z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=ror(w,2);
#define R4(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=ror(w,2);

/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */






void SHA1Transform(unsigned int state[5], const unsigned char buffer[64]){
  unsigned int qq[5]; /* a, b, c, d, e; */
  static int one = 1;
  unsigned int block[16];
  memcpy(block, buffer, 64);
  memcpy(qq,state,5*sizeof(unsigned int));

#define a qq[0]
#define b qq[1]
#define c qq[2]
#define d qq[3]
#define e qq[4]

  /* Copy p->state[] to working vars */
  /*
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];

  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;

#undef a
#undef b
#undef c
#undef d
#undef e
}


/* Initialize a SHA1 context */
static void hash_init(SHA1Context *p){
  /* SHA1 initialization constants */
  p->state[0] = 0x67452301;

  sqlite3_value **argv
){
  SHA1Context cx;
  int eType = sqlite3_value_type(argv[0]);
  int nByte = sqlite3_value_bytes(argv[0]);
  char zOut[44];

  assert( argc==1 );
  if( eType==SQLITE_NULL ) return;
  hash_init(&cx);
  if( eType==SQLITE_BLOB ){
    hash_step(&cx, sqlite3_value_blob(argv[0]), nByte);
  }else{
    hash_step(&cx, sqlite3_value_text(argv[0]), nByte);
  }

  int i;                      /* Loop counter */
  int rc;
  int n;
  const char *z;
  SHA1Context cx;
  char zOut[44];

  assert( argc==1 );
  if( zSql==0 ) return;
  hash_init(&cx);
  while( zSql[0] ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zSql);
    if( rc ){
      char *zMsg = sqlite3_mprintf("error SQL statement [%s]: %s",
                                   zSql, sqlite3_errmsg(db));

            x[0] = 'I';
            hash_step(&cx, x, 9);
            break;
          }
          case SQLITE_FLOAT: {
            sqlite3_uint64 u;
            int j;
            unsigned char x[9];
            double r = sqlite3_column_double(pStmt,i);
            memcpy(&u, &r, 8);
            for(j=8; j>=1; j--){
              x[j] = u & 0xff;
              u >>= 8;
            }
            x[0] = 'F';
            hash_step(&cx,x,9);
            break;
          }
          case SQLITE_TEXT: {
            int n2 = sqlite3_column_bytes(pStmt, i);
            const unsigned char *z2 = sqlite3_column_text(pStmt, i);
            hash_step_vformat(&cx,"T%d:",n2);
            hash_step(&cx, z2, n2);
            break;
          }
          case SQLITE_BLOB: {
            int n2 = sqlite3_column_bytes(pStmt, i);
            const unsigned char *z2 = sqlite3_column_blob(pStmt, i);
            hash_step_vformat(&cx,"B%d:",n2);
            hash_step(&cx, z2, n2);
            break;
          }
        }
      }
    }
    sqlite3_finalize(pStmt);
  }
  hash_finish(&cx, zOut);
  sqlite3_result_text(context, zOut, 40, SQLITE_TRANSIENT);
}


#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_sha_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sha1", 1, SQLITE_UTF8, 0,
                               sha1Func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha1_query", 1, SQLITE_UTF8, 0,
                                 sha1QueryFunc, 0, 0);
  }
  return rc;
}

  sqlite3_vtab base;          /* Base class.  Must be first */
  sqlite3 *db;                /* Host database connection */
  int iNodeSize;              /* Size in bytes of each node in the node table */
  u8 nDim;                    /* Number of dimensions */
  u8 nDim2;                   /* Twice the number of dimensions */
  u8 eCoordType;              /* RTREE_COORD_REAL32 or RTREE_COORD_INT32 */
  u8 nBytesPerCell;           /* Bytes consumed per cell */
  u8 inWrTrans;               /* True if inside write transaction */
  int iDepth;                 /* Current depth of the r-tree structure */
  char *zDb;                  /* Name of database containing r-tree table */
  char *zName;                /* Name of r-tree table */ 
  u32 nBusy;                  /* Current number of users of this structure */
  i64 nRowEst;                /* Estimated number of rows in this table */
  u32 nCursor;                /* Number of open cursors */

  /* List of nodes removed during a CondenseTree operation. List is
  ** linked together via the pointer normally used for hash chains -
  ** RtreeNode.pNext. RtreeNode.iNode stores the depth of the sub-tree 
  ** headed by the node (leaf nodes have RtreeNode.iNode==0).
  */
  RtreeNode *pDeleted;
  int iReinsertHeight;        /* Height of sub-trees Reinsert() has run on */

  /* Blob I/O on xxx_node */
  sqlite3_blob *pNodeBlob;

