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PHP Cross Reference of MediaWiki-1.24.0 |
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1 <?php 2 /** 3 * @defgroup FileBackend File backend 4 * 5 * File backend is used to interact with file storage systems, 6 * such as the local file system, NFS, or cloud storage systems. 7 */ 8 9 /** 10 * Base class for all file backends. 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License along 23 * with this program; if not, write to the Free Software Foundation, Inc., 24 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 25 * http://www.gnu.org/copyleft/gpl.html 26 * 27 * @file 28 * @ingroup FileBackend 29 * @author Aaron Schulz 30 */ 31 32 /** 33 * @brief Base class for all file backend classes (including multi-write backends). 34 * 35 * This class defines the methods as abstract that subclasses must implement. 36 * Outside callers can assume that all backends will have these functions. 37 * 38 * All "storage paths" are of the format "mwstore://<backend>/<container>/<path>". 39 * The "backend" portion is unique name for MediaWiki to refer to a backend, while 40 * the "container" portion is a top-level directory of the backend. The "path" portion 41 * is a relative path that uses UNIX file system (FS) notation, though any particular 42 * backend may not actually be using a local filesystem. Therefore, the relative paths 43 * are only virtual. 44 * 45 * Backend contents are stored under wiki-specific container names by default. 46 * Global (qualified) backends are achieved by configuring the "wiki ID" to a constant. 47 * For legacy reasons, the FSFileBackend class allows manually setting the paths of 48 * containers to ones that do not respect the "wiki ID". 49 * 50 * In key/value (object) stores, containers are the only hierarchy (the rest is emulated). 51 * FS-based backends are somewhat more restrictive due to the existence of real 52 * directory files; a regular file cannot have the same name as a directory. Other 53 * backends with virtual directories may not have this limitation. Callers should 54 * store files in such a way that no files and directories are under the same path. 55 * 56 * In general, this class allows for callers to access storage through the same 57 * interface, without regard to the underlying storage system. However, calling code 58 * must follow certain patterns and be aware of certain things to ensure compatibility: 59 * - a) Always call prepare() on the parent directory before trying to put a file there; 60 * key/value stores only need the container to exist first, but filesystems need 61 * all the parent directories to exist first (prepare() is aware of all this) 62 * - b) Always call clean() on a directory when it might become empty to avoid empty 63 * directory buildup on filesystems; key/value stores never have empty directories, 64 * so doing this helps preserve consistency in both cases 65 * - c) Likewise, do not rely on the existence of empty directories for anything; 66 * calling directoryExists() on a path that prepare() was previously called on 67 * will return false for key/value stores if there are no files under that path 68 * - d) Never alter the resulting FSFile returned from getLocalReference(), as it could 69 * either be a copy of the source file in /tmp or the original source file itself 70 * - e) Use a file layout that results in never attempting to store files over directories 71 * or directories over files; key/value stores allow this but filesystems do not 72 * - f) Use ASCII file names (e.g. base32, IDs, hashes) to avoid Unicode issues in Windows 73 * - g) Do not assume that move operations are atomic (difficult with key/value stores) 74 * - h) Do not assume that file stat or read operations always have immediate consistency; 75 * various methods have a "latest" flag that should always be used if up-to-date 76 * information is required (this trades performance for correctness as needed) 77 * - i) Do not assume that directory listings have immediate consistency 78 * 79 * Methods of subclasses should avoid throwing exceptions at all costs. 