builtin/show-index.c

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