builtin-show-index.c

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