server-info.con commit Merge branch 'jc/mailinfo-cleanup-fix' into maint (bffce88)
   1#include "cache.h"
   2#include "refs.h"
   3#include "object.h"
   4#include "commit.h"
   5#include "tag.h"
   6#include "packfile.h"
   7
   8/*
   9 * Create the file "path" by writing to a temporary file and renaming
  10 * it into place. The contents of the file come from "generate", which
  11 * should return non-zero if it encounters an error.
  12 */
  13static int update_info_file(char *path, int (*generate)(FILE *))
  14{
  15        char *tmp = mkpathdup("%s_XXXXXX", path);
  16        int ret = -1;
  17        int fd = -1;
  18        FILE *fp = NULL, *to_close;
  19
  20        safe_create_leading_directories(path);
  21        fd = git_mkstemp_mode(tmp, 0666);
  22        if (fd < 0)
  23                goto out;
  24        to_close = fp = fdopen(fd, "w");
  25        if (!fp)
  26                goto out;
  27        fd = -1;
  28        ret = generate(fp);
  29        if (ret)
  30                goto out;
  31        fp = NULL;
  32        if (fclose(to_close))
  33                goto out;
  34        if (adjust_shared_perm(tmp) < 0)
  35                goto out;
  36        if (rename(tmp, path) < 0)
  37                goto out;
  38        ret = 0;
  39
  40out:
  41        if (ret) {
  42                error_errno("unable to update %s", path);
  43                if (fp)
  44                        fclose(fp);
  45                else if (fd >= 0)
  46                        close(fd);
  47                unlink(tmp);
  48        }
  49        free(tmp);
  50        return ret;
  51}
  52
  53static int add_info_ref(const char *path, const struct object_id *oid,
  54                        int flag, void *cb_data)
  55{
  56        FILE *fp = cb_data;
  57        struct object *o = parse_object(oid);
  58        if (!o)
  59                return -1;
  60
  61        if (fprintf(fp, "%s     %s\n", oid_to_hex(oid), path) < 0)
  62                return -1;
  63
  64        if (o->type == OBJ_TAG) {
  65                o = deref_tag(o, path, 0);
  66                if (o)
  67                        if (fprintf(fp, "%s     %s^{}\n",
  68                                oid_to_hex(&o->oid), path) < 0)
  69                                return -1;
  70        }
  71        return 0;
  72}
  73
  74static int generate_info_refs(FILE *fp)
  75{
  76        return for_each_ref(add_info_ref, fp);
  77}
  78
  79static int update_info_refs(int force)
  80{
  81        char *path = git_pathdup("info/refs");
  82        int ret = update_info_file(path, generate_info_refs);
  83        free(path);
  84        return ret;
  85}
  86
  87/* packs */
  88static struct pack_info {
  89        struct packed_git *p;
  90        int old_num;
  91        int new_num;
  92        int nr_alloc;
  93        int nr_heads;
  94        unsigned char (*head)[20];
  95} **info;
  96static int num_pack;
  97static const char *objdir;
  98static int objdirlen;
  99
 100static struct pack_info *find_pack_by_name(const char *name)
 101{
 102        int i;
 103        for (i = 0; i < num_pack; i++) {
 104                struct packed_git *p = info[i]->p;
 105                /* skip "/pack/" after ".git/objects" */
 106                if (!strcmp(p->pack_name + objdirlen + 6, name))
 107                        return info[i];
 108        }
 109        return NULL;
 110}
 111
 112/* Returns non-zero when we detect that the info in the
 113 * old file is useless.
 114 */
 115static int parse_pack_def(const char *line, int old_cnt)
 116{
 117        struct pack_info *i = find_pack_by_name(line + 2);
 118        if (i) {
 119                i->old_num = old_cnt;
 120                return 0;
 121        }
 122        else {
 123                /* The file describes a pack that is no longer here */
 124                return 1;
 125        }
 126}
 127
 128/* Returns non-zero when we detect that the info in the
 129 * old file is useless.