80 * As a corollary, external dependencies should be kept to a minimum. 81 * 82 * @ingroup FileBackend 83 * @since 1.19 84 */ 85 abstract class FileBackend { 86 /** @var string Unique backend name */ 87 protected $name; 88 89 /** @var string Unique wiki name */ 90 protected $wikiId; 91 92 /** @var string Read-only explanation message */ 93 protected $readOnly; 94 95 /** @var string When to do operations in parallel */ 96 protected $parallelize; 97 98 /** @var int How many operations can be done in parallel */ 99 protected $concurrency; 100 101 /** @var LockManager */ 102 protected $lockManager; 103 104 /** @var FileJournal */ 105 protected $fileJournal; 106 107 /** Bitfield flags for supported features */ 108 const ATTR_HEADERS = 1; // files can be tagged with standard HTTP headers 109 const ATTR_METADATA = 2; // files can be stored with metadata key/values 110 const ATTR_UNICODE_PATHS = 4; // files can have Unicode paths (not just ASCII) 111 112 /** 113 * Create a new backend instance from configuration. 114 * This should only be called from within FileBackendGroup. 115 * 116 * @param array $config Parameters include: 117 * - name : The unique name of this backend. 118 * This should consist of alphanumberic, '-', and '_' characters. 119 * This name should not be changed after use (e.g. with journaling). 120 * Note that the name is *not* used in actual container names. 121 * - wikiId : Prefix to container names that is unique to this backend. 122 * It should only consist of alphanumberic, '-', and '_' characters. 123 * This ID is what avoids collisions if multiple logical backends 124 * use the same storage system, so this should be set carefully. 125 * - lockManager : LockManager object to use for any file locking. 126 * If not provided, then no file locking will be enforced. 127 * - fileJournal : FileJournal object to use for logging changes to files. 128 * If not provided, then change journaling will be disabled. 129 * - readOnly : Write operations are disallowed if this is a non-empty string. 130 * It should be an explanation for the backend being read-only. 131 * - parallelize : When to do file operations in parallel (when possible). 132 * Allowed values are "implicit", "explicit" and "off". 133 * - concurrency : How many file operations can be done in parallel. 134 * @throws FileBackendException 135 */ 136 public function __construct( array $config ) { 137 $this->name = $config['name']; 138 $this->wikiId = $config['wikiId']; // e.g. "my_wiki-en_" 139 if ( !preg_match( '!^[a-zA-Z0-9-_]{1,255}$!', $this->name ) ) { 140 throw new FileBackendException( "Backend name '{$this->name}' is invalid." ); 141 } elseif ( !is_string( $this->wikiId ) ) { 142 throw new FileBackendException( "Backend wiki ID not provided for '{$this->name}'." ); 143 } 144 $this->lockManager = isset( $config['lockManager'] ) 145 ? $config['lockManager'] 146 : new NullLockManager( array() ); 147 $this->fileJournal = isset( $config['fileJournal'] ) 148 ? $config['fileJournal'] 149 : FileJournal::factory( array( 'class' => 'NullFileJournal' ), $this->name ); 150 $this->readOnly = isset( $config['readOnly'] ) 151 ? (string)$config['readOnly'] 152 : ''; 153 $this->parallelize = isset( $config['parallelize'] ) 154 ? (string)$config['parallelize'] 155 : 'off'; 156 $this->concurrency = isset( $config['concurrency'] ) 157 ? (int)$config['concurrency'] 158 : 50; 159 } 160 161 /** 162 * Get the unique backend name. 163 * We may have multiple different backends of the same type. 164 * For example, we can have two Swift backends using different proxies. 165 * 166 * @return string 167 */ 168 final public function getName() { 169 return $this->name; 170 } 171 172 /** 173 * Get the wiki identifier used for this backend (possibly empty). 174 * Note that this might *not* be in the same format as wfWikiID(). 