remote: handle negative refspecs in git remote show
[alt-git.git] / pack-mtimes.c
blob0e0aafdcb061cd2e93f8d594e2d2d3d8da7636bf
1 #include "git-compat-util.h"
2 #include "pack-mtimes.h"
3 #include "object-store.h"
4 #include "packfile.h"
6 static char *pack_mtimes_filename(struct packed_git *p)
8 size_t len;
9 if (!strip_suffix(p->pack_name, ".pack", &len))
10 BUG("pack_name does not end in .pack");
11 return xstrfmt("%.*s.mtimes", (int)len, p->pack_name);
14 #define MTIMES_HEADER_SIZE (12)
16 struct mtimes_header {
17 uint32_t signature;
18 uint32_t version;
19 uint32_t hash_id;
22 static int load_pack_mtimes_file(char *mtimes_file,
23 uint32_t num_objects,
24 const uint32_t **data_p, size_t *len_p)
26 int fd, ret = 0;
27 struct stat st;
28 uint32_t *data = NULL;
29 size_t mtimes_size, expected_size;
30 struct mtimes_header header;
32 fd = git_open(mtimes_file);
34 if (fd < 0) {
35 ret = -1;
36 goto cleanup;
38 if (fstat(fd, &st)) {
39 ret = error_errno(_("failed to read %s"), mtimes_file);
40 goto cleanup;
43 mtimes_size = xsize_t(st.st_size);
45 if (mtimes_size < MTIMES_HEADER_SIZE) {
46 ret = error(_("mtimes file %s is too small"), mtimes_file);
47 goto cleanup;
50 data = xmmap(NULL, mtimes_size, PROT_READ, MAP_PRIVATE, fd, 0);
52 header.signature = ntohl(data[0]);
53 header.version = ntohl(data[1]);
54 header.hash_id = ntohl(data[2]);
56 if (header.signature != MTIMES_SIGNATURE) {
57 ret = error(_("mtimes file %s has unknown signature"), mtimes_file);
58 goto cleanup;
61 if (header.version != 1) {
62 ret = error(_("mtimes file %s has unsupported version %"PRIu32),
63 mtimes_file, header.version);
64 goto cleanup;
67 if (!(header.hash_id == 1 || header.hash_id == 2)) {
68 ret = error(_("mtimes file %s has unsupported hash id %"PRIu32),
69 mtimes_file, header.hash_id);
70 goto cleanup;
74 expected_size = MTIMES_HEADER_SIZE;
75 expected_size = st_add(expected_size, st_mult(sizeof(uint32_t), num_objects));
76 expected_size = st_add(expected_size, 2 * (header.hash_id == 1 ? GIT_SHA1_RAWSZ : GIT_SHA256_RAWSZ));
78 if (mtimes_size != expected_size) {
79 ret = error(_("mtimes file %s is corrupt"), mtimes_file);
80 goto cleanup;
83 cleanup:
84 if (ret) {
85 if (data)
86 munmap(data, mtimes_size);
87 } else {
88 *len_p = mtimes_size;
89 *data_p = data;
92 close(fd);
93 return ret;
96 int load_pack_mtimes(struct packed_git *p)
98 char *mtimes_name = NULL;
99 int ret = 0;
101 if (!p->is_cruft)
102 return ret; /* not a cruft pack */
103 if (p->mtimes_map)
104 return ret; /* already loaded */
106 ret = open_pack_index(p);
107 if (ret < 0)
108 goto cleanup;
110 mtimes_name = pack_mtimes_filename(p);
111 ret = load_pack_mtimes_file(mtimes_name,
112 p->num_objects,
113 &p->mtimes_map,
114 &p->mtimes_size);
115 cleanup:
116 free(mtimes_name);
117 return ret;
120 uint32_t nth_packed_mtime(struct packed_git *p, uint32_t pos)
122 if (!p->mtimes_map)
123 BUG("pack .mtimes file not loaded for %s", p->pack_name);
124 if (p->num_objects <= pos)
125 BUG("pack .mtimes out-of-bounds (%"PRIu32" vs %"PRIu32")",
126 pos, p->num_objects);
128 return get_be32(p->mtimes_map + pos + 3);