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                                 const struct checkout *state, int to_tempfile,
 120                                 int *fstat_done, struct stat *statbuf)
 121{
 122        struct git_istream *st;
 123        enum object_type type;
 124        unsigned long sz;
 125        int result = -1;
 126        ssize_t kept = 0;
 127        int fd = -1;
 128
 129        st = open_istream(ce->sha1, &type, &sz);
 130        if (!st)
 131                return -1;
 132        if (type != OBJ_BLOB)
 133                goto close_and_exit;
 134
 135        fd = open_output_fd(path, ce, to_tempfile);
 136        if (fd < 0)
 137                goto close_and_exit;
 138
 139        for (;;) {
 140                char buf[1024 * 16];
 141                ssize_t wrote, holeto;
 142                ssize_t readlen = read_istream(st, buf, sizeof(buf));
 143
 144                if (!readlen)
 145                        break;
 146                if (sizeof(buf) == readlen) {
 147                        for (holeto = 0; holeto < readlen; holeto++)
 148                                if (buf[holeto])
 149                                        break;
 150                        if (readlen == holeto) {
 151                                kept += holeto;
 152                                continue;
 153                        }
 154                }
 155
 156                if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
 157                        goto close_and_exit;
 158                else
 159                        kept = 0;
 160                wrote = write_in_full(fd, buf, readlen);
 161
 162                if (wrote != readlen)
 163                        goto close_and_exit;
 164        }
 165        if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 ||
 166                     write(fd, "", 1) != 1))
 167                goto close_and_exit;
 168        *fstat_done = fstat_output(fd, state, statbuf);
 169
 170close_and_exit:
 171        close_istream(st);
 172        if (0 <= fd)
 173                result = close(fd);
 174        if (result && 0 <= fd)
 175                unlink(path);
 176        return result;
 177}
 178
 179static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
 180{
 181        unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 182        int fd, ret, fstat_done = 0;
 183        char *new;
 184        struct strbuf buf = STRBUF_INIT;
 185        unsigned long size;
 186        size_t wrote, newsize = 0;
 187        struct stat st;
 188
 189        if ((ce_mode_s_ifmt == S_IFREG) &&
 190            can_bypass_conversion(path) &&
 191            !streaming_write_entry(ce, path, state, to_tempfile,
 192                                   &fstat_done, &st))
 193                goto finish;
 194
 195        switch (ce_mode_s_ifmt) {
 196        case S_IFREG:
 197        case S_IFLNK:
 198                new = read_blob_entry(ce, &size);
 199                if (!new)
 200                        return error("unable to read sha1 file of %s (%s)",
 201                                path, sha1_to_hex(ce->sha1));
 202
 203                if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 204                        ret = symlink(new, path);
 205                        free(new);
 206                        if (ret)
 207                                return error("unable to create symlink %s (%s)",
 208                                             path, strerror(errno));
 209                        break;
 210                }
 211
 212                /*
 213                 * Convert from git internal format to working tree format
 214                 */
 215                if (ce_mode_s_ifmt == S_IFREG &&
 216                    convert_to_working_tree(ce->name, new, size, &buf)) {
 217                        free(new);
 218                        new = strbuf_detach(&buf, &newsize);
 219                        size = newsize;
 220                }
 221
 222                fd = open_output_fd(path, ce, to_tempfile);
 223                if (fd < 0) {
 224                        free(new);
 225                        return error("unable to create file %s (%s)",
 226                                path, strerror(errno));
 227                }
 228
 229                wrote = write_in_full(fd, new, size);
 230                if (!to_tempfile)
 231                        fstat_done = fstat_output(fd, state, &st);
 232                close(fd);
 233                free(new);
 234                if (wrote != size)
 235                        return error("unable to write file %s", path);
 236                break;
 237        case S_IFGITLINK:
 238                if (to_tempfile)
 239                        return error("cannot create temporary subproject %s", path);
 240                if (mkdir(path, 0777) < 0)
 241                        return error("cannot create subproject directory %s", path);
 242                break;
 243        default:
 244                return error("unknown file mode for %s in index", path);
 245        }
 246
 247finish:
 248        if (state->refresh_cache) {
 249                if (!fstat_done)
 250                        lstat(ce->name, &st);
 251                fill_stat_cache_info(ce, &st);
 252        }
 253        return 0;
 254}
 255
 256/*
 257 * This is like 'lstat()', except it refuses to follow symlinks
 258 * in the path, after skipping "skiplen".
 259 */
 260static int check_path(const char *path, int len, struct stat *st, int skiplen)
 261{
 262        const char *slash = path + len;
 263
 264        while (path < slash && *slash != '/')
 265                slash--;
 266        if (!has_dirs_only_path(path, slash - path, skiplen)) {
 267                errno = ENOENT;
 268                return -1;
 269        }
 270        return lstat(path, st);
 271}
 272
 273int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 274{
 275        static char path[PATH_MAX + 1];
 276        struct stat st;
 277        int len = state->base_dir_len;
 278
 279        if (topath)
 280                return write_entry(ce, topath, state, 1);
 281
 282        memcpy(path, state->base_dir, len);
 283        strcpy(path + len, ce->name);
 284        len += ce_namelen(ce);
 285
 286        if (!check_path(path, len, &st, state->base_dir_len)) {
 287                unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 288                if (!changed)
 289                        return 0;
 290                if (!state->force) {
 291                        if (!state->quiet)
 292                                fprintf(stderr, "%s already exists, no checkout\n", path);
 293                        return -1;
 294                }
 295
 296                /*
 297                 * We unlink the old file, to get the new one with the
 298                 * right permissions (including umask, which is nasty
 299                 * to emulate by hand - much easier to let the system
 300                 * just do the right thing)
 301                 */
 302                if (S_ISDIR(st.st_mode)) {
 303                        /* If it is a gitlink, leave it alone! */
 304                        if (S_ISGITLINK(ce->ce_mode))
 305                                return 0;
 306                        if (!state->force)
 307                                return error("%s is a directory", path);
 308                        remove_subtree(path);
 309                } else if (unlink(path))
 310                        return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 311        } else if (state->not_new)
 312                return 0;
 313        create_directories(path, len, state);
 314        return write_entry(ce, path, state, 0);
 315}