pike.git/lib/modules/Filesystem.pmod/Monitor.pmod/symlinks.pike:5f58bdeecb41320455102b95b9180cba3c5d04f5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 #pike __REAL_VERSION__ // // Filesystem monitor with support for symbolic links. // // // 2010-01-25 Henrik Grubbström // //! Filesystem monitor with support for symbolic links. //! //! This module extends @[Filesystem.Monitor.basic] with //! support for symbolic links. //! //! @note //! For operating systems where symbolic links aren't supported, //! this module will behave exactly like @[Filesystem.Monitor.basic]. //! //! @seealso //! @[Filesystem.Monitor.basic] //! @decl inherit Filesystem.Monitor.basic inherit "basic.pike" : basic; #if constant(readlink) //! @decl void attr_changed(string path, Stdio.Stat st) //! //! File attribute changed callback. //! //! @param path //! Path of the file or directory which has changed attributes. //! //! @param st //! Status information for @[path] as obtained by @expr{file_stat(path)@}. //! //! This function is called when a change has been detected for an //! attribute for a monitored file or directory. //! //! Called by @[check()] and @[check_monitor()]. //! //! @note //! If there is a @[data_changed()] callback, it may supersede this //! callback if the file content also has changed. //! //! @note //! It differs from the @[Filesystem.Monitor.basic] version in that //! symbolic links have the @[st] of their targets. //! //! Overload this to do something useful. //! @decl void file_exists(string path, Stdio.Stat st) //! //! File existance callback. //! //! @param path //! Path of the file or directory. //! //! @param st //! Status information for @[path] as obtained by @expr{file_stat(path)@}. //! //! This function is called during initialization for all monitored paths, //! and subpaths for monitored directories. It represents the initial state //! for the monitor. //! //! @note //! For directories, @[file_created()] will be called for the subpaths //! before the call for the directory itself. This can be used to detect //! when the initialization for a directory is finished. //! //! @note //! It differs from the @[Filesystem.Monitor.basic] version in that //! symbolic links have the @[st] of their targets. //! //! Called by @[check()] and @[check_monitor()] the first time a monitored //! path is checked (and only if it exists). //! //! Overload this to do something useful. //! @decl void file_created(string path, Stdio.Stat st) //! //! File creation callback. //! //! @param path //! Path of the new file or directory. //! //! @param st //! Status information for @[path] as obtained by @expr{file_stat(path)@}. //! //! This function is called when either a monitored path has started //! existing, or when a new file or directory has been added to a //! monitored directory. //! //! @note //! It differs from the @[Filesystem.Monitor.basic] version in that //! symbolic links have the @[st] of their targets. //! //! Called by @[check()] and @[check_monitor()]. //! //! Overload this to do something useful. //! @decl void stable_data_change(string path, Stdio.Stat st) //! //! Stable change callback. //! //! @param path //! Path of the file or directory that has stopped changing. //! //! @param st //! Status information for @[path] as obtained by @expr{file_stat(path)@}. //! //! This function is called when previous changes to @[path] are //! considered "stable". //! //! "Stable" in this case means that there have been no detected //! changes for at lease @[stable_time] seconds. //! //! @note //! It differs from the @[Filesystem.Monitor.basic] version in that //! symbolic links have the @[st] of their targets. //! //! Called by @[check()] and @[check_monitor()]. //! //! Overload this to do something useful. //! Monitoring information for a single filesystem path. //! //! With support for expansion of symbolic links. //! //! @seealso //! @[monitor()] protected class DefaultMonitor { //! Based on @[Filesystem.Monitor.basic.DefaultMonitor]. inherit basic::DefaultMonitor; //! Mask of symlink ids that can reach this monitor. int symlinks; //! Call a notification callback and handle symlink expansion. //! //! @param cb //! Callback to call or @[UNDEFINED] for no operation. //! //! @param state //! State mapping to avoid multiple notification and infinite loops. //! Call with an empty mapping. //! //! @param symlinks //! Symlinks