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328 lines (288 sloc) 6.989 kb
#include "builtin.h"
#include "cache.h"
#include "object.h"
#include "delta.h"
#include "pack.h"
#include "blob.h"
#include "commit.h"
#include "tag.h"
#include "tree.h"
#include <sys/time.h>
static int dry_run, quiet, recover, has_errors;
static const char unpack_usage[] = "git-unpack-objects [-n] [-q] [-r] < pack-file";
/* We always read in 4kB chunks. */
static unsigned char buffer[4096];
static unsigned long offset, len;
static SHA_CTX ctx;
/*
* Make sure at least "min" bytes are available in the buffer, and
* return the pointer to the buffer.
*/
static void * fill(int min)
{
if (min <= len)
return buffer + offset;
if (min > sizeof(buffer))
die("cannot fill %d bytes", min);
if (offset) {
SHA1_Update(&ctx, buffer, offset);
memcpy(buffer, buffer + offset, len);
offset = 0;
}
do {
int ret = xread(0, buffer + len, sizeof(buffer) - len);
if (ret <= 0) {
if (!ret)
die("early EOF");
die("read error on input: %s", strerror(errno));
}
len += ret;
} while (len < min);
return buffer;
}
static void use(int bytes)
{
if (bytes > len)
die("used more bytes than were available");
len -= bytes;
offset += bytes;
}
static void *get_data(unsigned long size)
{
z_stream stream;
void *buf = xmalloc(size);
memset(&stream, 0, sizeof(stream));
stream.next_out = buf;
stream.avail_out = size;
stream.next_in = fill(1);
stream.avail_in = len;
inflateInit(&stream);
for (;;) {
int ret = inflate(&stream, 0);
use(len - stream.avail_in);
if (stream.total_out == size && ret == Z_STREAM_END)
break;
if (ret != Z_OK) {
error("inflate returned %d\n", ret);
free(buf);
buf = NULL;
if (!recover)
exit(1);
has_errors = 1;
break;
}
stream.next_in = fill(1);
stream.avail_in = len;
}
inflateEnd(&stream);
return buf;
}
struct delta_info {
unsigned char base_sha1[20];
unsigned long size;
void *delta;
struct delta_info *next;
};
static struct delta_info *delta_list;
static void add_delta_to_list(unsigned char *base_sha1, void *delta, unsigned long size)
{
struct delta_info *info = xmalloc(sizeof(*info));
hashcpy(info->base_sha1, base_sha1);
info->size = size;
info->delta = delta;
info->next = delta_list;
delta_list = info;
}
static void added_object(unsigned char *sha1, const char *type, void *data, unsigned long size);
static void write_object(void *buf, unsigned long size, const char *type)
{
unsigned char sha1[20];
if (write_sha1_file(buf, size, type, sha1) < 0)
die("failed to write object");
added_object(sha1, type, buf, size);
}
static void resolve_delta(const char *type,
void *base, unsigned long base_size,
void *delta, unsigned long delta_size)
{
void *result;
unsigned long result_size;
result = patch_delta(base, base_size,
delta, delta_size,
&result_size);
if (!result)
die("failed to apply delta");
free(delta);
write_object(result, result_size, type);
free(result);
}
static void added_object(unsigned char *sha1, const char *type, void *data, unsigned long size)
{
struct delta_info **p = &delta_list;
struct delta_info *info;
while ((info = *p) != NULL) {
if (!hashcmp(info->base_sha1, sha1)) {
*p = info->next;
p = &delta_list;
resolve_delta(type, data, size, info->delta, info->size);
free(info);
continue;
}
p = &info->next;
}
}
static void unpack_non_delta_entry(enum object_type kind, unsigned long size)
{
void *buf = get_data(size);
