server-info.con commit Merge branch 'bp/fsmonitor-bufsize-fix' (beed7e2)
   1#include "cache.h"
   2#include "repository.h"
   3#include "refs.h"
   4#include "object.h"
   5#include "commit.h"
   6#include "tag.h"
   7#include "packfile.h"
   8#include "object-store.h"
   9
  10/*
  11 * Create the file "path" by writing to a temporary file and renaming
  12 * it into place. The contents of the file come from "generate", which
  13 * should return non-zero if it encounters an error.
  14 */
  15static int update_info_file(char *path, int (*generate)(FILE *))
  16{
  17        char *tmp = mkpathdup("%s_XXXXXX", path);
  18        int ret = -1;
  19        int fd = -1;
  20        FILE *fp = NULL, *to_close;
  21
  22        safe_create_leading_directories(path);
  23        fd = git_mkstemp_mode(tmp, 0666);
  24        if (fd < 0)
  25                goto out;
  26        to_close = fp = fdopen(fd, "w");
  27        if (!fp)
  28                goto out;
  29        fd = -1;
  30        ret = generate(fp);
  31        if (ret)
  32                goto out;
  33        fp = NULL;
  34        if (fclose(to_close))
  35                goto out;
  36        if (adjust_shared_perm(tmp) < 0)
  37                goto out;
  38        if (rename(tmp, path) < 0)
  39                goto out;
  40        ret = 0;
  41
  42out:
  43        if (ret) {
  44                error_errno("unable to update %s", path);
  45                if (fp)
  46                        fclose(fp);
  47                else if (fd >= 0)
  48                        close(fd);
  49                unlink(tmp);
  50        }
  51        free(tmp);
  52        return ret;
  53}
  54
  55static int add_info_ref(const char *path, const struct object_id *oid,
  56                        int flag, void *cb_data)
  57{
  58        FILE *fp = cb_data;
  59        struct object *o = parse_object(oid);
  60        if (!o)
  61                return -1;
  62
  63        if (fprintf(fp, "%s     %s\n", oid_to_hex(oid), path) < 0)
  64                return -1;
  65
  66        if (o->type == OBJ_TAG) {
  67                o = deref_tag(o, path, 0);
  68                if (o)
  69                        if (fprintf(fp, "%s     %s^{}\n",
  70                                oid_to_hex(&o->oid), path) < 0)
  71                                return -1;
  72        }
  73        return 0;
  74}
  75
  76static int generate_info_refs(FILE *fp)
  77{
  78        return for_each_ref(add_info_ref, fp);
  79}
  80
  81static int update_info_refs(int force)
  82{
  83        char *path = git_pathdup("info/refs");
  84        int ret = update_info_file(path, generate_info_refs);
  85        free(path);
  86        return ret;
  87}
  88
  89/* packs */
  90static struct pack_info {
  91        struct packed_git *p;
  92        int old_num;
  93        int new_num;
  94        int nr_alloc;
  95        int nr_heads;
  96        unsigned char (*head)[20];
  97} **info;
  98static int num_pack;
  99static const char *objdir;
 100static int objdirlen;
 101
 102static struct pack_info *find_pack_by_name(const char *name)
 103{
 104        int i;
 105        for (i = 0; i < num_pack; i++) {
 106                struct packed_git *p = info[i]->p;
 107                /* skip "/pack/" after ".git/objects" */
 108                if (!strcmp(p->pack_name + objdirlen + 6, name))
 109                        return info[i];
 110        }
 111        return NULL;
 112}
 113
 114/* Returns non-zero when we detect that the info in the
 115 * old file is useless.
 116 */
 117static int parse_pack_def(const char *line, int old_cnt)
 118{
 119        struct pack_info *i = find_pack_by_name(line + 2);
 120        if (i) {
 121                i->old_num = old_cnt;
 122                return 0;
 123        }
 124        else {
 125                /* The file describes a pack that is no longer here */
 126                return 1;
 127        }
 128}
 129
 130/* Returns non-zero when we detect that the info in the
 131 * old file is useless.