that have not been expanded yet. //! //! @param path //! Path to notify on. //! //! @param extras //! Extra arguments to @[cb]. //! //! @param symlink //! Symbolic link that must have been followed for the //! callback to be called. void low_call_callback(function(string, mixed ...:void) cb, mapping(string:int) state, mapping(string:string) symlink_targets, string path, Stdio.Stat|void st, string|void symlink) { if (!cb || state[path] || (st && st->islnk)) return; state[path] = 1; if (!symlink || !symlink_targets[symlink]) { cb(path, st); } if (sizeof(symlink_targets)) { // Check the list of symlink targets. foreach(reverse(sort(indices(symlink_targets))), string src) { string dest = symlink_targets[src]; if (has_prefix(path, dest)) { low_call_callback(cb, state, symlink_targets - ([ src : dest ]), src + path[sizeof(dest)..], st, symlink); } } } } //! Call a notification callback and handle symlink expansion. //! //! @param cb //! Callback to call or @[UNDEFINED] for no operation. //! //! @param extras //! Extra arguments after the @[path] argument to @[cb]. protected void call_callback(function(string, mixed ...:void) cb, string path, Stdio.Stat|void st) { if (!cb) return; low_call_callback(cb, ([]), global::symlink_targets, path, st); } protected void notify_symlink(function(string, mixed ...:void) cb, string sym) { int sym_id = global::symlink_ids[sym]; if (sym_id) { // Depth-first. foreach(reverse(sort(filter(values(monitors), lambda(Monitor m, int sym_id) { return m->symlinks & sym_id; }, sym_id)->path)), string m_path) { Monitor m = monitors[m_path]; m->low_call_callback(cb, ([]), global::symlink_targets, m_path, m->st, sym); } } } //! Called when the symlink @[path] is no more. protected void zap_symlink(string path) { string old_dest = global::symlink_targets[path]; if (old_dest) { int sym_id = global::symlink_ids[path]; foreach(monitors; string m_path; Monitor m) { if (m->symlinks & sym_id) { m->low_call_callback(global::file_deleted, ([]), global::symlink_targets, m_path, UNDEFINED, path); m->symlinks -= sym_id; // Unregister the monitor if it is the last ref, // and there are no hard links to the file. m->check_for_release(MF_AUTO|MF_HARD, MF_AUTO); } } global::available_ids |= m_delete(symlink_ids, path); m_delete(global::symlink_targets, path); } } //! Check whether a symlink has changed. protected void check_symlink(string path, Stdio.Stat st, int|void inhibit_notify) { string dest; if (st && st->islnk) { dest = readlink(path); if (dest) { dest = canonic_path(combine_path(path, "..", dest)); if (symlink_targets[path] == dest) return; } } if (symlink_targets[path]) { zap_symlink(path); } if (dest) { // We have a new symbolic link. symlink_targets[path] = dest; int sym_id = allocate_symlink(path); int sym_mask = sym_id | symlink_ids[dest]; int sym_done = sym_id; Monitor m; if (!(m = monitors[dest])) { MonitorFlags m_flags = (flags & ~MF_HARD) | MF_AUTO; if (inhibit_notify) { m_flags &= ~MF_INITED; } monitor(dest, m_flags, max_dir_check_interval, file_interval_factor, stable_time); m = monitors[dest]; } m->symlinks |= sym_id; if (!has_suffix(dest, "/")) { dest += "/"; } foreach(monitors; string mm_path; Monitor mm) { if (has_prefix(mm_path, dest)) { mm->symlinks |= sym_id; sym_mask |= symlink_ids[mm_path]; } } // Follow any found symlinks. while (sym_mask != sym_done) { int mask = sym_mask - sym_done; foreach(monitors; string mm_path; Monitor mm) { if ((mm->symlinks & mask) && !(mm->symlinks & sym_id)) { mm->symlinks |= sym_id; sym_mask |= symlink_ids[mm_path]; } } sym_done |= mask; } if (!inhibit_notify) { notify_symlink(global::file_created, path); } } } //! File attribute or content changed callback. //! //! @param st //! Status information for @[path] as obtained by //! @expr{file_stat(path, 1)@}. //! //! This function is called when a change has been detected for an //! attribute for a monitored file or directory. //! //! Called by @[check()] and @[check_monitor()]. //! //! @note //! If there is a @[data_changed()] callback, it may supersede this //! callback if the file content also has changed. protected void attr_changed(string path, Stdio.Stat st) { check_symlink(path, st); if (st && st->islnk) { return; } ::attr_changed(path, st); } protected void low_file_exists(string path, Stdio.Stat st) { // Note: May be called for symlink targets before they have // initialized properly, in