From c6d72c49720aa333e9c646f447147e8e546df174 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 14 Jul 2011 11:02:06 -0700
Subject: Revert clock-skew based attempt to optimize tag --contains traversal

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/.gitignore b/.gitignore
index 90aff17..14e2b6b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -132,7 +132,6 @@
 /git-show-branch
 /git-show-index
 /git-show-ref
-/git-skew
 /git-stage
 /git-stash
 /git-status
diff --git a/Makefile b/Makefile
index e673bdf..9aca8a1 100644
--- a/Makefile
+++ b/Makefile
@@ -725,7 +725,6 @@ BUILTIN_OBJS += builtin/send-pack.o
 BUILTIN_OBJS += builtin/shortlog.o
 BUILTIN_OBJS += builtin/show-branch.o
 BUILTIN_OBJS += builtin/show-ref.o
-BUILTIN_OBJS += builtin/skew.o
 BUILTIN_OBJS += builtin/stripspace.o
 BUILTIN_OBJS += builtin/symbolic-ref.o
 BUILTIN_OBJS += builtin/tag.o
diff --git a/builtin.h b/builtin.h
index 5f5dc0a..ed6ee26 100644
--- a/builtin.h
+++ b/builtin.h
@@ -141,6 +141,5 @@ extern int cmd_verify_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_show_ref(int argc, const char **argv, const char *prefix);
 extern int cmd_pack_refs(int argc, const char **argv, const char *prefix);
 extern int cmd_replace(int argc, const char **argv, const char *prefix);
-extern int cmd_skew(int argc, const char **argv, const char *prefix);
 
 #endif
diff --git a/builtin/skew.c b/builtin/skew.c
deleted file mode 100644
index 1046f5f..0000000
--- a/builtin/skew.c
+++ /dev/null
@@ -1,50 +0,0 @@
-#include "cache.h"
-#include "commit.h"
-#include "diff.h"
-#include "revision.h"
-
-unsigned long worst_skew = 0;
-
-static void check_skew_recurse(struct commit *c, unsigned long when)
-{
-	struct commit_list *p;
-
-	if (c->object.flags & SEEN)
-		return;
-	c->object.flags |= SEEN;
-
-	if (parse_commit(c) < 0)
-		return;
-
-	if (c->date > when) {
-		unsigned long skew = c->date - when;
-		if (skew > worst_skew)
-			worst_skew = skew;
-	}
-
-	for (p = c->parents; p; p = p->next)
-		check_skew_recurse(p->item, c->date < when ? c->date : when);
-}
-
-static void check_skew(struct commit *c)
-{
-	check_skew_recurse(c, time(NULL));
-}
-
-int cmd_skew(int argc, const char **argv, const char *prefix) {
-	struct rev_info revs;
-	int i;
-
-	git_config(git_default_config, NULL);
-	init_revisions(&revs, prefix);
-	argc = setup_revisions(argc, argv, &revs, NULL);
-
-	for (i = 0; i < revs.pending.nr; i++) {
-		struct object *o = revs.pending.objects[i].item;
-		if (o->type == OBJ_COMMIT)
-			check_skew((struct commit *)o);
-	}
-
-	printf("%lu\n", worst_skew);
-	return 0;
-}
diff --git a/builtin/tag.c b/builtin/tag.c
index e468696..f7a7943 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -25,8 +25,6 @@ static const char * const git_tag_usage[] = {
 
 static char signingkey[1000];
 
-static int core_clock_skew = 86400;
-
 struct tag_filter {
 	const char *pattern;
 	int lines;
@@ -44,8 +42,7 @@ static int in_commit_list(const struct commit_list *want, struct commit *c)
 }
 
 static int contains_recurse(struct commit *candidate,
-			    const struct commit_list *want,
-			    unsigned long cutoff)
+			    const struct commit_list *want)
 {
 	struct commit_list *p;
 
@@ -62,13 +59,9 @@ static int contains_recurse(struct commit *candidate,
 	if (parse_commit(candidate) < 0)
 		return 0;
 
-	/* stop searching if we go too far back in time */
-	if (candidate->date < cutoff)
-		return 0;
-
 	/* Otherwise recurse and mark ourselves for future traversals. */
 	for (p = candidate->parents; p; p = p->next) {
-		if (contains_recurse(p->item, want, cutoff)) {
+		if (contains_recurse(p->item, want)) {
 			candidate->object.flags |= TMP_MARK;
 			return 1;
 		}
@@ -79,22 +72,7 @@ static int contains_recurse(struct commit *candidate,
 
 static int contains(struct commit *candidate, const struct commit_list *want)
 {
-	unsigned long cutoff = 0;
-
-	if (core_clock_skew >= 0) {
-		const struct commit_list *c;
-		unsigned long min_date = ULONG_MAX;
-		for (c = want; c; c = c->next) {
-			if (parse_commit(c->item) < 0)
-				continue;
-			if (c->item->date < min_date)
-				min_date = c->item->date;
-		}
-		if (min_date > core_clock_skew)
-			cutoff = min_date - core_clock_skew;
-	}
-
-	return contains_recurse(candidate, want, cutoff);
+	return contains_recurse(candidate, want);
 }
 
 static int show_reference(const char *refname, const unsigned char *sha1,
@@ -301,14 +279,6 @@ static int git_tag_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.clockskew")) {
-		if (!value || !strcmp(value, "none"))
-			core_clock_skew = -1;
-		else
-			core_clock_skew = git_config_int(var, value);
-		return 0;
-	}
-
 	return git_default_config(var, value, cb);
 }
 
diff --git a/git.c b/git.c
index 8a77fe3..265fa09 100644
--- a/git.c
+++ b/git.c
@@ -399,7 +399,6 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "verify-pack", cmd_verify_pack },
 		{ "show-ref", cmd_show_ref, RUN_SETUP },
 		{ "pack-refs", cmd_pack_refs, RUN_SETUP },
-		{ "skew", cmd_skew, RUN_SETUP },
 	};
 	int i;
 	static const char ext[] = STRIP_EXTENSION;
-- 
cgit v0.10.2-6-g49f6