mirror of
https://github.com/git/git
synced 2024-08-25 02:35:46 +00:00
Add git-index-pack utility
git-index-pack builds a pack index file for an existing packed archive. With this utility a packed archive which was transferred without the corresponding pack index can be added to objects/pack/ without repacking. Signed-off-by: Sergey Vlasov <vsu@altlinux.ru> Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
parent
a1451104ac
commit
9cf6d3357a
44
Documentation/git-index-pack.txt
Normal file
44
Documentation/git-index-pack.txt
Normal file
|
@ -0,0 +1,44 @@
|
|||
git-index-pack(1)
|
||||
=================
|
||||
|
||||
NAME
|
||||
----
|
||||
git-index-pack - Build pack index file for an existing packed archive
|
||||
|
||||
|
||||
SYNOPSIS
|
||||
--------
|
||||
'git-index-pack' [-o <index-file>] <pack-file>
|
||||
|
||||
|
||||
DESCRIPTION
|
||||
-----------
|
||||
Reads a packed archive (.pack) from the specified file, and
|
||||
builds a pack index file (.idx) for it. The packed archive
|
||||
together with the pack index can then be placed in the
|
||||
objects/pack/ directory of a git repository.
|
||||
|
||||
|
||||
OPTIONS
|
||||
-------
|
||||
-o <index-file>::
|
||||
Write the generated pack index into the specified
|
||||
file. Without this option the name of pack index
|
||||
file is constructed from the name of packed archive
|
||||
file by replacing .pack with .idx (and the program
|
||||
fails if the name of packed archive does not end
|
||||
with .pack).
|
||||
|
||||
|
||||
Author
|
||||
------
|
||||
Written by Sergey Vlasov <vsu@altlinux.ru>
|
||||
|
||||
Documentation
|
||||
-------------
|
||||
Documentation by Sergey Vlasov
|
||||
|
||||
GIT
|
||||
---
|
||||
Part of the gitlink:git[7] suite
|
||||
|
|
@ -68,6 +68,9 @@ gitlink:git-commit-tree[1]::
|
|||
gitlink:git-hash-object[1]::
|
||||
Computes the object ID from a file.
|
||||
|
||||
gitlink:git-index-pack.html[1]::
|
||||
Build pack index file for an existing packed archive.
|
||||
|
||||
gitlink:git-init-db[1]::
|
||||
Creates an empty git object database
|
||||
|
||||
|
|
2
Makefile
2
Makefile
|
@ -110,7 +110,7 @@ PROGRAMS = \
|
|||
git-convert-objects$X git-diff-files$X \
|
||||
git-diff-index$X git-diff-stages$X \
|
||||
git-diff-tree$X git-fetch-pack$X git-fsck-objects$X \
|
||||
git-hash-object$X git-init-db$X \
|
||||
git-hash-object$X git-index-pack$X git-init-db$X \
|
||||
git-local-fetch$X git-ls-files$X git-ls-tree$X git-merge-base$X \
|
||||
git-merge-index$X git-mktag$X git-pack-objects$X git-patch-id$X \
|
||||
git-peek-remote$X git-prune-packed$X git-read-tree$X \
|
||||
|
|
451
index-pack.c
Normal file
451
index-pack.c
Normal file
|
@ -0,0 +1,451 @@
|
|||
#include "cache.h"
|
||||
#include "delta.h"
|
||||
#include "pack.h"
|
||||
#include "csum-file.h"
|
||||
|
||||
static const char index_pack_usage[] =
|
||||
"git-index-pack [-o index-file] pack-file";
|
||||
|
||||
struct object_entry
|
||||
{
|
||||
unsigned long offset;
|
||||
enum object_type type;
|
||||
enum object_type real_type;
|
||||
unsigned char sha1[20];
|
||||
};
|
||||
|
||||
struct delta_entry
|
||||
{
|
||||
struct object_entry *obj;
|
||||
unsigned char base_sha1[20];
|
||||
};
|
||||
|
||||
static const char *pack_name;
|
||||
static unsigned char *pack_base;
|
||||
static unsigned long pack_size;
|
||||
static struct object_entry *objects;
|
||||
static struct delta_entry *deltas;
|
||||
static int nr_objects;
|
||||
static int nr_deltas;
|
||||
|
||||
static void open_pack_file(void)
|
||||
{
|
||||
int fd;
|
||||
struct stat st;
|
||||
|
||||
