From b463776086a12c587f6d91c0347641fb6f7ddd72 Mon Sep 17 00:00:00 2001 From: Brian Downing Date: Thu, 14 Aug 2008 00:36:51 -0500 Subject: [PATCH] Use strbuf for struct xdiff_emit_state's remainder 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 Signed-off-by: Junio C Hamano --- xdiff-interface.c | 32 ++++++++++---------------------- xdiff-interface.h | 4 ++-- 2 files changed, 12 insertions(+), 24 deletions(-) diff --git a/xdiff-interface.c b/xdiff-interface.c index 828b4966a..bf98866c4 100644 --- a/xdiff-interface.c +++ b/xdiff-interface.c @@ -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; } diff --git a/xdiff-interface.h b/xdiff-interface.h index 6f3b361a8..f6a1ec222 100644 --- a/xdiff-interface.h +++ b/xdiff-interface.h @@ -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); -- 2.30.2