vdbe.c

最新的sqlite3.6.2源代码

  }else{
    rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
  }
  goto vdbe_return;
}

/* Opcode: Integer P1 P2 * * *
**
** The 32-bit integer value P1 is written into register P2.
*/
case OP_Integer: {         /* out2-prerelease */
  pOut->flags = MEM_Int;
  pOut->u.i = pOp->p1;
  break;
}

/* Opcode: Int64 * P2 * P4 *
**
** P4 is a pointer to a 64-bit integer value.
** Write that value into register P2.
*/
case OP_Int64: {           /* out2-prerelease */
  assert( pOp->p4.pI64!=0 );
  pOut->flags = MEM_Int;
  pOut->u.i = *pOp->p4.pI64;
  break;
}

/* Opcode: Real * P2 * P4 *
**
** P4 is a pointer to a 64-bit floating point value.
** Write that value into register P2.
*/
case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
  pOut->flags = MEM_Real;
  assert( !sqlite3IsNaN(*pOp->p4.pReal) );
  pOut->r = *pOp->p4.pReal;
  break;
}

/* Opcode: String8 * P2 * P4 *
**
** P4 points to a nul terminated UTF-8 string. This opcode is transformed 
** into an OP_String before it is executed for the first time.
*/
case OP_String8: {         /* same as TK_STRING, out2-prerelease */
  assert( pOp->p4.z!=0 );
  pOp->opcode = OP_String;
  pOp->p1 = strlen(pOp->p4.z);

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemMakeWriteable(pOut) ) goto no_mem;
    pOut->zMalloc = 0;
    pOut->flags |= MEM_Static;
    pOut->flags &= ~MEM_Dyn;
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3DbFree(db, pOp->p4.z);
    }
    pOp->p4type = P4_DYNAMIC;
    pOp->p4.z = pOut->z;
    pOp->p1 = pOut->n;
    if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    UPDATE_MAX_BLOBSIZE(pOut);
    break;
  }
#endif
  if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
    goto too_big;
  }
  /* Fall through to the next case, OP_String */
}
  
/* Opcode: String P1 P2 * P4 *
**
** The string value P4 of length P1 (bytes) is stored in register P2.
*/
case OP_String: {          /* out2-prerelease */
  assert( pOp->p4.z!=0 );
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = pOp->p4.z;
  pOut->n = pOp->p1;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Null * P2 * * *
**
** Write a NULL into register P2.
*/
case OP_Null: {           /* out2-prerelease */
  break;
}


#ifndef SQLITE_OMIT_BLOB_LITERAL
/* Opcode: Blob P1 P2 * P4
**
** P4 points to a blob of data P1 bytes long.  Store this
** blob in register P2. This instruction is not coded directly
** by the compiler. Instead, the compiler layer specifies
** an OP_HexBlob opcode, with the hex string representation of
** the blob as P4. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {                /* out2-prerelease */
  assert( pOp->p1 <= SQLITE_MAX_LENGTH );
  sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 P2 * * *
**
** The value of variable P1 is written into register P2. A variable is
** an unknown in the original SQL string as handed to sqlite3_compile().
** Any occurrence of the '?' character in the original SQL is considered
** a variable.  Variables in the SQL string are number from left to
** right beginning with 1.  The values of variables are set using the
** sqlite3_bind() API.
*/
case OP_Variable: {           /* out2-prerelease */
  int j = pOp->p1 - 1;
  Mem *pVar;
  assert( j>=0 && j<p->nVar );

