entry.c

   1 #include "cache.h"
   2 #include "blob.h"
   3 #include "dir.h"
   4 #include "streaming.h"
   5 #include "submodule.h"
   6 #include "progress.h"
   7
   8 static void create_directories(const char *path, int path_len,
   9                                const struct checkout *state)
  10 {
  11         char *buf = xmallocz(path_len);
  12         int len = 0;
  13
  14         while (len < path_len) {
  15                 do {
  16                         buf[len] = path[len];
  17                         len++;
  18                 } while (len < path_len && path[len] != '/');
  19                 if (len >= path_len)
  20                         break;
  21                 buf[len] = 0;
  22
  23                 /*
  24                  * For 'checkout-index --prefix=<dir>', <dir> is
  25                  * allowed to be a symlink to an existing directory,
  26                  * and we set 'state->base_dir_len' below, such that
  27                  * we test the path components of the prefix with the
  28                  * stat() function instead of the lstat() function.
  29                  */
  30                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  31                         continue; /* ok, it is already a directory. */
  32
  33                 /*
  34                  * If this mkdir() would fail, it could be that there
  35                  * is already a symlink or something else exists
  36                  * there, therefore we then try to unlink it and try
  37                  * one more time to create the directory.
  38                  */
  39                 if (mkdir(buf, 0777)) {
  40                         if (errno == EEXIST && state->force &&
  41                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  42                                 continue;
  43                         die_errno("cannot create directory at '%s'", buf);
  44                 }
  45         }
  46         free(buf);
  47 }
  48
  49 static void remove_subtree(struct strbuf *path)
  50 {
  51         DIR *dir = opendir(path->buf);
  52         struct dirent *de;
  53         int origlen = path->len;
  54
  55         if (!dir)
  56                 die_errno("cannot opendir '%s'", path->buf);
  57         while ((de = readdir(dir)) != NULL) {
  58                 struct stat st;
  59
  60                 if (is_dot_or_dotdot(de->d_name))
  61                         continue;
  62
  63                 strbuf_addch(path, '/');
  64                 strbuf_addstr(path, de->d_name);
  65                 if (lstat(path->buf, &st))
  66                         die_errno("cannot lstat '%s'", path->buf);
  67                 if (S_ISDIR(st.st_mode))
  68                         remove_subtree(path);
  69                 else if (unlink(path->buf))
  70                         die_errno("cannot unlink '%s'", path->buf);
  71                 strbuf_setlen(path, origlen);
  72         }
  73         closedir(dir);
  74         if (rmdir(path->buf))
  75                 die_errno("cannot rmdir '%s'", path->buf);
  76 }
  77
  78 static int create_file(const char *path, unsigned int mode)
  79 {
  80         mode = (mode & 0100) ? 0777 : 0666;
  81         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  82 }
  83
  84 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  85 {
  86         enum object_type type;
  87         void *new = read_sha1_file(ce->oid.hash, &type, size);
  88
  89         if (new) {
  90                 if (type == OBJ_BLOB)
  91                         return new;
  92                 free(new);
  93         }
  94         return NULL;
  95 }
  96
  97 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
  98 {
  99         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
 100         if (to_tempfile) {
 101                 xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
 102                           symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 103                 return mkstemp(path);
 104         } else {
 105                 return create_file(path, !symlink ? ce->ce_mode : 0666);
 106         }
 107 }
 108
 109 static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 110 {
 111         /* use fstat() only when path == ce->name */
 112         if (fstat_is_reliable() &&
 113             state->refresh_cache && !state->base_dir_len) {
 114                 fstat(fd, st);
 115                 return 1;
 116         }
 117         return 0;
 118 }
 119
 120 static int streaming_write_entry(const struct cache_entry *ce, char *path,