fd = open(pack_name, O_RDONLY);
|
||||
if (fd < 0)
|
||||
die("cannot open packfile '%s': %s", pack_name,
|
||||
strerror(errno));
|
||||
if (fstat(fd, &st)) {
|
||||
int err = errno;
|
||||
close(fd);
|
||||
die("cannot fstat packfile '%s': %s", pack_name,
|
||||
strerror(err));
|
||||
}
|
||||
pack_size = st.st_size;
|
||||
pack_base = mmap(NULL, pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
|
||||
if (pack_base == MAP_FAILED) {
|
||||
int err = errno;
|
||||
close(fd);
|
||||
die("cannot mmap packfile '%s': %s", pack_name,
|
||||
strerror(err));
|
||||
}
|
||||
close(fd);
|
||||
}
|
||||
|
||||
static void parse_pack_header(void)
|
||||
{
|
||||
const struct pack_header *hdr;
|
||||
unsigned char sha1[20];
|
||||
SHA_CTX ctx;
|
||||
|
||||
/* Ensure there are enough bytes for the header and final SHA1 */
|
||||
if (pack_size < sizeof(struct pack_header) + 20)
|
||||
die("packfile '%s' is too small", pack_name);
|
||||
|
||||
/* Header consistency check */
|
||||
hdr = (void *)pack_base;
|
||||
if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
|
||||
die("packfile '%s' signature mismatch", pack_name);
|
||||
if (hdr->hdr_version != htonl(PACK_VERSION))
|
||||
die("packfile '%s' version %d different from ours %d",
|
||||
pack_name, ntohl(hdr->hdr_version), PACK_VERSION);
|
||||
|
||||
nr_objects = ntohl(hdr->hdr_entries);
|
||||
|
||||
/* Check packfile integrity */
|
||||
SHA1_Init(&ctx);
|
||||
SHA1_Update(&ctx, pack_base, pack_size - 20);
|
||||
SHA1_Final(sha1, &ctx);
|
||||
if (memcmp(sha1, pack_base + pack_size - 20, 20))
|
||||
die("packfile '%s' SHA1 mismatch", pack_name);
|
||||
}
|
||||
|
||||
static void bad_object(unsigned long offset, const char *format,
|
||||
...) NORETURN __attribute__((format (printf, 2, 3)));
|
||||
|
||||
static void bad_object(unsigned long offset, const char *format, ...)
|
||||
{
|
||||
va_list params;
|
||||
char buf[1024];
|
||||
|
||||
va_start(params, format);
|
||||
vsnprintf(buf, sizeof(buf), format, params);
|
||||
va_end(params);
|
||||
die("packfile '%s': bad object at offset %lu: %s",
|
||||
pack_name, offset, buf);
|
||||
}
|
||||
|
||||
static void *unpack_entry_data(unsigned long offset,
|
||||
unsigned long *current_pos, unsigned long size)
|
||||
{
|
||||
unsigned long pack_limit = pack_size - 20;
|
||||
unsigned long pos = *current_pos;
|
||||
z_stream stream;
|
||||
void *buf = xmalloc(size);
|
||||
|
||||
memset(&stream, 0, sizeof(stream));
|
||||
stream.next_out = buf;
|
||||
stream.avail_out = size;
|
||||
stream.next_in = pack_base + pos;
|
||||
stream.avail_in = pack_limit - pos;
|
||||
inflateInit(&stream);
|
||||
|
||||
for (;;) {
|
||||
int ret = inflate(&stream, 0);
|
||||
if (ret == Z_STREAM_END)
|
||||
break;
|
||||
if (ret != Z_OK)
|
||||
bad_object(offset, "inflate returned %d", ret);
|
||||
}
|
||||
inflateEnd(&stream);
|
||||
if (stream.total_out != size)
|
||||
bad_object(offset, "size mismatch (expected %lu, got %lu)",
|
||||
size, stream.total_out);
|
||||
*current_pos = pack_limit - stream.avail_in;
|
||||
return buf;
|
||||
}
|
||||
|
||||
static void *unpack_raw_entry(unsigned long offset,
|
||||
enum object_type *obj_type,
|
||||
unsigned long *obj_size,
|
||||
unsigned char *delta_base,
|
||||
unsigned long *next_obj_offset)
|
||||
{
|
||||
unsigned long pack_limit = pack_size - 20;
|
||||
unsigned long pos = offset;
|
||||
unsigned char c;
|
||||
unsigned long size;
|
||||
unsigned shift;
|
||||
enum object_type type;
|
||||
void *data;
|
||||
|
||||
c = pack_base[pos++];
|
||||
type = (c >> 4) & 7;
|
||||
size = (c & 15);
|
||||