  /* Statements to read/write/delete a record from xxx_node */

  sqlite3_stmt *pWriteNode;
  sqlite3_stmt *pDeleteNode;

  /* Statements to read/write/delete a record from xxx_rowid */
  sqlite3_stmt *pReadRowid;
  sqlite3_stmt *pWriteRowid;
  sqlite3_stmt *pDeleteRowid;

    pNode->nRef = 1;
    pNode->pParent = pParent;
    pNode->isDirty = 1;
    nodeReference(pParent);
  }
  return pNode;
}

/*
** Clear the Rtree.pNodeBlob object
*/
static void nodeBlobReset(Rtree *pRtree){
  if( pRtree->pNodeBlob && pRtree->inWrTrans==0 && pRtree->nCursor==0 ){
    sqlite3_blob *pBlob = pRtree->pNodeBlob;
    pRtree->pNodeBlob = 0;
    sqlite3_blob_close(pBlob);
  }
}

/*
** Obtain a reference to an r-tree node.
*/
static int nodeAcquire(
  Rtree *pRtree,             /* R-tree structure */
  i64 iNode,                 /* Node number to load */
  RtreeNode *pParent,        /* Either the parent node or NULL */
  RtreeNode **ppNode         /* OUT: Acquired node */
){
  int rc = SQLITE_OK;

  RtreeNode *pNode = 0;

  /* Check if the requested node is already in the hash table. If so,
  ** increase its reference count and return it.
  */
  if( (pNode = nodeHashLookup(pRtree, iNode)) ){
    assert( !pParent || !pNode->pParent || pNode->pParent==pParent );
    if( pParent && !pNode->pParent ){
      nodeReference(pParent);
      pNode->pParent = pParent;
    }
    pNode->nRef++;
    *ppNode = pNode;
    return SQLITE_OK;
  }

  if( pRtree->pNodeBlob ){
    sqlite3_blob *pBlob = pRtree->pNodeBlob;
    pRtree->pNodeBlob = 0;
    rc = sqlite3_blob_reopen(pBlob, iNode);
    pRtree->pNodeBlob = pBlob;
    if( rc ){
      nodeBlobReset(pRtree);
      if( rc==SQLITE_NOMEM ) return SQLITE_NOMEM;
    }
  }
  if( pRtree->pNodeBlob==0 ){
    char *zTab = sqlite3_mprintf("%s_node", pRtree->zName);
    if( zTab==0 ) return SQLITE_NOMEM;
    rc = sqlite3_blob_open(pRtree->db, pRtree->zDb, zTab, "data", iNode, 0,
                           &pRtree->pNodeBlob);
    sqlite3_free(zTab);
  }
  if( rc ){
    nodeBlobReset(pRtree);
    *ppNode = 0;
    /* If unable to open an sqlite3_blob on the desired row, that can only
    ** be because the shadow tables hold erroneous data. */
    if( rc==SQLITE_ERROR ) rc = SQLITE_CORRUPT_VTAB;
  }else if( pRtree->iNodeSize==sqlite3_blob_bytes(pRtree->pNodeBlob) ){
    pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
    if( !pNode ){
      rc = SQLITE_NOMEM;
    }else{
      pNode->pParent = pParent;
      pNode->zData = (u8 *)&pNode[1];
      pNode->nRef = 1;
      pNode->iNode = iNode;
      pNode->isDirty = 0;
      pNode->pNext = 0;
      rc = sqlite3_blob_read(pRtree->pNodeBlob, pNode->zData,
                             pRtree->iNodeSize, 0);
      nodeReference(pParent);
    }
  }




  /* If the root node was just loaded, set pRtree->iDepth to the height
  ** of the r-tree structure. A height of zero means all data is stored on
  ** the root node. A height of one means the children of the root node
  ** are the leaves, and so on. If the depth as specified on the root node
  ** is greater than RTREE_MAX_DEPTH, the r-tree structure must be corrupt.
  */

