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authorJunio C Hamano <junkio@cox.net>2005-07-01 00:13:07 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-07-01 05:33:47 (GMT)
commitc62266f37c677c1de7415ac6cf1e2eb6726590e1 (patch)
tree995538e5c635827aee1075b62d8d5b61899bbdb0 /sha1_file.c
parentd0efc8a71da1855c705fd2074b219bcb158b6dbd (diff)
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[PATCH] Avoid unnecessarily inflating and interpreting delta
This teaches packed_delta_info() that it only needs to look at the type of the base object to figure out both type and size of a deltified object. This saves quite a many calls to inflate() when dealing with a deep delta chain. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'sha1_file.c')
-rw-r--r--sha1_file.c79
1 files changed, 42 insertions, 37 deletions
diff --git a/sha1_file.c b/sha1_file.c
index 63cbdde..3178fbf 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -624,41 +624,49 @@ static int packed_delta_info(unsigned char *base_sha1,
char *type,
unsigned long *sizep)
{
- const unsigned char *data;
- unsigned char delta_head[64];
- unsigned long result_size, base_size, verify_base_size;
- z_stream stream;
- int st;
-
if (left < 20)
die("truncated pack file");
- if (sha1_object_info(base_sha1, type, &base_size))
- die("cannot get info for delta-pack base");
-
- memset(&stream, 0, sizeof(stream));
- data = stream.next_in = base_sha1 + 20;
- stream.avail_in = left - 20;
- stream.next_out = delta_head;
- stream.avail_out = sizeof(delta_head);
+ /* We choose to only get the type of the base object and
+ * ignore potentially corrupt pack file that expects the delta
+ * based on a base with a wrong size. This saves tons of
+ * inflate() calls.
+ */
- inflateInit(&stream);
- st = inflate(&stream, Z_FINISH);
- inflateEnd(&stream);
- if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
- die("delta data unpack-initial failed");
+ if (sha1_object_info(base_sha1, type, NULL))
+ die("cannot get info for delta-pack base");
- /* Examine the initial part of the delta to figure out
- * the result size. Verify the base size while we are at it.
- */
- data = delta_head;
- verify_base_size = get_delta_hdr_size(&data);
- if (verify_base_size != base_size)
- die("delta base size mismatch");
+ if (sizep) {
+ const unsigned char *data;
+ unsigned char delta_head[64];
+ unsigned long result_size;
+ z_stream stream;
+ int st;
+
+ memset(&stream, 0, sizeof(stream));
+
+ data = stream.next_in = base_sha1 + 20;
+ stream.avail_in = left - 20;
+ stream.next_out = delta_head;
+ stream.avail_out = sizeof(delta_head);
+
+ inflateInit(&stream);
+ st = inflate(&stream, Z_FINISH);
+ inflateEnd(&stream);
+ if ((st != Z_STREAM_END) &&
+ stream.total_out != sizeof(delta_head))
+ die("delta data unpack-initial failed");
+
+ /* Examine the initial part of the delta to figure out
+ * the result size.
+ */
+ data = delta_head;
+ get_delta_hdr_size(&data); /* ignore base size */
- /* Read the result size */
- result_size = get_delta_hdr_size(&data);
- *sizep = result_size;
+ /* Read the result size */
+ result_size = get_delta_hdr_size(&data);
+ *sizep = result_size;
+ }
return 0;
}
@@ -726,7 +734,8 @@ static int packed_object_info(struct pack_entry *entry,
default:
die("corrupted pack file");
}
- *sizep = size;
+ if (sizep)
+ *sizep = size;
unuse_packed_git(p);
return 0;
}
@@ -915,12 +924,7 @@ int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep
if (!find_pack_entry(sha1, &e))
return error("unable to find %s", sha1_to_hex(sha1));
- if (!packed_object_info(&e, type, sizep))
- return 0;
- /* sheesh */
- map = unpack_entry(&e, type, sizep);
- free(map);
- return (map == NULL) ? 0 : -1;
+ return packed_object_info(&e, type, sizep);
}
if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
status = error("unable to unpack %s header",
@@ -929,7 +933,8 @@ int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep
status = error("unable to parse %s header", sha1_to_hex(sha1));
else {
status = 0;
- *sizep = size;
+ if (sizep)
+ *sizep = size;
}
inflateEnd(&stream);
munmap(map, mapsize);