const char *type;
switch (kind) {
case OBJ_COMMIT: type = commit_type; break;
case OBJ_TREE: type = tree_type; break;
case OBJ_BLOB: type = blob_type; break;
case OBJ_TAG: type = tag_type; break;
default: die("bad type %d", kind);
}
if (!dry_run && buf)
write_object(buf, size, type);
free(buf);
}
static void unpack_delta_entry(unsigned long delta_size)
{
void *delta_data, *base;
unsigned long base_size;
char type[20];
unsigned char base_sha1[20];
hashcpy(base_sha1, fill(20));
use(20);
delta_data = get_data(delta_size);
if (dry_run || !delta_data) {
free(delta_data);
return;
}
if (!has_sha1_file(base_sha1)) {
add_delta_to_list(base_sha1, delta_data, delta_size);
return;
}
base = read_sha1_file(base_sha1, type, &base_size);
if (!base) {
error("failed to read delta-pack base object %s",
sha1_to_hex(base_sha1));
if (!recover)
exit(1);
has_errors = 1;
return;
}
resolve_delta(type, base, base_size, delta_data, delta_size);
free(base);
}
static void unpack_one(unsigned nr, unsigned total)
{
unsigned shift;
unsigned char *pack, c;
unsigned long size;
enum object_type type;
pack = fill(1);
c = *pack;
use(1);
type = (c >> 4) & 7;
size = (c & 15);
shift = 4;
while (c & 0x80) {
pack = fill(1);
c = *pack++;
use(1);
size += (c & 0x7f) << shift;
shift += 7;
}
if (!quiet) {
static unsigned long last_sec;
static unsigned last_percent;
struct timeval now;
unsigned percentage = (nr * 100) / total;
gettimeofday(&now, NULL);
if (percentage != last_percent || now.tv_sec != last_sec) {
last_sec = now.tv_sec;
last_percent = percentage;
fprintf(stderr, "%4u%% (%u/%u) done\r", percentage, nr, total);
}
}
switch (type) {
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
unpack_non_delta_entry(type, size);
return;
case OBJ_DELTA:
unpack_delta_entry(size);
return;
default:
error("bad object type %d", type);
has_errors = 1;
if (recover)
return;
exit(1);
}
}
static void unpack_all(void)
{
int i;
struct pack_header *hdr = fill(sizeof(struct pack_header));
unsigned nr_objects = ntohl(hdr->hdr_entries);
if (ntohl(hdr->hdr_signature) != PACK_SIGNATURE)
die("bad pack file");
if (!pack_version_ok(hdr->hdr_version))
die("unknown pack file version %d", ntohl(hdr->hdr_version));
fprintf(stderr, "Unpacking %d objects\n", nr_objects);
use(sizeof(struct pack_header));
for (i = 0; i < nr_objects; i++)
unpack_one(i+1, nr_objects);
if (delta_list)
die("unresolved deltas left after unpacking");
}
int cmd_unpack_objects(int argc, const char **argv, const char *prefix)
{
int i;
unsigned char sha1[20];
git_config(git_default_config);
quiet = !isatty(2);
for (i = 1 ; i < argc; i++) {
const char *arg = argv[i];
if (*arg == '-') {
if (!strcmp(arg, "-n")) {
dry_run = 1;
continue;
}
if (!strcmp(arg, "-q")) {
quiet = 1;
continue;
}
if (!strcmp(arg, "-r")) {
recover = 1;
continue;
}
usage(unpack_usage);
}
/* We don't take any non-flag arguments now.. Maybe some day */
usage(unpack_usage);
}
SHA1_Init(&ctx);
unpack_all();
SHA1_Update(&ctx, buffer, offset);
SHA1_Final(sha1, &ctx);
if (hashcmp(fill(20), sha1))
die("final sha1 did not match");
use(20);
/* Write the last part of the buffer to stdout */
while (len) {
int ret = xwrite(1, buffer + offset, len);
if (ret <= 0)
break;
len -= ret;
offset += ret;
}
/* All done */
if (!quiet)
fprintf(stderr, "\n");
return has_errors;
}
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