/*
** Decrement the r-tree reference count. When the reference count reaches
** zero the structure is deleted.
*/
static void rtreeRelease(Rtree *pRtree){
  pRtree->nBusy--;
  if( pRtree->nBusy==0 ){
    pRtree->inWrTrans = 0;
    pRtree->nCursor = 0;
    nodeBlobReset(pRtree);
    sqlite3_finalize(pRtree->pWriteNode);
    sqlite3_finalize(pRtree->pDeleteNode);
    sqlite3_finalize(pRtree->pReadRowid);
    sqlite3_finalize(pRtree->pWriteRowid);
    sqlite3_finalize(pRtree->pDeleteRowid);
    sqlite3_finalize(pRtree->pReadParent);
    sqlite3_finalize(pRtree->pWriteParent);

    pRtree->zDb, pRtree->zName, 
    pRtree->zDb, pRtree->zName,
    pRtree->zDb, pRtree->zName
  );
  if( !zCreate ){
    rc = SQLITE_NOMEM;
  }else{
    nodeBlobReset(pRtree);
    rc = sqlite3_exec(pRtree->db, zCreate, 0, 0, 0);
    sqlite3_free(zCreate);
  }
  if( rc==SQLITE_OK ){
    rtreeRelease(pRtree);
  }

  return rc;
}

/* 
** Rtree virtual table module xOpen method.
*/
static int rtreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  int rc = SQLITE_NOMEM;
  Rtree *pRtree = (Rtree *)pVTab;
  RtreeCursor *pCsr;

  pCsr = (RtreeCursor *)sqlite3_malloc(sizeof(RtreeCursor));
  if( pCsr ){
    memset(pCsr, 0, sizeof(RtreeCursor));
    pCsr->base.pVtab = pVTab;
    rc = SQLITE_OK;
    pRtree->nCursor++;
  }
  *ppCursor = (sqlite3_vtab_cursor *)pCsr;

  return rc;
}

/* 
** Rtree virtual table module xClose method.
*/
static int rtreeClose(sqlite3_vtab_cursor *cur){
  Rtree *pRtree = (Rtree *)(cur->pVtab);
  int ii;
  RtreeCursor *pCsr = (RtreeCursor *)cur;
  assert( pRtree->nCursor>0 );
  freeCursorConstraints(pCsr);
  sqlite3_free(pCsr->aPoint);
  for(ii=0; ii<RTREE_CACHE_SZ; ii++) nodeRelease(pRtree, pCsr->aNode[ii]);
  sqlite3_free(pCsr);
  pRtree->nCursor--;
  nodeBlobReset(pRtree);
  return SQLITE_OK;
}

/*
** Rtree virtual table module xEof method.
**
** Return non-zero if the cursor does not currently point to a valid 

  RtreeConstraint *pConstraint,  /* The constraint to test */
  int eInt,                      /* True if RTree holding integer coordinates */
  u8 *pCellData,                 /* Raw cell content */
  RtreeSearchPoint *pSearch,     /* Container of this cell */
  sqlite3_rtree_dbl *prScore,    /* OUT: score for the cell */
  int *peWithin                  /* OUT: visibility of the cell */
){

  sqlite3_rtree_query_info *pInfo = pConstraint->pInfo; /* Callback info */
  int nCoord = pInfo->nCoord;                           /* No. of coordinates */
  int rc;                                             /* Callback return code */
  RtreeCoord c;                                       /* Translator union */
  sqlite3_rtree_dbl aCoord[RTREE_MAX_DIMENSIONS*2];   /* Decoded coordinates */

  assert( pConstraint->op==RTREE_MATCH || pConstraint->op==RTREE_QUERY );

      case 4:   readCoord(pCellData+12, &c); aCoord[3] = c.i;
                readCoord(pCellData+8,  &c); aCoord[2] = c.i;
      default:  readCoord(pCellData+4,  &c); aCoord[1] = c.i;
                readCoord(pCellData,    &c); aCoord[0] = c.i;
    }
  }
  if( pConstraint->op==RTREE_MATCH ){
    int eWithin = 0;
    rc = pConstraint->u.xGeom((sqlite3_rtree_geometry*)pInfo,
                              nCoord, aCoord, &eWithin);
    if( eWithin==0 ) *peWithin = NOT_WITHIN;
    *prScore = RTREE_ZERO;
  }else{
    pInfo->aCoord = aCoord;
    pInfo->iLevel = pSearch->iLevel - 1;
    pInfo->rScore = pInfo->rParentScore = pSearch->rScore;
    pInfo->eWithin = pInfo->eParentWithin = pSearch->eWithin;
    rc = pConstraint->u.xQueryFunc(pInfo);

    }
  }

constraint:
  rtreeRelease(pRtree);
  return rc;
}

/*
** Called when a transaction starts.
*/
static int rtreeBeginTransaction(sqlite3_vtab *pVtab){
  Rtree *pRtree = (Rtree *)pVtab;
  assert( pRtree->inWrTrans==0 );
  pRtree->inWrTrans++;
  return SQLITE_OK;
}

/*
** Called when a transaction completes (either by COMMIT or ROLLBACK).
** The sqlite3_blob object should be released at this point.
*/
static int rtreeEndTransaction(sqlite3_vtab *pVtab){
  Rtree *pRtree = (Rtree *)pVtab;
  pRtree->inWrTrans = 0;
  nodeBlobReset(pRtree);
  return SQLITE_OK;
}

