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[PATCH] Obtain sha1_file_info() for deltified pack entry properly. 

The initial one was not doing enough to figure things out
without uncompressing too much.  It also fixes a potential
segfault resulting from missing use_packed_git() call.

We would need to introduce unuse_packed_git() call and do proper
use counting to figure out when it is safe to unmap, but
currently we do not unmap packed file yet.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Junio C Hamano 2005-06-27 23:58:08 -07:00 committed by Linus Torvalds
parent 635f67f943
commit 5db47c2bb3
1 changed files with 69 additions and 4 deletions
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73
sha1_file.c
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@ -601,9 +601,70 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l
return unpack_sha1_rest(&stream, hdr, *size);
}
/* Returns 0 on fast-path success, returns 1 on deltified
* and need to unpack to see info.
*/
static int packed_delta_info(unsigned char *base_sha1,
unsigned long delta_size,
unsigned long left,
char *type,
unsigned long *sizep)
{
unsigned char *data;
unsigned char delta_head[64];
int i;
unsigned char cmd;
unsigned long data_size, 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");
data = base_sha1 + 20;
data_size = left - 20;
memset(&stream, 0, sizeof(stream));
stream.next_in = data;
stream.avail_in = data_size;
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. Verify the base size while we are at it.
*/
data = delta_head;
verify_base_size = i = 0;
cmd = *data++;
while (cmd) {
if (cmd & 1)
verify_base_size |= *data++ << i;
i += 8;
cmd >>= 1;
}
/* Read the result size */
result_size = i = 0;
cmd = *data++;
while (cmd) {
if (cmd & 1)
result_size |= *data++ << i;
i += 8;
cmd >>= 1;
}
if (verify_base_size != base_size)
die("delta base size mismatch");
*sizep = result_size;
return 0;
}
static int packed_object_info(struct pack_entry *entry,
char *type, unsigned long *sizep)
{
@ -614,12 +675,16 @@ static int packed_object_info(struct pack_entry *entry,
offset = entry->offset;
if (p->pack_size - 5 < offset)
die("object offset outside of pack file");
if (use_packed_git(p))
die("cannot map packed file");
pack = p->pack_base + offset;
size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4];
left = p->pack_size - offset - 5;
switch (*pack) {
case 'D':
return 1;
return packed_delta_info(pack+5, size, left, type, sizep);
break;
case 'C':
strcpy(type, "commit");