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Overview
Comment:Slightly smaller and faster implementation of the OP_MakeRecord opcode.
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SHA3-256: 3bdce7ef1a6bb03affe978243fec603d5a55c071aa6d87c469a3c199d23f3b5e
User & Date: drh 2019-04-30 01:08:42.471
Context
2019-04-30
11:54
Small performance increase and size reduction in the implementation of the LIKE and GLOB operators. (check-in: f97626f921 user: drh tags: trunk)
01:08
Slightly smaller and faster implementation of the OP_MakeRecord opcode. (check-in: 3bdce7ef1a user: drh tags: trunk)
2019-04-29
16:44
Changes to oserror.test so that it works even on systems that allow an unusually large number of file descriptors. (check-in: a27b0b880d user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/vdbe.c.
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**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P4 is NULL then all index fields have the affinity BLOB.
*/
case OP_MakeRecord: {
  u8 *zNewRecord;        /* A buffer to hold the data for the new record */
  Mem *pRec;             /* The new record */
  u64 nData;             /* Number of bytes of data space */
  int nHdr;              /* Number of bytes of header space */
  i64 nByte;             /* Data space required for this record */
  i64 nZero;             /* Number of zero bytes at the end of the record */
  int nVarint;           /* Number of bytes in a varint */
  u32 serial_type;       /* Type field */
  Mem *pData0;           /* First field to be combined into the record */
  Mem *pLast;            /* Last field of the record */
  int nField;            /* Number of fields in the record */
  char *zAffinity;       /* The affinity string for the record */
  int file_format;       /* File format to use for encoding */
  int i;                 /* Space used in zNewRecord[] header */
  int j;                 /* Space used in zNewRecord[] content */
  u32 len;               /* Length of a field */



  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------








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**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P4 is NULL then all index fields have the affinity BLOB.
*/
case OP_MakeRecord: {

  Mem *pRec;             /* The new record */
  u64 nData;             /* Number of bytes of data space */
  int nHdr;              /* Number of bytes of header space */
  i64 nByte;             /* Data space required for this record */
  i64 nZero;             /* Number of zero bytes at the end of the record */
  int nVarint;           /* Number of bytes in a varint */
  u32 serial_type;       /* Type field */
  Mem *pData0;           /* First field to be combined into the record */
  Mem *pLast;            /* Last field of the record */
  int nField;            /* Number of fields in the record */
  char *zAffinity;       /* The affinity string for the record */
  int file_format;       /* File format to use for encoding */


  u32 len;               /* Length of a field */
  u8 *zHdr;              /* Where to write next byte of the header */
  u8 *zPayload;          /* Where to write next byte of the payload */

  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
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    if( nByte+nZero>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    if( sqlite3VdbeMemClearAndResize(pOut, (int)nByte) ){
      goto no_mem;
    }
  }







  zNewRecord = (u8 *)pOut->z;


  /* Write the record */
  i = putVarint32(zNewRecord, nHdr);
  j = nHdr;
  assert( pData0<=pLast );
  pRec = pData0;
  do{
    serial_type = pRec->uTemp;
    /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more
    ** additional varints, one per column. */
    i += putVarint32(&zNewRecord[i], serial_type);            /* serial type */
    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
    ** immediately follow the header. */
    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
  }while( (++pRec)<=pLast );
  assert( i==nHdr );
  assert( j==nByte );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  pOut->n = (int)nByte;
  pOut->flags = MEM_Blob;
  if( nZero ){
    pOut->u.nZero = nZero;
    pOut->flags |= MEM_Zero;
  }
  REGISTER_TRACE(pOp->p3, pOut);
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Count P1 P2 * * *
** Synopsis: r[P2]=count()
**
** Store the number of entries (an integer value) in the table or index 








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    if( nByte+nZero>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    if( sqlite3VdbeMemClearAndResize(pOut, (int)nByte) ){
      goto no_mem;
    }
  }
  pOut->n = (int)nByte;
  pOut->flags = MEM_Blob;
  if( nZero ){
    pOut->u.nZero = nZero;
    pOut->flags |= MEM_Zero;
  }
  UPDATE_MAX_BLOBSIZE(pOut);
  zHdr = (u8 *)pOut->z;
  zPayload = zHdr + nHdr;

  /* Write the record */
  zHdr += putVarint32(zHdr, nHdr);

  assert( pData0<=pLast );
  pRec = pData0;
  do{
    serial_type = pRec->uTemp;
    /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more
    ** additional varints, one per column. */
    zHdr += putVarint32(zHdr, serial_type);            /* serial type */
    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
    ** immediately follow the header. */
    zPayload += sqlite3VdbeSerialPut(zPayload, pRec, serial_type); /* content */
  }while( (++pRec)<=pLast );
  assert( nHdr==(int)(zHdr - (u8*)pOut->z) );
  assert( nByte==(int)(zPayload - (u8*)pOut->z) );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );






  REGISTER_TRACE(pOp->p3, pOut);

  break;
}

/* Opcode: Count P1 P2 * * *
** Synopsis: r[P2]=count()
**
** Store the number of entries (an integer value) in the table or index
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