/*
** The xRename method for rtree module virtual tables.
*/
static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
  Rtree *pRtree = (Rtree *)pVtab;
  int rc = SQLITE_NOMEM;

  );
  if( zSql ){
    rc = sqlite3_exec(pRtree->db, zSql, 0, 0, 0);
    sqlite3_free(zSql);
  }
  return rc;
}


/*
** This function populates the pRtree->nRowEst variable with an estimate
** of the number of rows in the virtual table. If possible, this is based
** on sqlite_stat1 data. Otherwise, use RTREE_DEFAULT_ROWEST.
*/
static int rtreeQueryStat1(sqlite3 *db, Rtree *pRtree){

  rtreeClose,                 /* xClose - close a cursor */
  rtreeFilter,                /* xFilter - configure scan constraints */
  rtreeNext,                  /* xNext - advance a cursor */
  rtreeEof,                   /* xEof */
  rtreeColumn,                /* xColumn - read data */
  rtreeRowid,                 /* xRowid - read data */
  rtreeUpdate,                /* xUpdate - write data */
  rtreeBeginTransaction,      /* xBegin - begin transaction */
  0,                          /* xSync - sync transaction */
  rtreeEndTransaction,        /* xCommit - commit transaction */
  rtreeEndTransaction,        /* xRollback - rollback transaction */
  0,                          /* xFindFunction - function overloading */
  rtreeRename,                /* xRename - rename the table */
  0,                          /* xSavepoint */
  0,                          /* xRelease */
  0,                          /* xRollbackTo */
};

static int rtreeSqlInit(
  Rtree *pRtree, 
  sqlite3 *db, 
  const char *zDb, 
  const char *zPrefix, 
  int isCreate
){
  int rc = SQLITE_OK;

  #define N_STATEMENT 8
  static const char *azSql[N_STATEMENT] = {
    /* Write the xxx_node table */

    "INSERT OR REPLACE INTO '%q'.'%q_node' VALUES(:1, :2)",
    "DELETE FROM '%q'.'%q_node' WHERE nodeno = :1",

    /* Read and write the xxx_rowid table */
    "SELECT nodeno FROM '%q'.'%q_rowid' WHERE rowid = :1",
    "INSERT OR REPLACE INTO '%q'.'%q_rowid' VALUES(:1, :2)",
    "DELETE FROM '%q'.'%q_rowid' WHERE rowid = :1",

    rc = sqlite3_exec(db, zCreate, 0, 0, 0);
    sqlite3_free(zCreate);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }

  appStmt[0] = &pRtree->pWriteNode;
  appStmt[1] = &pRtree->pDeleteNode;
  appStmt[2] = &pRtree->pReadRowid;
  appStmt[3] = &pRtree->pWriteRowid;
  appStmt[4] = &pRtree->pDeleteRowid;
  appStmt[5] = &pRtree->pReadParent;
  appStmt[6] = &pRtree->pWriteParent;
  appStmt[7] = &pRtree->pDeleteParent;


  rc = rtreeQueryStat1(db, pRtree);
  for(i=0; i<N_STATEMENT && rc==SQLITE_OK; i++){
    char *zSql = sqlite3_mprintf(azSql[i], zDb, zPrefix);
    if( zSql ){
      rc = sqlite3_prepare_v2(db, zSql, -1, appStmt[i], 0); 
    }else{

  }
  memset(pRtree, 0, sizeof(Rtree)+nDb+nName+2);
  pRtree->nBusy = 1;
  pRtree->base.pModule = &rtreeModule;
  pRtree->zDb = (char *)&pRtree[1];
  pRtree->zName = &pRtree->zDb[nDb+1];
  pRtree->nDim = (u8)((argc-4)/2);
  pRtree->nDim2 = pRtree->nDim*2;
  pRtree->nBytesPerCell = 8 + pRtree->nDim2*4;
  pRtree->eCoordType = (u8)eCoordType;
  memcpy(pRtree->zDb, argv[1], nDb);
  memcpy(pRtree->zName, argv[2], nName);

  /* Figure out the node size to use. */
  rc = getNodeSize(db, pRtree, isCreate, pzErr);

  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
  4   "SELECT * FROM t1 WHERE x1<10 AND x2>12"
}

do_execsql_test  rtreeA-1.2.0 { DROP TABLE t1_node } {}
do_corruption_tests rtreeA-1.2 -error "database disk image is malformed" {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
  4   "SELECT * FROM t1 WHERE x1<10 AND x2>12"
}

