Sync with 'maint'
[git/gitster.git] / pack-mtimes.c
blobcdf30b8d2b0e809db7ee7e219b39863fad702bd4
1 #include "git-compat-util.h"
2 #include "gettext.h"
3 #include "pack-mtimes.h"
4 #include "object-file.h"
5 #include "object-store-ll.h"
6 #include "packfile.h"
7 #include "strbuf.h"
9 static char *pack_mtimes_filename(struct packed_git *p)
11 size_t len;
12 if (!strip_suffix(p->pack_name, ".pack", &len))
13 BUG("pack_name does not end in .pack");
14 return xstrfmt("%.*s.mtimes", (int)len, p->pack_name);
17 #define MTIMES_HEADER_SIZE (12)
19 struct mtimes_header {
20 uint32_t signature;
21 uint32_t version;
22 uint32_t hash_id;
25 static int load_pack_mtimes_file(char *mtimes_file,
26 uint32_t num_objects,
27 const uint32_t **data_p, size_t *len_p)
29 int fd, ret = 0;
30 struct stat st;
31 uint32_t *data = NULL;
32 size_t mtimes_size, expected_size;
33 struct mtimes_header header;
35 fd = git_open(mtimes_file);
37 if (fd < 0) {
38 ret = -1;
39 goto cleanup;
41 if (fstat(fd, &st)) {
42 ret = error_errno(_("failed to read %s"), mtimes_file);
43 goto cleanup;
46 mtimes_size = xsize_t(st.st_size);
48 if (mtimes_size < MTIMES_HEADER_SIZE) {
49 ret = error(_("mtimes file %s is too small"), mtimes_file);
50 goto cleanup;
53 data = xmmap(NULL, mtimes_size, PROT_READ, MAP_PRIVATE, fd, 0);
55 header.signature = ntohl(data[0]);
56 header.version = ntohl(data[1]);
57 header.hash_id = ntohl(data[2]);
59 if (header.signature != MTIMES_SIGNATURE) {
60 ret = error(_("mtimes file %s has unknown signature"), mtimes_file);
61 goto cleanup;
64 if (header.version != 1) {
65 ret = error(_("mtimes file %s has unsupported version %"PRIu32),
66 mtimes_file, header.version);
67 goto cleanup;
70 if (!(header.hash_id == 1 || header.hash_id == 2)) {
71 ret = error(_("mtimes file %s has unsupported hash id %"PRIu32),
72 mtimes_file, header.hash_id);
73 goto cleanup;
77 expected_size = MTIMES_HEADER_SIZE;
78 expected_size = st_add(expected_size, st_mult(sizeof(uint32_t), num_objects));
79 expected_size = st_add(expected_size, 2 * (header.hash_id == 1 ? GIT_SHA1_RAWSZ : GIT_SHA256_RAWSZ));
81 if (mtimes_size != expected_size) {
82 ret = error(_("mtimes file %s is corrupt"), mtimes_file);
83 goto cleanup;
86 cleanup:
87 if (ret) {
88 if (data)
89 munmap(data, mtimes_size);
90 } else {
91 *len_p = mtimes_size;
92 *data_p = data;
95 if (fd >= 0)
96 close(fd);
97 return ret;
100 int load_pack_mtimes(struct packed_git *p)
102 char *mtimes_name = NULL;
103 int ret = 0;
105 if (!p->is_cruft)
106 return ret; /* not a cruft pack */
107 if (p->mtimes_map)
108 return ret; /* already loaded */
110 ret = open_pack_index(p);
111 if (ret < 0)
112 goto cleanup;
114 mtimes_name = pack_mtimes_filename(p);
115 ret = load_pack_mtimes_file(mtimes_name,
116 p->num_objects,
117 &p->mtimes_map,
118 &p->mtimes_size);
119 cleanup:
120 free(mtimes_name);
121 return ret;
124 uint32_t nth_packed_mtime(struct packed_git *p, uint32_t pos)
126 if (!p->mtimes_map)
127 BUG("pack .mtimes file not loaded for %s", p->pack_name);
128 if (p->num_objects <= pos)
129 BUG("pack .mtimes out-of-bounds (%"PRIu32" vs %"PRIu32")",
130 pos, p->num_objects);
132 return get_be32(p->mtimes_map + pos + 3);