зеркало из https://github.com/microsoft/git.git
Fix object packing/unpacking.
This actually successfully packed and unpacked a git archive down to 1.3MB (17MB unpacked). Right now unpacking is way too noisy, lots of debug messages left.
This commit is contained in:
Linus Torvalds
Родитель
8ee378a0f0
Коммит
c4fb06c0d0
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@ -96,7 +96,7 @@ static unsigned long write_object(FILE *f, struct object_entry *entry)
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unsigned long size;
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char type[10];
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void *buf = read_sha1_file(entry->sha1, type, &size);
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char header[21];
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char header[25];
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unsigned hdrlen, datalen;
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if (!buf)
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@ -110,16 +110,16 @@ static unsigned long write_object(FILE *f, struct object_entry *entry)
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* instead.
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*/
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header[0] = ".CTB"[entry->type];
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datalen = htonl(size);
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memcpy(header+1, &datalen, 4);
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hdrlen = 5;
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if (entry->delta) {
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header[0] = 'D';
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memcpy(header+1, entry->delta, 20);
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memcpy(header+5, entry->delta, 20);
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buf = delta_against(buf, size, entry);
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size = entry->delta_size;
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hdrlen = 21;
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hdrlen = 25;
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}
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datalen = htonl(size);
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memcpy(header+1, &datalen, 4);
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fwrite(header, hdrlen, 1, f);
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datalen = fwrite_compressed(buf, size, f);
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free(buf);
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@ -88,26 +88,26 @@ static int check_index(void)
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}
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static int unpack_non_delta_entry(struct pack_entry *entry,
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unsigned char *pack)
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int kind,
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unsigned char *data,
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unsigned long size,
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unsigned long left)
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{
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int st, kind;
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unsigned long size;
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int st;
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z_stream stream;
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char *buffer;
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unsigned char sha1[20];
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char *type_s;
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unsigned long offset = ntohl(entry->offset);
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kind = pack[0];
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size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4];
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printf("%s %c %lu\n", sha1_to_hex(entry->sha1), kind, size);
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pack += 5;
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if (dry_run)
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return 0;
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buffer = xmalloc(size + 1);
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buffer[size] = 0;
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memset(&stream, 0, sizeof(stream));
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stream.next_in = pack;
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stream.avail_in = pack_size - offset; /* sheesh. */
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stream.next_in = data;
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stream.avail_in = left;
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stream.next_out = buffer;
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stream.avail_out = size;
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@ -148,14 +148,15 @@ static int find_pack_entry(unsigned char *sha1, struct pack_entry **ent)
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do {
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int mi = (lo + hi) / 2;
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int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
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printf("lo=%d mi=%d hi=%d cmp=%d\n", lo, mi, hi, cmp);
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if (!cmp) {
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*ent = index + 24 * mi;
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return 1;
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}
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if (cmp < 0)
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if (cmp > 0)
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hi = mi;
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else
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lo = mi;
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lo = mi+1;
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} while (lo < hi);
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return 0;
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}
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@ -163,70 +164,55 @@ static int find_pack_entry(unsigned char *sha1, struct pack_entry **ent)
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/* forward declaration for a mutually recursive function */
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static void unpack_entry(struct pack_entry *);
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static int unpack_delta_entry(struct pack_entry *entry, unsigned char *pack)
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static int unpack_delta_entry(struct pack_entry *entry,
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unsigned char *base_sha1,
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unsigned long delta_size,
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unsigned long left)
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{
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void *delta_data, *result, *base;
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unsigned long delta_alloc, delta_size, result_size, base_size;
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void *data, *delta_data, *result, *base;
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unsigned long data_size, result_size, base_size;
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z_stream stream;
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int st;
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char type[20];
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unsigned char sha1[20];
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printf("%s D", sha1_to_hex(entry->sha1));
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printf(" %s\n", sha1_to_hex(pack+1));
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if (left < 20)
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die("truncated pack file");
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data = base_sha1 + 20;
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data_size = left - 20;
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printf("%s D %lu", sha1_to_hex(entry->sha1), delta_size);
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printf(" %s\n", sha1_to_hex(base_sha1));
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/* pack+1 is the base sha1, unless we have it, we need to
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if (dry_run)
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return 0;
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/* pack+5 is the base sha1, unless we have it, we need to
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* unpack it first.
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*/
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if (!has_sha1_file(pack+1)) {
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if (!has_sha1_file(base_sha1)) {
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struct pack_entry *base;
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if (!find_pack_entry(pack+1, &base))
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if (!find_pack_entry(base_sha1, &base))
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die("cannot find delta-pack base object");
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unpack_entry(base);
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}
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/* pack+1 thru pack+20 is the base sha1 and
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* pack+21 thru unknown number is the delta data.
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* we do not even have size of the delta data uncompressed.
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* sheesh!
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*/
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delta_alloc = 1024;
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delta_data = xmalloc(delta_alloc);
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delta_data = xmalloc(delta_size);
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memset(&stream, 0, sizeof(stream));
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stream.next_in = pack + 21;
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stream.avail_in = pack_size - ntohl(entry->offset); /* sheesh. */
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stream.next_in = data;
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stream.avail_in = data_size;
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stream.next_out = delta_data;
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stream.avail_out = delta_alloc;
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delta_size = 0;
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stream.avail_out = delta_size;
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inflateInit(&stream);
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while (1) {
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st = inflate(&stream, Z_FINISH);
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if (st == Z_STREAM_END) {
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delta_size = stream.total_out;
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break;
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}
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if (st < 0)
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break;
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if (delta_alloc <= stream.total_out) {
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delta_alloc = (delta_alloc +1024) * 3 / 2;
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delta_data = xrealloc(delta_data, delta_alloc);
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stream.next_out = delta_data + stream.total_out;
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stream.avail_out = delta_alloc - stream.total_out;
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}
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}
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inflateEnd(&stream);
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if (st != Z_STREAM_END) {
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free(delta_data);
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return -1;
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}
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if ((st != Z_STREAM_END) || stream.total_out != delta_size)
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die("delta data unpack failed");
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base = read_sha1_file(pack+1, type, &base_size);
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base = read_sha1_file(base_sha1, type, &base_size);
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if (!base)
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die("failed to read delta-pack base object");
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die("failed to read delta-pack base object %s", sha1_to_hex(base_sha1));
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result = patch_delta(base, base_size,
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delta_data, delta_size,
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&result_size);
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@ -246,7 +232,7 @@ static int unpack_delta_entry(struct pack_entry *entry, unsigned char *pack)
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static void unpack_entry(struct pack_entry *entry)
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{
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unsigned long offset;
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unsigned long offset, size, left;
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unsigned char *pack;
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/* Have we done this one already due to deltas based on it? */
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@ -257,13 +243,14 @@ static void unpack_entry(struct pack_entry *entry)
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if (offset > pack_size - 5)
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die("object offset outside of pack file");
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pack = pack_base + offset;
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offset = pack_size - offset;
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size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4];
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left = pack_size - offset - 5;
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switch (*pack) {
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case 'C': case 'T': case 'B':
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unpack_non_delta_entry(entry, pack);
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unpack_non_delta_entry(entry, *pack, pack+5, size, left);
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break;
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case 'D':
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unpack_delta_entry(entry, pack);
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unpack_delta_entry(entry, pack+5, size, left);
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break;
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default:
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die("corrupted pack file");
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