175 * 176 * @return string 177 * @since 1.20 178 */ 179 final public function getWikiId() { 180 return $this->wikiId; 181 } 182 183 /** 184 * Check if this backend is read-only 185 * 186 * @return bool 187 */ 188 final public function isReadOnly() { 189 return ( $this->readOnly != '' ); 190 } 191 192 /** 193 * Get an explanatory message if this backend is read-only 194 * 195 * @return string|bool Returns false if the backend is not read-only 196 */ 197 final public function getReadOnlyReason() { 198 return ( $this->readOnly != '' ) ? $this->readOnly : false; 199 } 200 201 /** 202 * Get the a bitfield of extra features supported by the backend medium 203 * 204 * @return int Bitfield of FileBackend::ATTR_* flags 205 * @since 1.23 206 */ 207 public function getFeatures() { 208 return self::ATTR_UNICODE_PATHS; 209 } 210 211 /** 212 * Check if the backend medium supports a field of extra features 213 * 214 * @param int $bitfield Bitfield of FileBackend::ATTR_* flags 215 * @return bool 216 * @since 1.23 217 */ 218 final public function hasFeatures( $bitfield ) { 219 return ( $this->getFeatures() & $bitfield ) === $bitfield; 220 } 221 222 /** 223 * This is the main entry point into the backend for write operations. 224 * Callers supply an ordered list of operations to perform as a transaction. 225 * Files will be locked, the stat cache cleared, and then the operations attempted. 226 * If any serious errors occur, all attempted operations will be rolled back. 227 * 228 * $ops is an array of arrays. The outer array holds a list of operations. 229 * Each inner array is a set of key value pairs that specify an operation. 230 * 231 * Supported operations and their parameters. The supported actions are: 232 * - create 233 * - store 234 * - copy 235 * - move 236 * - delete 237 * - describe (since 1.21) 238 * - null 239 * 240 * a) Create a new file in storage with the contents of a string 241 * @code 242 * array( 243 * 'op' => 'create', 244 * 'dst' => <storage path>, 245 * 'content' => <string of new file contents>, 246 * 'overwrite' => <boolean>, 247 * 'overwriteSame' => <boolean>, 248 * 'headers' => <HTTP header name/value map> # since 1.21 249 * ); 250 * @endcode 251 * 252 * b) Copy a file system file into storage 253 * @code 254 * array( 255 * 'op' => 'store', 256 * 'src' => <file system path>, 257 * 'dst' => <storage path>, 258 * 'overwrite' => <boolean>, 259 * 'overwriteSame' => <boolean>, 260 * 'headers' => <HTTP header name/value map> # since 1.21 261 * ) 262 * @endcode 263 * 264 * c) Copy a file within storage 265 * @code 266 * array( 267 * 'op' => 'copy', 268 * 'src' => <storage path>, 269 * 'dst' => <storage path>, 270 * 'overwrite' => <boolean>, 271 * 'overwriteSame' => <boolean>, 272 * 'ignoreMissingSource' => <boolean>, # since 1.21 273 * 'headers' => <HTTP header name/value map> # since 1.21 274 * ) 275 * @endcode 276 * 277 * d) Move a file within storage 278 * @code 279 * array( 280 * 'op' => 'move', 281 * 'src' => <storage path>, 282 * 'dst' => <storage path>, 283 * 'overwrite' => <boolean>, 284 * 'overwriteSame' => <boolean>, 285 * 'ignoreMissingSource' => <boolean>, # since 1.21 286 * 'headers' => <HTTP header name/value map> # since 1.21 287 * ) 288 * @endcode 289 * 290 * e) Delete a file within storage 291 * @code 292 * array( 293 * 'op' => 'delete', 294 * 'src' => <storage path>, 295 * 'ignoreMissingSource' => <boolean> 296 * ) 297 * @endcode 298 * 299 * f) Update metadata for a file within storage 300 * @code 301 * array( 302 * 'op' => 'describe', 303 * 'src' => <storage path>, 304 * 'headers' => <HTTP header name/value map> 305 * ) 306 * @endcode 307 * 308 * g) Do nothing (no-op) 309 * @code 310 * array( 311 * 'op' => 'null', 312 * ) 313 * @endcode 314 * 315 * Boolean flags for operations (operation-specific): 316 * - ignoreMissingSource : The operation will simply succeed and do 317 * nothing if the source file does not exist. 318 * - overwrite : Any destination file will be overwritten. 319 * - overwriteSame : If a file already exists at the destination with the 320 * same contents, then do nothing to the destination file 321 * instead of giving an error. This does not compare headers. 322 * This option is ignored if 'overwrite' is already provided. 