archive: handle commits with an empty tree
[git/jnareb-git.git] / server-info.c
blob9ec744e9f2da294a21ac02b46f0ea0b35889ae54
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "commit.h"
5 #include "tag.h"
7 /* refs */
8 static FILE *info_ref_fp;
10 static int add_info_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
12 struct object *o = parse_object(sha1);
13 if (!o)
14 return -1;
16 fprintf(info_ref_fp, "%s %s\n", sha1_to_hex(sha1), path);
17 if (o->type == OBJ_TAG) {
18 o = deref_tag(o, path, 0);
19 if (o)
20 fprintf(info_ref_fp, "%s %s^{}\n",
21 sha1_to_hex(o->sha1), path);
23 return 0;
26 static int update_info_refs(int force)
28 char *path0 = git_pathdup("info/refs");
29 int len = strlen(path0);
30 char *path1 = xmalloc(len + 2);
32 strcpy(path1, path0);
33 strcpy(path1 + len, "+");
35 safe_create_leading_directories(path0);
36 info_ref_fp = fopen(path1, "w");
37 if (!info_ref_fp)
38 return error("unable to update %s", path1);
39 for_each_ref(add_info_ref, NULL);
40 fclose(info_ref_fp);
41 adjust_shared_perm(path1);
42 rename(path1, path0);
43 free(path0);
44 free(path1);
45 return 0;
48 /* packs */
49 static struct pack_info {
50 struct packed_git *p;
51 int old_num;
52 int new_num;
53 int nr_alloc;
54 int nr_heads;
55 unsigned char (*head)[20];
56 } **info;
57 static int num_pack;
58 static const char *objdir;
59 static int objdirlen;
61 static struct pack_info *find_pack_by_name(const char *name)
63 int i;
64 for (i = 0; i < num_pack; i++) {
65 struct packed_git *p = info[i]->p;
66 /* skip "/pack/" after ".git/objects" */
67 if (!strcmp(p->pack_name + objdirlen + 6, name))
68 return info[i];
70 return NULL;
73 /* Returns non-zero when we detect that the info in the
74 * old file is useless.
76 static int parse_pack_def(const char *line, int old_cnt)
78 struct pack_info *i = find_pack_by_name(line + 2);
79 if (i) {
80 i->old_num = old_cnt;
81 return 0;
83 else {
84 /* The file describes a pack that is no longer here */
85 return 1;
89 /* Returns non-zero when we detect that the info in the
90 * old file is useless.
92 static int read_pack_info_file(const char *infofile)
94 FILE *fp;
95 char line[1000];
96 int old_cnt = 0;
98 fp = fopen(infofile, "r");
99 if (!fp)
100 return 1; /* nonexistent is not an error. */
102 while (fgets(line, sizeof(line), fp)) {
103 int len = strlen(line);
104 if (len && line[len-1] == '\n')
105 line[--len] = 0;
107 if (!len)
108 continue;
110 switch (line[0]) {
111 case 'P': /* P name */
112 if (parse_pack_def(line, old_cnt++))
113 goto out_stale;
114 break;
115 case 'D': /* we used to emit D but that was misguided. */
116 case 'T': /* we used to emit T but nobody uses it. */
117 goto out_stale;
118 default:
119 error("unrecognized: %s", line);
120 break;
123 fclose(fp);
124 return 0;
125 out_stale:
126 fclose(fp);
127 return 1;
130 static int compare_info(const void *a_, const void *b_)
132 struct pack_info *const *a = a_;
133 struct pack_info *const *b = b_;
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;
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;
154 static void init_pack_info(const char *infofile, int force)
156 struct packed_git *p;
157 int stale;
158 int i = 0;
160 objdir = get_object_directory();
161 objdirlen = strlen(objdir);
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.
168 if (!p->pack_local)
169 continue;
170 i++;
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++;
183 if (infofile && !force)
184 stale = read_pack_info_file(infofile);
185 else
186 stale = 1;
188 for (i = 0; i < num_pack; i++) {
189 if (stale) {
190 info[i]->old_num = -1;
191 info[i]->nr_heads = 0;
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;
201 static void write_pack_info_file(FILE *fp)
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);
209 static int update_info_packs(int force)
211 char infofile[PATH_MAX];
212 char name[PATH_MAX];
213 int namelen;
214 FILE *fp;
216 namelen = sprintf(infofile, "%s/info/packs", get_object_directory());
217 strcpy(name, infofile);
218 strcpy(name + namelen, "+");
220 init_pack_info(infofile, force);
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 adjust_shared_perm(name);
229 rename(name, infofile);
230 return 0;
233 /* public */
234 int update_server_info(int force)
236 /* We would add more dumb-server support files later,
237 * including index of available pack files and their
238 * intended audiences.
240 int errs = 0;
242 errs = errs | update_info_refs(force);
243 errs = errs | update_info_packs(force);
245 /* remove leftover rev-cache file if there is any */
246 unlink_or_warn(git_path("info/rev-cache"));
248 return errs;