Add new `git update` tool
[git] / 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;
54                 ALLOC_ARRAY(entries, nr);
55                 for (i = 0; i < nr; i++)
56                         if (fread(entries[i].sha1, 20, 1, stdin) != 1)
57                                 die("unable to read sha1 %u/%u", i, nr);
58                 for (i = 0; i < nr; i++)
59                         if (fread(&entries[i].crc, 4, 1, stdin) != 1)
60                                 die("unable to read crc %u/%u", i, nr);
61                 for (i = 0; i < nr; i++)
62                         if (fread(&entries[i].off, 4, 1, stdin) != 1)
63                                 die("unable to read 32b offset %u/%u", i, nr);
64                 for (i = 0; i < nr; i++) {
65                         uint64_t offset;
66                         uint32_t off = ntohl(entries[i].off);
67                         if (!(off & 0x80000000)) {
68                                 offset = off;
69                         } else {
70                                 uint32_t off64[2];
71                                 if ((off & 0x7fffffff) != off64_nr)
72                                         die("inconsistent 64b offset index");
73                                 if (fread(off64, 8, 1, stdin) != 1)
74                                         die("unable to read 64b offset %u", off64_nr);
75                                 offset = (((uint64_t)ntohl(off64[0])) << 32) |
76                                                      ntohl(off64[1]);
77                                 off64_nr++;
78                         }
79                         printf("%" PRIuMAX " %s (%08"PRIx32")\n",
80                                (uintmax_t) offset,
81                                sha1_to_hex(entries[i].sha1),
82                                ntohl(entries[i].crc));
83                 }
84                 free(entries);
85         }
86         return 0;
87 }