323 * - headers : If supplied, the result of merging these headers with any 324 * existing source file headers (replacing conflicting ones) 325 * will be set as the destination file headers. Headers are 326 * deleted if their value is set to the empty string. When a 327 * file has headers they are included in responses to GET and 328 * HEAD requests to the backing store for that file. 329 * Header values should be no larger than 255 bytes, except for 330 * Content-Disposition. The system might ignore or truncate any 331 * headers that are too long to store (exact limits will vary). 332 * Backends that don't support metadata ignore this. (since 1.21) 333 * 334 * $opts is an associative of boolean flags, including: 335 * - force : Operation precondition errors no longer trigger an abort. 336 * Any remaining operations are still attempted. Unexpected 337 * failures may still cause remaining operations to be aborted. 338 * - nonLocking : No locks are acquired for the operations. 339 * This can increase performance for non-critical writes. 340 * This has no effect unless the 'force' flag is set. 341 * - nonJournaled : Don't log this operation batch in the file journal. 342 * This limits the ability of recovery scripts. 343 * - parallelize : Try to do operations in parallel when possible. 344 * - bypassReadOnly : Allow writes in read-only mode. (since 1.20) 345 * - preserveCache : Don't clear the process cache before checking files. 346 * This should only be used if all entries in the process 347 * cache were added after the files were already locked. (since 1.20) 348 * 349 * @remarks Remarks on locking: 350 * File system paths given to operations should refer to files that are 351 * already locked or otherwise safe from modification from other processes. 352 * Normally these files will be new temp files, which should be adequate. 353 * 354 * @par Return value: 355 * 356 * This returns a Status, which contains all warnings and fatals that occurred 357 * during the operation. The 'failCount', 'successCount', and 'success' members 358 * will reflect each operation attempted. 359 * 360 * The status will be "OK" unless: 361 * - a) unexpected operation errors occurred (network partitions, disk full...) 362 * - b) significant operation errors occurred and 'force' was not set 363 * 364 * @param array $ops List of operations to execute in order 365 * @param array $opts Batch operation options 366 * @return Status 367 */ 368 final public function doOperations( array $ops, array $opts = array() ) { 369 if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) { 370 return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly ); 371 } 372 if ( !count( $ops ) ) { 373 return Status::newGood(); // nothing to do 374 } 375 if ( empty( $opts['force'] ) ) { // sanity 376 unset( $opts['nonLocking'] ); 377 } 378 foreach ( $ops as &$op ) { 379 if ( isset( $op['disposition'] ) ) { // b/c (MW 1.20) 380 $op['headers']['Content-Disposition'] = $op['disposition']; 381 } 382 } 383 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts 384 return $this->doOperationsInternal( $ops, $opts ); 385 } 386 387 /** 388 * @see FileBackend::doOperations() 389 */ 390 abstract protected function doOperationsInternal( array $ops, array $opts ); 391 392 /** 393 * Same as doOperations() except it takes a single operation. 394 * If you are doing a batch of operations that should either 395 * all succeed or all fail, then use that function instead. 396 * 397 * @see FileBackend::doOperations() 398 * 399 * @param array $op Operation 400 * @param array $opts Operation options 401 * @return Status 402 */ 403 final public function doOperation( array $op, array $opts = array() ) { 404 return $this->doOperations( array( $op ), $opts ); 405 } 406 407 /** 408 * Performs a single create operation. 409 * This sets $params['op'] to 'create' and passes it to doOperation(). 410 * 411 * @see FileBackend::doOperation() 412 * 413 * @param array $params Operation parameters 414 * @param array $opts Operation options 415 * @return Status 416 */ 417 final public function create( array $params, array $opts = array() ) { 418 return $this->doOperation( array( 'op' => 'create' ) + $params, $opts ); 419 } 420 421 /** 422 * Performs a single store operation. 423 * This sets $params['op'] to 'store' and passes it to doOperation(). 