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, int flag, void *cb_data)
  11 {
  12         struct object *o = parse_object(sha1);
  13         if (!o)
  14                 return -1;
  15
  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);
  22         }
  23         return 0;
  24 }
  25
  26 static int update_info_refs(int force)
  27 {
  28         char *path0 = xstrdup(git_path("info/refs"));
  29         int len = strlen(path0);
  30         char *path1 = xmalloc(len + 2);
  31
  32         strcpy(path1, path0);
  33         strcpy(path1 + len, "+");
  34
  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", path0);
  39         for_each_ref(add_info_ref, NULL);
  40         fclose(info_ref_fp);
  41         rename(path1, path0);
  42         free(path0);
  43         free(path1);
  44         return 0;
  45 }
  46
  47 /* packs */
  48 static struct pack_info {
  49         struct packed_git *p;
  50         int old_num;
  51         int new_num;
  52         int nr_alloc;
  53         int nr_heads;
  54         unsigned char (*head)[20];
  55 } **info;
  56 static int num_pack;
  57 static const char *objdir;
  58 static int objdirlen;
  59
  60 static struct pack_info *find_pack_by_name(const char *name)
  61 {
  62         int i;
  63         for (i = 0; i < num_pack; i++) {
  64                 struct packed_git *p = info[i]->p;
  65                 /* skip "/pack/" after ".git/objects" */
  66                 if (!strcmp(p->pack_name + objdirlen + 6, name))
  67                         return info[i];
  68         }
  69         return NULL;
  70 }
  71
  72 /* Returns non-zero when we detect that the info in the
  73  * old file is useless.
  74  */
  75 static int parse_pack_def(const char *line, int old_cnt)
  76 {
  77         struct pack_info *i = find_pack_by_name(line + 2);
  78         if (i) {
  79                 i->old_num = old_cnt;
  80                 return 0;
  81         }
  82         else {
  83                 /* The file describes a pack that is no longer here */
  84                 return 1;
  85         }
  86 }
  87
  88 /* Returns non-zero when we detect that the info in the
  89  * old file is useless.
  90  */
  91 static int read_pack_info_file(const char *infofile)
  92 {
  93         FILE *fp;
  94         char line[1000];
  95         int old_cnt = 0;
  96
  97         fp = fopen(infofile, "r");
  98         if (!fp)
  99                 return 1; /* nonexistent is not an error. */
 100
 101         while (fgets(line, sizeof(line), fp)) {
 102                 int len = strlen(line);
 103                 if (line[len-1] == '\n')
 104                         line[--len] = 0;
 105
 106                 if (!len)
 107                         continue;
 108
 109                 switch (line[0]) {
 110                 case 'P': /* P name */
 111                         if (parse_pack_def(line, old_cnt++))
 112                                 goto out_stale;
 113                         break;
 114                 case 'D': /* we used to emit D but that was misguided. */
 115                         goto out_stale;
 116                         break;
 117                 case 'T': /* we used to emit T but nobody uses it. */
 118                         goto out_stale;
 119                         break;
 120                 default:
 121                         error("unrecognized: %s", line);
 122                         break;
 123                 }
 124         }
 125         fclose(fp);
 126         return 0;
 127  out_stale:
 128         fclose(fp);
 129         return 1;
 130 }
 131
 132 static int compare_info(const void *a_, const void *b_)
 133 {
 134         struct pack_info * const* a = a_;
 135         struct pack_info * const* b = b_;
 136
 137         if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
 138                 /* Keep the order in the original */
 139                 return (*a)->old_num - (*b)->old_num;
 140         else if (0 <= (*a)->old_num)
 141                 /* Only A existed in the original so B is obviously newer */
 142                 return -1;
 143         else if (0 <= (*b)->old_num)
 144                 /* The other way around. */
 145                 return 1;
 146
 147         /* then it does not matter but at least keep the comparison stable */
 148         if ((*a)->p == (*b)->p)
 149                 return 0;
 150         else if ((*a)->p < (*b)->p)
 151                 return -1;
 152         else
 153                 return 1;
 154 }
 155
 156 static void init_pack_info(const char *infofile, int force)
 157 {
 158         struct packed_git *p;
 159         int stale;
 160         int i = 0;
 161
 162         objdir = get_object_directory();
 163         objdirlen = strlen(objdir);
 164
 165         prepare_packed_git();
 166         for (p = packed_git; p; p = p->next) {
 167                 /* we ignore things on alternate path since they are
 168                  * not available to the pullers in general.
 169                  */
 170                 if (!p->pack_local)
 171                         continue;
 172                 i++;
 173         }
 174         num_pack = i;
 175         info = xcalloc(num_pack, sizeof(struct pack_info *));
 176         for (i = 0, p = packed_git; p; p = p->next) {
 177                 if (!p->pack_local)
 178                         continue;
 179                 info[i] = xcalloc(1, sizeof(struct pack_info));
 180                 info[i]->p = p;
 181                 info[i]->old_num = -1;
 182                 i++;
 183         }
 184
 185         if (infofile && !force)
 186                 stale = read_pack_info_file(infofile);
 187         else
 188                 stale = 1;
 189
 190         for (i = 0; i < num_pack; i++) {
 191                 if (stale) {
 192                         info[i]->old_num = -1;
 193                         info[i]->nr_heads = 0;
 194                 }
 195         }
 196
 197         /* renumber them */
 198         qsort(info, num_pack, sizeof(info[0]), compare_info);
 199         for (i = 0; i < num_pack; i++)
 200                 info[i]->new_num = i;
 201 }
 202
 203 static void write_pack_info_file(FILE *fp)
 204 {
 205         int i;
 206         for (i = 0; i < num_pack; i++)
 207                 fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6);
 208         fputc('\n', fp);
 209 }
 210
 211 static int update_info_packs(int force)
 212 {
 213         char infofile[PATH_MAX];
 214         char name[PATH_MAX];
 215         int namelen;
 216         FILE *fp;
 217
 218         namelen = sprintf(infofile, "%s/info/packs", get_object_directory());
 219         strcpy(name, infofile);
 220         strcpy(name + namelen, "+");
 221
 222         init_pack_info(infofile, force);
 223
 224         safe_create_leading_directories(name);
 225         fp = fopen(name, "w");
 226         if (!fp)
 227                 return error("cannot open %s", name);
 228         write_pack_info_file(fp);
 229         fclose(fp);
 230         rename(name, infofile);
 231         return 0;
 232 }
 233
 234 /* public */
 235 int update_server_info(int force)
 236 {
 237         /* We would add more dumb-server support files later,
 238          * including index of available pack files and their
 239          * intended audiences.
 240          */
 241         int errs = 0;
 242
 243         errs = errs | update_info_refs(force);
 244         errs = errs | update_info_packs(force);
 245
 246         /* remove leftover rev-cache file if there is any */
 247         unlink(git_path("info/rev-cache"));
 248
 249         return errs;
 250 }