *id;
  if( pFile==pAllFiles ){
    pAllFiles = pFile->pNext;
  }else{
    OsTestFile *p;
    for(p=pAllFiles; p->pNext!=pFile; p=p->pNext ){
      assert( p );
    }
    p->pNext = pFile->pNext;
  }
  sqliteFree(pFile);
  *id = 0;
}

/*
** Return the current seek offset from the start of the file. This
** is unix-only code.
*/
static i64 osTell(OsTestFile *pFile){
  return lseek(pFile->fd.h, 0, SEEK_CUR);
}

/*
** Load block 'blk' into the cache of pFile.
*/
static int cacheBlock(OsTestFile *pFile, int blk){
  if( blk>=pFile->nBlk ){
    int n = ((pFile->nBlk * 2) + 100 + blk);
    /* if( pFile->nBlk==0 ){ printf("DIRTY %s\n", pFile->zName); } */
    pFile->apBlk = (u8 **)sqliteRealloc(pFile->apBlk, n * sizeof(u8*));
    if( !pFile->apBlk ) return SQLITE_NOMEM;
    memset(&pFile->apBlk[pFile->nBlk], 0, (n - pFile->nBlk)*sizeof(u8*));
    pFile->nBlk = n;
  }

  if( !pFile->apBlk[blk] ){
    i64 filesize;
    int rc;

    u8 *p = sqliteMalloc(BLOCKSIZE);
    if( !p ) return SQLITE_NOMEM;
    pFile->apBlk[blk] = p;

    rc = sqlite3RealFileSize(&pFile->fd, &filesize);
    if( rc!=SQLITE_OK ) return rc;

    if( BLOCK_OFFSET(blk)<filesize ){
      int len = BLOCKSIZE;
      rc = sqlite3RealSeek(&pFile->fd, blk*BLOCKSIZE);
      if( BLOCK_OFFSET(blk+1)>filesize ){
        len = filesize - BLOCK_OFFSET(blk);
      }
      if( rc!=SQLITE_OK ) return rc;
      rc = sqlite3RealRead(&pFile->fd, p, len);
      if( rc!=SQLITE_OK ) return rc;
    }
  }

  return SQLITE_OK;
}

/* #define TRACE_WRITECACHE */

/*
** Write the cache of pFile to disk. If crash is non-zero, randomly
** skip blocks when writing. The cache is deleted before returning.
*/
static int writeCache2(OsTestFile *pFile, int crash){
  int i;
  int nMax = pFile->nMaxWrite;
  i64 offset;
  int rc = SQLITE_OK;

  offset = osTell(pFile);
  for(i=0; i<pFile->nBlk; i++){
    u8 *p = pFile->apBlk[i];
    if( p ){
      int skip = 0;
      int trash = 0;
      if( crash ){
        char random;
        sqlite3Randomness(1, &random);
        if( random & 0x01 ){
          if( random & 0x02 ){
            trash = 1;
#ifdef TRACE_WRITECACHE
printf("Trashing block %d of %s\n", i, pFile->zName); 
#endif
          }else{
            skip = 1;
#ifdef TRACE_WRITECACHE
printf("Skiping block %d of %s\n", i, pFile->zName); 
#endif
          }
        }else{
#ifdef TRACE_WRITECACHE
printf("Writing block %d of %s\n", i, pFile->zName); 
#endif
        }
      }
      if( rc==SQLITE_OK ){
        rc = sqlite3RealSeek(&pFile->fd, BLOCK_OFFSET(i));
      }
      if( rc==SQLITE_OK && !skip ){
        int len = BLOCKSIZE;
        if( BLOCK_OFFSET(i+1)>nMax ){
          len = nMax-BLOCK_OFFSET(i);
        }
        if( len>0 ){
          if( trash ){
            sqlite3Randomness(len, p);
          }
          rc = sqlite3RealWrite(&pFile->fd, p, len);
        }
      }
      sqliteFree(p);
    }
  }
  sqliteFree(pFile->apBlk);
  pFile->nBlk = 0;
  pFile->apBlk = 0;
  pFile->nMaxWrite = 0;

  if( rc==SQLITE_OK ){
    rc = sqlite3RealSeek(&pFile->fd, offset);
  }
  return rc;
}

