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Commit | Line | Data |
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f859c846 JH |
1 | #include "cache.h" |
2 | ||
fab78a0c MT |
3 | static int threaded_check_leading_path(struct cache_def *cache, const char *name, |
4 | int len, int warn_on_lstat_err); | |
72f3196a JH |
5 | static int threaded_has_dirs_only_path(struct cache_def *cache, const char *name, int len, int prefix_len); |
6 | ||
92604b46 KB |
7 | /* |
8 | * Returns the length (on a path component basis) of the longest | |
148bc06b | 9 | * common prefix match of 'name_a' and 'name_b'. |
92604b46 | 10 | */ |
148bc06b KB |
11 | static int longest_path_match(const char *name_a, int len_a, |
12 | const char *name_b, int len_b, | |
13 | int *previous_slash) | |
c40641b7 | 14 | { |
aeabab5c | 15 | int max_len, match_len = 0, match_len_prev = 0, i = 0; |
92604b46 | 16 | |
148bc06b KB |
17 | max_len = len_a < len_b ? len_a : len_b; |
18 | while (i < max_len && name_a[i] == name_b[i]) { | |
19 | if (name_a[i] == '/') { | |
aeabab5c | 20 | match_len_prev = match_len; |
92604b46 | 21 | match_len = i; |
aeabab5c | 22 | } |
92604b46 KB |
23 | i++; |
24 | } | |
60b458b7 | 25 | /* |
148bc06b KB |
26 | * Is 'name_b' a substring of 'name_a', the other way around, |
27 | * or is 'name_a' and 'name_b' the exact same string? | |
60b458b7 | 28 | */ |
148bc06b KB |
29 | if (i >= max_len && ((len_a > len_b && name_a[len_b] == '/') || |
30 | (len_a < len_b && name_b[len_a] == '/') || | |
31 | (len_a == len_b))) { | |
aeabab5c | 32 | match_len_prev = match_len; |
60b458b7 | 33 | match_len = i; |
aeabab5c KB |
34 | } |
35 | *previous_slash = match_len_prev; | |
92604b46 | 36 | return match_len; |
c40641b7 LT |
37 | } |
38 | ||
e7c73053 | 39 | static struct cache_def default_cache = CACHE_DEF_INIT; |
148bc06b | 40 | |
867f72bf | 41 | static inline void reset_lstat_cache(struct cache_def *cache) |
c40641b7 | 42 | { |
e7c73053 | 43 | strbuf_reset(&cache->path); |
867f72bf | 44 | cache->flags = 0; |
60b458b7 KB |
45 | /* |
46 | * The track_flags and prefix_len_stat_func members is only | |
47 | * set by the safeguard rule inside lstat_cache() | |
48 | */ | |
c40641b7 LT |
49 | } |
50 | ||
92604b46 | 51 | #define FL_DIR (1 << 0) |
09c93066 KB |
52 | #define FL_NOENT (1 << 1) |
53 | #define FL_SYMLINK (1 << 2) | |
54 | #define FL_LSTATERR (1 << 3) | |
55 | #define FL_ERR (1 << 4) | |
bad4a54f | 56 | #define FL_FULLPATH (1 << 5) |
92604b46 KB |
57 | |
58 | /* | |
59 | * Check if name 'name' of length 'len' has a symlink leading | |
09c93066 | 60 | * component, or if the directory exists and is real, or not. |
92604b46 KB |
61 | * |
62 | * To speed up the check, some information is allowed to be cached. | |
bad4a54f KB |
63 | * This can be indicated by the 'track_flags' argument, which also can |
64 | * be used to indicate that we should check the full path. | |
65 | * | |
66 | * The 'prefix_len_stat_func' parameter can be used to set the length | |
67 | * of the prefix, where the cache should use the stat() function | |
68 | * instead of the lstat() function to test each path component. | |
92604b46 | 69 | */ |
4856ff2a CB |
70 | static int lstat_cache_matchlen(struct cache_def *cache, |
71 | const char *name, int len, | |
72 | int *ret_flags, int track_flags, | |
73 | int prefix_len_stat_func) | |
c40641b7 | 74 | { |
aeabab5c | 75 | int match_len, last_slash, last_slash_dir, previous_slash; |
fab78a0c | 76 | int save_flags, ret, saved_errno = 0; |
c40641b7 | 77 | struct stat st; |
f859c846 | 78 | |
867f72bf LT |
79 | if (cache->track_flags != track_flags || |
80 | cache->prefix_len_stat_func != prefix_len_stat_func) { | |
