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Overview
Comment:Performance improvement in the printf() logic by avoiding unnecessary stack pointer movement.
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SHA1: f7f2160db014f0ae11ad13c8ad70ad3444124e3e
User & Date: drh 2014-08-22 15:40:20.728
Context
2014-08-22
18:00
Split the sqlite3Error() routine into sqlite3Error() and sqlite3ErrorWithMsg(), for a slight size reduction and performance increase. (check-in: cf561d1f0b user: drh tags: trunk)
15:40
Performance improvement in the printf() logic by avoiding unnecessary stack pointer movement. (check-in: f7f2160db0 user: drh tags: trunk)
15:19
Improve the performance and reduce the size of the sqlite3VdbeSerialGet() routine by avoiding the use of stack. (check-in: ebc10e46c1 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/printf.c.
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** The StrAccum "p" is not large enough to accept N new bytes of z[].
** So enlarge if first, then do the append.
**
** This is a helper routine to sqlite3StrAccumAppend() that does special-case
** work (enlarging the buffer) using tail recursion, so that the
** sqlite3StrAccumAppend() routine can use fast calling semantics.
*/
static void enlargeAndAppend(StrAccum *p, const char *z, int N){
  N = sqlite3StrAccumEnlarge(p, N);
  if( N>0 ){
    memcpy(&p->zText[p->nChar], z, N);
    p->nChar += N;
  }
}

/*
** Append N bytes of text from z to the StrAccum object.  Increase the
** size of the memory allocation for StrAccum if necessary.
*/
void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
  assert( z!=0 );
  assert( p->zText!=0 || p->nChar==0 || p->accError );
  assert( N>=0 );
  assert( p->accError==0 || p->nAlloc==0 );
  if( p->nChar+N >= p->nAlloc ){
    enlargeAndAppend(p,z,N);
    return;
  }
  assert( p->zText );
  memcpy(&p->zText[p->nChar], z, N);
  p->nChar += N;


}

/*
** Append the complete text of zero-terminated string z[] to the p string.
*/
void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
  sqlite3StrAccumAppend(p, z, sqlite3Strlen30(z));








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** The StrAccum "p" is not large enough to accept N new bytes of z[].
** So enlarge if first, then do the append.
**
** This is a helper routine to sqlite3StrAccumAppend() that does special-case
** work (enlarging the buffer) using tail recursion, so that the
** sqlite3StrAccumAppend() routine can use fast calling semantics.
*/
static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
  N = sqlite3StrAccumEnlarge(p, N);
  if( N>0 ){
    memcpy(&p->zText[p->nChar], z, N);
    p->nChar += N;
  }
}

/*
** Append N bytes of text from z to the StrAccum object.  Increase the
** size of the memory allocation for StrAccum if necessary.
*/
void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
  assert( z!=0 );
  assert( p->zText!=0 || p->nChar==0 || p->accError );
  assert( N>=0 );
  assert( p->accError==0 || p->nAlloc==0 );
  if( p->nChar+N >= p->nAlloc ){
    enlargeAndAppend(p,z,N);

  }else{
    assert( p->zText );

    p->nChar += N;
    memcpy(&p->zText[p->nChar-N], z, N);
  }
}

/*
** Append the complete text of zero-terminated string z[] to the p string.
*/
void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
  sqlite3StrAccumAppend(p, z, sqlite3Strlen30(z));
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