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 = xmalloc(nr * sizeof(entries[0]));
  54                 for (i = 0; i < nr; i++)
  55                         if (fread(entries[i].sha1, 20, 1, stdin) != 1)
  56                                 die("unable to read sha1 %u/%u", i, nr);
  57                 for (i = 0; i < nr; i++)
  58                         if (fread(&entries[i].crc, 4, 1, stdin) != 1)
  59                                 die("unable to read crc %u/%u", i, nr);
  60                 for (i = 0; i < nr; i++)
  61                         if (fread(&entries[i].off, 4, 1, stdin) != 1)
  62                                 die("unable to read 32b offset %u/%u", i, nr);
  63                 for (i = 0; i < nr; i++) {
  64                         uint64_t offset;
  65                         uint32_t off = ntohl(entries[i].off);
  66                         if (!(off & 0x80000000)) {
  67                                 offset = off;
  68                         } else {
  69                                 uint32_t off64[2];
  70                                 if ((off & 0x7fffffff) != off64_nr)
  71                                         die("inconsistent 64b offset index");
  72                                 if (fread(off64, 8, 1, stdin) != 1)
  73                                         die("unable to read 64b offset %u", off64_nr);
  74                                 offset = (((uint64_t)ntohl(off64[0])) << 32) |
  75                                                      ntohl(off64[1]);
  76                                 off64_nr++;
  77                         }
  78                         printf("%" PRIuMAX " %s (%08"PRIx32")\n",
  79                                (uintmax_t) offset,
  80                                sha1_to_hex(entries[i].sha1),
  81                                ntohl(entries[i].crc));
  82                 }
  83                 free(entries);
  84         }
  85         return 0;
  86 }