Merge branch 'dl/difftool-mergetool'
[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 }