From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 22 Jul 2012 19:56:30 +0000 (-0700)
Subject: Merge branch 'jk/revision-walk-stop-at-max-count'
X-Git-Tag: v1.7.12-rc0~15
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/d05e56ea67743b68336aede7f4c42fece7ae764c?hp=-c

Merge branch 'jk/revision-walk-stop-at-max-count'

"git log -n 1 -- rarely-touched-path" was spending unnecessary
cycles after showing the first change to find the next one, only to
discard it.

* jk/revision-walk-stop-at-max-count:
revision: avoid work after --max-count is reached
---

d05e56ea67743b68336aede7f4c42fece7ae764c
diff --combined revision.c
index c64bf68fa1,7e3965557a..9e8f47a25d
--- a/revision.c
+++ b/revision.c
@@@ -1000,7 -1000,7 +1000,7 @@@ static int add_parents_only(struct rev_
  		flags ^= UNINTERESTING;
  		arg++;
  	}
 -	if (get_sha1(arg, sha1))
 +	if (get_sha1_committish(arg, sha1))
  		return 0;
  	while (1) {
  		it = get_reference(revs, arg, sha1, 0);
@@@ -1114,16 -1114,16 +1114,16 @@@ static void prepare_show_merge(struct r
  	revs->limited = 1;
  }
  
 -int handle_revision_arg(const char *arg_, struct rev_info *revs,
 -			int flags,
 -			int cant_be_filename)
 +int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
  {
 -	unsigned mode;
 +	struct object_context oc;
  	char *dotdot;
  	struct object *object;
  	unsigned char sha1[20];
  	int local_flags;
  	const char *arg = arg_;
 +	int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
 +	unsigned get_sha1_flags = 0;
  
  	dotdot = strstr(arg, "..");
  	if (dotdot) {
@@@ -1141,8 -1141,8 +1141,8 @@@
  			next = "HEAD";
  		if (dotdot == arg)
  			this = "HEAD";
 -		if (!get_sha1(this, from_sha1) &&
 -		    !get_sha1(next, sha1)) {
 +		if (!get_sha1_committish(this, from_sha1) &&
 +		    !get_sha1_committish(next, sha1)) {
  			struct commit *a, *b;
  			struct commit_list *exclude;
  
@@@ -1201,17 -1201,13 +1201,17 @@@
  		local_flags = UNINTERESTING;
  		arg++;
  	}
 -	if (get_sha1_with_mode(arg, sha1, &mode))
 +
 +	if (revarg_opt & REVARG_COMMITTISH)
 +		get_sha1_flags = GET_SHA1_COMMITTISH;
 +
 +	if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
  		return revs->ignore_missing ? 0 : -1;
  	if (!cant_be_filename)
  		verify_non_filename(revs->prefix, arg);
  	object = get_reference(revs, arg, sha1, flags ^ local_flags);
  	add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
 -	add_pending_object_with_mode(revs, object, arg, mode);
 +	add_pending_object_with_mode(revs, object, arg, oc.mode);
  	return 0;
  }
  
@@@ -1261,7 -1257,7 +1261,7 @@@ static void read_revisions_from_stdin(s
  			}
  			die("options not supported in --stdin mode");
  		}
 -		if (handle_revision_arg(sb.buf, revs, 0, 1))
 +		if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
  			die("bad revision '%s'", sb.buf);
  	}
  	if (seen_dashdash)
@@@ -1712,7 -1708,7 +1712,7 @@@ static int handle_revision_pseudo_opt(c
   */
  int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
  {
 -	int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
 +	int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
  	struct cmdline_pathspec prune_data;
  	const char *submodule = NULL;
  
@@@ -1740,9 -1736,6 +1740,9 @@@
  
  	/* Second, deal with arguments and options */
  	flags = 0;
 +	revarg_opt = opt ? opt->revarg_opt : 0;
 +	if (seen_dashdash)
 +		revarg_opt |= REVARG_CANNOT_BE_FILENAME;
  	read_from_stdin = 0;
  	for (left = i = 1; i < argc; i++) {
  		const char *arg = argv[i];
@@@ -1778,8 -1771,7 +1778,8 @@@
  			continue;
  		}
  
 -		if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
 +
 +		if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
  			int j;
  			if (seen_dashdash || *arg == '^')
  				die("bad revision '%s'", arg);
@@@ -1830,11 -1822,11 +1830,11 @@@
  	if (revs->def && !revs->pending.nr && !got_rev_arg) {
  		unsigned char sha1[20];
  		struct object *object;
 -		unsigned mode;
 -		if (get_sha1_with_mode(revs->def, sha1, &mode))
 +		struct object_context oc;
 +		if (get_sha1_with_context(revs->def, 0, sha1, &oc))
  			die("bad default revision '%s'", revs->def);
  		object = get_reference(revs, revs->def, sha1, 0);
 -		add_pending_object_with_mode(revs, object, revs->def, mode);
 +		add_pending_object_with_mode(revs, object, revs->def, oc.mode);
  	}
  
  	/* Did the user ask for any diff output? Run the diff! */
@@@ -2369,29 -2361,28 +2369,28 @@@ static struct commit *get_revision_inte
  	}
  
  	/*
- 	 * Now pick up what they want to give us
+ 	 * If our max_count counter has reached zero, then we are done. We
+ 	 * don't simply return NULL because we still might need to show
+ 	 * boundary commits. But we want to avoid calling get_revision_1, which
+ 	 * might do a considerable amount of work finding the next commit only
+ 	 * for us to throw it away.
+ 	 *
+ 	 * If it is non-zero, then either we don't have a max_count at all
+ 	 * (-1), or it is still counting, in which case we decrement.
  	 */
- 	c = get_revision_1(revs);
- 	if (c) {
- 		while (0 < revs->skip_count) {
- 			revs->skip_count--;
- 			c = get_revision_1(revs);
- 			if (!c)
- 				break;
+ 	if (revs->max_count) {
+ 		c = get_revision_1(revs);
+ 		if (c) {
+ 			while (0 < revs->skip_count) {
+ 				revs->skip_count--;
+ 				c = get_revision_1(revs);
+ 				if (!c)
+ 					break;
+ 			}
  		}
- 	}
  
- 	/*
- 	 * Check the max_count.
- 	 */
- 	switch (revs->max_count) {
- 	case -1:
- 		break;
- 	case 0:
- 		c = NULL;
- 		break;
- 	default:
- 		revs->max_count--;
+ 		if (revs->max_count > 0)
+ 			revs->max_count--;
  	}
  
  	if (c)