show-index.c

   1 #include "cache.h"
   2 #include "pack.h"
   3
   4 static const char show_index_usage[] =
   5 "git show-index";
   6
   7 int main(int argc, char **argv)
   8 {
   9         int i;
  10         unsigned nr;
  11         unsigned int version;
  12         static unsigned int top_index[256];
  13
  14         git_setup_gettext();
  15
  16         if (argc != 1)
  17                 usage(show_index_usage);
  18         if (fread(top_index, 2 * 4, 1, stdin) != 1)
  19                 die("unable to read header");
  20         if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
  21                 version = ntohl(top_index[1]);
  22                 if (version < 2 || version > 2)
  23                         die("unknown index version");
  24                 if (fread(top_index, 256 * 4, 1, stdin) != 1)
  25                         die("unable to read index");
  26         } else {
  27                 version = 1;
  28                 if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
  29                         die("unable to read index");
  30         }
  31         nr = 0;
  32         for (i = 0; i < 256; i++) {
  33                 unsigned n = ntohl(top_index[i]);
  34                 if (n < nr)
  35                         die("corrupt index file");
  36                 nr = n;
  37         }
  38         if (version == 1) {
  39                 for (i = 0; i < nr; i++) {
  40                         unsigned int offset, entry[6];
  41
  42                         if (fread(entry, 4 + 20, 1, stdin) != 1)
  43                                 die("unable to read entry %u/%u", i, nr);
  44                         offset = ntohl(entry[0]);
  45                         printf("%u %s\n", offset, sha1_to_hex((void *)(entry+1)));
  46                 }
  47         } else {
  48                 unsigned off64_nr = 0;
  49                 struct {
  50                         unsigned char sha1[20];
  51                         uint32_t crc;
  52                         uint32_t off;
  53                 } *entries;
  54                 ALLOC_ARRAY(entries, nr);
  55                 for (i = 0; i < nr; i++)
  56                         if (fread(entries[i].sha1, 20, 1, stdin) != 1)
  57                                 die("unable to read sha1 %u/%u", i, nr);
  58                 for (i = 0; i < nr; i++)
  59                         if (fread(&entries[i].crc, 4, 1, stdin) != 1)
  60                                 die("unable to read crc %u/%u", i, nr);
  61                 for (i = 0; i < nr; i++)
  62                         if (fread(&entries[i].off, 4, 1, stdin) != 1)
  63                                 die("unable to read 32b offset %u/%u", i, nr);
  64                 for (i = 0; i < nr; i++) {
  65                         uint64_t offset;
  66                         uint32_t off = ntohl(entries[i].off);
  67                         if (!(off & 0x80000000)) {
  68                                 offset = off;
  69                         } else {
  70                                 uint32_t off64[2];
  71                                 if ((off & 0x7fffffff) != off64_nr)
  72                                         die("inconsistent 64b offset index");
  73                                 if (fread(off64, 8, 1, stdin) != 1)
  74                                         die("unable to read 64b offset %u", off64_nr);
  75                                 offset = (((uint64_t)ntohl(off64[0])) << 32) |
  76                                                      ntohl(off64[1]);
  77                                 off64_nr++;
  78                         }
  79                         printf("%" PRIuMAX " %s (%08"PRIx32")\n",
  80                                (uintmax_t) offset,
  81                                sha1_to_hex(entries[i].sha1),
  82                                ntohl(entries[i].crc));
  83                 }
  84                 free(entries);
  85         }
  86         return 0;
  87 }