]> git.ipfire.org Git - thirdparty/git.git/blob - server-info.c
server-info: use strbuf to read old info/packs file
[thirdparty/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(int force)
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 int nr_alloc;
95 } **info;
96 static int num_pack;
97 static const char *objdir;
98 static int objdirlen;
99
100 static struct pack_info *find_pack_by_name(const char *name)
101 {
102 int i;
103 for (i = 0; i < num_pack; i++) {
104 struct packed_git *p = info[i]->p;
105 /* skip "/pack/" after ".git/objects" */
106 if (!strcmp(p->pack_name + objdirlen + 6, name))
107 return info[i];
108 }
109 return NULL;
110 }
111
112 /* Returns non-zero when we detect that the info in the
113 * old file is useless.
114 */
115 static int parse_pack_def(const char *packname, int old_cnt)
116 {
117 struct pack_info *i = find_pack_by_name(packname);
118 if (i) {
119 i->old_num = old_cnt;
120 return 0;
121 }
122 else {
123 /* The file describes a pack that is no longer here */
124 return 1;
125 }
126 }
127
128 /* Returns non-zero when we detect that the info in the
129 * old file is useless.
130 */
131 static int read_pack_info_file(const char *infofile)
132 {
133 FILE *fp;
134 struct strbuf line = STRBUF_INIT;
135 int old_cnt = 0;
136 int stale = 1;
137
138 fp = fopen_or_warn(infofile, "r");
139 if (!fp)
140 return 1; /* nonexistent is not an error. */
141
142 while (strbuf_getline(&line, fp) != EOF) {
143 const char *arg;
144
145 if (!line.len)
146 continue;
147
148 if (skip_prefix(line.buf, "P ", &arg)) {
149 /* P name */
150 if (parse_pack_def(arg, old_cnt++))
151 goto out_stale;
152 } else if (line.buf[0] == 'D') {
153 /* we used to emit D but that was misguided. */
154 goto out_stale;
155 } else if (line.buf[0] == 'T') {
156 /* we used to emit T but nobody uses it. */
157 goto out_stale;
158 } else {
159 error("unrecognized: %s", line.buf);
160 }
161 }
162 stale = 0;
163
164 out_stale:
165 strbuf_release(&line);
166 fclose(fp);
167 return stale;
168 }
169
170 static int compare_info(const void *a_, const void *b_)
171 {
172 struct pack_info *const *a = a_;
173 struct pack_info *const *b = b_;
174
175 if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
176 /* Keep the order in the original */
177 return (*a)->old_num - (*b)->old_num;
178 else if (0 <= (*a)->old_num)
179 /* Only A existed in the original so B is obviously newer */
180 return -1;
181 else if (0 <= (*b)->old_num)
182 /* The other way around. */
183 return 1;
184
185 /* then it does not matter but at least keep the comparison stable */
186 if ((*a)->p == (*b)->p)
187 return 0;
188 else if ((*a)->p < (*b)->p)
189 return -1;
190 else
191 return 1;
192 }
193
194 static void init_pack_info(const char *infofile, int force)
195 {
196 struct packed_git *p;
197 int stale;
198 int i = 0;
199
200 objdir = get_object_directory();
201 objdirlen = strlen(objdir);
202
203 for (p = get_all_packs(the_repository); p; p = p->next) {
204 /* we ignore things on alternate path since they are
205 * not available to the pullers in general.
206 */
207 if (!p->pack_local)
208 continue;
209 i++;
210 }
211 num_pack = i;
212 info = xcalloc(num_pack, sizeof(struct pack_info *));
213 for (i = 0, p = get_all_packs(the_repository); p; p = p->next) {
214 if (!p->pack_local)
215 continue;
216 info[i] = xcalloc(1, sizeof(struct pack_info));
217 info[i]->p = p;
218 info[i]->old_num = -1;
219 i++;
220 }
221
222 if (infofile && !force)
223 stale = read_pack_info_file(infofile);
224 else
225 stale = 1;
226
227 for (i = 0; i < num_pack; i++)
228 if (stale)
229 info[i]->old_num = -1;
230
231 /* renumber them */
232 QSORT(info, num_pack, compare_info);
233 for (i = 0; i < num_pack; i++)
234 info[i]->new_num = i;
235 }
236
237 static void free_pack_info(void)
238 {
239 int i;
240 for (i = 0; i < num_pack; i++)
241 free(info[i]);
242 free(info);
243 }
244
245 static int write_pack_info_file(FILE *fp)
246 {
247 int i;
248 for (i = 0; i < num_pack; i++) {
249 if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
250 return -1;
251 }
252 if (fputc('\n', fp) == EOF)
253 return -1;
254 return 0;
255 }
256
257 static int update_info_packs(int force)
258 {
259 char *infofile = mkpathdup("%s/info/packs", get_object_directory());
260 int ret;
261
262 init_pack_info(infofile, force);
263 ret = update_info_file(infofile, write_pack_info_file);
264 free_pack_info();
265 free(infofile);
266 return ret;
267 }
268
269 /* public */
270 int update_server_info(int force)
271 {
272 /* We would add more dumb-server support files later,
273 * including index of available pack files and their
274 * intended audiences.
275 */
276 int errs = 0;
277
278 errs = errs | update_info_refs(force);
279 errs = errs | update_info_packs(force);
280
281 /* remove leftover rev-cache file if there is any */
282 unlink_or_warn(git_path("info/rev-cache"));
283
284 return errs;
285 }