#-------------------------------------------------------------------------

**
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
*/

/*
** CAPI3REF: A Handle To An Open BLOB
** KEYWORDS: {BLOB handle} {BLOB handles} {sqlite3_blob object}
**
** An instance of this object represents a connection to a single
** column in a single row of a table that holds either a BLOB or string
** and on which [sqlite3_blob_open | incremental BLOB I/O] can be performed.
**
** ^Objects of this type are created by [sqlite3_blob_open()]
** and destroyed by [sqlite3_blob_close()].
** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
** can be used to read or write small subsections of the BLOB.
** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
**
** An sqlite3_blob object can be in two states: ACTIVE and RESET.  When in
** the ACTIVE state, the object is pointing to a specific entry and is
** ready to do I/O.  When RESET, the sqlite3_blob object is in standby mode,
** is not associated with any particular row of its table, 
** and is not available for I/O.
**
** The sqlite3_blob object does not contain a mutex and so a single
** sqlite3_blob object may not be safely used by multiple threads
** concurrently.
*/
typedef struct sqlite3_blob sqlite3_blob;

/*
** CAPI3REF: Open A BLOB For Incremental I/O
** METHOD: sqlite3
** CONSTRUCTOR: sqlite3_blob
**
** ^(This interfaces creates an sqlite3_blob object pointing to the string
** or BLOB located in row iRow, column zColumn, table zTable in database zDb;
** in other words, the same BLOB that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
** </pre>)^
**
** ^(Parameter zDb is not the filename that contains the database, but 
** rather the symbolic name of the database. For attached databases, this is
** the name that appears after the AS keyword in the [ATTACH] statement.
** For the main database file, the database name is "main". For TEMP
** tables, the database name is "temp".)^
**
** ^If the flags parameter is non-zero, then the BLOB is opened for read
** and write access. ^If the flags parameter is zero, the BLOB is opened for
** read-only access.
**
** ^(On success, [SQLITE_OK] is returned and the new [sqlite3_blob object]
** is stored in *ppBlob. Otherwise an [error code] is returned and
** *ppBlob is set to NULL.)^ ^Because *ppBlob is always set to either a
** valid sqlite3_blob object or NULL
** it is always safe to call [sqlite3_blob_close()] 
** on *ppBlob after this function it returns.
**
** This function fails with SQLITE_ERROR if any of the following are true:
** <ul>
**   <li> ^(Database zDb does not exist)^, 
**   <li> ^(Table zTable does not exist within database zDb)^, 
**   <li> ^(Table zTable is a WITHOUT ROWID table)^, 

** [sqlite3_blob_write()].  The [BLOB handle] can be moved to a
** different row of the same table using the [sqlite3_blob_reopen()]
** interface.  However, the column, table, or database of a [BLOB handle]
** cannot be changed after the [BLOB handle] is opened.
**
** ^(If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired" and cannot be used
** successfully with first being [sqlite3_blob_reopen|reopened].
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.)^
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
** ^(Changes written into a BLOB prior to the BLOB expiring are not
** rolled back by the expiration of the BLOB.  Such changes will eventually
** commit if the transaction continues to completion.)^
**
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
** the opened blob.  ^The size of a blob may not be changed by this
** interface.  Use the [UPDATE] SQL command to change the size of a
** blob.  The [sqlite3_blob_bytes()] interface returns an arbitrary
** number when used on an expired sqlite3_blob object.
**
** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
** and the built-in [zeroblob] SQL function may be used to create a 
** zero-filled blob to read or write using the incremental-blob interface.
**
** To avoid a resource leak, every open [BLOB handle] should eventually
** be released by a call to [sqlite3_blob_close()].
**
** See also: [sqlite3_blob_close()],
** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
** [sqlite3_blob_bytes()], [sqlite3_blob_write()],
** [sqlite3_blob_reset()].
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
  int flags,
  sqlite3_blob **ppBlob
);

/*
** CAPI3REF: Move an sqlite3_blob object to a New Row
** METHOD: sqlite3_blob
**
** ^This function updates an existing [sqlite3_blob object] so that it points
** to a different row of the same database table. ^The new row is identified
** by the rowid value passed as the second argument. Only the row can be
** changed. ^The database, table and column on which the blob handle is open
** remain the same. Moving an existing [sqlite3_blob object] to a new row is
** faster than closing the existing handle and opening a new one.
**
** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
** it must exist and there must be either a blob or text value stored in
** the nominated column.)^ ^If the new row is not present in the table, or if
** it does not contain a blob or text value, or if another error occurs, an
** SQLite error code is returned and the [sqlite3_blob object] is changed
** to the RESET state.

** ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
** always returns zero.
**
** ^This function sets the database handle error code and message.
*/
int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);

/*
** CAPI3REF: Close an sqlite3_blob object
** DESTRUCTOR: sqlite3_blob
**
** ^This function is the destructor for an [sqlite3_blob object]. 
** ^(The [sqlite3_blob object] is closed
** unconditionally.  Even if this routine returns an error code, the 
** object is still closed.)^
**
** ^If the sqlite3_blob object being closed was opened for read-write access,
** and is in the ACTIVE state,
** and if the database is in auto-commit mode and there are no other open 
** read-write
** blob handles or active write statements, the current transaction is
** committed. ^If an error occurs while committing the transaction, an error
** code is returned and the transaction rolled back.
**
** Calling this function with an argument that is not a NULL pointer or a
** valid sqlite3_blob object pointer results in undefined behaviour. 
** ^Calling this routine 
** with a null pointer (such as would be returned by a failed call to 
** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
** is passed a valid sqlite3_blob objecct pointer, the values returned by the 
** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF: Reset an sqlite3_blob object
** METHOD: sqlite3_blob
**
** ^This function changes an [sqlite3_blob object] to the RESET state.
** ^If the [sqlite3_blob object] was already in the RESET state, then this
** routine is a harmless no-op.
*/
int sqlite3_blob_reset(sqlite3_blob *);

/*
** CAPI3REF: Return The Size Of A BLOB
** METHOD: sqlite3_blob
**
** ^Returns the size in bytes of the BLOB or string accessible via the 
** ACTIVE [sqlite3_blob object] in its only argument.  ^The
** incremental blob I/O routines can only read or overwriting existing
** content; they cannot change the size of a blob or string.
**
** This routine only works on an [sqlite3_blob object] that has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF: Read Data From A BLOB Incrementally
** METHOD: sqlite3_blob
**
** ^(This function is used to read data from string or BLOB that an
** [sqlite3_blob object] is pointing to into a caller-supplied buffer. 
** N bytes of data are copied into buffer Z starting at offset iOffset.)^
**
** ^If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
** less than zero, [SQLITE_ERROR] is returned and no data is read.
** ^The size of the blob (and hence the maximum value of N+iOffset)
** can be determined using the [sqlite3_blob_bytes()] interface.
**
** ^An attempt to read from an [sqlite3_blob object] that is in the RESET
** state, or from a database row that has changed since the most recent
** call to [sqlite3_blob_open()] or [sqlite3_blob_reopen()] fails with an
** error code of [SQLITE_ABORT].
**
** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
** Otherwise, an [error code] or an [extended error code] is returned.)^
**





** See also: [sqlite3_blob_write()].
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF: Write Data Into A BLOB Incrementally
** METHOD: sqlite3_blob
**
** ^(This function is used to write data from a caller-supplied buffer
** into a BLOB or string pointed to by an [sqlite3_blob object].
** N bytes of data are copied from the buffer Z
** into the BLOB or string, starting at offset iOffset.)^
**
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
** Otherwise, an  [error code] or an [extended error code] is returned.)^
** ^Unless SQLITE_MISUSE is returned, this function sets the 
** [database connection] error code and message accessible via 
** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 
**
** ^If the [BLOB handle] passed as the first argument was not opened for
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
** this function returns [SQLITE_READONLY].
**
** This function may only modify the contents of the BLOB; it is
** not possible to increase the size of a BLOB using this API.
** ^If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is written. The size of the 
** BLOB (and hence the maximum value of N+iOffset) can be determined 
** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 
** than zero [SQLITE_ERROR] is returned and no data is written.
**
** ^An attempt to write into an [sqlite3_blob object] that is in the RESET
** state, or into a database row that has changed since the most recent
** call to [sqlite3_blob_open()] or [sqlite3_blob_reopen()] fails with an
** error code of [SQLITE_ABORT].









**
** See also: [sqlite3_blob_read()].
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF: Virtual File System Objects

#ifndef SQLITE_OMIT_INCRBLOB

/*
** Valid sqlite3_blob* handles point to Incrblob structures.
*/
typedef struct Incrblob Incrblob;
struct Incrblob {
  int nByte;              /* Size of open blob if ACTIVE. -1 if RESET */
  int iOffset;            /* Byte offset of blob in cursor data */
  u16 iCol;               /* Table column this handle is open on */
  BtCursor *pCsr;         /* Cursor pointing at blob row */
  sqlite3_stmt *pStmt;    /* Statement holding cursor open */
  sqlite3 *db;            /* The associated database */
  char *zDb;              /* Database name */
  Table *pTab;            /* Table object */
};


