mirror of
https://github.com/git/git.git
synced 2024-05-09 04:26:08 +02:00
sha1_file.c: learn about index version 2
With this patch, packs larger than 4GB are usable, even on a 32-bit machine (at least on Linux). If off_t is not large enough to deal with a large pack then die() is called instead of attempting to use the pack and producing garbage. This was tested with a 8GB pack specially created for the occasion on a 32-bit machine. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
parent
d1a46a9eab
commit
74e34e1fca
118
sha1_file.c
118
sha1_file.c
|
@ -437,7 +437,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
|
||||||
void *idx_map;
|
void *idx_map;
|
||||||
struct pack_idx_header *hdr;
|
struct pack_idx_header *hdr;
|
||||||
size_t idx_size;
|
size_t idx_size;
|
||||||
uint32_t nr, i, *index;
|
uint32_t version, nr, i, *index;
|
||||||
int fd = open(path, O_RDONLY);
|
int fd = open(path, O_RDONLY);
|
||||||
struct stat st;
|
struct stat st;
|
||||||
|
|
||||||
|
@ -455,21 +455,23 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
|
||||||
idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
|
idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
|
||||||
close(fd);
|
close(fd);
|
||||||
|
|
||||||
/* a future index format would start with this, as older git
|
|
||||||
* binaries would fail the non-monotonic index check below.
|
|
||||||
* give a nicer warning to the user if we can.
|
|
||||||
*/
|
|
||||||
hdr = idx_map;
|
hdr = idx_map;
|
||||||
if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
|
if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
|
||||||
munmap(idx_map, idx_size);
|
version = ntohl(hdr->idx_version);
|
||||||
return error("index file %s is a newer version"
|
if (version < 2 || version > 2) {
|
||||||
" and is not supported by this binary"
|
munmap(idx_map, idx_size);
|
||||||
" (try upgrading GIT to a newer version)",
|
return error("index file %s is version %d"
|
||||||
path);
|
" and is not supported by this binary"
|
||||||
}
|
" (try upgrading GIT to a newer version)",
|
||||||
|
path, version);
|
||||||
|
}
|
||||||
|
} else
|
||||||
|
version = 1;
|
||||||
|
|
||||||
nr = 0;
|
nr = 0;
|
||||||
index = idx_map;
|
index = idx_map;
|
||||||
|
if (version > 1)
|
||||||
|
index += 2; /* skip index header */
|
||||||
for (i = 0; i < 256; i++) {
|
for (i = 0; i < 256; i++) {
|
||||||
uint32_t n = ntohl(index[i]);
|
uint32_t n = ntohl(index[i]);
|
||||||
if (n < nr) {
|
if (n < nr) {
|
||||||
|
@ -479,19 +481,48 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
|
||||||
nr = n;
|
nr = n;
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
if (version == 1) {
|
||||||
* Total size:
|
/*
|
||||||
* - 256 index entries 4 bytes each
|
* Total size:
|
||||||
* - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
|
* - 256 index entries 4 bytes each
|
||||||
* - 20-byte SHA1 of the packfile
|
* - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
|
||||||
* - 20-byte SHA1 file checksum
|
* - 20-byte SHA1 of the packfile
|
||||||
*/
|
* - 20-byte SHA1 file checksum
|
||||||
if (idx_size != 4*256 + nr * 24 + 20 + 20) {
|
*/
|
||||||
munmap(idx_map, idx_size);
|
if (idx_size != 4*256 + nr * 24 + 20 + 20) {
|
||||||
return error("wrong index file size in %s", path);
|
munmap(idx_map, idx_size);
|
||||||
|
return error("wrong index file size in %s", path);
|
||||||
|
}
|
||||||
|
} else if (version == 2) {
|
||||||
|
/*
|
||||||
|
* Minimum size:
|
||||||
|
* - 8 bytes of header
|
||||||
|
* - 256 index entries 4 bytes each
|
||||||
|
* - 20-byte sha1 entry * nr
|
||||||
|
* - 4-byte crc entry * nr
|
||||||
|
* - 4-byte offset entry * nr
|
||||||
|
* - 20-byte SHA1 of the packfile
|
||||||
|
* - 20-byte SHA1 file checksum
|
||||||
|
* And after the 4-byte offset table might be a
|
||||||
|
* variable sized table containing 8-byte entries
|
||||||
|
* for offsets larger than 2^31.