  pVar = &p->aVar[j];
  if( sqlite3VdbeMemTooBig(pVar) ){
    goto too_big;
  }
  sqlite3VdbeMemShallowCopy(pOut, &p->aVar[j], MEM_Static);
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Move P1 P2 P3 * *
**
** Move the values in register P1..P1+P3-1 over into
** registers P2..P2+P3-1.  Registers P1..P1+P1-1 are
** left holding a NULL.  It is an error for register ranges
** P1..P1+P3-1 and P2..P2+P3-1 to overlap.
*/
case OP_Move: {
  char *zMalloc;
  int n = pOp->p3;
  int p1 = pOp->p1;
  int p2 = pOp->p2;
  assert( n>0 );
  assert( p1>0 );
  assert( p1+n<p->nMem );
  pIn1 = &p->aMem[p1];
  assert( p2>0 );
  assert( p2+n<p->nMem );
  pOut = &p->aMem[p2];
  assert( p1+n<=p2 || p2+n<=p1 );
  while( n-- ){
    zMalloc = pOut->zMalloc;
    pOut->zMalloc = 0;
    sqlite3VdbeMemMove(pOut, pIn1);
    pIn1->zMalloc = zMalloc;
    REGISTER_TRACE(p2++, pOut);
    pIn1++;
    pOut++;
  }
  break;
}

/* Opcode: Copy P1 P2 * * *
**
** Make a copy of register P1 into register P2.
**
** This instruction makes a deep copy of the value.  A duplicate
** is made of any string or blob constant.  See also OP_SCopy.
*/
case OP_Copy: {
  assert( pOp->p1>0 );
  assert( pOp->p1<=p->nMem );
  pIn1 = &p->aMem[pOp->p1];
  assert( pOp->p2>0 );
  assert( pOp->p2<=p->nMem );
  pOut = &p->aMem[pOp->p2];
  assert( pOut!=pIn1 );
  sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
  Deephemeralize(pOut);
  REGISTER_TRACE(pOp->p2, pOut);
  break;
}

/* Opcode: SCopy P1 P2 * * *
**
** Make a shallow copy of register P1 into register P2.
**
** This instruction makes a shallow copy of the value.  If the value
** is a string or blob, then the copy is only a pointer to the
** original and hence if the original changes so will the copy.
** Worse, if the original is deallocated, the copy becomes invalid.
** Thus the program must guarantee that the original will not change
** during the lifetime of the copy.  Use OP_Copy to make a complete
** copy.
*/
case OP_SCopy: {
  assert( pOp->p1>0 );
  assert( pOp->p1<=p->nMem );
  pIn1 = &p->aMem[pOp->p1];
  REGISTER_TRACE(pOp->p1, pIn1);
  assert( pOp->p2>0 );
  assert( pOp->p2<=p->nMem );
  pOut = &p->aMem[pOp->p2];
  assert( pOut!=pIn1 );
  sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
  REGISTER_TRACE(pOp->p2, pOut);
  break;
}

/* Opcode: ResultRow P1 P2 * * *
**
** The registers P1 through P1+P2-1 contain a single row of
** results. This opcode causes the sqlite3_step() call to terminate
** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
** structure to provide access to the top P1 values as the result
** row.
*/
case OP_ResultRow: {
  Mem *pMem;
  int i;
  assert( p->nResColumn==pOp->p2 );
  assert( pOp->p1>0 );
  assert( pOp->p1+pOp->p2<=p->nMem );

  /* Invalidate all ephemeral cursor row caches */
  p->cacheCtr = (p->cacheCtr + 2)|1;

  /* Make sure the results of the current row are \000 terminated
  ** and have an assigned type.  The results are de-ephemeralized as
  ** as side effect.
  */
  pMem = p->pResultSet = &p->aMem[pOp->p1];
  for(i=0; i<pOp->p2; i++){
    sqlite3VdbeMemNulTerminate(&pMem[i]);
    storeTypeInfo(&pMem[i], encoding);
    REGISTER_TRACE(pOp->p1+i, &pMem[i]);
  }
  if( db->mallocFailed ) goto no_mem;

  /* Return SQLITE_ROW
  */
  p->nCallback++;
  p->pc = pc + 1;
  rc = SQLITE_ROW;
  goto vdbe_return;
}

