SQLite

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**
** $Id: vdbe.c,v 1.340 2004/05/27 17:22:56 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

    pTail->pNext = pLeft;
  }else if( pRight ){
    pTail->pNext = pRight;
  }
  return sHead.pNext;
}

/*
** The following routine works like a replacement for the standard
** library routine fgets().  The difference is in how end-of-line (EOL)
** is handled.  Standard fgets() uses LF for EOL under unix, CRLF
** under windows, and CR under mac.  This routine accepts any of these
** character sequences as an EOL mark.  The EOL mark is replaced by
** a single LF character in zBuf.
*/
static char *vdbe_fgets(char *zBuf, int nBuf, FILE *in){
  int i, c;
  for(i=0; i<nBuf-1 && (c=getc(in))!=EOF; i++){
    zBuf[i] = c;
    if( c=='\r' || c=='\n' ){
      if( c=='\r' ){
        zBuf[i] = '\n';
        c = getc(in);
        if( c!=EOF && c!='\n' ) ungetc(c, in);
      }
      i++;
      break;
    }
  }
  zBuf[i]  = 0;
  return i>0 ? zBuf : 0;
}

/*
** Make sure there is space in the Vdbe structure to hold at least
** mxCursor cursors.  If there is not currently enough space, then
** allocate more.
**
** If a memory allocation error occurs, return 1.  Return 0 if
** everything works.

** next on the stack is used.  And so forth.  The value pushed is always
** just a pointer into the record which is stored further down on the
** stack.  The column value is not copied. The number of columns in the
** record is stored on the stack just above the record itself.
*/
case OP_Column: {
  int payloadSize;   /* Number of bytes in the record */
  int i = pOp->p1;
  int p2 = pOp->p2;  /* column number to retrieve */
  Cursor *pC = 0;
  char *zRec;        /* Pointer to record-data from stack or pseudo-table. */
  BtCursor *pCrsr;


  u64 nField;        /* number of fields in the record */

  int len;           /* The length of the serialized data for the column */
  int offset = 0;
  int nn;

  char *zData;       
  Mem sMem;
  sMem.flags = 0;


  assert( i<p->nCursor );
  pTos++;

  /* If the record is coming from the stack, not from a cursor, then there
  ** is nowhere to cache the record header infomation. This simplifies
  ** things greatly, so deal with this case seperately.
  */
  if( i<0 ){
    char *zRec;     /* Pointer to record data from the stack. */
    int off = 0;    /* Offset in zRec to start of the columns data. */
    int off2 = 0;   /* Offset in zRec to the next serial type to read */
    u64 colType;    /* The serial type of the value being read. */

    assert( &pTos[i-1]>=p->aStack );

    /* FIX ME: I don't understand this either. How is it related to
    ** OP_SortNext? (I thought it would be the commented out assert())
    */
    /* assert( pTos[i].flags & MEM_Blob ); */
    assert( pTos[i].flags & (MEM_Blob|MEM_Str) );
    assert( pTos[i-1].flags & MEM_Int );

    if( pTos[i].n==0 ){
      pTos->flags = MEM_Null;
      break;
    }

    zRec = pTos[i].z;
    nField = pTos[i-1].i;
     
    for( nn=0; nn<nField; nn++ ){
      u64 v;
      off2 += sqlite3GetVarint(&zRec[off2], &v);
      if( nn==p2 ){
        colType = v;
      }else if( nn<p2 ){
        off += sqlite3VdbeSerialTypeLen(v);
      }
    }
    off += off2;
    
    sqlite3VdbeSerialGet(&zRec[off], colType, pTos, p->db->enc);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    break;
  }


  /* This block sets the variable payloadSize, and if the data is coming
  ** from the stack or from a pseudo-table zRec. If the data is coming
  ** from a real cursor, then zRec is left as NULL.





