**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $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
................................................................................
  **   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

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.341 2004/05/27 19:59:32 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;
}



























/*
** 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 p1 = pOp->p1;  /* P1 value of the opcode */
  int p2 = pOp->p2;  /* column number to retrieve */
  Cursor *pC = 0;    /* The VDBE cursor */
  char *zRec;        /* Pointer to record-data from stack or pseudo-table. */
  BtCursor *pCrsr;   /* The BTree cursor */

  u32 *aType;        /* aType[i] holds the numeric type of the i-th column */
  u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
  u64 nField;        /* number of fields in the record */
  u32 szHdr;         /* Number of bytes in the record header */
  int len;           /* The length of the serialized data for the column */
  int offset = 0;    /* Offset into the data */

  int idx;           /* Index into the header */
  int i;             /* Loop counter */
  char *zData;       /* Part of the record being decoded */
  Mem sMem;          /* For storing the record being decoded */



  sMem.flags = 0;

  assert( p1<p->nCursor );
  pTos++;















































  /* 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.
  **
  ** We also compute the number of columns in the record.  For cursors,
  ** the number of columns is stored in the Cursor.nField element.  For
  ** records on the stack, the next entry down on the stack is an integer
  ** which is the number of records.
  */
  if( p1<0 ){
    Mem *pRec = &pTos[p1];
    Mem *pCnt = &pRec[-1];
    assert( pRec>=p->aStack );
    assert( pRec->flags & MEM_Blob );
    payloadSize = pRec->n;
    zRec = pRec->z;
    assert( pCnt>=p->aStack );
    assert( pCnt->flags & MEM_Int );
    nField = pCnt->i;
  }else if( (pC = p->apCsr[p1])->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);
    }
    nField = pC->nField;
  }else if( pC->pseudoTable ){
    payloadSize = pC->nData;
    zRec = pC->pData;
    pC->cacheValid = 0;
    assert( payloadSize==0 || zRec!=0 );
    nField = pC->nField;
  }else{
    payloadSize = 0;
  }

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






  assert( p2<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 ){

    aType = pC->aType;
    aOffset = pC->aOffset;
  }else{
    aType = sqliteMallocRaw( 2*nField*sizeof(aType) );
    aOffset = &aType[nField];
    if( aType==0 ){
      goto no_mem;
    }


    /* Figure out how many bytes are in the header */
    if( zRec ){
      zData = zRec;
    }else{
      int sz = payloadSize<5 ? payloadSize : 5;
      if( pC->keyAsData ){
        zData = (char*)sqlite3BtreeKeyFetch(pCrsr, sz);
      }else{
        zData = (char*)sqlite3BtreeDataFetch(pCrsr, sz);
      }
    }
    idx = sqlite3GetVarint32(zData, &szHdr);

    /* Get the complete header text */
    if( !zRec ){
      rc = getBtreeMem(pCrsr, 0, szHdr, pC->keyAsData, &sMem);



      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      zData = sMem.z;
    }

    /* Scan the header and use it to fill in the aType[] and aOffset[]
    ** arrays.  aType[i] will contain the type integer for the i-th
    ** column and aOffset[i] will contain the offset from the beginning
    ** of the record to the start of the data for the i-th column
    */



    offset = szHdr;
    i = 0;
    while( idx<szHdr && i<nField && offset<=payloadSize ){
      aOffset[i] = offset;

      idx += sqlite3GetVarint32(&zData[idx], &aType[i]);
      offset += sqlite3VdbeSerialTypeLen(aType[i]);
      i++;
    }
    Release(&sMem);
    sMem.flags = MEM_Null;




    /* The header should end at the start of data and the data should
    ** end at last byte of the record. If this is not the case then
    ** we are dealing with a malformed record.
    */
    if( idx!=szHdr || offset!=payloadSize ){
      sqliteFree(aType);
      if( pC ) pC->aType = 0;
      rc = SQLITE_CORRUPT;
      break;
    }

    /* Remember all aType and aColumn information if we have a cursor
    ** to remember it in. */
    if( pC ){
      pC->payloadSize = payloadSize;
      pC->aType = aType;
      pC->aOffset = aOffset;


      pC->cacheValid = 1;
    }
  }

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

  Release(&sMem);

