Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "blob.h"
   3#include "dir.h"
   4#include "streaming.h"
   5
   6static void create_directories(const char *path, int path_len,
   7                               const struct checkout *state)
   8{
   9        char *buf = xmalloc(path_len + 1);
  10        int len = 0;
  11
  12        while (len < path_len) {
  13                do {
  14                        buf[len] = path[len];
  15                        len++;
  16                } while (len < path_len && path[len] != '/');
  17                if (len >= path_len)
  18                        break;
  19                buf[len] = 0;
  20
  21                /*
  22                 * For 'checkout-index --prefix=<dir>', <dir> is
  23                 * allowed to be a symlink to an existing directory,
  24                 * and we set 'state->base_dir_len' below, such that
  25                 * we test the path components of the prefix with the
  26                 * stat() function instead of the lstat() function.
  27                 */
  28                if (has_dirs_only_path(buf, len, state->base_dir_len))
  29                        continue; /* ok, it is already a directory. */
  30
  31                /*
  32                 * If this mkdir() would fail, it could be that there
  33                 * is already a symlink or something else exists
  34                 * there, therefore we then try to unlink it and try
  35                 * one more time to create the directory.
  36                 */
  37                if (mkdir(buf, 0777)) {
  38                        if (errno == EEXIST && state->force &&
  39                            !unlink_or_warn(buf) && !mkdir(buf, 0777))
  40                                continue;
  41                        die_errno("cannot create directory at '%s'", buf);
  42                }
  43        }
  44        free(buf);
  45}
  46
  47static void remove_subtree(const char *path)
  48{
  49        DIR *dir = opendir(path);
  50        struct dirent *de;
  51        char pathbuf[PATH_MAX];
  52        char *name;
  53
  54        if (!dir)
  55                die_errno("cannot opendir '%s'", path);
  56        strcpy(pathbuf, path);
  57        name = pathbuf + strlen(path);
  58        *name++ = '/';
  59        while ((de = readdir(dir)) != NULL) {
  60                struct stat st;
  61                if (is_dot_or_dotdot(de->d_name))
  62                        continue;
  63                strcpy(name, de->d_name);
  64                if (lstat(pathbuf, &st))
  65                        die_errno("cannot lstat '%s'", pathbuf);
  66                if (S_ISDIR(st.st_mode))
  67                        remove_subtree(pathbuf);
  68                else if (unlink(pathbuf))
  69                        die_errno("cannot unlink '%s'", pathbuf);
  70        }
  71        closedir(dir);
  72        if (rmdir(path))
  73                die_errno("cannot rmdir '%s'", path);
  74}
  75
  76static int create_file(const char *path, unsigned int mode)
  77{
  78        mode = (mode & 0100) ? 0777 : 0666;
  79        return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  80}
  81
  82static void *read_blob_entry(struct cache_entry *ce, unsigned long *size)
  83{
  84        enum object_type type;
  85        void *new = read_sha1_file(ce->sha1, &type, size);
  86
  87        if (new) {
  88                if (type == OBJ_BLOB)
  89                        return new;
  90                free(new);
  91        }
  92        return NULL;
  93}
  94
  95static int open_output_fd(char *path, struct cache_entry *ce, int to_tempfile)
  96{
  97        int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
  98        if (to_tempfile) {
  99                strcpy(path, symlink
 100                       ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 101                return mkstemp(path);
 102        } else {
 103                return create_file(path, !symlink ? ce->ce_mode : 0666);
 104        }
 105}
 106
 107static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 108{
 109        /* use fstat() only when path == ce->name */
 110        if (fstat_is_reliable() &&
 111            state->refresh_cache && !state->base_dir_len) {
 112                fstat(fd, st);
 113                return 1;
 114        }
 115        return 0;
 116}
 117
 118static int streaming_write_entry(struct cache_entry *ce, char *path,
 119                                 struct stream_filter *filter,
 120                                 const struct checkout *state, int to_tempfile,
 121                                 int *fstat_done, struct stat *statbuf)
 122{
 123        struct git_istream *st;
 124        enum object_type type;
 125        unsigned long sz;
 126        int result = -1;
 127        ssize_t kept = 0;
 128        int fd = -1;
 129
 130        st = open_istream(ce->sha1, &type, &sz, filter);
 131        if (!st)
 132                return -1;
 133        if (type != OBJ_BLOB)
 134                goto close_and_exit;
 135
 136        fd = open_output_fd(path, ce, to_tempfile);
 137        if (fd < 0)
 138                goto close_and_exit;
 139
 140        for (;;) {
 141                char buf[1024 * 16];
 142                ssize_t wrote, holeto;
 143                ssize_t readlen = read_istream(st, buf, sizeof(buf));
 144
 145                if (!readlen)
 146                        break;
 147                if (sizeof(buf) == readlen) {
 148                        for (holeto = 0; holeto < readlen; holeto++)
 149                                if (buf[holeto])
 150                                        break;
 151                        if (readlen == holeto) {
 152                                kept += holeto;
 153                                continue;
 154                        }
 155                }
 156
 157                if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
 158                        goto close_and_exit;
 159                else
 160                        kept = 0;
 161                wrote = write_in_full(fd, buf, readlen);
 162
 163                if (wrote != readlen)
 164                        goto close_and_exit;
