41274d098bc3b07b7f0130e7b9efcc20873cf46d
[git/git.git] / server-info.c
1 #include "cache.h"
2 #include "repository.h"
3 #include "refs.h"
4 #include "object.h"
5 #include "commit.h"
6 #include "tag.h"
7 #include "packfile.h"
8 #include "object-store.h"
9
10 /*
11 * Create the file "path" by writing to a temporary file and renaming
12 * it into place. The contents of the file come from "generate", which
13 * should return non-zero if it encounters an error.
14 */
15 static int update_info_file(char *path, int (*generate)(FILE *))
16 {
17 char *tmp = mkpathdup("%s_XXXXXX", path);
18 int ret = -1;
19 int fd = -1;
20 FILE *fp = NULL, *to_close;
21
22 safe_create_leading_directories(path);
23 fd = git_mkstemp_mode(tmp, 0666);
24 if (fd < 0)
25 goto out;
26 to_close = fp = fdopen(fd, "w");
27 if (!fp)
28 goto out;
29 fd = -1;
30 ret = generate(fp);
31 if (ret)
32 goto out;
33 fp = NULL;
34 if (fclose(to_close))
35 goto out;
36 if (adjust_shared_perm(tmp) < 0)
37 goto out;
38 if (rename(tmp, path) < 0)
39 goto out;
40 ret = 0;
41
42 out:
43 if (ret) {
44 error_errno("unable to update %s", path);
45 if (fp)
46 fclose(fp);
47 else if (fd >= 0)
48 close(fd);
49 unlink(tmp);
50 }
51 free(tmp);
52 return ret;
53 }
54
55 static int add_info_ref(const char *path, const struct object_id *oid,
56 int flag, void *cb_data)
57 {
58 FILE *fp = cb_data;
59 struct object *o = parse_object(the_repository, oid);
60 if (!o)
61 return -1;
62
63 if (fprintf(fp, "%s %s\n", oid_to_hex(oid), path) < 0)
64 return -1;
65
66 if (o->type == OBJ_TAG) {
67 o = deref_tag(the_repository, o, path, 0);
68 if (o)
69 if (fprintf(fp, "%s %s^{}\n",
70 oid_to_hex(&o->oid), path) < 0)
71 return -1;
72 }
73 return 0;
74 }
75
76 static int generate_info_refs(FILE *fp)
77 {
78 return for_each_ref(add_info_ref, fp);
79 }
80
81 static int update_info_refs(void)
82 {
83 char *path = git_pathdup("info/refs");
84 int ret = update_info_file(path, generate_info_refs);
85 free(path);
86 return ret;
87 }
88
89 /* packs */
90 static struct pack_info {
91 struct packed_git *p;
92 int old_num;
93 int new_num;
94 } **info;
95 static int num_pack;
96
97 static struct pack_info *find_pack_by_name(const char *name)
98 {
99 int i;
100 for (i = 0; i < num_pack; i++) {
101 struct packed_git *p = info[i]->p;
102 if (!strcmp(pack_basename(p), name))
103 return info[i];
104 }
105 return NULL;
106 }
107
108 /* Returns non-zero when we detect that the info in the
109 * old file is useless.
110 */
111 static int parse_pack_def(const char *packname, int old_cnt)
112 {
113 struct pack_info *i = find_pack_by_name(packname);
114 if (i) {
115 i->old_num = old_cnt;
116 return 0;
117 }
118 else {
119 /* The file describes a pack that is no longer here */
120 return 1;
121 }
122 }
123
124 /* Returns non-zero when we detect that the info in the
125 * old file is useless.