09c93066 | 81 | /* |
60b458b7 KB |
82 | * As a safeguard rule we clear the cache if the |
83 | * values of track_flags and/or prefix_len_stat_func | |
84 | * does not match with the last supplied values. | |
09c93066 | 85 | */ |
867f72bf LT |
86 | reset_lstat_cache(cache); |
87 | cache->track_flags = track_flags; | |
88 | cache->prefix_len_stat_func = prefix_len_stat_func; | |
09c93066 KB |
89 | match_len = last_slash = 0; |
90 | } else { | |
91 | /* | |
92 | * Check to see if we have a match from the cache for | |
93 | * the 2 "excluding" path types. | |
94 | */ | |
aeabab5c | 95 | match_len = last_slash = |
e7c73053 KB |
96 | longest_path_match(name, len, cache->path.buf, |
97 | cache->path.len, &previous_slash); | |
4856ff2a | 98 | *ret_flags = cache->flags & track_flags & (FL_NOENT|FL_SYMLINK); |
77716755 KB |
99 | |
100 | if (!(track_flags & FL_FULLPATH) && match_len == len) | |
101 | match_len = last_slash = previous_slash; | |
102 | ||
e7c73053 | 103 | if (*ret_flags && match_len == cache->path.len) |
4856ff2a | 104 | return match_len; |
09c93066 KB |
105 | /* |
106 | * If we now have match_len > 0, we would know that | |
107 | * the matched part will always be a directory. | |
108 | * | |
109 | * Also, if we are tracking directories and 'name' is | |
110 | * a substring of the cache on a path component basis, | |
111 | * we can return immediately. | |
112 | */ | |
4856ff2a CB |
113 | *ret_flags = track_flags & FL_DIR; |
114 | if (*ret_flags && len == match_len) | |
115 | return match_len; | |
09c93066 | 116 | } |
c40641b7 | 117 | |
92604b46 KB |
118 | /* |
119 | * Okay, no match from the cache so far, so now we have to | |
120 | * check the rest of the path components. | |
121 | */ | |
4856ff2a | 122 | *ret_flags = FL_DIR; |
92604b46 | 123 | last_slash_dir = last_slash; |
e7c73053 KB |
124 | if (len > cache->path.len) |
125 | strbuf_grow(&cache->path, len - cache->path.len); | |
126 | while (match_len < len) { | |
92604b46 | 127 | do { |
e7c73053 | 128 | cache->path.buf[match_len] = name[match_len]; |
92604b46 | 129 | match_len++; |
e7c73053 KB |
130 | } while (match_len < len && name[match_len] != '/'); |
131 | if (match_len >= len && !(track_flags & FL_FULLPATH)) | |
92604b46 KB |
132 | break; |
133 | last_slash = match_len; | |
e7c73053 | 134 | cache->path.buf[last_slash] = '\0'; |
f859c846 | 135 | |
bad4a54f | 136 | if (last_slash <= prefix_len_stat_func) |
e7c73053 | 137 | ret = stat(cache->path.buf, &st); |
bad4a54f | 138 | else |
e7c73053 | 139 | ret = lstat(cache->path.buf, &st); |
bad4a54f KB |
140 | |
141 | if (ret) { | |
4856ff2a | 142 | *ret_flags = FL_LSTATERR; |
fab78a0c | 143 | saved_errno = errno; |
09c93066 | 144 | if (errno == ENOENT) |
4856ff2a | 145 | *ret_flags |= FL_NOENT; |
92604b46 KB |
146 | } else if (S_ISDIR(st.st_mode)) { |
147 | last_slash_dir = last_slash; | |
c40641b7 | 148 | continue; |
92604b46 | 149 | } else if (S_ISLNK(st.st_mode)) { |
4856ff2a | 150 | *ret_flags = FL_SYMLINK; |
92604b46 | 151 | } else { |
4856ff2a | 152 | *ret_flags = FL_ERR; |
f859c846 | 153 | } |
c40641b7 | 154 | break; |
f859c846 | 155 | } |
92604b46 KB |
156 | |
157 | /* | |
09c93066 KB |
158 | * At the end update the cache. Note that max 3 different |
159 | * path types, FL_NOENT, FL_SYMLINK and FL_DIR, can be cached | |
160 | * for the moment! | |
92604b46 | 161 | */ |
4856ff2a | 162 | save_flags = *ret_flags & track_flags & (FL_NOENT|FL_SYMLINK); |
e7c73053 KB |
163 | if (save_flags && last_slash > 0) { |
164 | cache->path.buf[last_slash] = '\0'; | |
165 | cache->path.len = last_slash; | |
867f72bf | 166 | cache->flags = save_flags; |
e7c73053 | 167 | } else if ((track_flags & FL_DIR) && last_slash_dir > 0) { |
