1#include "cache.h"
2#include "refs.h"
3#include "object.h"
4#include "commit.h"
5#include "tag.h"
6
7/* refs */
8static FILE *info_ref_fp;
9
10static int add_info_ref(const char *path, const unsigned char *sha1)
11{
12 struct object *o = parse_object(sha1);
13
14 fprintf(info_ref_fp, "%s %s\n", sha1_to_hex(sha1), path);
15 if (o->type == TYPE_TAG) {
16 o = deref_tag(o, path, 0);
17 if (o)
18 fprintf(info_ref_fp, "%s %s^{}\n",
19 sha1_to_hex(o->sha1), path);
20 }
21 return 0;
22}
23
24static int update_info_refs(int force)
25{
26 char *path0 = strdup(git_path("info/refs"));
27 int len = strlen(path0);
28 char *path1 = xmalloc(len + 2);
29
30 strcpy(path1, path0);
31 strcpy(path1 + len, "+");
32
33 safe_create_leading_directories(path0);
34 info_ref_fp = fopen(path1, "w");
35 if (!info_ref_fp)
36 return error("unable to update %s", path0);
37 for_each_ref(add_info_ref);
38 fclose(info_ref_fp);
39 rename(path1, path0);
40 free(path0);
41 free(path1);
42 return 0;
43}
44
45/* packs */
46static struct pack_info {
47 struct packed_git *p;
48 int old_num;
49 int new_num;
50 int nr_alloc;
51 int nr_heads;
52 unsigned char (*head)[20];
53} **info;
54static int num_pack;
55static const char *objdir;
56static int objdirlen;
57
58static struct pack_info *find_pack_by_name(const char *name)
59{
60 int i;
61 for (i = 0; i < num_pack; i++) {
62 struct packed_git *p = info[i]->p;
63 /* skip "/pack/" after ".git/objects" */
64 if (!strcmp(p->pack_name + objdirlen + 6, name))
65 return info[i];
66 }
67 return NULL;
68}
69
70/* Returns non-zero when we detect that the info in the
71 * old file is useless.
72 */
73static int parse_pack_def(const char *line, int old_cnt)
74{
75 struct pack_info *i = find_pack_by_name(line + 2);
76 if (i) {
77 i->old_num = old_cnt;
78 return 0;
79 }
80 else {
81 /* The file describes a pack that is no longer here */
82 return 1;
83 }
84}
85
86/* Returns non-zero when we detect that the info in the
87 * old file is useless.
88 */
89static int read_pack_info_file(const char *infofile)
90{
91 FILE *fp;
92 char line[1000];
93 int old_cnt = 0;
94
95 fp = fopen(infofile, "r");
96 if (!fp)
97 return 1; /* nonexistent is not an error. */
98
99 while (fgets(line, sizeof(line), fp)) {
100 int len = strlen(line);
101 if (line[len-1] == '\n')
102 line[--len] = 0;
103
104 if (!len)
105 continue;
106
107 switch (line[0]) {
108 case 'P': /* P name */
109 if (parse_pack_def(line, old_cnt++))
110 goto out_stale;
111 break;
112 case 'D': /* we used to emit D but that was misguided. */
113 goto out_stale;
114 break;
115 case 'T': /* we used to emit T but nobody uses it. */
116 goto out_stale;
117 break;
118 default:
119 error("unrecognized: %s", line);
120 break;
121 }
122 }
123 fclose(fp);
124 return 0;
125 out_stale:
126 fclose(fp);
127 return 1;
128}
129
130static int compare_info(const void *a_, const void *b_)
131{
132 struct pack_info * const* a = a_;
133 struct pack_info * const* b = b_;
134
135 if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
136 /* Keep the order in the original */
137 return (*a)->old_num - (*b)->old_num;
138 else if (0 <= (*a)->old_num)
139 /* Only A existed in the original so B is obviously newer */
140 return -1;
141 else if (0 <= (*b)->old_num)
142 /* The other way around. */
143 return 1;
144
145 /* then it does not matter but at least keep the comparison stable */
146 if ((*a)->p == (*b)->p)
147 return 0;
148 else if ((*a)->p < (*b)->p)
149 return -1;
150 else
151 return 1;
152}
153
154static void init_pack_info(const char *infofile, int force)
155{
156 struct packed_git *p;
157 int stale;
158 int i = 0;
159
160 objdir = get_object_directory();
161 objdirlen = strlen(objdir);
162
163 prepare_packed_git();
164 for (p = packed_git; p; p = p->next) {
165 /* we ignore things on alternate path since they are
166 * not available to the pullers in general.
167 */
168 if (!p->pack_local)
169 continue;
170 i++;
171 }
172 num_pack = i;
173 info = xcalloc(num_pack, sizeof(struct pack_info *));
174 for (i = 0, p = packed_git; p; p = p->next) {
175 if (!p->pack_local)
176 continue;
177 info[i] = xcalloc(1, sizeof(struct pack_info));
178 info[i]->p = p;
179 info[i]->old_num = -1;
180 i++;
181 }
182
183 if (infofile && !force)
184 stale = read_pack_info_file(infofile);
185 else
186 stale = 1;
187
188 for (i = 0; i < num_pack; i++) {
189 if (stale) {
190 info[i]->old_num = -1;
191 info[i]->nr_heads = 0;
192 }
193 }
194
195 /* renumber them */
196 qsort(info, num_pack, sizeof(info[0]), compare_info);
197 for (i = 0; i < num_pack; i++)
198 info[i]->new_num = i;
199}
200
201static void write_pack_info_file(FILE *fp)
202{
203 int i;
204 for (i = 0; i < num_pack; i++)
205 fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6);
206 fputc('\n', fp);
207}
208
209static int update_info_packs(int force)
210{
211 char infofile[PATH_MAX];
212 char name[PATH_MAX];
213 int namelen;
214 FILE *fp;
215
216 namelen = sprintf(infofile, "%s/info/packs", get_object_directory());
217 strcpy(name, infofile);
218 strcpy(name + namelen, "+");
219
220 init_pack_info(infofile, force);
221
222 safe_create_leading_directories(name);
223 fp = fopen(name, "w");
224 if (!fp)
225 return error("cannot open %s", name);
226 write_pack_info_file(fp);
227 fclose(fp);
228 rename(name, infofile);
229 return 0;
230}
231
232/* public */
233int update_server_info(int force)
234{
235 /* We would add more dumb-server support files later,
236 * including index of available pack files and their
237 * intended audiences.
238 */
239 int errs = 0;
240
241 errs = errs | update_info_refs(force);
242 errs = errs | update_info_packs(force);
243
244 /* remove leftover rev-cache file if there is any */
245 unlink(git_path("info/rev-cache"));
246
247 return errs;
248}