SQLite

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**
** $Id: vdbe.c,v 1.293 2004/05/14 21:59:40 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

** allocate more.
**
** If a memory allocation error occurs, return 1.  Return 0 if
** everything works.
*/
static int expandCursorArraySize(Vdbe *p, int mxCursor){
  if( mxCursor>=p->nCursor ){
    p->apCsr = sqliteRealloc( p->apCsr, (mxCursor+1)*sizeof(Cursor*) );
    if( p->apCsr==0 ) return 1;

    while( p->nCursor<=mxCursor ){
      Cursor *pC;
      p->apCsr[p->nCursor++] = pC = sqliteMalloc( sizeof(Cursor) );
      if( pC==0 ) return 1;
    }
  }
  return 0;
}

/*
** Apply any conversion required by the supplied column affinity to
** memory cell pRec. affinity may be one of:

  unsigned long long start;  /* CPU clock count at start of opcode */
  int origPc;                /* Program counter at start of opcode */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int nProgressOps = 0;      /* Opcodes executed since progress callback. */
#endif




  if( p->magic!=VDBE_MAGIC_RUN ) return SQLITE_MISUSE;
  assert( db->magic==SQLITE_MAGIC_BUSY );
  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
  p->rc = SQLITE_OK;
  assert( p->explain==0 );
  if( sqlite3_malloc_failed ) goto no_mem;
  pTos = p->pTos;

  */
  if( i<0 ){
    assert( &pTos[i]>=p->aStack );
    assert( pTos[i].flags & MEM_Str );
    zRec = pTos[i].z;
    payloadSize = pTos[i].n;
    pC->cacheValid = 0;
  }else if( (pC = p->apCsr[i])->pCursor!=0 ){
    sqlite3VdbeCursorMoveto(pC);
    zRec = 0;
    pCrsr = pC->pCursor;
    if( pC->nullRow ){
      payloadSize = 0;
    }else if( pC->cacheValid ){
      payloadSize = pC->payloadSize;

      sqlite3SetString(&p->zErrMsg, "root page number less than 2", (char*)0);
      rc = SQLITE_INTERNAL;
      break;
    }
  }
  assert( i>=0 );
  if( expandCursorArraySize(p, i) ) goto no_mem;
  pCur = p->apCsr[i];
  sqlite3VdbeCleanupCursor(pCur);

  pCur->nullRow = 1;
  if( pX==0 ) break;
  do{
    /* When opening cursors, always supply the comparison function
    ** sqlite3VdbeKeyCompare(). If the table being opened is of type
    ** INTKEY, the btree layer won't call the comparison function anyway.
    */

** of the connection to the database.  Same word; different meanings.
*/
case OP_OpenTemp: {
  int i = pOp->p1;
  Cursor *pCx;
  assert( i>=0 );
  if( expandCursorArraySize(p, i) ) goto no_mem;
  pCx = p->apCsr[i];
  sqlite3VdbeCleanupCursor(pCx);
  memset(pCx, 0, sizeof(*pCx));
  pCx->nullRow = 1;
  rc = sqlite3BtreeFactory(db, 0, 1, TEMP_PAGES, &pCx->pBt);

  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(pCx->pBt);

** NEW or OLD tables in a trigger.
*/
case OP_OpenPseudo: {
  int i = pOp->p1;
  Cursor *pCx;
  assert( i>=0 );
  if( expandCursorArraySize(p, i) ) goto no_mem;
  pCx = p->apCsr[i];
  sqlite3VdbeCleanupCursor(pCx);
  memset(pCx, 0, sizeof(*pCx));
  pCx->nullRow = 1;
  pCx->pseudoTable = 1;
  break;
}

/* Opcode: Close P1 * *
**
** Close a cursor previously opened as P1.  If P1 is not
** currently open, this instruction is a no-op.
*/
case OP_Close: {
  int i = pOp->p1;
  if( i>=0 && i<p->nCursor ){
    sqlite3VdbeCleanupCursor(p->apCsr[i]);
  }
  break;
}

/* Opcode: MoveTo P1 P2 *
**
** Pop the top of the stack and use its value as a key.  Reposition

case OP_MoveLt:
case OP_MoveTo: {
  int i = pOp->p1;
  Cursor *pC;

  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  if( pC->pCursor!=0 ){
    int res, oc;
    pC->nullRow = 0;
    if( pC->intKey ){
      i64 iKey;
      assert( !pOp->p3 );
      Integerify(pTos);

case OP_NotFound:
case OP_Found: {
  int i = pOp->p1;
  int alreadyExists = 0;
  Cursor *pC;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res, rx;
    assert( pC->intKey==0 );
    Stringify(pTos);
    rx = sqlite3BtreeMoveto(pC->pCursor, pTos->z, pTos->n, &res);
    alreadyExists = rx==SQLITE_OK && res==0;
    pC->deferredMoveto = 0;
    pC->cacheValid = 0;