92604b46 KB |
168 | /* |
169 | * We have a separate test for the directory case, | |
09c93066 KB |
170 | * since it could be that we have found a symlink or a |
171 | * non-existing directory and the track_flags says | |
172 | * that we cannot cache this fact, so the cache would | |
173 | * then have been left empty in this case. | |
92604b46 KB |
174 | * |
175 | * But if we are allowed to track real directories, we | |
176 | * can still cache the path components before the last | |
09c93066 | 177 | * one (the found symlink or non-existing component). |
92604b46 | 178 | */ |
e7c73053 KB |
179 | cache->path.buf[last_slash_dir] = '\0'; |
180 | cache->path.len = last_slash_dir; | |
867f72bf | 181 | cache->flags = FL_DIR; |
92604b46 | 182 | } else { |
867f72bf | 183 | reset_lstat_cache(cache); |
92604b46 | 184 | } |
fab78a0c MT |
185 | if (saved_errno) |
186 | errno = saved_errno; | |
4856ff2a CB |
187 | return match_len; |
188 | } | |
189 | ||
190 | static int lstat_cache(struct cache_def *cache, const char *name, int len, | |
191 | int track_flags, int prefix_len_stat_func) | |
192 | { | |
193 | int flags; | |
194 | (void)lstat_cache_matchlen(cache, name, len, &flags, track_flags, | |
195 | prefix_len_stat_func); | |
196 | return flags; | |
92604b46 KB |
197 | } |
198 | ||
bad4a54f KB |
199 | #define USE_ONLY_LSTAT 0 |
200 | ||
b9fd2846 LT |
201 | /* |
202 | * Return non-zero if path 'name' has a leading symlink component | |
203 | */ | |
204 | int threaded_has_symlink_leading_path(struct cache_def *cache, const char *name, int len) | |
205 | { | |
206 | return lstat_cache(cache, name, len, FL_SYMLINK|FL_DIR, USE_ONLY_LSTAT) & FL_SYMLINK; | |
207 | } | |
208 | ||
57199892 | 209 | int has_symlink_leading_path(const char *name, int len) |
92604b46 | 210 | { |
b9fd2846 | 211 | return threaded_has_symlink_leading_path(&default_cache, name, len); |
f859c846 | 212 | } |
09c93066 | 213 | |
fab78a0c | 214 | int check_leading_path(const char *name, int len, int warn_on_lstat_err) |
09c93066 | 215 | { |
fab78a0c MT |
216 | return threaded_check_leading_path(&default_cache, name, len, |
217 | warn_on_lstat_err); | |
15438d5a JH |
218 | } |
219 | ||
220 | /* | |
462b4e8d | 221 | * Return zero if some leading path component of 'name' does not exist. |
15438d5a JH |
222 | * |
223 | * Return -1 if leading path exists and is a directory. | |
224 | * | |
462b4e8d | 225 | * Return the length of a leading component if it either exists but it's not a |
fab78a0c MT |
226 | * directory, or if we were unable to lstat() it. If warn_on_lstat_err is true, |
227 | * also emit a warning for this error. | |
15438d5a | 228 | */ |
fab78a0c MT |
229 | static int threaded_check_leading_path(struct cache_def *cache, const char *name, |
230 | int len, int warn_on_lstat_err) | |
15438d5a | 231 | { |
f66caaf9 CB |
232 | int flags; |
233 | int match_len = lstat_cache_matchlen(cache, name, len, &flags, | |
234 | FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT); | |
fab78a0c MT |
235 | int saved_errno = errno; |
236 | ||
1d718a51 | 237 | if (flags & FL_NOENT) |
f66caaf9 CB |
238 | return 0; |
239 | else if (flags & FL_DIR) | |
240 | return -1; | |
fab78a0c MT |
241 | if (warn_on_lstat_err && (flags & FL_LSTATERR)) { |
242 | char *path = xmemdupz(name, match_len); | |
243 | errno = saved_errno; | |
244 | warning_errno(_("failed to lstat '%s'"), path); | |
245 | free(path); | |
246 | } | |
247 | return match_len; | |
09c93066 | 248 | } |
bad4a54f | 249 | |
57199892 | 250 | int has_dirs_only_path(const char *name, int len, int prefix_len) |
bad4a54f | 251 | { |
15438d5a JH |
252 | return threaded_has_dirs_only_path(&default_cache, name, len, prefix_len); |