/*
** This function is used by both blob_open() and blob_reopen(). It seeks
** the b-tree cursor associated with blob handle p to point to row iRow.
** If successful, SQLITE_OK is returned and subsequent calls to
** sqlite3_blob_read() or sqlite3_blob_write() access the specified row.
**

    testcase( pC->nHdrParsed==p->iCol );
    testcase( pC->nHdrParsed==p->iCol+1 );
    if( type<12 ){
      zErr = sqlite3MPrintf(p->db, "cannot open value of type %s",
          type==0?"null": type==7?"real": "integer"
      );
      rc = SQLITE_ERROR;
      sqlite3_reset(p->pStmt);
      p->nByte = -1;
    }else{
      p->iOffset = pC->aType[p->iCol + pC->nField];
      p->nByte = sqlite3VdbeSerialTypeLen(type);
      p->pCsr =  pC->uc.pCursor;
      sqlite3BtreeIncrblobCursor(p->pCsr);
    }
  }

  if( rc==SQLITE_ROW ){
    rc = SQLITE_OK;
  }else if( p->nByte>=0 ){
    rc = sqlite3_reset(p->pStmt);
    p->nByte = -1;
    if( rc==SQLITE_OK ){
      zErr = sqlite3MPrintf(p->db, "no such rowid: %lld", iRow);
      rc = SQLITE_ERROR;
    }else{
      zErr = sqlite3MPrintf(p->db, "%s", sqlite3_errmsg(p->db));
    }
  }

  if( !pParse ) goto blob_open_out;

  do {
    memset(pParse, 0, sizeof(Parse));
    pParse->db = db;
    sqlite3DbFree(db, zErr);
    zErr = 0;
    sqlite3_finalize(pBlob->pStmt);

    sqlite3BtreeEnterAll(db);
    pTab = sqlite3LocateTable(pParse, 0, zTable, zDb);
    if( pTab && IsVirtual(pTab) ){
      pTab = 0;
      sqlite3ErrorMsg(pParse, "cannot open virtual table: %s", zTable);
    }

        pParse->nTab = 1;
        sqlite3VdbeMakeReady(v, pParse);
      }
    }
   
    pBlob->iCol = iCol;
    pBlob->db = db;
    pBlob->nByte = 0;
    sqlite3BtreeLeaveAll(db);
    if( db->mallocFailed ){
      goto blob_open_out;
    }
    rc = blobSeekToRow(pBlob, iRow, &zErr);
  } while( (++nAttempt)<SQLITE_MAX_SCHEMA_RETRY && rc==SQLITE_SCHEMA );

  Incrblob *p = (Incrblob *)pBlob;
  int rc;
  sqlite3 *db;

  if( p ){
    db = p->db;
    sqlite3_mutex_enter(db->mutex);
    rc = sqlite3VdbeFinalize((Vdbe*)p->pStmt);
    sqlite3DbFree(db, p);
    sqlite3_mutex_leave(db->mutex);
  }else{
    rc = SQLITE_OK;
  }
  return rc;
}

){
  int rc;
  Incrblob *p = (Incrblob *)pBlob;
  Vdbe *v;
  sqlite3 *db;

  if( p==0 ) return SQLITE_MISUSE_BKPT;
  if( p->nByte<0 ){
    /* The blob handle is in the RESET state.  Always return SQLITE_ABORT. */
    return SQLITE_ABORT;
  }
  db = p->db;
  sqlite3_mutex_enter(db->mutex);
  v = (Vdbe*)p->pStmt;

  if( n<0 || iOffset<0 || ((sqlite3_int64)iOffset+n)>p->nByte ){
    /* Request is out of range. Return a transient error. */
    rc = SQLITE_ERROR;





  }else{
    /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is
    ** returned, clean-up the statement handle.
    */
    assert( db == v->db );
    sqlite3BtreeEnterCursor(p->pCsr);

      );
    }
#endif

    rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
    sqlite3BtreeLeaveCursor(p->pCsr);
    if( rc==SQLITE_ABORT ){
      sqlite3_reset(p->pStmt);
      p->nByte = -1;
    }else{
      v->rc = rc;
    }
  }
  sqlite3Error(db, rc);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);

int sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int iOffset){
  return blobReadWrite(pBlob, (void *)z, n, iOffset, sqlite3BtreePutData);
}

