+static int cmp_uint32(const void *a_, const void *b_)
+{
+ uint32_t a = *((uint32_t *)a_);
+ uint32_t b = *((uint32_t *)b_);
+
+ return (a < b) ? -1 : (a != b);
+}
+
+static void read_v2_anomalous_offsets(struct packed_git *p,
+ struct pack_idx_option *opts)
+{
+ const uint32_t *idx1, *idx2;
+ uint32_t i;
+
+ /* The address of the 4-byte offset table */
+ idx1 = (((const uint32_t *)p->index_data)
+ + 2 /* 8-byte header */
+ + 256 /* fan out */
+ + 5 * p->num_objects /* 20-byte SHA-1 table */
+ + p->num_objects /* CRC32 table */
+ );
+
+ /* The address of the 8-byte offset table */
+ idx2 = idx1 + p->num_objects;
+
+ for (i = 0; i < p->num_objects; i++) {
+ uint32_t off = ntohl(idx1[i]);
+ if (!(off & 0x80000000))
+ continue;
+ off = off & 0x7fffffff;
+ if (idx2[off * 2])
+ continue;
+ /*
+ * The real offset is ntohl(idx2[off * 2]) in high 4
+ * octets, and ntohl(idx2[off * 2 + 1]) in low 4
+ * octets. But idx2[off * 2] is Zero!!!
+ */
+ ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
+ opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
+ }
+
+ if (1 < opts->anomaly_nr)
+ qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
+}
+
+static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
+{
+ struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
+
+ if (!p)
+ die("Cannot open existing pack file '%s'", pack_name);
+ if (open_pack_index(p))
+ die("Cannot open existing pack idx file for '%s'", pack_name);
+
+ /* Read the attributes from the existing idx file */
+ opts->version = p->index_version;
+
+ if (opts->version == 2)
+ read_v2_anomalous_offsets(p, opts);
+
+ /*
+ * Get rid of the idx file as we do not need it anymore.
+ * NEEDSWORK: extract this bit from free_pack_by_name() in
+ * sha1_file.c, perhaps? It shouldn't matter very much as we
+ * know we haven't installed this pack (hence we never have
+ * read anything from it).
+ */
+ close_pack_index(p);
+ free(p);
+}
+
+static void show_pack_info(int stat_only)
+{
+ int i, baseobjects = nr_objects - nr_deltas;
+ unsigned long *chain_histogram = NULL;
+
+ if (deepest_delta)
+ chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
+
+ for (i = 0; i < nr_objects; i++) {
+ struct object_entry *obj = &objects[i];
+
+ if (is_delta_type(obj->type))
+ chain_histogram[obj->delta_depth - 1]++;
+ if (stat_only)
+ continue;
+ printf("%s %-6s %lu %lu %"PRIuMAX,
+ sha1_to_hex(obj->idx.sha1),
+ typename(obj->real_type), obj->size,
+ (unsigned long)(obj[1].idx.offset - obj->idx.offset),
+ (uintmax_t)obj->idx.offset);
+ if (is_delta_type(obj->type)) {
+ struct object_entry *bobj = &objects[obj->base_object_no];
+ printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
+ }
+ putchar('\n');
+ }
+
+ if (baseobjects)
+ printf("non delta: %d object%s\n",
+ baseobjects, baseobjects > 1 ? "s" : "");
+ for (i = 0; i < deepest_delta; i++) {
+ if (!chain_histogram[i])
+ continue;
+ printf("chain length = %d: %lu object%s\n",
+ i + 1,
+ chain_histogram[i],
+ chain_histogram[i] > 1 ? "s" : "");
+ }
+}
+