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authorMatthias Kestenholz <matthias@spinlock.ch>2006-08-03 15:24:37 (GMT)
committerJunio C Hamano <junkio@cox.net>2006-08-04 06:15:11 (GMT)
commit6441363079d85cf17aee21b8925e9745c8abda16 (patch)
tree2a9cf130a8ad94dc8899a7489dcb34b6f0301549 /builtin-unpack-objects.c
parent5d4a60033543e063bc9d77ca957de0187fb58fb3 (diff)
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Make git-unpack-objects a builtin
Signed-off-by: Matthias Kestenholz <matthias@spinlock.ch> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'builtin-unpack-objects.c')
-rw-r--r--builtin-unpack-objects.c310
1 files changed, 310 insertions, 0 deletions
diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c
new file mode 100644
index 0000000..09d264d
--- /dev/null
+++ b/builtin-unpack-objects.c
@@ -0,0 +1,310 @@
+#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;
+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 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 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 int 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);
+ return 0;
+}
+
+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 (!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;
+ }
+}
+
+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_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)
+ write_object(buf, size, type);
+ free(buf);
+ return 0;
+}
+
+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;
+
+ memcpy(base_sha1, fill(20), 20);
+ use(20);
+
+ 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);
+ }
+}
+
+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];
+
+ 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;
+ }
+ 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 (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;
+}