From: Joachim B Haga <cjhaga@fys.uio.no>
Date: Mon, 3 Jul 2006 20:11:47 +0000 (+0200)
Subject: Make zlib compression level configurable, and change default.
X-Git-Tag: v1.4.2-rc1~96
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=12f6c308d53509dcb11e309604457d21d60438db;p=git.git

Make zlib compression level configurable, and change default.

With the change in default, "git add ." on kernel dir is about
twice as fast as before, with only minimal (0.5%) change in
object size. The speed difference is even more noticeable
when committing large files, which is now up to 8 times faster.

The configurability is through setting core.compression = [-1..9]
which maps to the zlib constants; -1 is the default, 0 is no
compression, and 1..9 are various speed/size tradeoffs, 9
being slowest.

Signed-off-by: Joachim B Haga (cjhaga@fys.uio.no)
Acked-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
---

diff --git a/Documentation/config.txt b/Documentation/config.txt
index a04c5adf8..16bdd5523 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -91,6 +91,12 @@ core.warnAmbiguousRefs::
 	If true, git will warn you if the ref name you passed it is ambiguous
 	and might match multiple refs in the .git/refs/ tree. True by default.
 
+core.compression:
+	An integer -1..9, indicating the compression level for objects that
+	are not in a pack file. -1 is the zlib and git default. 0 means no
+	compression, and 1..9 are various speed/size tradeoffs, 9 being
+	slowest.
+
 alias.*::
 	Command aliases for the gitlink:git[1] command wrapper - e.g.
 	after defining "alias.last = cat-file commit HEAD", the invocation
diff --git a/cache.h b/cache.h
index 87199396a..84770bf67 100644
--- a/cache.h
+++ b/cache.h
@@ -183,6 +183,7 @@ extern int log_all_ref_updates;
 extern int warn_ambiguous_refs;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
+extern int zlib_compression_level;
 
 #define GIT_REPO_VERSION 0
 extern int repository_format_version;
diff --git a/config.c b/config.c
index ec44827da..b23f4bf48 100644
--- a/config.c
+++ b/config.c
@@ -279,6 +279,16 @@ int git_default_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.compression")) {
+		int level = git_config_int(var, value);
+		if (level == -1)
+			level = Z_DEFAULT_COMPRESSION;
+		else if (level < 0 || level > Z_BEST_COMPRESSION)
+			die("bad zlib compression level %d", level);
+		zlib_compression_level = level;
+		return 0;
+	}
+
 	if (!strcmp(var, "user.name")) {
 		strlcpy(git_default_name, value, sizeof(git_default_name));
 		return 0;
diff --git a/csum-file.c b/csum-file.c
index ebaad0397..6a7b40fd0 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -122,7 +122,7 @@ int sha1write_compressed(struct sha1file *f, void *in, unsigned int size)
 	void *out;
 
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_DEFAULT_COMPRESSION);
+	deflateInit(&stream, zlib_compression_level);
 	maxsize = deflateBound(&stream, size);
 	out = xmalloc(maxsize);
 
diff --git a/diff.c b/diff.c
index 5a71489a4..428ff786e 100644
--- a/diff.c
+++ b/diff.c
@@ -583,7 +583,7 @@ static unsigned char *deflate_it(char *data,
 	z_stream stream;
 
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_BEST_COMPRESSION);
+	deflateInit(&stream, zlib_compression_level);
 	bound = deflateBound(&stream, size);
 	deflated = xmalloc(bound);
 	stream.next_out = deflated;
diff --git a/environment.c b/environment.c
index 3de8eb3b2..43823ff7d 100644
--- a/environment.c
+++ b/environment.c
@@ -20,6 +20,7 @@ int repository_format_version = 0;
 char git_commit_encoding[MAX_ENCODING_LENGTH] = "utf-8";
 int shared_repository = PERM_UMASK;
 const char *apply_default_whitespace = NULL;
+int zlib_compression_level = Z_DEFAULT_COMPRESSION;
 
 static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,
 	*git_graft_file;
diff --git a/http-push.c b/http-push.c
index e281f70e5..f761584d7 100644
--- a/http-push.c
+++ b/http-push.c
@@ -492,7 +492,7 @@ static void start_put(struct transfer_request *request)
 
 	/* Set it up */
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_BEST_COMPRESSION);
+	deflateInit(&stream, zlib_compression_level);
 	size = deflateBound(&stream, len + hdrlen);
 	request->buffer.buffer = xmalloc(size);
 
diff --git a/sha1_file.c b/sha1_file.c
index 817963045..bc3580844 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1458,7 +1458,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 
 	/* Set it up */
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_BEST_COMPRESSION);
+	deflateInit(&stream, zlib_compression_level);
 	size = deflateBound(&stream, len+hdrlen);
 	compressed = xmalloc(size);
 
@@ -1511,7 +1511,7 @@ static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
 
 	/* Set it up */
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_BEST_COMPRESSION);
+	deflateInit(&stream, zlib_compression_level);
 	size = deflateBound(&stream, len + hdrlen);
 	buf = xmalloc(size);