/*
** Write the cache to disk.
*/
static int writeCache(OsTestFile *pFile){
  if( pFile->apBlk ){
    int c = crashRequired(pFile->zName);
    if( c ){
      OsTestFile *p;
#ifdef TRACE_WRITECACHE
      printf("\nCrash during sync of %s\n", pFile->zName);
#endif
      for(p=pAllFiles; p; p=p->pNext){
        writeCache2(p, 1);
      }
      exit(-1);
    }else{
      return writeCache2(pFile, 0);
    }
  }
  return SQLITE_OK;
}

/*
** Close the file.
*/
int sqlite3OsClose(OsFile *id){
  if( !(*id) ) return SQLITE_OK;
  if( (*id)->fd.isOpen ){
    /* printf("CLOSE %s (%d blocks)\n", (*id)->zName, (*id)->nBlk); */
    writeCache(*id);
    sqlite3RealClose(&(*id)->fd);
  }
  closeFile(id);
  return SQLITE_OK;
}

int sqlite3OsRead(OsFile *id, void *pBuf, int amt){
  i64 offset;       /* The current offset from the start of the file */
  i64 end;          /* The byte just past the last byte read */
  int blk;            /* Block number the read starts on */
  int i;
  u8 *zCsr;
  int rc = SQLITE_OK;
  OsTestFile *pFile = *id;

  offset = osTell(pFile);
  end = offset+amt;
  blk = (offset/BLOCKSIZE);

  zCsr = (u8 *)pBuf;
  for(i=blk; i*BLOCKSIZE<end; i++){
    int off = 0;
    int len = 0;


    if( BLOCK_OFFSET(i) < offset ){
      off = offset-BLOCK_OFFSET(i);
    }
    len = BLOCKSIZE - off;
    if( BLOCK_OFFSET(i+1) > end ){
      len = len - (BLOCK_OFFSET(i+1)-end);
    }

    if( i<pFile->nBlk && pFile->apBlk[i]){
      u8 *pBlk = pFile->apBlk[i];
      memcpy(zCsr, &pBlk[off], len);
    }else{
      rc = sqlite3RealSeek(&pFile->fd, BLOCK_OFFSET(i) + off);
      if( rc!=SQLITE_OK ) return rc;
      rc = sqlite3RealRead(&pFile->fd, zCsr, len);
      if( rc!=SQLITE_OK ) return rc;
    }

    zCsr += len;
  }
  assert( zCsr==&((u8 *)pBuf)[amt] );

  rc = sqlite3RealSeek(&pFile->fd, end);
  return rc;
}

int sqlite3OsWrite(OsFile *id, const void *pBuf, int amt){
  i64 offset;       /* The current offset from the start of the file */
  i64 end;          /* The byte just past the last byte written */
  int blk;            /* Block number the write starts on */
  int i;
  const u8 *zCsr;
  int rc = SQLITE_OK;
  OsTestFile *pFile = *id;

  offset = osTell(pFile);
  end = offset+amt;
  blk = (offset/BLOCKSIZE);

  zCsr = (u8 *)pBuf;
  for(i=blk; i*BLOCKSIZE<end; i++){
    u8 *pBlk;
    int off = 0;
    int len = 0;

    /* Make sure the block is in the cache */
    rc = cacheBlock(pFile, i);
    if( rc!=SQLITE_OK ) return rc;

    /* Write into the cache */
    pBlk = pFile->apBlk[i];
    assert( pBlk );

    if( BLOCK_OFFSET(i) < offset ){
      off = offset-BLOCK_OFFSET(i);
    }
    len = BLOCKSIZE - off;
    if( BLOCK_OFFSET(i+1) > end ){
      len = len - (BLOCK_OFFSET(i+1)-end);
    }
    memcpy(&pBlk[off], zCsr, len);
    zCsr += len;
  }
  if( pFile->nMaxWrite<end ){
    pFile->nMaxWrite = end;
  }
  assert( zCsr==&((u8 *)pBuf)[amt] );

  rc = sqlite3RealSeek(&pFile->fd, end);
  return rc;
}

/*
** Sync the file. First flush the write-cache to disk, then call the
** real sync() function.
*/
int sqlite3OsSync(OsFile *id, int dataOnly){
  int rc;
  /* printf("SYNC %s (%d blocks)\n", (*id)->zName, (*id)->nBlk); */
  rc = writeCache(*id);
  if( rc!=SQLITE_OK ) return rc;
  rc = sqlite3RealSync(&(*id)->fd, dataOnly);
  return rc;
}

