[PATCH 3/3] use cache for function names in hunk headers

From

Clemens Buchacher <drizzd@aon.at>

Date

Sep 19, 2010, 09:59 UTC

Message-ID

<1284890369-4136-4-git-send-email-drizzd@aon.at>

In-Reply-To

<1284890369-4136-1-git-send-email-drizzd@aon.at>

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
---
 xdiff/xemit.c |   44 ++++++++++++++++++++++++++++++++------------
 1 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index c4bedf0..349bd6b 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -85,8 +85,15 @@ static long def_ff(const char *rec, long len, char *buf, long sz, void *priv)
 	return -1;
 }
 
-static void xdl_find_func(xdfile_t *xf, long i, char *buf, long sz, long *ll,
-		find_func_t ff, void *ff_priv) {
+struct xdl_find_func_cache {
+	char buf[80];
+	long len;
+	xdfile_t *xf;
+	int line;
+};
+
+static void xdl_find_func(xdfile_t *xf, long line, find_func_t ff,
+		          void *ff_priv, struct xdl_find_func_cache *cache) {
 
 	/*
 	 * Be quite stupid about this for now.  Find a line in the old file
@@ -96,13 +103,28 @@ static void xdl_find_func(xdfile_t *xf, long i, char *buf, long sz, long *ll,
 
 	const char *rec;
 	long len;
+	int i, l;
 
-	while (i-- > 0) {
-		len = xdl_get_rec(xf, i, &rec);
-		if ((*ll = ff(rec, len, buf, sz, ff_priv)) >= 0)
+	if (line < cache->line)
+		cache->xf = 0;
+
+	i = line;
+	l = -1;
+	while (--i >= 0 && l < 0) {
+		if (xf == cache->xf && i < cache->line) {
+			cache->line = line;
 			return;
+		}
+
+		len = xdl_get_rec(xf, i, &rec);
+		l = ff(rec, len, cache->buf, sizeof(cache->buf), ff_priv);
 	}
-	*ll = 0;
+	if (l < 0)
+		l = 0;
+
+	cache->xf = xf;
+	cache->len = l;
+	cache->line = line;
 }
 
 
@@ -125,8 +147,7 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 		  xdemitconf_t const *xecfg) {
 	long s1, s2, e1, e2, lctx;
 	xdchange_t *xch, *xche;
-	char funcbuf[80];
-	long funclen = 0;
+	struct xdl_find_func_cache func_cache = { "", 0, NULL, -1 };
 	find_func_t ff = xecfg->find_func ?  xecfg->find_func : def_ff;
 
 	if (xecfg->flags & XDL_EMIT_COMMON)
@@ -150,12 +171,11 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 		 */
 
 		if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
-			xdl_find_func(&xe->xdf1, s1, funcbuf,
-				      sizeof(funcbuf), &funclen,
-				      ff, xecfg->find_func_priv);
+			xdl_find_func(&xe->xdf1, s1, ff, xecfg->find_func_priv,
+					&func_cache);
 		}
 		if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
-				      funcbuf, funclen, ecb) < 0)
+				      func_cache.buf, func_cache.len, ecb) < 0)
 			return -1;
 
 		/*

-- 
1.7.1.571.gba4d01