|
||||||
|
*/
|
||||||
|
unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
|
||||||
|
if (idx_size < min_size || idx_size > min_size + (nr - 1)*8) {
|
||||||
|
munmap(idx_map, idx_size);
|
||||||
|
return error("wrong index file size in %s", path);
|
||||||
|
}
|
||||||
|
if (idx_size != min_size) {
|
||||||
|
/* make sure we can deal with large pack offsets */
|
||||||
|
off_t x = 0x7fffffffUL, y = 0xffffffffUL;
|
||||||
|
if (x > (x + 1) || y > (y + 1)) {
|
||||||
|
munmap(idx_map, idx_size);
|
||||||
|
return error("pack too large for current definition of off_t in %s", path);
|
||||||
|
}
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
p->index_version = 1;
|
p->index_version = version;
|
||||||
p->index_data = idx_map;
|
p->index_data = idx_map;
|
||||||
p->index_size = idx_size;
|
p->index_size = idx_size;
|
||||||
p->num_objects = nr;
|
p->num_objects = nr;
|
||||||
|
@ -1531,27 +1562,56 @@ const unsigned char *nth_packed_object_sha1(const struct packed_git *p,
|
||||||
uint32_t n)
|
uint32_t n)
|
||||||
{
|
{
|
||||||
const unsigned char *index = p->index_data;
|
const unsigned char *index = p->index_data;
|
||||||
index += 4 * 256;
|
|
||||||
if (n >= p->num_objects)
|
if (n >= p->num_objects)
|
||||||
return NULL;
|
return NULL;
|
||||||
return index + 24 * n + 4;
|
index += 4 * 256;
|
||||||
|
if (p->index_version == 1) {
|
||||||
|
return index + 24 * n + 4;
|
||||||
|
} else {
|
||||||
|
index += 8;
|
||||||
|
return index + 20 * n;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static 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;
|
||||||
|
return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
|
||||||
|
ntohl(*((uint32_t *)(index + 4)));
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
off_t find_pack_entry_one(const unsigned char *sha1,
|
off_t find_pack_entry_one(const unsigned char *sha1,
|
||||||
struct packed_git *p)
|
struct packed_git *p)
|
||||||
{
|
{
|
||||||
const uint32_t *level1_ofs = p->index_data;
|
const uint32_t *level1_ofs = p->index_data;
|
||||||
int hi = ntohl(level1_ofs[*sha1]);
|
|
||||||
int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
|
|
||||||
const unsigned char *index = p->index_data;
|
const unsigned char *index = p->index_data;
|
||||||
|
unsigned hi, lo;
|
||||||
|
|
||||||
|
if (p->index_version > 1) {
|
||||||
|
level1_ofs += 2;
|
||||||
|
index += 8;
|
||||||
|
}
|
||||||
index += 4 * 256;
|
index += 4 * 256;
|
||||||
|
hi = ntohl(level1_ofs[*sha1]);
|
||||||
|
lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
|
||||||
|
|
||||||
do {
|
do {
|
||||||
int mi = (lo + hi) / 2;
|
unsigned mi = (lo + hi) / 2;
|
||||||
int cmp = hashcmp(index + 24 * mi + 4, sha1);
|
unsigned x = (p->index_version > 1) ? (mi * 20) : (mi * 24 + 4);
|
||||||
|
int cmp = hashcmp(index + x, sha1);
|
||||||
if (!cmp)
|
if (!cmp)
|
||||||
return ntohl(*((uint32_t *)((char *)index + (24 * mi))));
|
return nth_packed_object_offset(p, mi);
|
||||||
if (cmp > 0)
|
if (cmp > 0)
|
||||||
hi = mi;
|
hi = mi;
|
||||||
else
|
else
|
||||||
|
|
Loading…
Reference in New Issue