  */










  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;
    }else if( pC->keyAsData ){
      i64 payloadSize64;
      sqlite3BtreeKeySize(pCrsr, &payloadSize64);
      payloadSize = payloadSize64;
    }else{
      sqlite3BtreeDataSize(pCrsr, &payloadSize);
    }

  }else if( pC->pseudoTable ){
    payloadSize = pC->nData;
    zRec = pC->pData;
    pC->cacheValid = 0;
    assert( payloadSize==0 || zRec!=0 );

  }else{
    payloadSize = 0;
  }

  /* If payloadSize is 0, then just push a NULL onto the stack. */
  if( payloadSize==0 ){
    pTos->flags = MEM_Null;
    break;
  }

  /* If the row data is coming from a cursor, then OP_SetNumColumns must of
  ** been executed on that cursor. Also, p2 (the column to read) must be
  ** less than nField.
  */
  assert( !pC || pC->nField>0 );
  assert( p2<pC->nField );
  nField = pC->nField;

  /* Read and parse the table header.  Store the results of the parse
  ** into the record header cache fields of the cursor.
  */
  if( !pC || !pC->cacheValid ){
    pC->payloadSize = payloadSize;
    if( !pC->aType ){


      pC->aType = sqliteMallocRaw( nField*sizeof(pC->aType[0]) );

      if( pC->aType==0 ){
        goto no_mem;
      }
    }

    if( zRec ){
      zData = zRec;
    }else{
      /* Estimate the maximum space required by the nField varints by
      ** assuming the maximum space for each is the length required to store:
      **
      **     (<record length> * 2) + 13
      **
      ** This is the serial-type for a text object as long as the record
      ** itself. In almost all cases the length required to store this is
      ** three bytes or less. 
      */
      int max_space = sqlite3VarintLen((((u64)payloadSize)<<1)+13)*nField;
      if( max_space>payloadSize ){
        max_space = payloadSize;




      }





      rc = getBtreeMem(pCrsr, 0, max_space, pC->keyAsData, &sMem);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      zData = sMem.z;
    }


    /* Read all the serial types for the record.  At the end of this block
    ** variable offset is set to the offset to the start of Data0 in the record.

    */


    for(nn=0; nn<nField; nn++){

      offset += sqlite3GetVarint(&zData[offset], &pC->aType[nn]);
    }
    pC->nHeader = offset;
    pC->cacheValid = 1;


    Release(&sMem);
    sMem.flags = 0;
  }

  /* Compute the offset from the beginning of the record to the beginning
  ** of the data.  And get the length of the data.

  */
  offset = pC->nHeader;





  for(nn=0; nn<p2; nn++){




    offset += sqlite3VdbeSerialTypeLen(pC->aType[nn]);


  }




  if( zRec ){
    zData = &zRec[offset];
  }else{
    len = sqlite3VdbeSerialTypeLen(pC->aType[p2]);
    getBtreeMem(pCrsr, offset, len, pC->keyAsData, &sMem);
    zData = sMem.z;
  }
  sqlite3VdbeSerialGet(zData, pC->aType[p2], pTos, p->db->enc);
  if( rc!=SQLITE_OK ){
    goto abort_due_to_error;
  }


  Release(&sMem);



  break;
}

/* Opcode MakeRecord P1 * P3
**
** This opcode (not yet in use) is a replacement for the current
** OP_MakeRecord that supports the SQLite3 manifest typing feature.
** It drops the (P2==1) option that was never use.
**
** Convert the top P1 entries of the stack into a single entry
** suitable for use as a data record in a database table.  The
** details of the format are irrelavant as long as the OP_Column
** opcode can decode the record later.  Refer to source code
** comments for the details of the record format.
**
** P3 may be a string that is P1 characters long.  The nth character of the

** If P3 is NULL then all index fields have the affinity NONE.
*/
case OP_MakeRecord: {
  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** --------------------------------------------------------------------------
  ** | num-fields | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** --------------------------------------------------------------------------
  **
  ** Data(0) is taken from the lowest element of the stack and data(N-1) is
  ** the top of the stack.
  **
  ** Each type field is a varint representing the serial type of the 
  ** corresponding data element (see sqlite3VdbeSerialType()). The
  ** num-fields field is also a varint storing N.
  ** 
  ** TODO: Even when the record is short enough for Mem::zShort, this opcode
  **   allocates it dynamically.
  */
  int nField = pOp->p1;
  unsigned char *zNewRecord;
  unsigned char *zCsr;
  char *zAffinity;
  Mem *pRec;


  int nBytes = 0;    /* Space required for this record */

  Mem *pData0 = &pTos[1-nField];
  assert( pData0>=p->aStack );
  zAffinity = pOp->p3;