shift = 4;
|
||||
while (c & 0x80) {
|
||||
if (pos >= pack_limit)
|
||||
bad_object(offset, "object extends past end of pack");
|
||||
c = pack_base[pos++];
|
||||
size += (c & 0x7fUL) << shift;
|
||||
shift += 7;
|
||||
}
|
||||
|
||||
switch (type) {
|
||||
case OBJ_DELTA:
|
||||
if (pos + 20 >= pack_limit)
|
||||
bad_object(offset, "object extends past end of pack");
|
||||
memcpy(delta_base, pack_base + pos, 20);
|
||||
pos += 20;
|
||||
/* fallthru */
|
||||
case OBJ_COMMIT:
|
||||
case OBJ_TREE:
|
||||
case OBJ_BLOB:
|
||||
case OBJ_TAG:
|
||||
data = unpack_entry_data(offset, &pos, size);
|
||||
break;
|
||||
default:
|
||||
bad_object(offset, "bad object type %d", type);
|
||||
}
|
||||
|
||||
*obj_type = type;
|
||||
*obj_size = size;
|
||||
*next_obj_offset = pos;
|
||||
return data;
|
||||
}
|
||||
|
||||
static int find_delta(const unsigned char *base_sha1)
|
||||
{
|
||||
int first = 0, last = nr_deltas;
|
||||
|
||||
while (first < last) {
|
||||
int next = (first + last) / 2;
|
||||
struct delta_entry *delta = &deltas[next];
|
||||
int cmp;
|
||||
|
||||
cmp = memcmp(base_sha1, delta->base_sha1, 20);
|
||||
if (!cmp)
|
||||
return next;
|
||||
if (cmp < 0) {
|
||||
last = next;
|
||||
continue;
|
||||
}
|
||||
first = next+1;
|
||||
}
|
||||
return -first-1;
|
||||
}
|
||||
|
||||
static int find_deltas_based_on_sha1(const unsigned char *base_sha1,
|
||||
int *first_index, int *last_index)
|
||||
{
|
||||
int first = find_delta(base_sha1);
|
||||
int last = first;
|
||||
int end = nr_deltas - 1;
|
||||
|
||||
if (first < 0)
|
||||
return -1;
|
||||
while (first > 0 && !memcmp(deltas[first-1].base_sha1, base_sha1, 20))
|
||||
--first;
|
||||
while (last < end && !memcmp(deltas[last+1].base_sha1, base_sha1, 20))
|
||||
++last;
|
||||
*first_index = first;
|
||||
*last_index = last;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void sha1_object(const void *data, unsigned long size,
|
||||
enum object_type type, unsigned char *sha1)
|
||||
{
|
||||
SHA_CTX ctx;
|
||||
char header[50];
|
||||
int header_size;
|
||||
const char *type_str;
|
||||
|
||||
switch (type) {
|
||||
case OBJ_COMMIT: type_str = "commit"; break;
|
||||
case OBJ_TREE: type_str = "tree"; break;
|
||||
case OBJ_BLOB: type_str = "blob"; break;
|
||||
case OBJ_TAG: type_str = "tag"; break;
|
||||
default:
|
||||
die("bad type %d", type);
|
||||
}
|
||||
|
||||
header_size = sprintf(header, "%s %lu", type_str, size) + 1;
|
||||
|
||||
SHA1_Init(&ctx);
|
||||
SHA1_Update(&ctx, header, header_size);
|
||||
SHA1_Update(&ctx, data, size);
|
||||
SHA1_Final(sha1, &ctx);
|
||||
}
|
||||
|
||||
static void resolve_delta(struct delta_entry *delta, void *base_data,
|
||||
unsigned long base_size, enum object_type type)
|
||||
{
|
||||
struct object_entry *obj = delta->obj;
|
||||
void *delta_data;
|
||||
unsigned long delta_size;
|
||||
void *result;
|
||||
unsigned long result_size;
|
||||
enum object_type delta_type;
|
||||
unsigned char base_sha1[20];
|
||||
unsigned long next_obj_offset;
|
||||
int j, first, last;
|
||||
|
||||
obj->real_type = type;
|
||||
delta_data = unpack_raw_entry(obj->offset, &delta_type,
|
||||
&delta_size, base_sha1,
|
||||
&next_obj_offset);
|
||||
result = patch_delta(base_data, base_size, delta_data, delta_size,
|
||||
&result_size);
|
||||
free(delta_data);
|
||||
if (!result)
|
||||
bad_object(obj->offset, "failed to apply delta");
|
||||
sha1_object(result, result_size, type, obj->sha1);
|
||||
if (!find_deltas_based_on_sha1(obj->sha1, &first, &last)) {
|
||||
for (j = first; j <= last; j++)
|
||||
