#include "cache.h"
+#include "object.h"
+#include "delta.h"
+#include "pack.h"
-static int nr_entries;
-static const char *base_name;
-static const char unpack_usage[] = "git-unpack-objects basename";
+#include <sys/time.h>
-struct pack_entry {
- unsigned int offset;
- unsigned char sha1[20];
+static int dry_run, quiet;
+static const char unpack_usage[] = "git-unpack-objects [-n] [-q] < pack-file";
+
+/* We always read in 4kB chunks. */
+static unsigned char buffer[4096];
+static unsigned long offset, len, eof;
+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 (eof)
+ die("unable to fill input");
+ 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)
+ die("inflate returned %d\n", ret);
+ 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 pack_entry **pack_list;
+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));
+
+ memcpy(info->base_sha1, base_sha1, 20);
+ 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 *map_file(const char *suffix, unsigned long *sizep)
+static void write_object(void *buf, unsigned long size, const char *type)
{
- static char pathname[PATH_MAX];
- unsigned long len;
- int fd;
- struct stat st;
- void *map;
-
- len = snprintf(pathname, PATH_MAX, "%s.%s", base_name, suffix);
- if (len >= PATH_MAX)
- die("bad pack base-name");
- fd = open(pathname, O_RDONLY);
- if (fd < 0 || fstat(fd, &st))
- die("unable to open '%s'", pathname);
- len = st.st_size;
- if (!len)
- die("bad pack file '%s'", pathname);
- map = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
- if (-1 == (int)(long)map)
- die("unable to mmap '%s'", pathname);
- close(fd);
- *sizep = len;
- return map;
+ 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 int sort_by_offset(const void *_a, const void *_b)
+static int resolve_delta(const char *type,
+ void *base, unsigned long base_size,
+ void *delta, unsigned long delta_size)
{
- struct pack_entry *a = *(struct pack_entry **)_a;
- struct pack_entry *b = *(struct pack_entry **)_b;
- unsigned int o1, o2;
+ void *result;
+ unsigned long result_size;
- o1 = ntohl(a->offset);
- o2 = ntohl(b->offset);
- return o1 < o2 ? -1 : 1;
+ 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);
+ return 0;
}
-static int check_index(void *index, unsigned long idx_size)
+static void added_object(unsigned char *sha1, const char *type, void *data, unsigned long size)
{
- unsigned int *array = index;
- unsigned int nr;
- int i;
+ struct delta_info **p = &delta_list;
+ struct delta_info *info;
- if (idx_size < 4*256)
- return error("index file too small");
- nr = 0;
- for (i = 0; i < 256; i++) {
- unsigned int n = ntohl(array[i]);
- if (n < nr)
- return error("non-monotonic index");
- nr = n;
+ while ((info = *p) != NULL) {
+ if (!memcmp(info->base_sha1, sha1, 20)) {
+ *p = info->next;
+ p = &delta_list;
+ resolve_delta(type, data, size, info->delta, info->size);
+ free(info);
+ continue;
+ }
+ p = &info->next;
}
- if (idx_size != 4*256 + nr * 24) {
- printf("idx_size=%d, expected %d (%d)\n", idx_size, 4*256 + nr * 24, nr);
- return error("wrong index file size");
+}
+
+static int 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"; break;
+ case OBJ_TREE: type = "tree"; break;
+ case OBJ_BLOB: type = "blob"; break;
+ case OBJ_TAG: type = "tag"; break;
+ default: die("bad type %d", kind);
}
+ if (!dry_run)
+ write_object(buf, size, type);
+ free(buf);
+ return 0;
+}
- nr_entries = nr;
- pack_list = xmalloc(nr * sizeof(struct pack_entry *));
- for (i = 0; i < nr; i++)
- pack_list[i] = index + 4*256 + i*24;
+static int unpack_delta_entry(unsigned long delta_size)
+{
+ void *delta_data, *base;
+ unsigned long base_size;
+ char type[20];
+ unsigned char base_sha1[20];
+ int result;
- qsort(pack_list, nr, sizeof(*pack_list), sort_by_offset);
+ memcpy(base_sha1, fill(20), 20);
+ use(20);
- printf("%d entries\n", nr);
- return 0;
+ delta_data = get_data(delta_size);
+ if (dry_run) {
+ free(delta_data);
+ return 0;
+ }
+
+ if (!has_sha1_file(base_sha1)) {
+ add_delta_to_list(base_sha1, delta_data, delta_size);
+ return 0;
+ }
+ base = read_sha1_file(base_sha1, type, &base_size);
+ if (!base)
+ die("failed to read delta-pack base object %s", sha1_to_hex(base_sha1));
+ result = resolve_delta(type, base, base_size, delta_data, delta_size);
+ free(base);
+ return result;
+}
+
+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:
+ die("bad object type %d", type);
+ }
+}
+
+/*
+ * We unpack from the end, older files first. Now, usually
+ * there are deltas etc, so we'll not actually write the
+ * objects in that order, but we might as well try..
+ */
+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 main(int argc, char **argv)
{
int i;
- unsigned long idx_size, pack_size;
- void *index, *pack;
+ unsigned char sha1[20];
+
+ setup_git_directory();
+
+ quiet = !isatty(2);
for (i = 1 ; i < argc; i++) {
const char *arg = argv[i];
if (*arg == '-') {
- /* Maybe we'll have some flags here some day.. */
+ if (!strcmp(arg, "-n")) {
+ dry_run = 1;
+ continue;
+ }
+ if (!strcmp(arg, "-q")) {
+ quiet = 1;
+ continue;
+ }
usage(unpack_usage);
}
- if (base_name)
- usage(unpack_usage);
- base_name = arg;
- }
- if (!base_name)
+
+ /* We don't take any non-flag arguments now.. Maybe some day */
usage(unpack_usage);
- index = map_file("idx", &idx_size);
- pack = map_file("pack", &pack_size);
- if (check_index(index, idx_size) < 0)
- die("bad index file");
+ }
+ SHA1_Init(&ctx);
+ unpack_all();
+ SHA1_Update(&ctx, buffer, offset);
+ SHA1_Final(sha1, &ctx);
+ if (memcmp(fill(20), sha1, 20))
+ 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 0;
}