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */
  for(pRec=pData0; pRec<=pTos; pRec++){
    u64 serial_type;
    if( zAffinity ){
      applyAffinity(pRec, zAffinity[pRec-pData0], db->enc);
    }
    serial_type = sqlite3VdbeSerialType(pRec);
    nBytes += sqlite3VdbeSerialTypeLen(serial_type);
    nBytes += sqlite3VarintLen(serial_type);
  }



  if( nBytes>MAX_BYTES_PER_ROW ){
    rc = SQLITE_TOOBIG;
    goto abort_due_to_error;
  }

  /* Allocate space for the new record. */
  zNewRecord = sqliteMallocRaw(nBytes);
  if( !zNewRecord ){
    goto no_mem;
  }

  /* Write the record */
  zCsr = zNewRecord;

  for(pRec=pData0; pRec<=pTos; pRec++){
    u64 serial_type = sqlite3VdbeSerialType(pRec);
    zCsr += sqlite3PutVarint(zCsr, serial_type);      /* serial type */
  }
  for(pRec=pData0; pRec<=pTos; pRec++){
    zCsr += sqlite3VdbeSerialPut(zCsr, pRec);  /* serial data */
  }

  /* If zCsr has not been advanced exactly nBytes bytes, then one
  ** of the sqlite3PutVarint() or sqlite3VdbeSerialPut() calls above
  ** failed. This indicates a corrupted memory cell or code bug.
  */
  if( zCsr!=(zNewRecord+nBytes) ){
    rc = SQLITE_INTERNAL;
    goto abort_due_to_error;
  }

  /* Pop nField entries from the stack and push the new entry on */
  popStack(&pTos, nField);
  pTos++;
  pTos->n = nBytes;
  pTos->z = zNewRecord;
  pTos->flags = MEM_Blob | MEM_Dyn;

  break;
}

/* Opcode: MakeKey P1 P2 P3

  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
  Btree *pBt;           /* Separate file holding temporary table */
  int nData;            /* Number of bytes in pData */
  char *pData;          /* Data for a NEW or OLD pseudo-table */
  i64 iKey;             /* Key for the NEW or OLD pseudo-table row */
  u8 *pIncrKey;         /* Pointer to pKeyInfo->incrKey */
  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */


  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to */
  Bool cacheValid;      /* True if the cache is valid */
  int nField;           /* Number of fields in the header */
  int nHeader;          /* Number of bytes in the entire header */
  int payloadSize;      /* Total number of bytes in the record */
  u64 *aType;           /* Type values for all entries in the record */

};
typedef struct Cursor Cursor;

/*
** A sorter builds a list of elements to be sorted.  Each element of
** the list is an instance of the following structure.
*/

int sqlite3VdbeMemDynamicify(Mem*);
int sqlite3VdbeMemStringify(Mem*, int);
int sqlite3VdbeMemIntegerify(Mem*);
int sqlite3VdbeMemRealify(Mem*);
#ifndef NDEBUG
void sqlite3VdbeMemSanity(Mem*, u8);
#endif

*/
int sqlite3VdbeRowCompare(
  void *userData,
  int nKey1, const void *pKey1, 
  int nKey2, const void *pKey2
){
  KeyInfo *pKeyInfo = (KeyInfo*)userData;
  int offset1 = 0;
  int offset2 = 0;
  int toffset1 = 0;
  int toffset2 = 0;
  int i;
  u8 enc = pKeyInfo->enc;
  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  const unsigned char *aKey2 = (const unsigned char *)pKey2;

  assert( pKeyInfo );
  assert( pKeyInfo->nField>0 );

  for( i=0; i<pKeyInfo->nField; i++ ){
    u64 dummy;
    offset1 += sqlite3GetVarint(&aKey1[offset1], &dummy);
    offset2 += sqlite3GetVarint(&aKey1[offset1], &dummy);
  }

  for( i=0; i<pKeyInfo->nField; i++ ){

    Mem mem1;
    Mem mem2;
    u64 serial_type1;
    u64 serial_type2;
    int rc;

