vdbe.c

sqlite-source-2_8_16.zip 轻量级嵌入式数据库源码

** invoke the callback function using the newly formed array as the
** 3rd parameter.
*/
case OP_Callback: {
  int i;
  char **azArgv = p->zArgv;
  Mem *pCol;

  pCol = &pTos[1-pOp->p1];
  assert( pCol>=p->aStack );
  for(i=0; i<pOp->p1; i++, pCol++){
    if( pCol->flags & MEM_Null ){
      azArgv[i] = 0;
    }else{
      Stringify(pCol);
      azArgv[i] = pCol->z;
    }
  }
  azArgv[i] = 0;
  p->nCallback++;
  p->azResColumn = azArgv;
  assert( p->nResColumn==pOp->p1 );
  p->popStack = pOp->p1;
  p->pc = pc + 1;
  p->pTos = pTos;
  return SQLITE_ROW;
}

/* Opcode: Concat P1 P2 P3
**
** Look at the first P1 elements of the stack.  Append them all 
** together with the lowest element first.  Use P3 as a separator.  
** Put the result on the top of the stack.  The original P1 elements
** are popped from the stack if P2==0 and retained if P2==1.  If
** any element of the stack is NULL, then the result is NULL.
**
** If P3 is NULL, then use no separator.  When P1==1, this routine
** makes a copy of the top stack element into memory obtained
** from sqliteMalloc().
*/
case OP_Concat: {
  char *zNew;
  int nByte;
  int nField;
  int i, j;
  char *zSep;
  int nSep;
  Mem *pTerm;

  nField = pOp->p1;
  zSep = pOp->p3;
  if( zSep==0 ) zSep = "";
  nSep = strlen(zSep);
  assert( &pTos[1-nField] >= p->aStack );
  nByte = 1 - nSep;
  pTerm = &pTos[1-nField];
  for(i=0; i<nField; i++, pTerm++){
    if( pTerm->flags & MEM_Null ){
      nByte = -1;
      break;
    }else{
      Stringify(pTerm);
      nByte += pTerm->n - 1 + nSep;
    }
  }
  if( nByte<0 ){
    if( pOp->p2==0 ){
      popStack(&pTos, nField);
    }
    pTos++;
    pTos->flags = MEM_Null;
    break;
  }
  zNew = sqliteMallocRaw( nByte );
  if( zNew==0 ) goto no_mem;
  j = 0;
  pTerm = &pTos[1-nField];
  for(i=j=0; i<nField; i++, pTerm++){
    assert( pTerm->flags & MEM_Str );
    memcpy(&zNew[j], pTerm->z, pTerm->n-1);
    j += pTerm->n-1;
    if( nSep>0 && i<nField-1 ){
      memcpy(&zNew[j], zSep, nSep);
      j += nSep;
    }
  }
  zNew[j] = 0;
  if( pOp->p2==0 ){
    popStack(&pTos, nField);
  }
  pTos++;
  pTos->n = nByte;
  pTos->flags = MEM_Str|MEM_Dyn;
  pTos->z = zNew;
  break;
}

