git/builtin-unpack-objects.c
Nicolas Pitre 96a02f8f6d common progress display support
Instead of having this code duplicated in multiple places, let's have
a common interface for progress display.  If someday someone wishes to
display a cheezy progress bar instead then only one file will have to
be changed.

Note: I left merge-recursive.c out since it has a strange notion of
progress as it apparently increase the expected total number as it goes.
Someone with more intimate knowledge of what that is supposed to mean
might look at converting it to the common progress interface.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-22 22:18:05 -07:00

407 lines
8.7 KiB
C

#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 "progress.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 int offset, len;
static off_t consumed_bytes;
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);
memmove(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;
/* make sure off_t is sufficiently large not to wrap */
if (consumed_bytes > consumed_bytes + bytes)
die("pack too large for current definition of off_t");
consumed_bytes += 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 nr;
off_t base_offset;
unsigned long size;
void *delta;
struct delta_info *next;
};
static struct delta_info *delta_list;
static void add_delta_to_list(unsigned nr, unsigned const char *base_sha1,
off_t base_offset,
void *delta, unsigned long size)
{
struct delta_info *info = xmalloc(sizeof(*info));
hashcpy(info->base_sha1, base_sha1);
info->base_offset = base_offset;
info->size = size;
info->delta = delta;
info->nr = nr;
info->next = delta_list;
delta_list = info;
}
struct obj_info {
off_t offset;
unsigned char sha1[20];
};
static struct obj_info *obj_list;
static void added_object(unsigned nr, enum object_type type,
void *data, unsigned long size);
static void write_object(unsigned nr, enum object_type type,
void *buf, unsigned long size)
{
if (write_sha1_file(buf, size, typename(type), obj_list[nr].sha1) < 0)
die("failed to write object");
added_object(nr, type, buf, size);
}
static void resolve_delta(unsigned nr, enum object_type 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(nr, type, result, result_size);
free(result);
}
static void added_object(unsigned nr, enum object_type 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, obj_list[nr].sha1) ||
info->base_offset == obj_list[nr].offset) {
*p = info->next;
p = &delta_list;
resolve_delta(info->nr, type, data, size,
info->delta, info->size);
free(info);
continue;
}
p = &info->next;
}
}
static void unpack_non_delta_entry(enum object_type type, unsigned long size,
unsigned nr)
{
void *buf = get_data(size);
if (!dry_run && buf)
write_object(nr, type, buf, size);
free(buf);
}
static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
unsigned nr)
{
void *delta_data, *base;
unsigned long base_size;
unsigned char base_sha1[20];
if (type == OBJ_REF_DELTA) {
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)) {
hashcpy(obj_list[nr].sha1, null_sha1);
add_delta_to_list(nr, base_sha1, 0, delta_data, delta_size);
return;
}
} else {
unsigned base_found = 0;
unsigned char *pack, c;
off_t base_offset;
unsigned lo, mid, hi;
pack = fill(1);
c = *pack;
use(1);
base_offset = c & 127;
while (c & 128) {
base_offset += 1;
if (!base_offset || MSB(base_offset, 7))
die("offset value overflow for delta base object");
pack = fill(1);
c = *pack;
use(1);
base_offset = (base_offset << 7) + (c & 127);
}
base_offset = obj_list[nr].offset - base_offset;
delta_data = get_data(delta_size);
if (dry_run || !delta_data) {
free(delta_data);
return;
}
lo = 0;
hi = nr;
while (lo < hi) {
mid = (lo + hi)/2;
if (base_offset < obj_list[mid].offset) {
hi = mid;
} else if (base_offset > obj_list[mid].offset) {
lo = mid + 1;
} else {
hashcpy(base_sha1, obj_list[mid].sha1);
base_found = !is_null_sha1(base_sha1);
break;
}
}
if (!base_found) {
/* The delta base object is itself a delta that
has not been resolved yet. */
hashcpy(obj_list[nr].sha1, null_sha1);
add_delta_to_list(nr, null_sha1, base_offset, 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(nr, type, base, base_size, delta_data, delta_size);
free(base);
}
static void unpack_one(unsigned nr)
{
unsigned shift;
unsigned char *pack, c;
unsigned long size;
enum object_type type;
obj_list[nr].offset = consumed_bytes;
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;
}
switch (type) {
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
unpack_non_delta_entry(type, size, nr);
return;
case OBJ_REF_DELTA:
case OBJ_OFS_DELTA:
unpack_delta_entry(type, size, nr);
return;
default:
error("bad object type %d", type);
has_errors = 1;
if (recover)
return;
exit(1);
}
}
static void unpack_all(void)
{
int i;
struct progress progress;
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));
use(sizeof(struct pack_header));
if (!quiet) {
fprintf(stderr, "Unpacking %d objects\n", nr_objects);
start_progress(&progress, "", nr_objects);
}
obj_list = xmalloc(nr_objects * sizeof(*obj_list));
for (i = 0; i < nr_objects; i++) {
unpack_one(i);
if (!quiet)
display_progress(&progress, i + 1);
}
if (!quiet)
stop_progress(&progress);
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;
}
if (!prefixcmp(arg, "--pack_header=")) {
struct pack_header *hdr;
char *c;
hdr = (struct pack_header *)buffer;
hdr->hdr_signature = htonl(PACK_SIGNATURE);
hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
if (*c != ',')
die("bad %s", arg);
hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
if (*c)
die("bad %s", arg);
len = sizeof(*hdr);
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 */
return has_errors;
}