/*
** Truncate the file. Set the internal OsFile.nMaxWrite variable to the new
** file size to ensure that nothing in the write-cache past this point
** is written to disk.
*/
int sqlite3OsTruncate(OsFile *id, i64 nByte){
  (*id)->nMaxWrite = nByte;
  return sqlite3RealTruncate(&(*id)->fd, nByte);
}

/*
** Return the size of the file. If the cache contains a write that extended
** the file, then return this size instead of the on-disk size.
*/
int sqlite3OsFileSize(OsFile *id, i64 *pSize){
  int rc = sqlite3RealFileSize(&(*id)->fd, pSize);
  if( rc==SQLITE_OK && pSize && *pSize<(*id)->nMaxWrite ){
    *pSize = (*id)->nMaxWrite;
  }
  return rc;
}

/*
** The three functions used to open files. All that is required is to
** initialise the os_test.c specific fields and then call the corresponding
** os_unix.c function to really open the file.
*/
int sqlite3OsOpenReadWrite(const char *zFilename, OsFile *id, int *pReadonly){
  initFile(id, zFilename);
  return sqlite3RealOpenReadWrite(zFilename, &(*id)->fd, pReadonly);
}
int sqlite3OsOpenExclusive(const char *zFilename, OsFile *id, int delFlag){
  initFile(id, zFilename);
  return sqlite3RealOpenExclusive(zFilename, &(*id)->fd, delFlag);
}
int sqlite3OsOpenReadOnly(const char *zFilename, OsFile *id){
  initFile(id, zFilename);
  return sqlite3RealOpenReadOnly(zFilename, &(*id)->fd);
}

/*
** These six function calls are passed straight through to the os_unix.c
** backend.
*/
int sqlite3OsSeek(OsFile *id, i64 offset){
  return sqlite3RealSeek(&(*id)->fd, offset);
}
int sqlite3OsCheckReservedLock(OsFile *id){
  return sqlite3RealCheckReservedLock(&(*id)->fd);
}
int sqlite3OsLock(OsFile *id, int locktype){
  return sqlite3RealLock(&(*id)->fd, locktype);
}
int sqlite3OsUnlock(OsFile *id, int locktype){
  return sqlite3RealUnlock(&(*id)->fd, locktype);
}
int sqlite3OsOpenDirectory(const char *zDirname, OsFile *id){
  return sqlite3RealOpenDirectory(zDirname, &(*id)->fd);
}

#endif /* OS_TEST */

/*
** 2004 May 22
**
** 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.
**
******************************************************************************
**
*/
#ifndef _SQLITE_OS_TEST_H_
#define _SQLITE_OS_TEST_H_

#define OsFile OsRealFile
#define OS_UNIX 1
#include "os_unix.h"
#undef OS_UNIX
#undef OsFile
#undef SET_FULLSYNC

/* Include sqliteInt.h now to get the type u8. */
#include "sqliteInt.h"

typedef struct OsTestFile* OsFile;
typedef struct OsTestFile OsTestFile;
struct OsTestFile {
  u8 **apBlk;       /* Array of blocks that have been written to. */
  int nBlk;         /* Size of apBlock. */
  int nMaxWrite;    /* Largest offset written to. */
  char *zName;      /* File name */
  OsRealFile fd;
  OsTestFile *pNext;
};

void sqlite3SetCrashParams(int iDelay, char const *zFile);

#endif /* _SQLITE_OS_UNIX_H_ */

/*
** 2004 May 22
**
** 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.
**
******************************************************************************
**
** This header file defined OS-specific features for Unix.
*/
#ifndef _SQLITE_OS_UNIX_H_
#define _SQLITE_OS_UNIX_H_

/*
** Helpful hint:  To get this to compile on HP/UX, add -D_INCLUDE_POSIX_SOURCE
** to the compiler command line.
*/

/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks
** large file support, or if the OS is windows, these should be no-ops.
**
** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
** on the compiler command line.  This is necessary if you are compiling
** on a recent machine (ex: RedHat 7.2) but you want your code to work
** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
** without this option, LFS is enable.  But LFS does not exist in the kernel
** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
** portability you should omit LFS.
**
** Similar is true for MacOS.  LFS is only supported on MacOS 9 and later.
*/
#ifndef SQLITE_DISABLE_LFS
# define _LARGE_FILE       1
# ifndef _FILE_OFFSET_BITS
#   define _FILE_OFFSET_BITS 64
# endif
# define _LARGEFILE_SOURCE 1
#endif