/* Opcode: Add * * *
**
** Pop the top two elements from the stack, add them together,
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the addition.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Multiply * * *
**
** Pop the top two elements from the stack, multiply them together,
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the multiplication.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Subtract * * *
**
** Pop the top two elements from the stack, subtract the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the subtraction.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Divide * * *
**
** Pop the top two elements from the stack, divide the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the division.  Division by zero returns NULL.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Remainder * * *
**
** Pop the top two elements from the stack, divide the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the remainder after division onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the division.  Division by zero returns NULL.
** If either operand is NULL, the result is NULL.
*/
case OP_Add:
case OP_Subtract:
case OP_Multiply:
case OP_Divide:
case OP_Remainder: {
  Mem *pNos = &pTos[-1];
  assert( pNos>=p->aStack );
  if( ((pTos->flags | pNos->flags) & MEM_Null)!=0 ){
    Release(pTos);
    pTos--;
    Release(pTos);
    pTos->flags = MEM_Null;
  }else if( (pTos->flags & pNos->flags & MEM_Int)==MEM_Int ){
    int a, b;
    a = pTos->i;
    b = pNos->i;
    switch( pOp->opcode ){
      case OP_Add:         b += a;       break;
      case OP_Subtract:    b -= a;       break;
      case OP_Multiply:    b *= a;       break;
      case OP_Divide: {
        if( a==0 ) goto divide_by_zero;
        b /= a;
        break;
      }
      default: {
        if( a==0 ) goto divide_by_zero;
        b %= a;
        break;
      }
    }
    Release(pTos);
    pTos--;
    Release(pTos);
    pTos->i = b;
    pTos->flags = MEM_Int;
  }else{
    double a, b;
    Realify(pTos);
    Realify(pNos);
    a = pTos->r;
    b = pNos->r;
    switch( pOp->opcode ){
      case OP_Add:         b += a;       break;
      case OP_Subtract:    b -= a;       break;
      case OP_Multiply:    b *= a;       break;
      case OP_Divide: {
        if( a==0.0 ) goto divide_by_zero;
        b /= a;
        break;
      }
      default: {
        int ia = (int)a;
        int ib = (int)b;
        if( ia==0.0 ) goto divide_by_zero;
        b = ib % ia;
        break;
      }
    }
    Release(pTos);
    pTos--;
    Release(pTos);
    pTos->r = b;
    pTos->flags = MEM_Real;
  }
  break;

divide_by_zero:
  Release(pTos);
  pTos--;
  Release(pTos);
  pTos->flags = MEM_Null;
  break;
}

/* Opcode: Function P1 * P3
**
** Invoke a user function (P3 is a pointer to a Function structure that
** defines the function) with P1 string arguments taken from the stack.
** Pop all arguments from the stack and push back the result.
**
** See also: AggFunc
*/
case OP_Function: {
  int n, i;
  Mem *pArg;
  char **azArgv;
  sqlite_func ctx;

  n = pOp->p1;
  pArg = &pTos[1-n];
  azArgv = p->zArgv;
  for(i=0; i<n; i++, pArg++){
    if( pArg->flags & MEM_Null ){
      azArgv[i] = 0;
    }else{
      Stringify(pArg);
      azArgv[i] = pArg->z;
    }
  }
  ctx.pFunc = (FuncDef*)pOp->p3;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.isError = 0;
  ctx.isStep = 0;
  if( sqliteSafetyOff(db) ) goto abort_due_to_misuse;
  (*ctx.pFunc->xFunc)(&ctx, n, (const char**)azArgv);
  if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
  popStack(&pTos, n);
  pTos++;
  *pTos = ctx.s;
  if( pTos->flags & MEM_Short ){
    pTos->z = pTos->zShort;
  }
  if( ctx.isError ){
    sqliteSetString(&p->zErrMsg, 
       (pTos->flags & MEM_Str)!=0 ? pTos->z : "user function error", (char*)0);
    rc = SQLITE_ERROR;
  }
  break;
}

/* Opcode: BitAnd * * *
**
** Pop the top two elements from the stack.  Convert both elements
** to integers.  Push back onto the stack the bit-wise AND of the
** two elements.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: BitOr * * *
**
** Pop the top two elements from the stack.  Convert both elements
** to integers.  Push back onto the stack the bit-wise OR of the
** two elements.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: ShiftLeft * * *
**
** Pop the top two elements from the stack.  Convert both elements
** to integers.  Push back onto the stack the top element shifted
** left by N bits where N is the second element on the stack.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: ShiftRight * * *
**
** Pop the top two elements from the stack.  Convert both elements
** to integers.  Push back onto the stack the top element shifted
** right by N bits where N is the second element on the stack.
** If either operand is NULL, the result is NULL.
*/
case OP_BitAnd:
case OP_BitOr:
case OP_ShiftLeft:
case OP_ShiftRight: {
  Mem *pNos = &pTos[-1];
  int a, b;