 121                                  struct stream_filter *filter,
 122                                  const struct checkout *state, int to_tempfile,
 123                                  int *fstat_done, struct stat *statbuf)
 124 {
 125         int result = 0;
 126         int fd;
 127
 128         fd = open_output_fd(path, ce, to_tempfile);
 129         if (fd < 0)
 130                 return -1;
 131
 132         result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
 133         *fstat_done = fstat_output(fd, state, statbuf);
 134         result |= close(fd);
 135
 136         if (result)
 137                 unlink(path);
 138         return result;
 139 }
 140
 141 void enable_delayed_checkout(struct checkout *state)
 142 {
 143         if (!state->delayed_checkout) {
 144                 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
 145                 state->delayed_checkout->state = CE_CAN_DELAY;
 146                 string_list_init(&state->delayed_checkout->filters, 0);
 147                 string_list_init(&state->delayed_checkout->paths, 0);
 148         }
 149 }
 150
 151 static int remove_available_paths(struct string_list_item *item, void *cb_data)
 152 {
 153         struct string_list *available_paths = cb_data;
 154         struct string_list_item *available;
 155
 156         available = string_list_lookup(available_paths, item->string);
 157         if (available)
 158                 available->util = (void *)item->string;
 159         return !available;
 160 }
 161
 162 int finish_delayed_checkout(struct checkout *state)
 163 {
 164         int errs = 0;
 165         unsigned delayed_object_count;
 166         off_t filtered_bytes = 0;
 167         struct string_list_item *filter, *path;
 168         struct progress *progress;
 169         struct delayed_checkout *dco = state->delayed_checkout;
 170
 171         if (!state->delayed_checkout)
 172                 return errs;
 173
 174         dco->state = CE_RETRY;
 175         delayed_object_count = dco->paths.nr;
 176         progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
 177         while (dco->filters.nr > 0) {
 178                 for_each_string_list_item(filter, &dco->filters) {
 179                         struct string_list available_paths = STRING_LIST_INIT_NODUP;
 180                         display_progress(progress, delayed_object_count - dco->paths.nr);
 181
 182                         if (!async_query_available_blobs(filter->string, &available_paths)) {
 183                                 /* Filter reported an error */
 184                                 errs = 1;
 185                                 filter->string = "";
 186                                 continue;
 187                         }
 188                         if (available_paths.nr <= 0) {
 189                                 /*
 190                                  * Filter responded with no entries. That means
 191                                  * the filter is done and we can remove the
 192                                  * filter from the list (see
 193                                  * "string_list_remove_empty_items" call below).
 194                                  */
 195                                 filter->string = "";
 196                                 continue;
 197                         }
 198
 199                         /*
 200                          * In dco->paths we store a list of all delayed paths.
 201                          * The filter just send us a list of available paths.
 202                          * Remove them from the list.
 203                          */
 204                         filter_string_list(&dco->paths, 0,
 205                                 &remove_available_paths, &available_paths);
 206
 207                         for_each_string_list_item(path, &available_paths) {
 208                                 struct cache_entry* ce;
 209
 210                                 if (!path->util) {
 211                                         error("external filter '%s' signaled that '%s' "
 212                                               "is now available although it has not been "
 213                                               "delayed earlier",
 214                                               filter->string, path->string);
 215                                         errs |= 1;
 216
 217                                         /*
 218                                          * Do not ask the filter for available blobs,
 219                                          * again, as the filter is likely buggy.
