object-store: free alt_odb_list
[git/git.git] / server-info.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include "packfile.h"
7
8 /*
9 * Create the file "path" by writing to a temporary file and renaming
10 * it into place. The contents of the file come from "generate", which
11 * should return non-zero if it encounters an error.
12 */
13 static int update_info_file(char *path, int (*generate)(FILE *))
14 {
15 char *tmp = mkpathdup("%s_XXXXXX", path);
16 int ret = -1;
17 int fd = -1;
18 FILE *fp = NULL, *to_close;
19
20 safe_create_leading_directories(path);
21 fd = git_mkstemp_mode(tmp, 0666);
22 if (fd < 0)
23 goto out;
24 to_close = fp = fdopen(fd, "w");
25 if (!fp)
26 goto out;
27 fd = -1;
28 ret = generate(fp);
29 if (ret)
30 goto out;
31 fp = NULL;
32 if (fclose(to_close))
33 goto out;
34 if (adjust_shared_perm(tmp) < 0)
35 goto out;
36 if (rename(tmp, path) < 0)
37 goto out;
38 ret = 0;
39
40 out:
41 if (ret) {
42 error_errno("unable to update %s", path);
43 if (fp)
44 fclose(fp);
45 else if (fd >= 0)
46 close(fd);
47 unlink(tmp);
48 }
49 free(tmp);
50 return ret;
51 }
52
53 static int add_info_ref(const char *path, const struct object_id *oid,
54 int flag, void *cb_data)
55 {
56 FILE *fp = cb_data;
57 struct object *o = parse_object(oid);
58 if (!o)
59 return -1;
60
61 if (fprintf(fp, "%s %s\n", oid_to_hex(oid), path) < 0)
62 return -1;
63
64 if (o->type == OBJ_TAG) {
65 o = deref_tag(o, path, 0);
66 if (o)
67 if (fprintf(fp, "%s %s^{}\n",
68 oid_to_hex(&o->oid), path) < 0)
69 return -1;
70 }
71 return 0;
72 }
73
74 static int generate_info_refs(FILE *fp)
75 {
76 return for_each_ref(add_info_ref, fp);
77 }
78
79 static int update_info_refs(int force)
80 {
81 char *path = git_pathdup("info/refs");
82 int ret = update_info_file(path, generate_info_refs);
83 free(path);
84 return ret;
85 }
86
87 /* packs */
88 static struct pack_info {
89 struct packed_git *p;
90 int old_num;
91 int new_num;
92 int nr_alloc;
93 int nr_heads;
94 unsigned char (*head)[20];
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 *line, int old_cnt)
116 {
117 struct pack_info *i = find_pack_by_name(line + 2);
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 char line[1000];
135 int old_cnt = 0;
136
137 fp = fopen_or_warn(infofile, "r");
138 if (!fp)
139 return 1; /* nonexistent is not an error. */
140
141 while (fgets(line, sizeof(line), fp)) {
142 int len = strlen(line);
143 if (len && line[len-1] == '\n')
144 line[--len] = 0;
145
146 if (!len)
147 continue;
148
149 switch (line[0]) {
150 case 'P': /* P name */
151 if (parse_pack_def(line, old_cnt++))
152 goto out_stale;
153 break;
154 case 'D': /* we used to emit D but that was misguided. */
155 case 'T': /* we used to emit T but nobody uses it. */
156 goto out_stale;
157 default:
158 error("unrecognized: %s", line);
159 break;
160 }
161 }
162 fclose(fp);
163 return 0;
164 out_stale:
165 fclose(fp);
166 return 1;
167 }
168
169 static int compare_info(const void *a_, const void *b_)
170 {
171 struct pack_info *const *a = a_;
172 struct pack_info *const *b = b_;
173
174 if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
175 /* Keep the order in the original */
176 return (*a)->old_num - (*b)->old_num;
177 else if (0 <= (*a)->old_num)
178 /* Only A existed in the original so B is obviously newer */
179 return -1;
180 else if (0 <= (*b)->old_num)
181 /* The other way around. */
182 return 1;
183
184 /* then it does not matter but at least keep the comparison stable */
185 if ((*a)->p == (*b)->p)
186 return 0;
187 else if ((*a)->p < (*b)->p)
188 return -1;
189 else
190 return 1;
191 }
192
193 static void init_pack_info(const char *infofile, int force)
194 {
195 struct packed_git *p;
196 int stale;
197 int i = 0;
198
199 objdir = get_object_directory();
200 objdirlen = strlen(objdir);
201
202 prepare_packed_git();
203 for (p = packed_git; 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 = packed_git; 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 info[i]->nr_heads = 0;
231 }
232 }
233
234 /* renumber them */
235 QSORT(info, num_pack, compare_info);
236 for (i = 0; i < num_pack; i++)
237 info[i]->new_num = i;
238 }
239
240 static void free_pack_info(void)
241 {
242 int i;
243 for (i = 0; i < num_pack; i++)
244 free(info[i]);
245 free(info);
246 }
247
248 static int write_pack_info_file(FILE *fp)
249 {
250 int i;
251 for (i = 0; i < num_pack; i++) {
252 if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
253 return -1;
254 }
255 if (fputc('\n', fp) == EOF)
256 return -1;
257 return 0;
258 }
259
260 static int update_info_packs(int force)
261 {
262 char *infofile = mkpathdup("%s/info/packs", get_object_directory());
263 int ret;
264
265 init_pack_info(infofile, force);
266 ret = update_info_file(infofile, write_pack_info_file);
267 free_pack_info();
268 free(infofile);
269 return ret;
270 }
271
272 /* public */
273 int update_server_info(int force)
274 {
275 /* We would add more dumb-server support files later,
276 * including index of available pack files and their
277 * intended audiences.
278 */
279 int errs = 0;
280
281 errs = errs | update_info_refs(force);
282 errs = errs | update_info_packs(force);
283
284 /* remove leftover rev-cache file if there is any */
285 unlink_or_warn(git_path("info/rev-cache"));
286
287 return errs;
288 }