  /* Pop the value R off the top of the stack
  */
  assert( pNos>=p->aStack );
  Integerify(pTos);
  R = pTos->i;
  pTos--;
  assert( i>=0 && i<=p->nCursor );
  pCx = p->apCsr[i];
  pCrsr = pCx->pCursor;
  if( pCrsr!=0 ){
    int res, rc;
    i64 v;         /* The record number on the P1 entry that matches K */
    char *zKey;    /* The value of K */
    int nKey;      /* Number of bytes in K */
    int len;       /* Number of bytes in K without the rowid at the end */

*/
case OP_NotExists: {
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    int res, rx;
    u64 iKey;
    assert( pTos->flags & MEM_Int );
    assert( p->apCsr[i]->intKey );
    iKey = intToKey(pTos->i);
    rx = sqlite3BtreeMoveto(pCrsr, 0, iKey, &res);
    pC->lastRecno = pTos->i;
    pC->recnoIsValid = res==0;
    pC->nullRow = 0;
    pC->cacheValid = 0;
    if( rx!=SQLITE_OK || res!=0 ){

** onto the stack.
*/
case OP_NewRecno: {
  int i = pOp->p1;
  i64 v = 0;
  Cursor *pC;
  assert( i>=0 && i<p->nCursor );
  if( (pC = p->apCsr[i])->pCursor==0 ){
    /* The zero initialization above is all that is needed */
  }else{
    /* The next rowid or record number (different terms for the same
    ** thing) is obtained in a two-step algorithm.
    **
    ** First we attempt to find the largest existing rowid and add one
    ** to that.  But if the largest existing rowid is already the maximum

case OP_PutIntKey:
case OP_PutStrKey: {
  Mem *pNos = &pTos[-1];
  int i = pOp->p1;
  Cursor *pC;
  assert( pNos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  if( ((pC = p->apCsr[i])->pCursor!=0 || pC->pseudoTable) ){
    char *zKey;
    i64 nKey; 
    i64 iKey;
    if( pOp->opcode==OP_PutStrKey ){
      Stringify(pNos);
      nKey = pNos->n;
      zKey = pNos->z;

**
** If P1 is a pseudo-table, then this instruction is a no-op.
*/
case OP_Delete: {
  int i = pOp->p1;
  Cursor *pC;
  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  if( pC->pCursor!=0 ){
    sqlite3VdbeCursorMoveto(pC);
    rc = sqlite3BtreeDelete(pC->pCursor);
    pC->nextRowidValid = 0;
    pC->cacheValid = 0;
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) db->nChange++;

** off (if P2==0).  In key-as-data mode, the OP_Column opcode pulls
** data off of the key rather than the data.  This is used for
** processing compound selects.
*/
case OP_KeyAsData: {
  int i = pOp->p1;
  assert( i>=0 && i<p->nCursor );
  p->apCsr[i]->keyAsData = pOp->p2;
  break;
}

/* Opcode: RowData P1 * *
**
** Push onto the stack the complete row data for cursor P1.
** There is no interpretation of the data.  It is just copied

case OP_RowData: {
  int i = pOp->p1;
  Cursor *pC;
  int n;

  pTos++;
  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  if( pC->nullRow ){
    pTos->flags = MEM_Null;
  }else if( pC->pCursor!=0 ){
    BtCursor *pCrsr = pC->pCursor;
    sqlite3VdbeCursorMoveto(pC);
    if( pC->nullRow ){
      pTos->flags = MEM_Null;

*/
case OP_Recno: {
  int i = pOp->p1;
  Cursor *pC;
  i64 v;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  sqlite3VdbeCursorMoveto(pC);
  pTos++;
  if( pC->recnoIsValid ){
    v = pC->lastRecno;
  }else if( pC->pseudoTable ){
    v = keyToInt(pC->iKey);
  }else if( pC->nullRow || pC->pCursor==0 ){

** integer.  This instruction pushes the entire key as a string.
**
** This opcode may not be used on a pseudo-table.
*/
case OP_FullKey: {
  int i = pOp->p1;
  BtCursor *pCrsr;
  Cursor *pC;

  assert( p->apCsr[i]->keyAsData );
  assert( !p->apCsr[i]->pseudoTable );
  assert( i>=0 && i<p->nCursor );
  pTos++;
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    u64 amt;
    char *z;

    sqlite3VdbeCursorMoveto(pC);
    assert( pC->intKey==0 );
    sqlite3BtreeKeySize(pCrsr, &amt);
    if( amt<=0 ){
      rc = SQLITE_CORRUPT;
      goto abort_due_to_error;
    }
    if( amt>NBFS ){
      z = sqliteMallocRaw( amt );