 220                                          */
 221                                         filter->string = "";
 222                                         continue;
 223                                 }
 224                                 ce = index_file_exists(state->istate, path->string,
 225                                                        strlen(path->string), 0);
 226                                 if (ce) {
 227                                         errs |= checkout_entry(ce, state, NULL);
 228                                         filtered_bytes += ce->ce_stat_data.sd_size;
 229                                         display_throughput(progress, filtered_bytes);
 230                                 } else
 231                                         errs = 1;
 232                         }
 233                 }
 234                 string_list_remove_empty_items(&dco->filters, 0);
 235         }
 236         stop_progress(&progress);
 237         string_list_clear(&dco->filters, 0);
 238
 239         /* At this point we should not have any delayed paths anymore. */
 240         errs |= dco->paths.nr;
 241         for_each_string_list_item(path, &dco->paths) {
 242                 error("'%s' was not filtered properly", path->string);
 243         }
 244         string_list_clear(&dco->paths, 0);
 245
 246         free(dco);
 247         state->delayed_checkout = NULL;
 248
 249         return errs;
 250 }
 251
 252 static int write_entry(struct cache_entry *ce,
 253                        char *path, const struct checkout *state, int to_tempfile)
 254 {
 255         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 256         struct delayed_checkout *dco = state->delayed_checkout;
 257         int fd, ret, fstat_done = 0;
 258         char *new;
 259         struct strbuf buf = STRBUF_INIT;
 260         unsigned long size;
 261         ssize_t wrote;
 262         size_t newsize = 0;
 263         struct stat st;
 264         const struct submodule *sub;
 265
 266         if (ce_mode_s_ifmt == S_IFREG) {
 267                 struct stream_filter *filter = get_stream_filter(ce->name,
 268                                                                  ce->oid.hash);
 269                 if (filter &&
 270                     !streaming_write_entry(ce, path, filter,
 271                                            state, to_tempfile,
 272                                            &fstat_done, &st))
 273                         goto finish;
 274         }
 275
 276         switch (ce_mode_s_ifmt) {
 277         case S_IFLNK:
 278                 new = read_blob_entry(ce, &size);
 279                 if (!new)
 280                         return error("unable to read sha1 file of %s (%s)",
 281                                      path, oid_to_hex(&ce->oid));
 282
 283                 /*
 284                  * We can't make a real symlink; write out a regular file entry
 285                  * with the symlink destination as its contents.
 286                  */
 287                 if (!has_symlinks || to_tempfile)
 288                         goto write_file_entry;
 289
 290                 ret = symlink(new, path);
 291                 free(new);
 292                 if (ret)
 293                         return error_errno("unable to create symlink %s", path);
 294                 break;
 295
 296         case S_IFREG:
 297                 /*
 298                  * We do not send the blob in case of a retry, so do not
 299                  * bother reading it at all.
 300                  */
 301                 if (dco && dco->state == CE_RETRY) {
 302                         new = NULL;
 303                         size = 0;
 304                 } else {
 305                         new = read_blob_entry(ce, &size);
 306                         if (!new)
 307                                 return error("unable to read sha1 file of %s (%s)",
 308                                              path, oid_to_hex(&ce->oid));
 309                 }
 310
 311                 /*
 312                  * Convert from git internal format to working tree format
 313                  */
 314                 if (dco && dco->state != CE_NO_DELAY) {
 315                         ret = async_convert_to_working_tree(ce->name, new,
 316                                                             size, &buf, dco);
 317                         if (ret && string_list_has_string(&dco->paths, ce->name)) {
 318                                 free(new);
 319                                 goto delayed;
 320                         }
 321                 } else
 322                         ret = convert_to_working_tree(ce->name, new, size, &buf);
 323
 324                 if (ret) {
 325                         free(new);
 326                         new = strbuf_detach(&buf, &newsize);
 327                         size = newsize;
 328                 }
 329                 /*
 330                  * No "else" here as errors from convert are OK at this
 331                  * point. If the error would have been fatal (e.g.
 332                  * filter is required), then we would have died already.