 132 */
 133static int read_pack_info_file(const char *infofile)
 134{
 135        FILE *fp;
 136        char line[1000];
 137        int old_cnt = 0;
 138
 139        fp = fopen_or_warn(infofile, "r");
 140        if (!fp)
 141                return 1; /* nonexistent is not an error. */
 142
 143        while (fgets(line, sizeof(line), fp)) {
 144                int len = strlen(line);
 145                if (len && line[len-1] == '\n')
 146                        line[--len] = 0;
 147
 148                if (!len)
 149                        continue;
 150
 151                switch (line[0]) {
 152                case 'P': /* P name */
 153                        if (parse_pack_def(line, old_cnt++))
 154                                goto out_stale;
 155                        break;
 156                case 'D': /* we used to emit D but that was misguided. */
 157                case 'T': /* we used to emit T but nobody uses it. */
 158                        goto out_stale;
 159                default:
 160                        error("unrecognized: %s", line);
 161                        break;
 162                }
 163        }
 164        fclose(fp);
 165        return 0;
 166 out_stale:
 167        fclose(fp);
 168        return 1;
 169}
 170
 171static int compare_info(const void *a_, const void *b_)
 172{
 173        struct pack_info *const *a = a_;
 174        struct pack_info *const *b = b_;
 175
 176        if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
 177                /* Keep the order in the original */
 178                return (*a)->old_num - (*b)->old_num;
 179        else if (0 <= (*a)->old_num)
 180                /* Only A existed in the original so B is obviously newer */
 181                return -1;
 182        else if (0 <= (*b)->old_num)
 183                /* The other way around. */
 184                return 1;
 185
 186        /* then it does not matter but at least keep the comparison stable */
 187        if ((*a)->p == (*b)->p)
 188                return 0;
 189        else if ((*a)->p < (*b)->p)
 190                return -1;
 191        else
 192                return 1;
 193}
 194
 195static void init_pack_info(const char *infofile, int force)
 196{
 197        struct packed_git *p;
 198        int stale;
 199        int i = 0;
 200
 201        objdir = get_object_directory();
 202        objdirlen = strlen(objdir);
 203
 204        for (p = get_packed_git(the_repository); p; p = p->next) {
 205                /* we ignore things on alternate path since they are
 206                 * not available to the pullers in general.
 207                 */
 208                if (!p->pack_local)
 209                        continue;
 210                i++;
 211        }
 212        num_pack = i;
 213        info = xcalloc(num_pack, sizeof(struct pack_info *));
 214        for (i = 0, p = get_packed_git(the_repository); p; p = p->next) {
 215                if (!p->pack_local)
 216                        continue;
 217                info[i] = xcalloc(1, sizeof(struct pack_info));
 218                info[i]->p = p;
 219                info[i]->old_num = -1;
 220                i++;
 221        }
 222
 223        if (infofile && !force)
 224                stale = read_pack_info_file(infofile);
 225        else
 226                stale = 1;
 227
 228        for (i = 0; i < num_pack; i++) {
 229                if (stale) {
 230                        info[i]->old_num = -1;
 231                        info[i]->nr_heads = 0;
 232                }
 233        }
 234
 235        /* renumber them */
 236        QSORT(info, num_pack, compare_info);
 237        for (i = 0; i < num_pack; i++)
 238                info[i]->new_num = i;
 239}
 240
 241static void free_pack_info(void)
 242{
 243        int i;
 244        for (i = 0; i < num_pack; i++)
 245                free(info[i]);
 246        free(info);
 247}
 248
 249static int write_pack_info_file(FILE *fp)
 250{
 251        int i;
 252        for (i = 0; i < num_pack; i++) {
 253                if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
 254                        return -1;
 255        }
 256        if (fputc('\n', fp) == EOF)
 257                return -1;
 258        return 0;
 259}
 260
 261static int update_info_packs(int force)
 262{
 263        char *infofile = mkpathdup("%s/info/packs", get_object_directory());
 264        int ret;
 265
 266        init_pack_info(infofile, force);
 267        ret = update_info_file(infofile, write_pack_info_file);
 268        free_pack_info();
 269        free(infofile);
 270        return ret;
 271}
 272
 273/* public */
 274int update_server_info(int force)
 275{
 276        /* We would add more dumb-server support files later,
 277         * including index of available pack files and their
 278         * intended audiences.
 279         */
 280        int errs = 0;
 281
 282        errs = errs | update_info_refs(force);
 283        errs = errs | update_info_packs(force);
 284
 285        /* remove leftover rev-cache file if there is any */
 286        unlink_or_warn(git_path("info/rev-cache"));
 287
 288        return errs;
 289}