253 | } | |
254 | ||
255 | /* | |
256 | * Return non-zero if all path components of 'name' exists as a | |
257 | * directory. If prefix_len > 0, we will test with the stat() | |
258 | * function instead of the lstat() function for a prefix length of | |
259 | * 'prefix_len', thus we then allow for symlinks in the prefix part as | |
260 | * long as those points to real existing directories. | |
261 | */ | |
72f3196a | 262 | static int threaded_has_dirs_only_path(struct cache_def *cache, const char *name, int len, int prefix_len) |
15438d5a | 263 | { |
684dd4c2 MT |
264 | /* |
265 | * Note: this function is used by the checkout machinery, which also | |
266 | * takes care to properly reset the cache when it performs an operation | |
267 | * that would leave the cache outdated. If this function starts caching | |
268 | * anything else besides FL_DIR, remember to also invalidate the cache | |
269 | * when creating or deleting paths that might be in the cache. | |
270 | */ | |
867f72bf | 271 | return lstat_cache(cache, name, len, |
bad4a54f KB |
272 | FL_DIR|FL_FULLPATH, prefix_len) & |
273 | FL_DIR; | |
274 | } | |
78478927 | 275 | |
e7c73053 | 276 | static struct strbuf removal = STRBUF_INIT; |
78478927 KB |
277 | |
278 | static void do_remove_scheduled_dirs(int new_len) | |
279 | { | |
280 | while (removal.len > new_len) { | |
e7c73053 | 281 | removal.buf[removal.len] = '\0'; |
00fcce28 EN |
282 | if ((startup_info->original_cwd && |
283 | !strcmp(removal.buf, startup_info->original_cwd)) || | |
284 | rmdir(removal.buf)) | |
78478927 KB |
285 | break; |
286 | do { | |
287 | removal.len--; | |
288 | } while (removal.len > new_len && | |
e7c73053 | 289 | removal.buf[removal.len] != '/'); |
78478927 KB |
290 | } |
291 | removal.len = new_len; | |
78478927 KB |
292 | } |
293 | ||
294 | void schedule_dir_for_removal(const char *name, int len) | |
295 | { | |
296 | int match_len, last_slash, i, previous_slash; | |
297 | ||
00fcce28 EN |
298 | if (startup_info->original_cwd && |
299 | !strcmp(name, startup_info->original_cwd)) | |
300 | return; /* Do not remove the current working directory */ | |
301 | ||
78478927 | 302 | match_len = last_slash = i = |
e7c73053 | 303 | longest_path_match(name, len, removal.buf, removal.len, |
78478927 KB |
304 | &previous_slash); |
305 | /* Find last slash inside 'name' */ | |
306 | while (i < len) { | |
307 | if (name[i] == '/') | |
308 | last_slash = i; | |
309 | i++; | |
310 | } | |
311 | ||
312 | /* | |
313 | * If we are about to go down the directory tree, we check if | |
314 | * we must first go upwards the tree, such that we then can | |
315 | * remove possible empty directories as we go upwards. | |
316 | */ | |
317 | if (match_len < last_slash && match_len < removal.len) | |
318 | do_remove_scheduled_dirs(match_len); | |
319 | /* | |
320 | * If we go deeper down the directory tree, we only need to | |
321 | * save the new path components as we go down. | |
322 | */ | |
e7c73053 KB |
323 | if (match_len < last_slash) |
324 | strbuf_add(&removal, &name[match_len], last_slash - match_len); | |
78478927 KB |
325 | } |
326 | ||
327 | void remove_scheduled_dirs(void) | |
328 | { | |
329 | do_remove_scheduled_dirs(0); | |
78478927 | 330 | } |
684dd4c2 MT |
331 | |
332 | void invalidate_lstat_cache(void) | |
333 | { | |
334 | reset_lstat_cache(&default_cache); | |
335 | } | |
336 | ||
337 | #undef rmdir | |
338 | int lstat_cache_aware_rmdir(const char *path) | |
339 | { | |
340 | /* Any change in this function must be made also in `mingw_rmdir()` */ | |
341 | int ret = rmdir(path); | |
342 | ||
343 | if (!ret) | |
344 | invalidate_lstat_cache(); | |
345 | ||
346 | return ret; | |
347 | } |