# [PATCH 2/2] Use cache_sha1_file() in git-blame and git-merge-recursive.

2 messages from 2007-02-05 to 2007-02-05. Participants: Junio C Hamano, Shawn O. Pearce.
Thread: https://gitlist.dev/t/6686

## Junio C Hamano, 2007-02-05 05:51

Subject: [PATCH 2/2] Use cache_sha1_file() in git-blame and git-merge-recursive.
Message-ID: <7v7iuxp2xt.fsf@assigned-by-dhcp.cox.net>
URL: https://gitlist.dev/e/7v7iuxp2xt.fsf%40assigned-by-dhcp.cox.net

```
git-merge-recursive wants an null tree as the fake merge base
while producing the merge result tree.  The null tree does not
have to be written out in the object store as it won't be part
of the result, and it is a prime example for using the new
cache_sha1_file() function.

git-blame needs to register an arbitrary data to in-core index
while annotating a working tree file (or standard input), but
git-blame is a read-only application and the user of it could
even lack the privilege to write into the object store; it is
another good example for cache_sha1_file().

Signed-off-by: Junio C Hamano <junkio@cox.net>
---
 builtin-blame.c   |    2 +-
 merge-recursive.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/builtin-blame.c b/builtin-blame.c
index 897323a..15d0707 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -2005,7 +2005,7 @@ static struct commit *fake_working_tree_commit(const char *path, const char *con
 	buf[fin_size] = 0;
 	origin->file.ptr = buf;
 	origin->file.size = fin_size;
-	write_sha1_file(buf, fin_size, blob_type, origin->blob_sha1);
+	cache_sha1_file(buf, fin_size, blob_type, origin->blob_sha1);
 	commit->util = origin;
 
 	/*
diff --git a/merge-recursive.c b/merge-recursive.c
index a68fcc6..d4e2460 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1213,7 +1213,7 @@ static int merge(struct commit *h1,
 
 		tree->object.parsed = 1;
 		tree->object.type = OBJ_TREE;
-		write_sha1_file(NULL, 0, tree_type, tree->object.sha1);
+		cache_sha1_file(NULL, 0, tree_type, tree->object.sha1);
 		merged_common_ancestors = make_virtual_commit(tree, "ancestor");
 	}
 
-- 
1.5.0.rc3.58.g79812

```

## Shawn O. Pearce, 2007-02-05 05:56

Subject: Re: [PATCH 2/2] Use cache_sha1_file() in git-blame and git-merge-recursive.
Message-ID: <20070205055659.GA13472@spearce.org>
URL: https://gitlist.dev/e/20070205055659.GA13472%40spearce.org
In-Reply-To: <7v7iuxp2xt.fsf@assigned-by-dhcp.cox.net>

```
Junio C Hamano <junkio@cox.net> wrote:
> git-blame needs to register an arbitrary data to in-core index
> while annotating a working tree file (or standard input), but
> git-blame is a read-only application and the user of it could
> even lack the privilege to write into the object store; it is
> another good example for cache_sha1_file().

*Excellent* reason for this.

But what about pretend_sha1_file() instead?

The term 'cache' suggests to me (on first glance) that its loading
an existing object and caching it in memory for faster, frequent
access, when compared to other non-cached objects.

-- 
Shawn.

```