  assert( pNos>=p->aStack );
  if( (pTos->flags | pNos->flags) & MEM_Null ){
    popStack(&pTos, 2);
    pTos++;
    pTos->flags = MEM_Null;
    break;
  }
  Integerify(pTos);
  Integerify(pNos);
  a = pTos->i;
  b = pNos->i;
  switch( pOp->opcode ){
    case OP_BitAnd:      a &= b;     break;
    case OP_BitOr:       a |= b;     break;
    case OP_ShiftLeft:   a <<= b;    break;
    case OP_ShiftRight:  a >>= b;    break;
    default:   /* CANT HAPPEN */     break;
  }
  assert( (pTos->flags & MEM_Dyn)==0 );
  assert( (pNos->flags & MEM_Dyn)==0 );
  pTos--;
  Release(pTos);
  pTos->i = a;
  pTos->flags = MEM_Int;
  break;
}

/* Opcode: AddImm  P1 * *
** 
** Add the value P1 to whatever is on top of the stack.  The result
** is always an integer.
**
** To force the top of the stack to be an integer, just add 0.
*/
case OP_AddImm: {
  assert( pTos>=p->aStack );
  Integerify(pTos);
  pTos->i += pOp->p1;
  break;
}

/* Opcode: ForceInt P1 P2 *
**
** Convert the top of the stack into an integer.  If the current top of
** the stack is not numeric (meaning that is is a NULL or a string that
** does not look like an integer or floating point number) then pop the
** stack and jump to P2.  If the top of the stack is numeric then
** convert it into the least integer that is greater than or equal to its
** current value if P1==0, or to the least integer that is strictly
** greater than its current value if P1==1.
*/
case OP_ForceInt: {
  int v;
  assert( pTos>=p->aStack );
  if( (pTos->flags & (MEM_Int|MEM_Real))==0
         && ((pTos->flags & MEM_Str)==0 || sqliteIsNumber(pTos->z)==0) ){
    Release(pTos);
    pTos--;
    pc = pOp->p2 - 1;
    break;
  }
  if( pTos->flags & MEM_Int ){
    v = pTos->i + (pOp->p1!=0);
  }else{
    Realify(pTos);
    v = (int)pTos->r;
    if( pTos->r>(double)v ) v++;
    if( pOp->p1 && pTos->r==(double)v ) v++;
  }
  Release(pTos);
  pTos->i = v;
  pTos->flags = MEM_Int;
  break;
}

/* Opcode: MustBeInt P1 P2 *
** 
** Force the top of the stack to be an integer.  If the top of the
** stack is not an integer and cannot be converted into an integer
** with out data loss, then jump immediately to P2, or if P2==0
** raise an SQLITE_MISMATCH exception.
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped.  In all other cases, the depth
** of the stack is unchanged.
*/
case OP_MustBeInt: {
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Int ){
    /* Do nothing */
  }else if( pTos->flags & MEM_Real ){
    int i = (int)pTos->r;
    double r = (double)i;
    if( r!=pTos->r ){
      goto mismatch;
    }
    pTos->i = i;
  }else if( pTos->flags & MEM_Str ){
    int v;
    if( !toInt(pTos->z, &v) ){
      double r;
      if( !sqliteIsNumber(pTos->z) ){
        goto mismatch;
      }
      Realify(pTos);
      v = (int)pTos->r;
      r = (double)v;
      if( r!=pTos->r ){
        goto mismatch;
      }
    }
    pTos->i = v;
  }else{
    goto mismatch;
  }
  Release(pTos);
  pTos->flags = MEM_Int;
  break;

mismatch:
  if( pOp->p2==0 ){
    rc = SQLITE_MISMATCH;
    goto abort_due_to_error;
  }else{
    if( pOp->p1 ) popStack(&pTos, 1);
    pc = pOp->p2 - 1;
  }
  break;
}