424 * 425 * @see FileBackend::doOperation() 426 * 427 * @param array $params Operation parameters 428 * @param array $opts Operation options 429 * @return Status 430 */ 431 final public function store( array $params, array $opts = array() ) { 432 return $this->doOperation( array( 'op' => 'store' ) + $params, $opts ); 433 } 434 435 /** 436 * Performs a single copy operation. 437 * This sets $params['op'] to 'copy' and passes it to doOperation(). 438 * 439 * @see FileBackend::doOperation() 440 * 441 * @param array $params Operation parameters 442 * @param array $opts Operation options 443 * @return Status 444 */ 445 final public function copy( array $params, array $opts = array() ) { 446 return $this->doOperation( array( 'op' => 'copy' ) + $params, $opts ); 447 } 448 449 /** 450 * Performs a single move operation. 451 * This sets $params['op'] to 'move' and passes it to doOperation(). 452 * 453 * @see FileBackend::doOperation() 454 * 455 * @param array $params Operation parameters 456 * @param array $opts Operation options 457 * @return Status 458 */ 459 final public function move( array $params, array $opts = array() ) { 460 return $this->doOperation( array( 'op' => 'move' ) + $params, $opts ); 461 } 462 463 /** 464 * Performs a single delete operation. 465 * This sets $params['op'] to 'delete' and passes it to doOperation(). 466 * 467 * @see FileBackend::doOperation() 468 * 469 * @param array $params Operation parameters 470 * @param array $opts Operation options 471 * @return Status 472 */ 473 final public function delete( array $params, array $opts = array() ) { 474 return $this->doOperation( array( 'op' => 'delete' ) + $params, $opts ); 475 } 476 477 /** 478 * Performs a single describe operation. 479 * This sets $params['op'] to 'describe' and passes it to doOperation(). 480 * 481 * @see FileBackend::doOperation() 482 * 483 * @param array $params Operation parameters 484 * @param array $opts Operation options 485 * @return Status 486 * @since 1.21 487 */ 488 final public function describe( array $params, array $opts = array() ) { 489 return $this->doOperation( array( 'op' => 'describe' ) + $params, $opts ); 490 } 491 492 /** 493 * Perform a set of independent file operations on some files. 494 * 495 * This does no locking, nor journaling, and possibly no stat calls. 496 * Any destination files that already exist will be overwritten. 497 * This should *only* be used on non-original files, like cache files. 498 * 499 * Supported operations and their parameters: 500 * - create 501 * - store 502 * - copy 503 * - move 504 * - delete 505 * - describe (since 1.21) 506 * - null 507 * 508 * a) Create a new file in storage with the contents of a string 509 * @code 510 * array( 511 * 'op' => 'create', 512 * 'dst' => <storage path>, 513 * 'content' => <string of new file contents>, 514 * 'headers' => <HTTP header name/value map> # since 1.21 515 * ) 516 * @endcode 517 * 518 * b) Copy a file system file into storage 519 * @code 520 * array( 521 * 'op' => 'store', 522 * 'src' => <file system path>, 523 * 'dst' => <storage path>, 524 * 'headers' => <HTTP header name/value map> # since 1.21 525 * ) 526 * @endcode 527 * 528 * c) Copy a file within storage 529 * @code 530 * array( 531 * 'op' => 'copy', 532 * 'src' => <storage path>, 533 * 'dst' => <storage path>, 534 * 'ignoreMissingSource' => <boolean>, # since 1.21 535 * 'headers' => <HTTP header name/value map> # since 1.21 536 * ) 537 * @endcode 538 * 539 * d) Move a file within storage 540 * @code 541 * array( 542 * 'op' => 'move', 543 * 'src' => <storage path>, 544 * 'dst' => <storage path>, 545 * 'ignoreMissingSource' => <boolean>, # since 1.21 546 * 'headers' => <HTTP header name/value map> # since 1.21 547 * ) 548 * @endcode 549 * 550 * e) Delete a file within storage 551 * @code 552 * array( 553 * 'op' => 'delete', 554 * 'src' => <storage path>, 555 * 'ignoreMissingSource' => <boolean> 556 * ) 557 * @endcode 558 * 559 * f) Update metadata for a file within storage 560 * @code 561 * array( 562 * 'op' => 'describe', 563 * 'src' => <storage path>, 564 * 'headers' => <HTTP header name/value map> 565 * ) 566 * @endcode 567 * 568 * g) Do nothing (no-op) 569 * @code 570 * array( 571 * 'op' => 'null', 572 * ) 573 * @endcode 574 * 575 * @par Boolean flags for operations (operation-specific): 576 * - ignoreMissingSource : The operation will simply succeed and do 577 * nothing if the source file does not exist. 