undef/git-commit-vandalism
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Use strbuf for struct xdiff_emit_state's remainder

Browse Source 
Continually xreallocing and freeing the remainder member of struct
xdiff_emit_state was a noticeable performance hit.  Use a strbuf
instead.

This yields a decent performance improvement on "git blame" on certain
repositories.  For example, before this commit:

$ time git blame -M -C -C -p --incremental server.c >/dev/null
101.52user 0.17system 1:41.73elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+39561minor)pagefaults 0swaps

With this commit:

$ time git blame -M -C -C -p --incremental server.c >/dev/null
80.38user 0.30system 1:20.81elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+50979minor)pagefaults 0swaps

Signed-off-by: Brian Downing <bdowning@lavos.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Brian Downing 2008-08-14 00:36:51 -05:00 committed by Junio C Hamano
parent c99db9d292
commit b463776086
2 changed files with 12 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
xdiff-interface.c
View File

@ -69,36 +69,22 @@ static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
for (i = 0; i < nbuf; i++) {
if (mb[i].ptr[mb[i].size-1] != '\n') {
/* Incomplete line */
priv->remainder = xrealloc(priv->remainder,
priv->remainder_size +
mb[i].size);
memcpy(priv->remainder + priv->remainder_size,
mb[i].ptr, mb[i].size);
priv->remainder_size += mb[i].size;
strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
continue;
}
/* we have a complete line */
if (!priv->remainder) {
if (!priv->remainder.len) {
consume_one(priv, mb[i].ptr, mb[i].size);
continue;
}
priv->remainder = xrealloc(priv->remainder,
priv->remainder_size +
mb[i].size);
memcpy(priv->remainder + priv->remainder_size,
mb[i].ptr, mb[i].size);
consume_one(priv, priv->remainder,
priv->remainder_size + mb[i].size);
free(priv->remainder);
priv->remainder = NULL;
priv->remainder_size = 0;
strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
consume_one(priv, priv->remainder.buf, priv->remainder.len);
strbuf_reset(&priv->remainder);
}
if (priv->remainder) {
consume_one(priv, priv->remainder, priv->remainder_size);
free(priv->remainder);
priv->remainder = NULL;
priv->remainder_size = 0;
if (priv->remainder.len) {
consume_one(priv, priv->remainder.buf, priv->remainder.len);
strbuf_reset(&priv->remainder);
}
return 0;
}
@ -148,7 +134,9 @@ int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
int ret;
xecb->outf = xdiff_outf;
xecb->priv = state;
strbuf_init(&state->remainder, 0);
ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
strbuf_release(&state->remainder);
return ret;
}

4
xdiff-interface.h
View File

@ -2,6 +2,7 @@
#define XDIFF_INTERFACE_H
#include "xdiff/xdiff.h"
#include "strbuf.h"
struct xdiff_emit_state;
@ -9,8 +10,7 @@ typedef void (*xdiff_emit_consume_fn)(void *, char *, unsigned long);
struct xdiff_emit_state {
xdiff_emit_consume_fn consume;
char *remainder;
unsigned long remainder_size;
struct strbuf remainder;
};
int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *ecb);