**
** Move the cursor P1 to a null row.  Any OP_Column operations
** that occur while the cursor is on the null row will always push 
** a NULL onto the stack.
*/
case OP_NullRow: {
  int i = pOp->p1;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  pC->nullRow = 1;
  pC->recnoIsValid = 0;
  break;
}

/* Opcode: Last P1 P2 *
**
** The next use of the Recno or Column or Next instruction for P1 
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Last: {
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  if( (pCrsr = pC->pCursor)!=0 ){
    int res;
    rc = sqlite3BtreeLast(pCrsr, &res);
    pC->nullRow = res;
    pC->deferredMoveto = 0;
    pC->cacheValid = 0;
    if( res && pOp->p2>0 ){

case OP_Rewind: {
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  int res;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  if( (pCrsr = pC->pCursor)!=0 ){
    rc = sqlite3BtreeFirst(pCrsr, &res);
    pC->atFirst = res==0;
    pC->deferredMoveto = 0;
    pC->cacheValid = 0;
  }else{
    res = 1;

case OP_Prev:
case OP_Next: {
  Cursor *pC;
  BtCursor *pCrsr;

  CHECK_FOR_INTERRUPT;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  if( (pCrsr = pC->pCursor)!=0 ){
    int res;
    if( pC->nullRow ){
      res = 1;
    }else{
      assert( pC->deferredMoveto==0 );
      rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :

case OP_IdxPut: {
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( pTos->flags & MEM_Str );
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    int nKey = pTos->n;
    const char *zKey = pTos->z;
    if( pOp->p2 ){
      int res;
      int len;
      u64 n;
   

case OP_IdxDelete: {
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
  assert( pTos->flags & MEM_Str );
  assert( i>=0 && i<p->nCursor );
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    int rx, res;
    rx = sqlite3BtreeMoveto(pCrsr, pTos->z, pTos->n, &res);
    if( rx==SQLITE_OK && res==0 ){
      rc = sqlite3BtreeDelete(pCrsr);
    }
    assert( pC->deferredMoveto==0 );
    pC->cacheValid = 0;

** the record number of the table entry to which this index entry points.
**
** See also: Recno, MakeIdxKey.
*/
case OP_IdxRecno: {
  int i = pOp->p1;
  BtCursor *pCrsr;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
  pTos++;
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    i64 rowid;

    assert( pC->deferredMoveto==0 );
    assert( pC->intKey==0 );
    rc = sqlite3VdbeIdxRowid(pCrsr, &rowid);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    pTos->flags = MEM_Int;
    pTos->i = rowid;

** In either case, the stack is popped once.
*/
case OP_IdxLT:
case OP_IdxGT:
case OP_IdxGE: {
  int i= pOp->p1;
  BtCursor *pCrsr;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
  assert( pTos>=p->aStack );
  if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
    int res, rc;

 
    Stringify(pTos);
    assert( pC->deferredMoveto==0 );
    if( pOp->p3 ){
      pC->incrKey = 1;
    }
    rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, pTos->z, 0, &res);
    pC->incrKey = 0;
    if( rc!=SQLITE_OK ){
      break;

  int nLabel;         /* Number of labels used */
  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
  int *aLabel;        /* Space to hold the labels */
  Mem *aStack;        /* The operand stack, except string values */
  Mem *pTos;          /* Top entry in the operand stack */
  char **zArgv;       /* Text values used by the callback */
  char **azColName;   /* Becomes the 4th parameter to callbacks */
  int nCursor;        /* Number of slots in apCsr[] */
  Cursor **apCsr;     /* One element of this array for each open cursor */
  Sorter *pSort;      /* A linked list of objects to be sorted */
  FILE *pFile;        /* At most one open file handler */
  int nField;         /* Number of file fields */
  char **azField;     /* Data for each file field */
  int nVar;           /* Number of entries in azVariable[] */
  char **azVar;       /* Values for the OP_Variable opcode */
  int *anVar;         /* Length of each value in azVariable[] */

    sqlite3BtreeCloseCursor(pCx->pCursor);
  }
  if( pCx->pBt ){
    sqlite3BtreeClose(pCx->pBt);
  }
  sqliteFree(pCx->pData);
  sqliteFree(pCx->aType);
  memset(pCx, 0, sizeof(*pCx));
}

/*
** Close all cursors
*/
static void closeAllCursors(Vdbe *p){
  int i;
  for(i=0; i<p->nCursor; i++){
    Cursor *pC = p->apCsr[i];
    sqlite3VdbeCleanupCursor(pC);
    sqliteFree(pC);
  }
  sqliteFree(p->apCsr);
  p->apCsr = 0;
  p->nCursor = 0;
}

/*
** Clean up the VM after execution.
**
** This routine will automatically close any cursors, lists, and/or