builtin/show-index.c

   1 #include "builtin.h"
   2 #include "gettext.h"
   3 #include "hash.h"
   4 #include "hex.h"
   5 #include "pack.h"
   6 #include "parse-options.h"
   7 #include "repository.h"
   8
   9 static const char *const show_index_usage[] = {
  10         "git show-index [--object-format=<hash-algorithm>]",
  11         NULL
  12 };
  13
  14 int cmd_show_index(int argc, const char **argv, const char *prefix)
  15 {
  16         int i;
  17         unsigned nr;
  18         unsigned int version;
  19         static unsigned int top_index[256];
  20         unsigned hashsz;
  21         const char *hash_name = NULL;
  22         int hash_algo;
  23         const struct option show_index_options[] = {
  24                 OPT_STRING(0, "object-format", &hash_name, N_("hash-algorithm"),
  25                            N_("specify the hash algorithm to use")),
  26                 OPT_END()
  27         };
  28
  29         argc = parse_options(argc, argv, prefix, show_index_options, show_index_usage, 0);
  30
  31         if (hash_name) {
  32                 hash_algo = hash_algo_by_name(hash_name);
  33                 if (hash_algo == GIT_HASH_UNKNOWN)
  34                         die(_("Unknown hash algorithm"));
  35                 repo_set_hash_algo(the_repository, hash_algo);
  36         }
  37
  38         hashsz = the_hash_algo->rawsz;
  39
  40         if (fread(top_index, 2 * 4, 1, stdin) != 1)
  41                 die("unable to read header");
  42         if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
  43                 version = ntohl(top_index[1]);
  44                 if (version < 2 || version > 2)
  45                         die("unknown index version");
  46                 if (fread(top_index, 256 * 4, 1, stdin) != 1)
  47                         die("unable to read index");
  48         } else {
  49                 version = 1;
  50                 if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
  51                         die("unable to read index");
  52         }
  53         nr = 0;
  54         for (i = 0; i < 256; i++) {
  55                 unsigned n = ntohl(top_index[i]);
  56                 if (n < nr)
  57                         die("corrupt index file");
  58                 nr = n;
  59         }
  60         if (version == 1) {
  61                 for (i = 0; i < nr; i++) {
  62                         unsigned int offset, entry[(GIT_MAX_RAWSZ + 4) / sizeof(unsigned int)];
  63
  64                         if (fread(entry, 4 + hashsz, 1, stdin) != 1)
  65                                 die("unable to read entry %u/%u", i, nr);
  66                         offset = ntohl(entry[0]);
  67                         printf("%u %s\n", offset, hash_to_hex((void *)(entry+1)));
  68                 }
  69         } else {
  70                 unsigned off64_nr = 0;
  71                 struct {
  72                         struct object_id oid;
  73                         uint32_t crc;
  74                         uint32_t off;
  75                 } *entries;
  76                 ALLOC_ARRAY(entries, nr);
  77                 for (i = 0; i < nr; i++) {
  78                         if (fread(entries[i].oid.hash, hashsz, 1, stdin) != 1)
  79                                 die("unable to read sha1 %u/%u", i, nr);
  80                         entries[i].oid.algo = hash_algo_by_ptr(the_hash_algo);
  81                 }
  82                 for (i = 0; i < nr; i++)
  83                         if (fread(&entries[i].crc, 4, 1, stdin) != 1)
  84                                 die("unable to read crc %u/%u", i, nr);
  85                 for (i = 0; i < nr; i++)
  86                         if (fread(&entries[i].off, 4, 1, stdin) != 1)
  87                                 die("unable to read 32b offset %u/%u", i, nr);
  88                 for (i = 0; i < nr; i++) {
  89                         uint64_t offset;
  90                         uint32_t off = ntohl(entries[i].off);
  91                         if (!(off & 0x80000000)) {
  92                                 offset = off;
  93                         } else {
  94                                 uint32_t off64[2];
  95                                 if ((off & 0x7fffffff) != off64_nr)
  96                                         die("inconsistent 64b offset index");
  97                                 if (fread(off64, 8, 1, stdin) != 1)
  98                                         die("unable to read 64b offset %u", off64_nr);
  99                                 offset = (((uint64_t)ntohl(off64[0])) << 32) |
 100                                                      ntohl(off64[1]);
 101                                 off64_nr++;
 102                         }
 103                         printf("%" PRIuMAX " %s (%08"PRIx32")\n",
 104                                (uintmax_t) offset,
 105                                oid_to_hex(&entries[i].oid),
 106                                ntohl(entries[i].crc));
 107                 }
 108                 free(entries);
 109         }
 110         return 0;
 111 }