resolve_delta(&deltas[j], result, result_size, type);
|
||||
}
|
||||
free(result);
|
||||
}
|
||||
|
||||
static int compare_delta_entry(const void *a, const void *b)
|
||||
{
|
||||
const struct delta_entry *delta_a = a;
|
||||
const struct delta_entry *delta_b = b;
|
||||
return memcmp(delta_a->base_sha1, delta_b->base_sha1, 20);
|
||||
}
|
||||
|
||||
static void parse_pack_objects(void)
|
||||
{
|
||||
int i;
|
||||
unsigned long offset = sizeof(struct pack_header);
|
||||
unsigned char base_sha1[20];
|
||||
void *data;
|
||||
unsigned long data_size;
|
||||
|
||||
/*
|
||||
* First pass:
|
||||
* - find locations of all objects;
|
||||
* - calculate SHA1 of all non-delta objects;
|
||||
* - remember base SHA1 for all deltas.
|
||||
*/
|
||||
for (i = 0; i < nr_objects; i++) {
|
||||
struct object_entry *obj = &objects[i];
|
||||
obj->offset = offset;
|
||||
data = unpack_raw_entry(offset, &obj->type, &data_size,
|
||||
base_sha1, &offset);
|
||||
obj->real_type = obj->type;
|
||||
if (obj->type == OBJ_DELTA) {
|
||||
struct delta_entry *delta = &deltas[nr_deltas++];
|
||||
delta->obj = obj;
|
||||
memcpy(delta->base_sha1, base_sha1, 20);
|
||||
} else
|
||||
sha1_object(data, data_size, obj->type, obj->sha1);
|
||||
free(data);
|
||||
}
|
||||
if (offset != pack_size - 20)
|
||||
die("packfile '%s' has junk at the end", pack_name);
|
||||
|
||||
/* Sort deltas by base SHA1 for fast searching */
|
||||
qsort(deltas, nr_deltas, sizeof(struct delta_entry),
|
||||
compare_delta_entry);
|
||||
|
||||
/*
|
||||
* Second pass:
|
||||
* - for all non-delta objects, look if it is used as a base for
|
||||
* deltas;
|
||||
* - if used as a base, uncompress the object and apply all deltas,
|
||||
* recursively checking if the resulting object is used as a base
|
||||
* for some more deltas.
|
||||
*/
|
||||
for (i = 0; i < nr_objects; i++) {
|
||||
struct object_entry *obj = &objects[i];
|
||||
int j, first, last;
|
||||
|
||||
if (obj->type == OBJ_DELTA)
|
||||
continue;
|
||||
if (find_deltas_based_on_sha1(obj->sha1, &first, &last))
|
||||
continue;
|
||||
data = unpack_raw_entry(obj->offset, &obj->type, &data_size,
|
||||
base_sha1, &offset);
|
||||
for (j = first; j <= last; j++)
|
||||
resolve_delta(&deltas[j], data, data_size, obj->type);
|
||||
free(data);
|
||||
}
|
||||
|
||||
/* Check for unresolved deltas */
|
||||
for (i = 0; i < nr_deltas; i++) {
|
||||
if (deltas[i].obj->real_type == OBJ_DELTA)
|
||||
die("packfile '%s' has unresolved deltas", pack_name);
|
||||
}
|
||||
}
|
||||
|
||||
static int sha1_compare(const void *_a, const void *_b)
|
||||
{
|
||||
struct object_entry *a = *(struct object_entry **)_a;
|
||||
struct object_entry *b = *(struct object_entry **)_b;
|
||||
return memcmp(a->sha1, b->sha1, 20);
|
||||
}
|
||||
|
||||
static void write_index_file(const char *index_name)
|
||||
{
|
||||
struct sha1file *f;
|
||||
struct object_entry **sorted_by_sha =
|
||||
xcalloc(nr_objects, sizeof(struct object_entry *));
|
||||
struct object_entry **list = sorted_by_sha;
|
||||
struct object_entry **last = sorted_by_sha + nr_objects;
|
||||
unsigned int array[256];
|
||||
int i;
|
||||
|
||||
for (i = 0; i < nr_objects; ++i)
|
||||
sorted_by_sha[i] = &objects[i];
|
||||
qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]),
|
||||
sha1_compare);
|
||||
|
||||
unlink(index_name);
|
||||
f = sha1create("%s", index_name);
|
||||
|
||||
/*
|
||||
* Write the first-level table (the list is sorted,
|
||||
* but we use a 256-entry lookup to be able to avoid
|
||||
* having to do eight extra binary search iterations).
