show-index.c

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