Reuse compression code in unpack_compressed_entry.

[PATCH 2/5] Reuse compression code in unpack_compressed_entry.

This cleans up the code by reusing a perfectly good decompression
implementation at the expense of 1 extra byte of memory allocated in
temporary memory while the delta is being decompressed and applied
to the base.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/sha1_file.c b/sha1_file.c
index 53beb917dd5fadf8c1dddb86c3479a7f84438f71..3d7358fe727453b6912098940dd139919f2e73c5 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1092,10 +1092,8 @@ static void *unpack_delta_entry(unsigned char *base_sha1,
                                struct packed_git *p)
 {
        struct pack_entry base_ent;
                                struct packed_git *p)
 {
        struct pack_entry base_ent;

-       void *data, *delta_data, *result, *base;
-       unsigned long data_size, result_size, base_size;
-       z_stream stream;
-       int st;
+       void *delta_data, *result, *base;
+       unsigned long result_size, base_size;

 
        if (left < 20)
                die("truncated pack file");
 
        if (left < 20)
                die("truncated pack file");


@@ -1109,23 +1107,8 @@ static void *unpack_delta_entry(unsigned char *base_sha1,
                die("failed to read delta-pack base object %s",
                    sha1_to_hex(base_sha1));
 
                die("failed to read delta-pack base object %s",
                    sha1_to_hex(base_sha1));
 

-       data = base_sha1 + 20;
-       data_size = left - 20;
-       delta_data = xmalloc(delta_size);
-
-       memset(&stream, 0, sizeof(stream));
-
-       stream.next_in = data;
-       stream.avail_in = data_size;
-       stream.next_out = delta_data;
-       stream.avail_out = delta_size;
-
-       inflateInit(&stream);
-       st = inflate(&stream, Z_FINISH);
-       inflateEnd(&stream);
-       if ((st != Z_STREAM_END) || stream.total_out != delta_size)
-               die("delta data unpack failed");
-
+       delta_data = unpack_compressed_entry(base_sha1 + 20,
+                            delta_size, left - 20);

        result = patch_delta(base, base_size,
                             delta_data, delta_size,
                             &result_size);
        result = patch_delta(base, base_size,
                             delta_data, delta_size,
                             &result_size);