packfile: replace lseek+read with pread

We already have pread emulation for portability, so there's
there's no reason to make two syscalls where one suffices.

Furthermore, readers of the packfile will be using mmap
(or pread to emulate mmap), anyways, so the file description
offset does not matter in this case.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Eric Wong 2019-12-26 10:42:20 +00:00 committed by Junio C Hamano
parent 280738c36e
commit 4e61b2214d
1 changed files with 2 additions and 3 deletions

View File

@ -555,9 +555,8 @@ static int open_packed_git_1(struct packed_git *p)
" while index indicates %"PRIu32" objects",
p->pack_name, ntohl(hdr.hdr_entries),
p->num_objects);
if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
return error("end of packfile %s is unavailable", p->pack_name);
read_result = read_in_full(p->pack_fd, hash, hashsz);
read_result = pread_in_full(p->pack_fd, hash, hashsz,
p->pack_size - hashsz);
if (read_result < 0)
return error_errno("error reading from %s", p->pack_name);
if (read_result != hashsz)