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