/*
** standard include files.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

/*
** Macros used to determine whether or not to use threads.  The
** SQLITE_UNIX_THREADS macro is defined if we are synchronizing for
** Posix threads and SQLITE_W32_THREADS is defined if we are
** synchronizing using Win32 threads.
*/
#if defined(THREADSAFE) && THREADSAFE
# include <pthread.h>
# define SQLITE_UNIX_THREADS 1
#endif

/*
** The OsFile structure is a operating-system independing representation
** of an open file handle.  It is defined differently for each architecture.
**
** This is the definition for Unix.
**
** OsFile.locktype takes one of the values SHARED_LOCK, RESERVED_LOCK,
** PENDING_LOCK or EXCLUSIVE_LOCK.
*/
typedef struct OsFile OsFile;
struct OsFile {
  struct Pager *pPager;     /* The pager that owns this OsFile.  Might be 0 */
  struct openCnt *pOpen;    /* Info about all open fd's on this inode */
  struct lockInfo *pLock;   /* Info about locks on this inode */
  int h;                    /* The file descriptor */
  unsigned char locktype;   /* The type of lock held on this fd */
  unsigned char isOpen;     /* True if needs to be closed */
  unsigned char fullSync;   /* Use F_FULLSYNC if available */
  int dirfd;                /* File descriptor for the directory */
#ifdef SQLITE_UNIX_THREADS
  pthread_t tid;            /* The thread authorized to use this OsFile */
#endif
};

/*
** A macro to set the OsFile.fullSync flag, if it exists.
*/
#define SET_FULLSYNC(x,y)  ((x).fullSync = (y))

/*
** Maximum number of characters in a temporary file name
*/
#define SQLITE_TEMPNAME_SIZE 200

/*
** Minimum interval supported by sqlite3OsSleep().
*/
#if defined(HAVE_USLEEP) && HAVE_USLEEP
# define SQLITE_MIN_SLEEP_MS 1
#else
# define SQLITE_MIN_SLEEP_MS 1000
#endif

/*
** Default permissions when creating a new file
*/
#ifndef SQLITE_DEFAULT_FILE_PERMISSIONS
# define SQLITE_DEFAULT_FILE_PERMISSIONS 0644
#endif


#endif /* _SQLITE_OS_UNIX_H_ */

/*
** 2004 May 22
**
** 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.
**
******************************************************************************
**
** This header file defines OS-specific features for Win32
*/
#ifndef _SQLITE_OS_WIN_H_
#define _SQLITE_OS_WIN_H_

#include <windows.h>
#include <winbase.h>

/*
** The OsFile structure is a operating-system independing representation
** of an open file handle.  It is defined differently for each architecture.
**
** This is the definition for Win32.
*/
typedef struct OsFile OsFile;
struct OsFile {
  HANDLE h;               /* Handle for accessing the file */
  unsigned char locktype; /* Type of lock currently held on this file */
  unsigned char isOpen;   /* True if needs to be closed */
  short sharedLockByte;   /* Randomly chosen byte used as a shared lock */
};


#define SQLITE_TEMPNAME_SIZE (MAX_PATH+50)
#define SQLITE_MIN_SLEEP_MS 1


#endif /* _SQLITE_OS_WIN_H_ */

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.215 2005/09/17 15:20:27 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

void sqlite3pager_dont_write(Pager *pPager, Pgno pgno){
  PgHdr *pPg;

  if( MEMDB ) return;

  pPg = pager_lookup(pPager, pgno);
  pPg->alwaysRollback = 1;
  if( pPg && pPg->dirty ){
    if( pPager->dbSize==(int)pPg->pgno && pPager->origDbSize<pPager->dbSize ){
      /* If this pages is the last page in the file and the file has grown
      ** during the current transaction, then do NOT mark the page as clean.
      ** When the database file grows, we must make sure that the last page
      ** gets written at least once so that the disk file will be the correct
      ** size. If you do not write this page and the size of the file
      ** on the disk ends up being too small, that can lead to database