Merge branch 'dh/pack'

* dh/pack:
  Custom compression levels for objects and packs

Documentation/config.txt

@@ -204,10 +204,16 @@ core.warnAmbiguousRefs::
 	and might match multiple refs in the .git/refs/ tree. True by default.
 
 core.compression::
+	An integer -1..9, indicating a default compression level.
+	-1 is the zlib default. 0 means no compression,
+	and 1..9 are various speed/size tradeoffs, 9 being slowest.
+
+core.loosecompression::
 	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
+	are not in a pack file. -1 is the zlib default. 0 means no
 	compression, and 1..9 are various speed/size tradeoffs, 9 being
-	slowest.
+	slowest.  If not set,  defaults to core.compression.  If that is
+	not set,  defaults to 0 (best speed).
 
 core.packedGitWindowSize::
 	Number of bytes of a pack file to map into memory in a
@@ -542,6 +548,13 @@ pack.depth::
 	The maximum delta depth used by gitlink:git-pack-objects[1] when no
 	maximum depth is given on the command line. Defaults to 50.
 
+pack.compression::
+	An integer -1..9, indicating the compression level for objects
+	in a pack file. -1 is the zlib default. 0 means no
+	compression, and 1..9 are various speed/size tradeoffs, 9 being
+	slowest.  If not set,  defaults to core.compression.  If that is
+	not set,  defaults to -1.
+
 pull.octopus::
 	The default merge strategy to use when pulling multiple branches
 	at once.

Documentation/git-pack-objects.txt

@@ -130,10 +130,22 @@ base-name::
 --no-reuse-object::
 	This flag tells the command not to reuse existing object data at all,
 	including non deltified object, forcing recompression of everything.
-	This implies --no-reuse-delta. Useful only in the obscur case where
+	This implies --no-reuse-delta. Useful only in the obscure case where
 	wholesale enforcement of a different compression level on the
 	packed data is desired.
 
+--compression=[N]::
+	Specifies compression level for newly-compressed data in the
+	generated pack.  If not specified,  pack compression level is
+	determined first by pack.compression,  then by core.compression,
+	and defaults to -1,  the zlib default,  if neither is set.
+	Data copied from loose objects will be recompressed
+	if core.legacyheaders was true when they were created or if
+	the loose compression level (see core.loosecompression and
+	core.compression) is now a different value than the pack
+	compression level.  Add --no-reuse-object if you want to force
+	a uniform compression level on all data no matter the source.
+
 --delta-base-offset::
 	A packed archive can express base object of a delta as
 	either 20-byte object name or as an offset in the

builtin-pack-objects.c

@@ -68,6 +68,8 @@ static int depth = 50;
 static int pack_to_stdout;
 static int num_preferred_base;
 static struct progress progress_state;
+static int pack_compression_level = Z_DEFAULT_COMPRESSION;
+static int pack_compression_seen;
 
 /*
  * The object names in objects array are hashed with this hashtable,
@@ -418,7 +420,7 @@ static unsigned long write_object(struct sha1file *f,
 			sha1write(f, entry->delta->sha1, 20);
 			hdrlen += 20;
 		}
-		datalen = sha1write_compressed(f, buf, size);
+		datalen = sha1write_compressed(f, buf, size, pack_compression_level);
 		free(buf);
 	}
 	else {
@@ -1427,6 +1429,16 @@ static int git_pack_config(const char *k, const char *v)
 		depth = git_config_int(k, v);
 		return 0;
 	}
+	if (!strcmp(k, "pack.compression")) {
+		int level = git_config_int(k, v);
+		if (level == -1)
+			level = Z_DEFAULT_COMPRESSION;
+		else if (level < 0 || level > Z_BEST_COMPRESSION)
+			die("bad pack compression level %d", level);
+		pack_compression_level = level;
+		pack_compression_seen = 1;
+		return 0;
+	}
 	return git_default_config(k, v);
 }
 
@@ -1538,6 +1550,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	rp_ac = 2;
 
 	git_config(git_pack_config);
+	if (!pack_compression_seen && core_compression_seen)
+		pack_compression_level = core_compression_level;
 
 	progress = isatty(2);
 	for (i = 1; i < argc; i++) {
@@ -1558,6 +1572,18 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			incremental = 1;
 			continue;
 		}
+		if (!prefixcmp(arg, "--compression=")) {
+			char *end;
+			int level = strtoul(arg+14, &end, 0);
+			if (!arg[14] || *end)
+				usage(pack_usage);
+			if (level == -1)
+				level = Z_DEFAULT_COMPRESSION;
+			else if (level < 0 || level > Z_BEST_COMPRESSION)
+				die("bad pack compression level %d", level);
+			pack_compression_level = level;
+			continue;
+		}
 		if (!prefixcmp(arg, "--window=")) {
 			char *end;
 			window = strtoul(arg+9, &end, 0);

cache.h

@@ -282,6 +282,8 @@ extern int warn_ambiguous_refs;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
 extern int zlib_compression_level;
+extern int core_compression_level;
+extern int core_compression_seen;
 extern size_t packed_git_window_size;
 extern size_t packed_git_limit;
 extern size_t delta_base_cache_limit;

config.c

@@ -12,6 +12,8 @@
 static FILE *config_file;
 static const char *config_file_name;
 static int config_linenr;
+static int zlib_compression_seen;
+
 static int get_next_char(void)
 {
 	int c;
@@ -299,12 +301,26 @@ int git_default_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.loosecompression")) {
+		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;
+		zlib_compression_seen = 1;
+		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);
+		core_compression_level = level;
+		core_compression_seen = 1;
+		if (!zlib_compression_seen)
 			zlib_compression_level = level;
 		return 0;
 	}

csum-file.c

@@ -119,14 +119,14 @@ struct sha1file *sha1fd(int fd, const char *name)
 	return f;
 }
 
-int sha1write_compressed(struct sha1file *f, void *in, unsigned int size)
+int sha1write_compressed(struct sha1file *f, void *in, unsigned int size, int level)
 {
 	z_stream stream;
 	unsigned long maxsize;
 	void *out;
 
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, zlib_compression_level);
+	deflateInit(&stream, level);
 	maxsize = deflateBound(&stream, size);
 	out = xmalloc(maxsize);
 

csum-file.h

@@ -16,7 +16,7 @@ extern struct sha1file *sha1fd(int fd, const char *name);
 extern struct sha1file *sha1create(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
 extern int sha1close(struct sha1file *, unsigned char *, int);
 extern int sha1write(struct sha1file *, void *, unsigned int);
-extern int sha1write_compressed(struct sha1file *, void *, unsigned int);
+extern int sha1write_compressed(struct sha1file *, void *, unsigned int, int);
 extern void crc32_begin(struct sha1file *);
 extern uint32_t crc32_end(struct sha1file *);
 

environment.c

@@ -23,7 +23,9 @@ const char *git_commit_encoding;
 const char *git_log_output_encoding;
 int shared_repository = PERM_UMASK;
 const char *apply_default_whitespace;
-int zlib_compression_level = Z_DEFAULT_COMPRESSION;
+int zlib_compression_level = Z_BEST_SPEED;
+int core_compression_level;
+int core_compression_seen;
 size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
 size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
 size_t delta_base_cache_limit = 16 * 1024 * 1024;