126 */
127 static int read_pack_info_file(const char *infofile)
128 {
129 FILE *fp;
130 struct strbuf line = STRBUF_INIT;
131 int old_cnt = 0;
132 int stale = 1;
133
134 fp = fopen_or_warn(infofile, "r");
135 if (!fp)
136 return 1; /* nonexistent is not an error. */
137
138 while (strbuf_getline(&line, fp) != EOF) {
139 const char *arg;
140
141 if (!line.len)
142 continue;
143
144 if (skip_prefix(line.buf, "P ", &arg)) {
145 /* P name */
146 if (parse_pack_def(arg, old_cnt++))
147 goto out_stale;
148 } else if (line.buf[0] == 'D') {
149 /* we used to emit D but that was misguided. */
150 goto out_stale;
151 } else if (line.buf[0] == 'T') {
152 /* we used to emit T but nobody uses it. */
153 goto out_stale;
154 } else {
155 error("unrecognized: %s", line.buf);
156 }
157 }
158 stale = 0;
159
160 out_stale:
161 strbuf_release(&line);
162 fclose(fp);
163 return stale;
164 }
165
166 static int compare_info(const void *a_, const void *b_)
167 {
168 struct pack_info *const *a = a_;
169 struct pack_info *const *b = b_;
170
171 if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
172 /* Keep the order in the original */
173 return (*a)->old_num - (*b)->old_num;
174 else if (0 <= (*a)->old_num)
175 /* Only A existed in the original so B is obviously newer */
176 return -1;
177 else if (0 <= (*b)->old_num)
178 /* The other way around. */
179 return 1;
180
181 /* then it does not matter but at least keep the comparison stable */
182 if ((*a)->p == (*b)->p)
183 return 0;
184 else if ((*a)->p < (*b)->p)
185 return -1;
186 else
187 return 1;
188 }
189
190 static void init_pack_info(const char *infofile, int force)
191 {
192 struct packed_git *p;
193 int stale;
194 int i = 0;
195
196 for (p = get_all_packs(the_repository); p; p = p->next) {
197 /* we ignore things on alternate path since they are
198 * not available to the pullers in general.
199 */
200 if (!p->pack_local)
201 continue;
202 i++;
203 }
204 num_pack = i;
205 info = xcalloc(num_pack, sizeof(struct pack_info *));
206 for (i = 0, p = get_all_packs(the_repository); p; p = p->next) {
207 if (!p->pack_local)
208 continue;
209 assert(i < num_pack);
210 info[i] = xcalloc(1, sizeof(struct pack_info));
211 info[i]->p = p;
212 info[i]->old_num = -1;
213 i++;
214 }
215
216 if (infofile && !force)
217 stale = read_pack_info_file(infofile);
218 else
219 stale = 1;
220
221 for (i = 0; i < num_pack; i++)
222 if (stale)
223 info[i]->old_num = -1;
224
225 /* renumber them */
226 QSORT(info, num_pack, compare_info);
227 for (i = 0; i < num_pack; i++)
228 info[i]->new_num = i;
229 }
230
231 static void free_pack_info(void)
232 {
233 int i;
234 for (i = 0; i < num_pack; i++)
235 free(info[i]);
236 free(info);
237 }
238
239 static int write_pack_info_file(FILE *fp)
240 {
241 int i;
242 for (i = 0; i < num_pack; i++) {
243 if (fprintf(fp, "P %s\n", pack_basename(info[i]->p)) < 0)
244 return -1;
245 }
246 if (fputc('\n', fp) == EOF)
247 return -1;
248 return 0;
249 }
250
251 static int update_info_packs(int force)
252 {
253 char *infofile = mkpathdup("%s/info/packs", get_object_directory());
254 int ret;
255
256 init_pack_info(infofile, force);
257 ret = update_info_file(infofile, write_pack_info_file);
258 free_pack_info();
259 free(infofile);
260 return ret;
261 }
262
263 /* public */
264 int update_server_info(int force)
265 {
266 /* We would add more dumb-server support files later,
267 * including index of available pack files and their
268 * intended audiences.
269 */
270 int errs = 0;
271
272 errs = errs | update_info_refs();
273 errs = errs | update_info_packs(force);
274
275 /* remove leftover rev-cache file if there is any */
276 unlink_or_warn(git_path("info/rev-cache"));
277
278 return errs;
279 }