Add --diff-filter= documentation paragraph
[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
7 /* refs */
8 static FILE *info_ref_fp;
9
10 static 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 == tag_type) {
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
24 static 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 */
46 static 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;
54 static int num_pack;
55 static const char *objdir;
56 static int objdirlen;
57
58 static 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  */
73 static 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  */
89 static 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; /* nonexisting 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
130 static 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
154 static 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
201 static 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
209 static 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 */
233 int 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 }