/*
** Query a blob handle for the size of the data.
**
** The Incrblob.nByte field is fixed for as long as the sqlite3_blob
** object is pointing to the same row, so no mutex is required for access.
**
** When the sqlite3_blob interface was first designed in 2007, we specified
** that sqlite3_blob_bytes() returned 0 when in the RESET state.  It would
** have been better to return -1 in order to distinguish a RESET blob handle
** from an ACTIVE blob handle pointing to a zero-length string or blob.
** But, sadly, we cannot change that now without breaking compatibility.
** So 0 is returned for RESET blob handles and for ACTIVE blob handles
** pointing to zero-length blobs.
*/
int sqlite3_blob_bytes(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;
  return (p && p->pStmt && p->nByte>0) ? p->nByte : 0;
}

/*
** Move the sqlite3_blob object to the RESET state.  This releases
** any locks and gets the object out of the way of commits and
** rollbacks.
*/
int sqlite3_blob_reset(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;
  if( p->nByte>=0 ){
    sqlite3_reset(p->pStmt);
    p->nByte = -1;
  }
  return SQLITE_OK;
}  

/*
** Move an existing blob handle to point to a different row of the same
** database table.
**
** If an error occurs, or if the specified row does not exist or does not
** contain a blob or text value, then an error code is returned and the
** database handle error code and message set. If this happens, then all 
** subsequent calls to sqlite3_blob_xxx() functions (except blob_close()) 
** immediately return SQLITE_ABORT.
*/
int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
  int rc;
  Incrblob *p = (Incrblob *)pBlob;
  sqlite3 *db;
  char *zErr;

  if( p==0 ) return SQLITE_MISUSE_BKPT;
  db = p->db;
  sqlite3_mutex_enter(db->mutex);








  rc = blobSeekToRow(p, iRow, &zErr);
  if( rc!=SQLITE_OK ){
    sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);
    sqlite3DbFree(db, zErr);


  }

  rc = sqlite3ApiExit(db, rc);
  assert( rc==SQLITE_OK || p->nByte<0 );
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

#endif /* #ifndef SQLITE_OMIT_INCRBLOB */

} {}
blob_write_error_test 2.3.1 $B 5 $blob 5 \
    SQLITE_ABORT {callback requested query abort}
do_test 2.3.2 {
  execsql { SELECT 1, 2, 3 }
  sqlite3_errcode db
} {SQLITE_OK}
#blob_write_error_test 2.3.3 $B 5 $blob 5 \
#    SQLITE_OK {not an error}
sqlite3_blob_close $B

# EVIDENCE-OF: R-08382-59936 Writes to the BLOB that occurred before the
# BLOB handle expired are not rolled back by the expiration of the
# handle, though of course those changes might have been overwritten by
# the statement that expired the BLOB handle or by other independent
# statements.

  list [catch {sqlite3_blob_reopen $::blob 3} msg] $msg
} {1 SQLITE_ERROR}
do_test incrblob3-2.1.2 {
  list [sqlite3_errcode db] [sqlite3_errmsg db]
} {SQLITE_ERROR {no such rowid: 3}}
do_test incrblob3-2.1.3 {
  list [catch {sqlite3_blob_reopen $::blob 1} msg] $msg
} {0 {}}
do_test incrblob3-2.1.4 { close $::blob } {}

do_execsql_test incrblob3-2.2.1 {
  INSERT INTO blobs VALUES(3, 42);
  INSERT INTO blobs VALUES(4, 54.4);
  INSERT INTO blobs VALUES(5, NULL);
}

  } {1 SQLITE_ERROR}
  do_test incrblob3-2.2.$tn.2 {
    list [sqlite3_errcode db] [sqlite3_errmsg db]
  } "SQLITE_ERROR {cannot open value of type $type}"

  do_test incrblob3-2.2.$tn.3 {
    list [catch {sqlite3_blob_reopen $::blob 1} msg] $msg
  } {0 {}}
  do_test incrblob3-2.2.$tn.4 {
    list [catch {sqlite3_blob_read $::blob 0 10} msg] $msg
  } {0 {hello worl}}
  do_test incrblob3-2.2.$tn.5 {
    list [catch {sqlite3_blob_write $::blob 0 "abcd"} msg] $msg
  } {0 {}}
  do_test incrblob3-2.2.$tn.6 {
    sqlite3_blob_bytes $::blob
  } {100}
  do_test incrblob3-2.2.$tn.7 {
    list [catch {sqlite3_blob_write $::blob 0 "hello"} msg] $msg
  } {0 {}}

  do_test incrblob3-2.2.$tn.8 { close $::blob } {}
}

# Test that passing NULL to sqlite3_blob_XXX() APIs returns SQLITE_MISUSE.
#
#   incrblob3-3.1: sqlite3_blob_reopen()
#   incrblob3-3.2: sqlite3_blob_read()
#   incrblob3-3.3: sqlite3_blob_write()