 333                  */
 334
 335         write_file_entry:
 336                 fd = open_output_fd(path, ce, to_tempfile);
 337                 if (fd < 0) {
 338                         free(new);
 339                         return error_errno("unable to create file %s", path);
 340                 }
 341
 342                 wrote = write_in_full(fd, new, size);
 343                 if (!to_tempfile)
 344                         fstat_done = fstat_output(fd, state, &st);
 345                 close(fd);
 346                 free(new);
 347                 if (wrote < 0)
 348                         return error("unable to write file %s", path);
 349                 break;
 350
 351         case S_IFGITLINK:
 352                 if (to_tempfile)
 353                         return error("cannot create temporary submodule %s", path);
 354                 if (mkdir(path, 0777) < 0)
 355                         return error("cannot create submodule directory %s", path);
 356                 sub = submodule_from_ce(ce);
 357                 if (sub)
 358                         return submodule_move_head(ce->name,
 359                                 NULL, oid_to_hex(&ce->oid),
 360                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 361                 break;
 362
 363         default:
 364                 return error("unknown file mode for %s in index", path);
 365         }
 366
 367 finish:
 368         if (state->refresh_cache) {
 369                 assert(state->istate);
 370                 if (!fstat_done)
 371                         if (lstat(ce->name, &st) < 0)
 372                                 return error_errno("unable to stat just-written file %s",
 373                                                    ce->name);
 374                 fill_stat_cache_info(ce, &st);
 375                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 376                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 377         }
 378 delayed:
 379         return 0;
 380 }
 381
 382 /*
 383  * This is like 'lstat()', except it refuses to follow symlinks
 384  * in the path, after skipping "skiplen".
 385  */
 386 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 387 {
 388         const char *slash = path + len;
 389
 390         while (path < slash && *slash != '/')
 391                 slash--;
 392         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 393                 errno = ENOENT;
 394                 return -1;
 395         }
 396         return lstat(path, st);
 397 }
 398
 399 /*
 400  * Write the contents from ce out to the working tree.
 401  *
 402  * When topath[] is not NULL, instead of writing to the working tree
 403  * file named by ce, a temporary file is created by this function and
 404  * its name is returned in topath[], which must be able to hold at
 405  * least TEMPORARY_FILENAME_LENGTH bytes long.
 406  */
 407 int checkout_entry(struct cache_entry *ce,
 408                    const struct checkout *state, char *topath)
 409 {
 410         static struct strbuf path = STRBUF_INIT;
 411         struct stat st;
 412
 413         if (topath)
 414                 return write_entry(ce, topath, state, 1);
 415
 416         strbuf_reset(&path);
 417         strbuf_add(&path, state->base_dir, state->base_dir_len);
 418         strbuf_add(&path, ce->name, ce_namelen(ce));
 419
 420         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 421                 const struct submodule *sub;
 422                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 423                 /*
 424                  * Needs to be checked before !changed returns early,
 425                  * as the possibly empty directory was not changed
 426                  */
 427                 sub = submodule_from_ce(ce);
 428                 if (sub) {
 429                         int err;
 430                         if (!is_submodule_populated_gently(ce->name, &err)) {
 431                                 struct stat sb;
 432                                 if (lstat(ce->name, &sb))
 433                                         die(_("could not stat file '%s'"), ce->name);
 434                                 if (!(st.st_mode & S_IFDIR))
 435                                         unlink_or_warn(ce->name);
 436
 437                                 return submodule_move_head(ce->name,
 438                                         NULL, oid_to_hex(&ce->oid), 0);
 439                         } else
 440                                 return submodule_move_head(ce->name,
 441                                         "HEAD", oid_to_hex(&ce->oid),
 442                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 443                 }
 444
 445                 if (!changed)
 446                         return 0;
 447                 if (!state->force) {
 448                         if (!state->quiet)
 449                                 fprintf(stderr,
 450                                         "%s already exists, no checkout\n",
 451                                         path.buf);
 452                         return -1;
 453                 }
 454
 455                 /*
 456                  * We unlink the old file, to get the new one with the
 457                  * right permissions (including umask, which is nasty
 458                  * to emulate by hand - much easier to let the system
 459                  * just do the right thing)
 460                  */
 461                 if (S_ISDIR(st.st_mode)) {
 462                         /* If it is a gitlink, leave it alone! */
 463                         if (S_ISGITLINK(ce->ce_mode))
 464                                 return 0;
 465                         if (!state->force)
 466                                 return error("%s is a directory", path.buf);
 467                         remove_subtree(&path);
 468                 } else if (unlink(path.buf))
 469                         return error_errno("unable to unlink old '%s'", path.buf);
 470         } else if (state->not_new)
 471                 return 0;
 472
 473         create_directories(path.buf, path.len, state);
 474         return write_entry(ce, path.buf, state, 0);
 475 }