builtin/show-index.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "pack.h"
   4
   5 static const char show_index_usage[] =
   6 "git show-index";
   7
   8 int cmd_show_index(int argc, const char **argv, const char *prefix)
   9 {
  10         int i;
  11         unsigned nr;
  12         unsigned int version;
  13         static unsigned int top_index[256];
  14
  15         if (argc != 1)
  16                 usage(show_index_usage);
  17         if (fread(top_index, 2 * 4, 1, stdin) != 1)
  18                 die("unable to read header");
  19         if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
  20                 version = ntohl(top_index[1]);
  21                 if (version < 2 || version > 2)
  22                         die("unknown index version");
  23                 if (fread(top_index, 256 * 4, 1, stdin) != 1)
  24                         die("unable to read index");
  25         } else {
  26                 version = 1;
  27                 if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
  28                         die("unable to read index");
  29         }
  30         nr = 0;
  31         for (i = 0; i < 256; i++) {
  32                 unsigned n = ntohl(top_index[i]);
  33                 if (n < nr)
  34                         die("corrupt index file");
  35                 nr = n;
  36         }
  37         if (version == 1) {
  38                 for (i = 0; i < nr; i++) {
  39                         unsigned int offset, entry[6];
  40
  41                         if (fread(entry, 4 + 20, 1, stdin) != 1)
  42                                 die("unable to read entry %u/%u", i, nr);
  43                         offset = ntohl(entry[0]);
  44                         printf("%u %s\n", offset, sha1_to_hex((void *)(entry+1)));
  45                 }
  46         } else {
  47                 unsigned off64_nr = 0;
  48                 struct {
  49                         unsigned char sha1[20];
  50                         uint32_t crc;
  51                         uint32_t off;
  52                 } *entries;
  53                 ALLOC_ARRAY(entries, nr);
  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 }