server-info.con commit Merge branch 'pj/remote-set-branches-usage-fix' into maint (67f8d5b)
   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, 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
  26static int update_info_refs(int force)
  27{
  28        char *path0 = git_pathdup("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", 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;
  46}
  47
  48/* packs */
  49static 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;
  57static int num_pack;
  58static const char *objdir;
  59static int objdirlen;
  60
  61static struct pack_info *find_pack_by_name(const char *name)
  62{
  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];
  69        }
  70        return NULL;
  71}
  72
  73/* Returns non-zero when we detect that the info in the
  74 * old file is useless.
  75 */
  76static int parse_pack_def(const char *line, int old_cnt)
  77{
  78        struct pack_info *i = find_pack_by_name(line + 2);
  79        if (i) {
  80                i->old_num = old_cnt;
  81                return 0;
  82        }
  83        else {
  84                /* The file describes a pack that is no longer here */
  85                return 1;
  86        }
  87}
  88
  89/* Returns non-zero when we detect that the info in the
  90 * old file is useless.
  91 */
  92static int read_pack_info_file(const char *infofile)
  93{
  94        FILE *fp;
  95        char line[1000];
  96        int old_cnt = 0;
  97
  98        fp = fopen(infofile, "r");
  99        if (!fp)
 100                return 1; /* nonexistent is not an error. */
 101
 102        while (fgets(line, sizeof(line), fp)) {
 103                int len = strlen(line);
 104                if (len && line[len-1] == '\n')
 105                        line[--len] = 0;
 106
 107                if (!len)
 108                        continue;
 109
 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;
 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        adjust_shared_perm(name);
 229        rename(name, infofile);
 230        return 0;
 231}
 232
 233/* public */
 234int update_server_info(int force)
 235{
 236        /* We would add more dumb-server support files later,
 237         * including index of available pack files and their
 238         * intended audiences.
 239         */
 240        int errs = 0;
 241
 242        errs = errs | update_info_refs(force);
 243        errs = errs | update_info_packs(force);
 244
 245        /* remove leftover rev-cache file if there is any */
 246        unlink_or_warn(git_path("info/rev-cache"));
 247
 248        return errs;
 249}