builtin/show-index.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "gettext.h"
   4 #include "hex.h"
   5 #include "pack.h"
   6 #include "parse-options.h"
   7
   8 static const char *const show_index_usage[] = {
   9         "git show-index [--object-format=<hash-algorithm>]",
  10         NULL
  11 };
  12
  13 int cmd_show_index(int argc, const char **argv, const char *prefix)
  14 {
  15         int i;
  16         unsigned nr;
  17         unsigned int version;
  18         static unsigned int top_index[256];
  19         unsigned hashsz;
  20         const char *hash_name = NULL;
  21         int hash_algo;
  22         const struct option show_index_options[] = {
  23                 OPT_STRING(0, "object-format", &hash_name, N_("hash-algorithm"),
  24                            N_("specify the hash algorithm to use")),
  25                 OPT_END()
  26         };
  27
  28         argc = parse_options(argc, argv, prefix, show_index_options, show_index_usage, 0);
  29
  30         if (hash_name) {
  31                 hash_algo = hash_algo_by_name(hash_name);
  32                 if (hash_algo == GIT_HASH_UNKNOWN)
  33                         die(_("Unknown hash algorithm"));
  34                 repo_set_hash_algo(the_repository, hash_algo);
  35         }
  36
  37         hashsz = the_hash_algo->rawsz;
  38
  39         if (fread(top_index, 2 * 4, 1, stdin) != 1)
  40                 die("unable to read header");
  41         if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
  42                 version = ntohl(top_index[1]);
  43                 if (version < 2 || version > 2)
  44                         die("unknown index version");
  45                 if (fread(top_index, 256 * 4, 1, stdin) != 1)
  46                         die("unable to read index");
  47         } else {
  48                 version = 1;
  49                 if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
  50                         die("unable to read index");
  51         }
  52         nr = 0;
  53         for (i = 0; i < 256; i++) {
  54                 unsigned n = ntohl(top_index[i]);
  55                 if (n < nr)
  56                         die("corrupt index file");
  57                 nr = n;
  58         }
  59         if (version == 1) {
  60                 for (i = 0; i < nr; i++) {
  61                         unsigned int offset, entry[(GIT_MAX_RAWSZ + 4) / sizeof(unsigned int)];
  62
  63                         if (fread(entry, 4 + hashsz, 1, stdin) != 1)
  64                                 die("unable to read entry %u/%u", i, nr);
  65                         offset = ntohl(entry[0]);
  66                         printf("%u %s\n", offset, hash_to_hex((void *)(entry+1)));
  67                 }
  68         } else {
  69                 unsigned off64_nr = 0;
  70                 struct {
  71                         struct object_id oid;
  72                         uint32_t crc;
  73                         uint32_t off;
  74                 } *entries;
  75                 ALLOC_ARRAY(entries, nr);
  76                 for (i = 0; i < nr; i++) {
  77                         if (fread(entries[i].oid.hash, hashsz, 1, stdin) != 1)
  78                                 die("unable to read sha1 %u/%u", i, nr);
  79                         entries[i].oid.algo = hash_algo_by_ptr(the_hash_algo);
  80                 }
  81                 for (i = 0; i < nr; i++)
  82                         if (fread(&entries[i].crc, 4, 1, stdin) != 1)
  83                                 die("unable to read crc %u/%u", i, nr);
  84                 for (i = 0; i < nr; i++)
  85                         if (fread(&entries[i].off, 4, 1, stdin) != 1)
  86                                 die("unable to read 32b offset %u/%u", i, nr);
  87                 for (i = 0; i < nr; i++) {
  88                         uint64_t offset;
  89                         uint32_t off = ntohl(entries[i].off);
  90                         if (!(off & 0x80000000)) {
  91                                 offset = off;
  92                         } else {
  93                                 uint32_t off64[2];
  94                                 if ((off & 0x7fffffff) != off64_nr)
  95                                         die("inconsistent 64b offset index");
  96                                 if (fread(off64, 8, 1, stdin) != 1)
  97                                         die("unable to read 64b offset %u", off64_nr);
  98                                 offset = (((uint64_t)ntohl(off64[0])) << 32) |
  99                                                      ntohl(off64[1]);
 100                                 off64_nr++;
 101                         }
 102                         printf("%" PRIuMAX " %s (%08"PRIx32")\n",
 103                                (uintmax_t) offset,
 104                                oid_to_hex(&entries[i].oid),
 105                                ntohl(entries[i].crc));
 106                 }
 107                 free(entries);
 108         }
 109         return 0;
 110 }