threads / patch / 7845

patchAvoid excessive rewrites in merge-recursive

Subject: [PATCH] Avoid excessive rewrites in merge-recursive

## tl;dr

4 messages between Apr 25, 2007 and Apr 26, 2007. Diffs are folded; open one to read it.

replies: 3people: 2as markdown or json

Alex Riesen· Apr 25, 2007, 20:06 UTC · lore

If a file is changed in one branch, and renamed and changed to the same content in another branch than we can skip the rewrite of this file in the working directory, as the content does not change.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
---

Just as you may have thought merge-recursive cannot get any uglier someone comes and does just this: puts another level of indentation.

It is a nice speed up, though. Besides, I had some directories moved between branches, and the rewrites caused a rebuild of hefty 8000 objects, which in windows terms is around 2 hours.

 merge-recursive.c |   32 +++++++++++++++++++-------------
 1 files changed, 19 insertions(+), 13 deletions(-)

Show changes to merge-recursive.c +19 −13

diff --git a/merge-recursive.c b/merge-recursive.c
index 403a4c8..37f1ba9 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1342,20 +1342,26 @@ static int process_renames(struct path_list *a_renames,
 				mfi = merge_file(o, a, b,
 						a_branch, b_branch);
 
-				if (mfi.merge || !mfi.clean)
-					output(1, "Renamed %s => %s", ren1_src, ren1_dst);
-				if (mfi.merge)
-					output(2, "Auto-merged %s", ren1_dst);
-				if (!mfi.clean) {
-					output(1, "CONFLICT (rename/modify): Merge conflict in %s",
-					       ren1_dst);
-					clean_merge = 0;
-
-					if (!index_only)
-						update_stages(ren1_dst,
-								o, a, b, 1);
+				if (mfi.merge && mfi.clean &&
+				    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
+				    mfi.mode == ren1->pair->two->mode)
+					output(3, "Skipped %s (merged same as existing)", ren1_dst);
+				else {
+					if (mfi.merge || !mfi.clean)
+						output(1, "Renamed %s => %s", ren1_src, ren1_dst);
+					if (mfi.merge)
+						output(2, "Auto-merged %s", ren1_dst);
+					if (!mfi.clean) {
+						output(1, "CONFLICT (rename/modify): Merge conflict in %s",
+						       ren1_dst);
+						clean_merge = 0;
+
+						if (!index_only)
+							update_stages(ren1_dst,
+								      o, a, b, 1);
+					}
+					update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 				}
-				update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 			}
 		}
 	}

-- 
1.5.2.rc0.63.gdfc8-dirty

Junio C Hamano· Apr 25, 2007, 21:18 UTC · re: Alex Riesen · lore

Re: [PATCH] Avoid excessive rewrites in merge-recursive

Alex Riesen <raa.lkml@gmail.com> writes:

> Just as you may have thought merge-recursive cannot get any uglier
> someone comes and does just this: puts another level of indentation.

It really was painful for me the last time I touched the file, so I share that feeling. The complexity of this program is getting out of hand.

Probably we would want a refactoring before doing something like this.

Alex Riesen· Apr 25, 2007, 22:13 UTC · re: Junio C Hamano · lore

Re: [PATCH] Avoid excessive rewrites in merge-recursive

Junio C Hamano, Wed, Apr 25, 2007 23:18:21 +0200:

Show 11 quoted lines

> 
> > Just as you may have thought merge-recursive cannot get any uglier
> > someone comes and does just this: puts another level of indentation.
> 
> It really was painful for me the last time I touched the file,
> so I share that feeling.  The complexity of this program is
> getting out of hand.
> 
> Probably we would want a refactoring before doing something like
> this.
>

I want. I just can't afford something like this lately. I'm even saving on "am"s and "not"s! :)

Alex Riesen· Apr 26, 2007, 19:13 UTC · re: Alex Riesen · lore

[PATCH] Ignore merged status of the file-level merge

as it is not relevant for whether the result should be written. Even if no real merge happened, there might be _no_ reason to rewrite the working tree file. Maybe even more so.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
---

 merge-recursive.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Show changes to merge-recursive.c +1 −1

diff --git a/merge-recursive.c b/merge-recursive.c
index 094ac59..8f72b2c 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1342,7 +1342,7 @@ static int process_renames(struct path_list *a_renames,
 				mfi = merge_file(o, a, b,
 						a_branch, b_branch);
 
-				if (mfi.merge && mfi.clean &&
+				if (mfi.clean &&
 				    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
 				    mfi.mode == ren1->pair->two->mode)
 					/*

-- 
1.5.2.rc0.65.g92b0b