/* Opcode: Concat P1 P2 P3 * *
**
** Add the text in register P1 onto the end of the text in
** register P2 and store the result in register P3.
** If either the P1 or P2 text are NULL then store NULL in P3.
**
**   P3 = P2 || P1
**
** It is illegal for P1 and P3 to be the same register. Sometimes,
** if P3 is the same register as P2, the implementation is able
** to avoid a memcpy().
*/
case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
  i64 nByte;

  assert( pIn1!=pOut );
  if( (pIn1->flags | pIn2->flags) & MEM_Null ){
    sqlite3VdbeMemSetNull(pOut);
    break;
  }
  ExpandBlob(pIn1);
  Stringify(pIn1, encoding);
  ExpandBlob(pIn2);
  Stringify(pIn2, encoding);
  nByte = pIn1->n + pIn2->n;
  if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
    goto too_big;
  }
  MemSetTypeFlag(pOut, MEM_Str);
  if( sqlite3VdbeMemGrow(pOut, nByte+2, pOut==pIn2) ){
    goto no_mem;
  }
  if( pOut!=pIn2 ){
    memcpy(pOut->z, pIn2->z, pIn2->n);
  }
  memcpy(&pOut->z[pIn2->n], pIn1->z, pIn1->n);
  pOut->z[nByte] = 0;
  pOut->z[nByte+1] = 0;
  pOut->flags |= MEM_Term;
  pOut->n = nByte;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Add P1 P2 P3 * *
**
** Add the value in register P1 to the value in register P2
** and store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Multiply P1 P2 P3 * *
**
**
** Multiply the value in register P1 by the value in register P2
** and store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Subtract P1 P2 P3 * *
**
** Subtract the value in register P1 from the value in register P2
** and store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Divide P1 P2 P3 * *
**
** Divide the value in register P1 by the value in register P2
** and store the result in register P3.  If the value in register P2
** is zero, then the result is NULL.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Remainder P1 P2 P3 * *
**
** Compute the remainder after integer division of the value in
** register P1 by the value in register P2 and store the result in P3. 
** If the value in register P2 is zero the result is NULL.
** If either operand is NULL, the result is NULL.
*/
case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */
case OP_Subtract:              /* same as TK_MINUS, in1, in2, out3 */
case OP_Multiply:              /* same as TK_STAR, in1, in2, out3 */
case OP_Divide:                /* same as TK_SLASH, in1, in2, out3 */
case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */
  int flags;
  applyNumericAffinity(pIn1);
  applyNumericAffinity(pIn2);
  flags = pIn1->flags | pIn2->flags;
  if( (flags & MEM_Null)!=0 ) goto arithmetic_result_is_null;
  if( (pIn1->flags & pIn2->flags & MEM_Int)==MEM_Int ){
    i64 a, b;
    a = pIn1->u.i;
    b = pIn2->u.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 arithmetic_result_is_null;
        /* Dividing the largest possible negative 64-bit integer (1<<63) by 
        ** -1 returns an integer too large to store in a 64-bit data-type. On
        ** some architectures, the value overflows to (1<<63). On others,
        ** a SIGFPE is issued. The following statement normalizes this
        ** behavior so that all architectures behave as if integer 
        ** overflow occurred.
        */
        if( a==-1 && b==SMALLEST_INT64 ) a = 1;
        b /= a;
        break;
      }
      default: {
        if( a==0 ) goto arithmetic_result_is_null;
        if( a==-1 ) a = 1;
        b %= a;
        break;
      }
    }
    pOut->u.i = b;
    MemSetTypeFlag(pOut, MEM_Int);
  }else{
    double a, b;
    a = sqlite3VdbeRealValue(pIn1);
    b = sqlite3VdbeRealValue(pIn2);
    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 arithmetic_result_is_null;
        b /= a;
        break;
      }
      default: {
        i64 ia = (i64)a;
        i64 ib = (i64)b;
        if( ia==0 ) goto arithmetic_result_is_null;
        if( ia==-1 ) ia = 1;
        b = ib % ia;
        break;
      }
    }
    if( sqlite3IsNaN(b) ){
      goto arithmetic_result_is_null;
    }
    pOut->r = b;
    MemSetTypeFlag(pOut, MEM_Real);
    if( (flags & MEM_Real)==0 ){
      sqlite3VdbeIntegerAffinity(pOut);
    }
  }
  break;

arithmetic_result_is_null:
  sqlite3VdbeMemSetNull(pOut);
  break;
}

/* Opcode: CollSeq * * P4
**
** P4 is a pointer to a CollSeq struct. If the next call to a user function
** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
** be returned. This is used by the built-in min(), max() and nullif()