  /* Release the aType[] memory if we are not dealing with cursor */
  if( !pC ){
    sqliteFree(aType);
  }
  break;
}

/* Opcode MakeRecord P1 * P3
**




** 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:
  **
  ** --------------------------------------------------------------------------
  ** | header-siz | 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
................................................................................
  **   allocates it dynamically.
  */
  int nField = pOp->p1;
  unsigned char *zNewRecord;
  unsigned char *zCsr;
  char *zAffinity;
  Mem *pRec;
  int nData = 0;     /* Number of bytes of data space */
  int nHdr = 0;      /* Number of bytes of header space */
  int nByte = 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);
    nData += sqlite3VdbeSerialTypeLen(serial_type);
    nHdr += sqlite3VarintLen(serial_type);
  }
  nHdr += sqlite3VarintLen(nHdr);
  nByte = nHdr+nData;

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

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

  /* Write the record */
  zCsr = zNewRecord;
  zCsr += sqlite3PutVarint(zCsr, nHdr);
  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 nByte bytes, then one
  ** of the sqlite3PutVarint() or sqlite3VdbeSerialPut() calls above
  ** failed. This indicates a corrupted memory cell or code bug.
  */
  if( zCsr!=(zNewRecord+nByte) ){
    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 = nByte;
  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

  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 */
  int nField;           /* Number of fields in the header */

  /* 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 payloadSize;      /* Total number of bytes in the record */
  u32 *aType;           /* Type values for all entries in the record */
  u32 *aOffset;         /* Cached offsets to the start of each columns data */
};
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.

*/
int sqlite3VdbeRowCompare(
  void *userData,
  int nKey1, const void *pKey1, 
  int nKey2, const void *pKey2
){
  KeyInfo *pKeyInfo = (KeyInfo*)userData;
  u32 d1, d2;          /* Offset into aKey[] of next data element */
  u32 idx1, idx2;      /* Offset into aKey[] of next header element */
  u32 szHdr1, szHdr2;  /* Number of bytes in header */
  int i = 0;
  int nField;
  int rc = 0;
  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  const unsigned char *aKey2 = (const unsigned char *)pKey2;
  





  idx1 = sqlite3GetVarint32(pKey1, &szHdr1);
  d1 = szHdr1;
  idx2 = sqlite3GetVarint32(pKey2, &szHdr2);


  d2 = szHdr2;
  nField = pKeyInfo->nField;
  while( idx1<szHdr1 && idx2<szHdr2 && d1<nKey1 && d2<nKey2 && i<nField ){
    Mem mem1;
    Mem mem2;
    u32 serial_type1;
    u32 serial_type2;


    /* Read the serial types for the next element in each key. */




    idx1 += sqlite3GetVarint32(&aKey1[idx1], &serial_type1);
    idx2 += sqlite3GetVarint32(&aKey2[idx2], &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.
    */
    d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1, 0);
    d2 += sqlite3VdbeSerialGet(&aKey2[d2], serial_type2, &mem2, 0);

    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 ){
      break;
    }
    i++;
  }

  /* One of the keys ran out of fields, but all the fields up to that point
  ** were equal. If the incrKey flag is true, then the second key is
  ** treated as larger.
  */
  if( rc==0 ){
    if( pKeyInfo->incrKey ){
      assert( d2==nKey2 );
      rc = -1;
    }else if( d1<nKey1 ){
      rc = 1;
    }else if( d2<nKey2 ){
      rc = -1;
    }
  }

  if( pKeyInfo->aSortOrder && i<pKeyInfo->nField && pKeyInfo->aSortOrder[i] ){
    rc = -rc;
  }

  return rc;
}
  

/*
** 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);
................................................................................
  }
} {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);
  }
................................................................................
  }
} {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;

#    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 1.7 2004/05/27 19:59:33 drh 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
} {3 3 3 4 4 6 6 10 10}

# 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);
................................................................................
  }
} {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
} {10 10 10}

# 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);
  }
................................................................................
  }
} {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
} {2}

# 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
} {12 503 500004}

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