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Overview
Comment:Performance improvement in sqlite3StrAccumFinish() for the common case where no memory allocation is required.
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SHA1: b6acf5d4ef016326a079463e70e71c2fc95a352d
User & Date: drh 2016-11-25 15:11:26.619
Context
2016-11-25
15:47
Performance enhancement to sqlite3_snprintf(). (check-in: c53dca7fad user: drh tags: trunk)
15:11
Performance improvement in sqlite3StrAccumFinish() for the common case where no memory allocation is required. (check-in: b6acf5d4ef user: drh tags: trunk)
14:30
Add a comment to help clarify the EP_FromJoin hack in exprCodeBetween(). (check-in: 6df7c5747e user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/printf.c.
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/*
** Finish off a string by making sure it is zero-terminated.
** Return a pointer to the resulting string.  Return a NULL
** pointer if any kind of error was encountered.
*/











char *sqlite3StrAccumFinish(StrAccum *p){
  if( p->zText ){
    assert( (p->zText==p->zBase)==!isMalloced(p) );
    p->zText[p->nChar] = 0;
    if( p->mxAlloc>0 && !isMalloced(p) ){
      p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
      if( p->zText ){
        memcpy(p->zText, p->zBase, p->nChar+1);
        p->printfFlags |= SQLITE_PRINTF_MALLOCED;
      }else{
        setStrAccumError(p, STRACCUM_NOMEM);
      }
    }
  }
  return p->zText;
}

/*
** Reset an StrAccum string.  Reclaim all malloced memory.








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/*
** Finish off a string by making sure it is zero-terminated.
** Return a pointer to the resulting string.  Return a NULL
** pointer if any kind of error was encountered.
*/
static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){
  assert( p->mxAlloc>0 && !isMalloced(p) );
  p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
  if( p->zText ){
    memcpy(p->zText, p->zBase, p->nChar+1);
    p->printfFlags |= SQLITE_PRINTF_MALLOCED;
  }else{
    setStrAccumError(p, STRACCUM_NOMEM);
  }
  return p->zText;
}
char *sqlite3StrAccumFinish(StrAccum *p){
  if( p->zText ){
    assert( (p->zText==p->zBase)==!isMalloced(p) );
    p->zText[p->nChar] = 0;
    if( p->mxAlloc>0 && !isMalloced(p) ){





      return strAccumFinishRealloc(p);

    }
  }
  return p->zText;
}

/*
** Reset an StrAccum string.  Reclaim all malloced memory.
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