    /* Read the serial types for the next element in each key. */
    toffset1 += sqlite3GetVarint(&aKey1[toffset1], &serial_type1);
    toffset2 += sqlite3GetVarint(&aKey2[toffset2], &serial_type2);

    assert( serial_type1 && serial_type2 );

    /* Assert that there is enough space left in each key for the blob of
    ** data to go with the serial type just read. This assert may fail if
    ** the file is corrupted.  Then read the value from each key into mem1
    ** and mem2 respectively.
    */
    offset1 += sqlite3VdbeSerialGet(&aKey1[offset1], serial_type1, &mem1, enc);
    offset2 += sqlite3VdbeSerialGet(&aKey2[offset2], serial_type2, &mem2, enc);

    rc = sqlite3MemCompare(&mem1, &mem2, pKeyInfo->aColl[i]);
    if( mem1.flags&MEM_Dyn ){
      sqliteFree(mem1.z);
    }
    if( mem2.flags&MEM_Dyn ){
      sqliteFree(mem2.z);
    }
    if( rc!=0 ){




      return rc;












    }
  }





  return 0;
}
  

/*
** pCur points at an index entry. Read the rowid (varint occuring at
** the end of the entry and store it in *rowid. Return SQLITE_OK if
** everything works, or an error code otherwise.

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library. Specfically
# it tests that the different storage classes (integer, real, text etc.)
# all work correctly.
#
# $Id: types.test,v 1.6 2004/05/24 12:55:55 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Tests in this file are organized roughly as follows:
#
# types-1.*.*: Test that values are stored using the expected storage

} [list 0 120 -120 30000 -30000 2100000000 -2100000000 \
        9000000000000000000 -9000000000000000000]

# Check that all the record sizes are as we expected.
do_test types-2.1.9 {
  set root [db eval {select rootpage from sqlite_master where name = 't1'}]
  record_sizes $root
} {2 2 2 3 3 5 5 9 9}

# Insert some reals. These should be 10 byte records.
do_test types-2.2.1 {
  execsql {
    CREATE TABLE t2(a float);
    INSERT INTO t2 VALUES(0.0);
    INSERT INTO t2 VALUES(12345.678);
    INSERT INTO t2 VALUES(-12345.678);
  }
} {}
do_test types-2.2.2 {
  execsql {
    SELECT a FROM t2;
  }
} {0 12345.678 -12345.678}

# Check that all the record sizes are as we expected.
do_test types-2.2.3 {
  set root [db eval {select rootpage from sqlite_master where name = 't2'}]
  record_sizes $root
} {9 9 9}

# Insert a NULL. This should be a two byte record.
do_test types-2.3.1 {
  execsql {
    CREATE TABLE t3(a nullvalue);
    INSERT INTO t3 VALUES(NULL);
  }
} {}
do_test types-2.3.2 {
  execsql {
    SELECT a ISNULL FROM t3;
  }
} {1}

# Check that all the record sizes are as we expected.
do_test types-2.3.3 {
  set root [db eval {select rootpage from sqlite_master where name = 't3'}]
  record_sizes $root
} {1}

# Insert a couple of strings.
do_test types-2.4.1 {
  set string10 abcdefghij
  set string500 [string repeat $string10 50]
  set string500000 [string repeat $string10 50000]

  }
} [list $string10 $string500 $string500000]

# Check that all the record sizes are as we expected.
do_test types-2.4.3 {
  set root [db eval {select rootpage from sqlite_master where name = 't4'}]
  record_sizes $root
} {11 502 500003}

do_test types-2.5.1 {
  execsql {
    DROP TABLE t1;
    DROP TABLE t2;
    DROP TABLE t3;
    DROP TABLE t4;