which case st will be 0. if (!st || !global::file_exists) return; global::file_exists(path, st); } //! File existance callback. //! //! @param st //! Status information for @[path] as obtained by //! @expr{file_stat(path, 1)@}. //! //! This function is called during initialization for all monitored paths, //! and subpaths for monitored directories. It represents the initial state //! for the monitor. //! //! @note //! For directories, @[file_created()] will be called for the subpaths //! before the call for the directory itself. This can be used to detect //! when the initialization for a directory is finished. //! //! Called by @[check()] and @[check_monitor()] the first time a monitored //! path is checked (and only if it exists). protected void file_exists(string path, Stdio.Stat st) { check_symlink(path, st, 1); if (st && st->islnk) { notify_symlink(low_file_exists, path); return; } ::file_exists(path, st); } //! File creation callback. //! //! @param st //! Status information for @[path] as obtained by //! @expr{file_stat(path, 1)@}. //! //! This function is called when either a monitored path has started //! existing, or when a new file or directory has been added to a //! monitored directory. //! //! Called by @[check()] and @[check_monitor()]. protected void file_created(string path, Stdio.Stat st) { check_symlink(path, st); if (st && st->islnk) { // Note: check_symlink() above has already called the file_created() // callback for us. return; } ::file_created(path, st); } //! File deletion callback. //! //! @param path //! Path of the new file or directory that has been deleted. //! //! This function is called when either a monitored path has stopped //! to exist, or when a file or directory has been deleted from a //! monitored directory. //! //! Called by @[check()] and @[check_monitor()]. protected void file_deleted(string path, Stdio.Stat old_st) { check_symlink(path, UNDEFINED); if (old_st && old_st->islnk) { return; } ::file_deleted(path, old_st); } //! Stable change callback. //! //! @param st //! Status information for @[path] as obtained by //! @expr{file_stat(path, 1)@}. //! //! This function is called when previous changes to @[path] are //! considered "stable". //! //! "Stable" in this case means that there have been no detected //! changes for at lease @[stable_time] seconds. //! //! Called by @[check()] and @[check_monitor()]. protected void stable_data_change(string path, Stdio.Stat st) { if (st && st->islnk) { int sym_id = global::symlink_ids[path]; if (sym_id) { foreach(monitors; string m_path; Monitor m) { if ((m->symlinks & sym_id) && (m->last_change == 0x7fffffff)) { m->low_call_callback(global::stable_data_change, ([]), global::symlink_targets, m_path, m->st, path); } } } return; } ::stable_data_change(path, st); } //! Check if this monitor should be removed automatically. void check_for_release(int mask, int flags) { if (symlinks) { // We need to check if this is the direct target of a symlink. foreach(symlink_targets;; string dest) { if (path == dest) { // The monitor still has a symlink pointing to it. return; } } } ::check_for_release(mask, flags); } //! Called to create a sub monitor. protected void monitor(string path, int flags, int max_dir_interval, int file_interval_factor, int stable_time) { object m; ::monitor(path, flags, max_dir_check_interval, file_interval_factor, stable_time); if((m = monitors[path])) m->symlinks |= symlinks; } //! Called when the status has changed for an existing file. protected int(0..1) status_change(Stdio.Stat old_st, Stdio.Stat st, int orig_flags, int flags) { check_symlink(path, st); if (st && st->islnk) { return 1; } return ::status_change(old_st, st, orig_flags, flags); } } #endif /* constant(readlink) */ //! Mapping from symlink name to symlink target. protected mapping(string:string) symlink_targets = ([]); //! Mapping from symlink name to symlink id. protected mapping(string:int) symlink_ids = ([]); //! Bitmask of all unallocated symlink ids. protected int available_ids = -1; //! Allocates a symlink id for the link @[sym]. protected int allocate_symlink(string sym) { int res = symlink_ids[sym]; if (res) return res; res = available_ids & ~(available_ids - 1); available_ids -= res; return symlink_ids[sym] = res; }

pike.git/ lib/ modules/ Filesystem.pmod/ Monitor.pmod/ symlinks.pike > 5f58bdeecb41320455102b95b9180cba3c5d04f5 [Annotate]