 130 */
 131static int read_pack_info_file(const char *infofile)
 132{
 133        FILE *fp;
 134        char line[1000];
 135        int old_cnt = 0;
 136
 137        fp = fopen_or_warn(infofile, "r");
 138        if (!fp)
 139                return 1; /* nonexistent is not an error. */
 140
 141        while (fgets(line, sizeof(line), fp)) {
 142                int len = strlen(line);
 143                if (len && line[len-1] == '\n')
 144                        line[--len] = 0;
 145
 146                if (!len)
 147                        continue;
 148
 149                switch (line[0]) {
 150                case 'P': /* P name */
 151                        if (parse_pack_def(line, old_cnt++))
 152                                goto out_stale;
 153                        break;
 154                case 'D': /* we used to emit D but that was misguided. */
 155                case 'T': /* we used to emit T but nobody uses it. */
 156                        goto out_stale;
 157                default:
 158                        error("unrecognized: %s", line);
 159                        break;
 160                }
 161        }
 162        fclose(fp);
 163        return 0;
 164 out_stale:
 165        fclose(fp);
 166        return 1;
 167}
 168
 169static int compare_info(const void *a_, const void *b_)
 170{
 171        struct pack_info *const *a = a_;
 172        struct pack_info *const *b = b_;
 173
 174        if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
 175                /* Keep the order in the original */
 176                return (*a)->old_num - (*b)->old_num;
 177        else if (0 <= (*a)->old_num)
 178                /* Only A existed in the original so B is obviously newer */
 179                return -1;
 180        else if (0 <= (*b)->old_num)
 181                /* The other way around. */
 182                return 1;
 183
 184        /* then it does not matter but at least keep the comparison stable */
 185        if ((*a)->p == (*b)->p)
 186                return 0;
 187        else if ((*a)->p < (*b)->p)
 188                return -1;
 189        else
 190                return 1;
 191}
 192
 193static void init_pack_info(const char *infofile, int force)
 194{
 195        struct packed_git *p;
 196        int stale;
 197        int i = 0;
 198
 199        objdir = get_object_directory();
 200        objdirlen = strlen(objdir);
 201
 202        prepare_packed_git();
 203        for (p = packed_git; p; p = p->next) {
 204                /* we ignore things on alternate path since they are
 205                 * not available to the pullers in general.
 206                 */
 207                if (!p->pack_local)
 208                        continue;
 209                i++;
 210        }
 211        num_pack = i;
 212        info = xcalloc(num_pack, sizeof(struct pack_info *));
 213        for (i = 0, p = packed_git; p; p = p->next) {
 214                if (!p->pack_local)
 215                        continue;
 216                info[i] = xcalloc(1, sizeof(struct pack_info));
 217                info[i]->p = p;
 218                info[i]->old_num = -1;
 219                i++;
 220        }
 221
 222        if (infofile && !force)
 223                stale = read_pack_info_file(infofile);
 224        else
 225                stale = 1;
 226
 227        for (i = 0; i < num_pack; i++) {
 228                if (stale) {
 229                        info[i]->old_num = -1;
 230                        info[i]->nr_heads = 0;
 231                }
 232        }
 233
 234        /* renumber them */
 235        QSORT(info, num_pack, compare_info);
 236        for (i = 0; i < num_pack; i++)
 237                info[i]->new_num = i;
 238}
 239
 240static void free_pack_info(void)
 241{
 242        int i;
 243        for (i = 0; i < num_pack; i++)
 244                free(info[i]);
 245        free(info);
 246}
 247
 248static int write_pack_info_file(FILE *fp)
 249{
 250        int i;
 251        for (i = 0; i < num_pack; i++) {
 252                if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
 253                        return -1;
 254        }
 255        if (fputc('\n', fp) == EOF)
 256                return -1;
 257        return 0;
 258}
 259
 260static int update_info_packs(int force)
 261{
 262        char *infofile = mkpathdup("%s/info/packs", get_object_directory());
 263        int ret;
 264
 265        init_pack_info(infofile, force);
 266        ret = update_info_file(infofile, write_pack_info_file);
 267        free_pack_info();
 268        free(infofile);
 269        return ret;
 270}
 271
 272/* public */
 273int update_server_info(int force)
 274{
 275        /* We would add more dumb-server support files later,
 276         * including index of available pack files and their
 277         * intended audiences.
 278         */
 279        int errs = 0;
 280
 281        errs = errs | update_info_refs(force);
 282        errs = errs | update_info_packs(force);
 283
 284        /* remove leftover rev-cache file if there is any */
 285        unlink_or_warn(git_path("info/rev-cache"));
 286
 287        return errs;
 288}