 165        }
 166        if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 ||
 167                     write(fd, "", 1) != 1))
 168                goto close_and_exit;
 169        *fstat_done = fstat_output(fd, state, statbuf);
 170
 171close_and_exit:
 172        close_istream(st);
 173        if (0 <= fd)
 174                result = close(fd);
 175        if (result && 0 <= fd)
 176                unlink(path);
 177        return result;
 178}
 179
 180static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
 181{
 182        unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 183        int fd, ret, fstat_done = 0;
 184        char *new;
 185        struct strbuf buf = STRBUF_INIT;
 186        unsigned long size;
 187        size_t wrote, newsize = 0;
 188        struct stat st;
 189
 190        if (ce_mode_s_ifmt == S_IFREG) {
 191                struct stream_filter *filter = get_stream_filter(path, ce->sha1);
 192                if (filter &&
 193                    !streaming_write_entry(ce, path, filter,
 194                                           state, to_tempfile,
 195                                           &fstat_done, &st))
 196                        goto finish;
 197        }
 198
 199        switch (ce_mode_s_ifmt) {
 200        case S_IFREG:
 201        case S_IFLNK:
 202                new = read_blob_entry(ce, &size);
 203                if (!new)
 204                        return error("unable to read sha1 file of %s (%s)",
 205                                path, sha1_to_hex(ce->sha1));
 206
 207                if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 208                        ret = symlink(new, path);
 209                        free(new);
 210                        if (ret)
 211                                return error("unable to create symlink %s (%s)",
 212                                             path, strerror(errno));
 213                        break;
 214                }
 215
 216                /*
 217                 * Convert from git internal format to working tree format
 218                 */
 219                if (ce_mode_s_ifmt == S_IFREG &&
 220                    convert_to_working_tree(ce->name, new, size, &buf)) {
 221                        free(new);
 222                        new = strbuf_detach(&buf, &newsize);
 223                        size = newsize;
 224                }
 225
 226                fd = open_output_fd(path, ce, to_tempfile);
 227                if (fd < 0) {
 228                        free(new);
 229                        return error("unable to create file %s (%s)",
 230                                path, strerror(errno));
 231                }
 232
 233                wrote = write_in_full(fd, new, size);
 234                if (!to_tempfile)
 235                        fstat_done = fstat_output(fd, state, &st);
 236                close(fd);
 237                free(new);
 238                if (wrote != size)
 239                        return error("unable to write file %s", path);
 240                break;
 241        case S_IFGITLINK:
 242                if (to_tempfile)
 243                        return error("cannot create temporary subproject %s", path);
 244                if (mkdir(path, 0777) < 0)
 245                        return error("cannot create subproject directory %s", path);
 246                break;
 247        default:
 248                return error("unknown file mode for %s in index", path);
 249        }
 250
 251finish:
 252        if (state->refresh_cache) {
 253                if (!fstat_done)
 254                        lstat(ce->name, &st);
 255                fill_stat_cache_info(ce, &st);
 256        }
 257        return 0;
 258}
 259
 260/*
 261 * This is like 'lstat()', except it refuses to follow symlinks
 262 * in the path, after skipping "skiplen".
 263 */
 264static int check_path(const char *path, int len, struct stat *st, int skiplen)
 265{
 266        const char *slash = path + len;
 267
 268        while (path < slash && *slash != '/')
 269                slash--;
 270        if (!has_dirs_only_path(path, slash - path, skiplen)) {
 271                errno = ENOENT;
 272                return -1;
 273        }
 274        return lstat(path, st);
 275}
 276
 277int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 278{
 279        static char path[PATH_MAX + 1];
 280        struct stat st;
 281        int len = state->base_dir_len;
 282
 283        if (topath)
 284                return write_entry(ce, topath, state, 1);
 285
 286        memcpy(path, state->base_dir, len);
 287        strcpy(path + len, ce->name);
 288        len += ce_namelen(ce);
 289
 290        if (!check_path(path, len, &st, state->base_dir_len)) {
 291                unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 292                if (!changed)
 293                        return 0;
 294                if (!state->force) {
 295                        if (!state->quiet)
 296                                fprintf(stderr, "%s already exists, no checkout\n", path);
 297                        return -1;
 298                }
 299
 300                /*
 301                 * We unlink the old file, to get the new one with the
 302                 * right permissions (including umask, which is nasty
 303                 * to emulate by hand - much easier to let the system
 304                 * just do the right thing)
 305                 */
 306                if (S_ISDIR(st.st_mode)) {
 307                        /* If it is a gitlink, leave it alone! */
 308                        if (S_ISGITLINK(ce->ce_mode))
 309                                return 0;
 310                        if (!state->force)
 311                                return error("%s is a directory", path);
 312                        remove_subtree(path);
 313                } else if (unlink(path))
 314                        return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 315        } else if (state->not_new)
 316                return 0;
 317        create_directories(path, len, state);
 318        return write_entry(ce, path, state, 0);
 319}