describe: make own copy of refname
[git] / entry.c
1 #include "cache.h"
2 #include "blob.h"
3 #include "dir.h"
4 #include "streaming.h"
5
6 static 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
47 static 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
76 static 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
82 static 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
95 static 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
107 static 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
118 static 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         int result = 0;
124         int fd;
125
126         fd = open_output_fd(path, ce, to_tempfile);
127         if (fd < 0)
128                 return -1;
129
130         result |= stream_blob_to_fd(fd, ce->sha1, filter, 1);
131         *fstat_done = fstat_output(fd, state, statbuf);
132         result |= close(fd);
133
134         if (result)
135                 unlink(path);
136         return result;
137 }
138
139 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
140 {
141         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
142         int fd, ret, fstat_done = 0;
143         char *new;
144         struct strbuf buf = STRBUF_INIT;
145         unsigned long size;
146         size_t wrote, newsize = 0;
147         struct stat st;
148
149         if (ce_mode_s_ifmt == S_IFREG) {
150                 struct stream_filter *filter = get_stream_filter(ce->name, ce->sha1);
151                 if (filter &&
152                     !streaming_write_entry(ce, path, filter,
153                                            state, to_tempfile,
154                                            &fstat_done, &st))
155                         goto finish;
156         }
157
158         switch (ce_mode_s_ifmt) {
159         case S_IFREG:
160         case S_IFLNK:
161                 new = read_blob_entry(ce, &size);
162                 if (!new)
163                         return error("unable to read sha1 file of %s (%s)",
164                                 path, sha1_to_hex(ce->sha1));
165
166                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
167                         ret = symlink(new, path);
168                         free(new);
169                         if (ret)
170                                 return error("unable to create symlink %s (%s)",
171                                              path, strerror(errno));
172                         break;
173                 }
174
175                 /*
176                  * Convert from git internal format to working tree format
177                  */
178                 if (ce_mode_s_ifmt == S_IFREG &&
179                     convert_to_working_tree(ce->name, new, size, &buf)) {
180                         free(new);
181                         new = strbuf_detach(&buf, &newsize);
182                         size = newsize;
183                 }
184
185                 fd = open_output_fd(path, ce, to_tempfile);
186                 if (fd < 0) {
187                         free(new);
188                         return error("unable to create file %s (%s)",
189                                 path, strerror(errno));
190                 }
191
192                 wrote = write_in_full(fd, new, size);
193                 if (!to_tempfile)
194                         fstat_done = fstat_output(fd, state, &st);
195                 close(fd);
196                 free(new);
197                 if (wrote != size)
198                         return error("unable to write file %s", path);
199                 break;
200         case S_IFGITLINK:
201                 if (to_tempfile)
202                         return error("cannot create temporary subproject %s", path);
203                 if (mkdir(path, 0777) < 0)
204                         return error("cannot create subproject directory %s", path);
205                 break;
206         default:
207                 return error("unknown file mode for %s in index", path);
208         }
209
210 finish:
211         if (state->refresh_cache) {
212                 if (!fstat_done)
213                         lstat(ce->name, &st);
214                 fill_stat_cache_info(ce, &st);
215         }
216         return 0;
217 }
218
219 /*
220  * This is like 'lstat()', except it refuses to follow symlinks
221  * in the path, after skipping "skiplen".
222  */
223 static int check_path(const char *path, int len, struct stat *st, int skiplen)
224 {
225         const char *slash = path + len;
226
227         while (path < slash && *slash != '/')
228                 slash--;
229         if (!has_dirs_only_path(path, slash - path, skiplen)) {
230                 errno = ENOENT;
231                 return -1;
232         }
233         return lstat(path, st);
234 }
235
236 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
237 {
238         static char path[PATH_MAX + 1];
239         struct stat st;
240         int len = state->base_dir_len;
241
242         if (topath)
243                 return write_entry(ce, topath, state, 1);
244
245         memcpy(path, state->base_dir, len);
246         strcpy(path + len, ce->name);
247         len += ce_namelen(ce);
248
249         if (!check_path(path, len, &st, state->base_dir_len)) {
250                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
251                 if (!changed)
252                         return 0;
253                 if (!state->force) {
254                         if (!state->quiet)
255                                 fprintf(stderr, "%s already exists, no checkout\n", path);
256                         return -1;
257                 }
258
259                 /*
260                  * We unlink the old file, to get the new one with the
261                  * right permissions (including umask, which is nasty
262                  * to emulate by hand - much easier to let the system
263                  * just do the right thing)
264                  */
265                 if (S_ISDIR(st.st_mode)) {
266                         /* If it is a gitlink, leave it alone! */
267                         if (S_ISGITLINK(ce->ce_mode))
268                                 return 0;
269                         if (!state->force)
270                                 return error("%s is a directory", path);
271                         remove_subtree(path);
272                 } else if (unlink(path))
273                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
274         } else if (state->not_new)
275                 return 0;
276         create_directories(path, len, state);
277         return write_entry(ce, path, state, 0);
278 }