pack: move check_pack_index_ptr(), nth_packed_object_offset()

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jonathan Tan
2017-08-18 15:20:32 -07:00
committed by Junio C Hamano
parent d5a1676182
commit 9e0f45f5a6
4 changed files with 49 additions and 49 deletions

View File

@ -1667,3 +1667,36 @@ const struct object_id *nth_packed_object_oid(struct object_id *oid,
hashcpy(oid->hash, hash);
return oid;
}
void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
{
const unsigned char *ptr = vptr;
const unsigned char *start = p->index_data;
const unsigned char *end = start + p->index_size;
if (ptr < start)
die(_("offset before start of pack index for %s (corrupt index?)"),
p->pack_name);
/* No need to check for underflow; .idx files must be at least 8 bytes */
if (ptr >= end - 8)
die(_("offset beyond end of pack index for %s (truncated index?)"),
p->pack_name);
}
off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
{
const unsigned char *index = p->index_data;
index += 4 * 256;
if (p->index_version == 1) {
return ntohl(*((uint32_t *)(index + 24 * n)));
} else {
uint32_t off;
index += 8 + p->num_objects * (20 + 4);
off = ntohl(*((uint32_t *)(index + 4 * n)));
if (!(off & 0x80000000))
return off;
index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
check_pack_index_ptr(p, index);
return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
ntohl(*((uint32_t *)(index + 4)));
}
}