|
||||
*/
|
||||
for (i = 0; i < 256; i++) {
|
||||
struct object_entry **next = list;
|
||||
while (next < last) {
|
||||
struct object_entry *obj = *next;
|
||||
if (obj->sha1[0] != i)
|
||||
break;
|
||||
next++;
|
||||
}
|
||||
array[i] = htonl(next - sorted_by_sha);
|
||||
list = next;
|
||||
}
|
||||
sha1write(f, array, 256 * sizeof(int));
|
||||
|
||||
/*
|
||||
* Write the actual SHA1 entries..
|
||||
*/
|
||||
list = sorted_by_sha;
|
||||
for (i = 0; i < nr_objects; i++) {
|
||||
struct object_entry *obj = *list++;
|
||||
unsigned int offset = htonl(obj->offset);
|
||||
sha1write(f, &offset, 4);
|
||||
sha1write(f, obj->sha1, 20);
|
||||
}
|
||||
sha1write(f, pack_base + pack_size - 20, 20);
|
||||
sha1close(f, NULL, 1);
|
||||
free(sorted_by_sha);
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int i;
|
||||
char *index_name = NULL;
|
||||
char *index_name_buf = NULL;
|
||||
|
||||
for (i = 1; i < argc; i++) {
|
||||
const char *arg = argv[i];
|
||||
|
||||
if (*arg == '-') {
|
||||
if (!strcmp(arg, "-o")) {
|
||||
if (index_name || (i+1) >= argc)
|
||||
usage(index_pack_usage);
|
||||
index_name = argv[++i];
|
||||
} else
|
||||
usage(index_pack_usage);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (pack_name)
|
||||
usage(index_pack_usage);
|
||||
pack_name = arg;
|
||||
}
|
||||
|
||||
if (!pack_name)
|
||||
usage(index_pack_usage);
|
||||
if (!index_name) {
|
||||
int len = strlen(pack_name);
|
||||
if (len < 5 || strcmp(pack_name + len - 5, ".pack"))
|
||||
die("packfile name '%s' does not end with '.pack'",
|
||||
pack_name);
|
||||
index_name_buf = xmalloc(len - 1);
|
||||
memcpy(index_name_buf, pack_name, len - 5);
|
||||
strcpy(index_name_buf + len - 5, ".idx");
|
||||
index_name = index_name_buf;
|
||||
}
|
||||
|
||||
open_pack_file();
|
||||
parse_pack_header();
|
||||
objects = xcalloc(nr_objects, sizeof(struct object_entry));
|
||||
deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
|
||||
parse_pack_objects();
|
||||
free(deltas);
|
||||
write_index_file(index_name);
|
||||
free(objects);
|
||||
free(index_name_buf);
|
||||
|
||||
return 0;
|
||||
}
|
|
@ -165,4 +165,22 @@ test_expect_success \
|
|||
|
||||
:'
|
||||
|
||||
test_expect_success \
|
||||
'build pack index for an existing pack' \
|
||||
'cp test-1-${packname_1}.pack test-3.pack &&
|
||||
git-index-pack -o tmp.idx test-3.pack &&
|
||||
cmp tmp.idx test-1-${packname_1}.idx &&
|
||||
|
||||
git-index-pack test-3.pack &&
|
||||
cmp test-3.idx test-1-${packname_1}.idx &&
|
||||
|
||||
cp test-2-${packname_2}.pack test-3.pack &&
|
||||
git-index-pack -o tmp.idx test-2-${packname_2}.pack &&
|
||||
cmp tmp.idx test-2-${packname_2}.idx &&
|
||||
|
||||
git-index-pack test-3.pack &&
|
||||
cmp test-3.idx test-2-${packname_2}.idx &&
|
||||
|
||||
:'
|
||||
|
||||
test_done
|
||||
|
|
Loading…
Reference in a new issue