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-1] = 0;
 103
 104                 switch (line[0]) {
 105                 case 'P': /* P name */
 106                         if (parse_pack_def(line, old_cnt++))
 107                                 goto out_stale;
 108                         break;
 109                 case 'D': /* we used to emit D but that was misguided. */
 110                         goto out_stale;
 111                         break;
 112                 case 'T': /* we used to emit T but nobody uses it. */
 113                         goto out_stale;
 114                         break;
 115                 default:
 116                         error("unrecognized: %s", line);
 117                         break;
 118                 }
 119         }
 120         fclose(fp);
 121         return 0;
 122  out_stale:
 123         fclose(fp);
 124         return 1;
 125 }
 126
 127 static int compare_info(const void *a_, const void *b_)
 128 {
 129         struct pack_info * const* a = a_;
 130         struct pack_info * const* b = b_;
 131
 132         if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
 133                 /* Keep the order in the original */
 134                 return (*a)->old_num - (*b)->old_num;
 135         else if (0 <= (*a)->old_num)
 136                 /* Only A existed in the original so B is obviously newer */
 137                 return -1;
 138         else if (0 <= (*b)->old_num)
 139                 /* The other way around. */
 140                 return 1;
 141
 142         /* then it does not matter but at least keep the comparison stable */
 143         return (*a)->p - (*b)->p;
 144 }
 145
 146 static void init_pack_info(const char *infofile, int force)
 147 {
 148         struct packed_git *p;
 149         int stale;
 150         int i = 0;
 151
 152         objdir = get_object_directory();
 153         objdirlen = strlen(objdir);
 154
 155         prepare_packed_git();
 156         for (p = packed_git; p; p = p->next) {
 157                 /* we ignore things on alternate path since they are
 158                  * not available to the pullers in general.
 159                  */
 160                 if (!p->pack_local)
 161                         continue;
 162                 i++;
 163         }
 164         num_pack = i;
 165         info = xcalloc(num_pack, sizeof(struct pack_info *));
 166         for (i = 0, p = packed_git; p; p = p->next) {
 167                 if (!p->pack_local)
 168                         continue;
 169                 info[i] = xcalloc(1, sizeof(struct pack_info));
 170                 info[i]->p = p;
 171                 info[i]->old_num = -1;
 172                 i++;
 173         }
 174
 175         if (infofile && !force)
 176                 stale = read_pack_info_file(infofile);
 177         else
 178                 stale = 1;
 179
 180         for (i = 0; i < num_pack; i++) {
 181                 if (stale) {
 182                         info[i]->old_num = -1;
 183                         info[i]->nr_heads = 0;
 184                 }
 185         }
 186
 187         /* renumber them */
 188         qsort(info, num_pack, sizeof(info[0]), compare_info);
 189         for (i = 0; i < num_pack; i++)
 190                 info[i]->new_num = i;
 191 }
 192
 193 static void write_pack_info_file(FILE *fp)
 194 {
 195         int i;
 196         for (i = 0; i < num_pack; i++)
 197                 fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6);
 198 }
 199
 200 static int update_info_packs(int force)
 201 {
 202         char infofile[PATH_MAX];
 203         char name[PATH_MAX];
 204         int namelen;
 205         FILE *fp;
 206
 207         namelen = sprintf(infofile, "%s/info/packs", get_object_directory());
 208         strcpy(name, infofile);
 209         strcpy(name + namelen, "+");
 210
 211         init_pack_info(infofile, force);
 212
 213         safe_create_leading_directories(name);
 214         fp = fopen(name, "w");
 215         if (!fp)
 216                 return error("cannot open %s", name);
 217         write_pack_info_file(fp);
 218         fclose(fp);
 219         rename(name, infofile);
 220         return 0;
 221 }
 222
 223 /* public */
 224 int update_server_info(int force)
 225 {
 226         /* We would add more dumb-server support files later,
 227          * including index of available pack files and their
 228          * intended audiences.
 229          */
 230         int errs = 0;
 231
 232         errs = errs | update_info_refs(force);
 233         errs = errs | update_info_packs(force);
 234
 235         /* remove leftover rev-cache file if there is any */
 236         unlink(git_path("info/rev-cache"));
 237
 238         return errs;
 239 }