578 * - headers : If supplied with a header name/value map, the backend will 579 * reply with these headers when GETs/HEADs of the destination 580 * file are made. Header values should be smaller than 256 bytes. 581 * Content-Disposition headers can be longer, though the system 582 * might ignore or truncate ones that are too long to store. 583 * Existing headers will remain, but these will replace any 584 * conflicting previous headers, and headers will be removed 585 * if they are set to an empty string. 586 * Backends that don't support metadata ignore this. (since 1.21) 587 * 588 * $opts is an associative of boolean flags, including: 589 * - bypassReadOnly : Allow writes in read-only mode (since 1.20) 590 * 591 * @par Return value: 592 * This returns a Status, which contains all warnings and fatals that occurred 593 * during the operation. The 'failCount', 'successCount', and 'success' members 594 * will reflect each operation attempted for the given files. The status will be 595 * considered "OK" as long as no fatal errors occurred. 596 * 597 * @param array $ops Set of operations to execute 598 * @param array $opts Batch operation options 599 * @return Status 600 * @since 1.20 601 */ 602 final public function doQuickOperations( array $ops, array $opts = array() ) { 603 if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) { 604 return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly ); 605 } 606 if ( !count( $ops ) ) { 607 return Status::newGood(); // nothing to do 608 } 609 foreach ( $ops as &$op ) { 610 $op['overwrite'] = true; // avoids RTTs in key/value stores 611 if ( isset( $op['disposition'] ) ) { // b/c (MW 1.20) 612 $op['headers']['Content-Disposition'] = $op['disposition']; 613 } 614 } 615 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts 616 return $this->doQuickOperationsInternal( $ops ); 617 } 618 619 /** 620 * @see FileBackend::doQuickOperations() 621 * @since 1.20 622 */ 623 abstract protected function doQuickOperationsInternal( array $ops ); 624 625 /** 626 * Same as doQuickOperations() except it takes a single operation. 627 * If you are doing a batch of operations, then use that function instead. 628 * 629 * @see FileBackend::doQuickOperations() 630 * 631 * @param array $op Operation 632 * @return Status 633 * @since 1.20 634 */ 635 final public function doQuickOperation( array $op ) { 636 return $this->doQuickOperations( array( $op ) ); 637 } 638 639 /** 640 * Performs a single quick create operation. 641 * This sets $params['op'] to 'create' and passes it to doQuickOperation(). 642 * 643 * @see FileBackend::doQuickOperation() 644 * 645 * @param array $params Operation parameters 646 * @return Status 647 * @since 1.20 648 */ 649 final public function quickCreate( array $params ) { 650 return $this->doQuickOperation( array( 'op' => 'create' ) + $params ); 651 } 652 653 /** 654 * Performs a single quick store operation. 655 * This sets $params['op'] to 'store' and passes it to doQuickOperation(). 656 * 657 * @see FileBackend::doQuickOperation() 658 * 659 * @param array $params Operation parameters 660 * @return Status 661 * @since 1.20 662 */ 663 final public function quickStore( array $params ) { 664 return $this->doQuickOperation( array( 'op' => 'store' ) + $params ); 665 } 666 667 /** 668 * Performs a single quick copy operation. 669 * This sets $params['op'] to 'copy' and passes it to doQuickOperation(). 670 * 671 * @see FileBackend::doQuickOperation() 672 * 673 * @param array $params Operation parameters 674 * @return Status 675 * @since 1.20 676 */ 677 final public function quickCopy( array $params ) { 678 return $this->doQuickOperation( array( 'op' => 'copy' ) + $params ); 679 } 680 681 /** 682 * Performs a single quick move operation. 683 * This sets $params['op'] to 'move' and passes it to doQuickOperation(). 684 * 685 * @see FileBackend::doQuickOperation() 686 * 687 * @param array $params Operation parameters 688 * @return Status 689 * @since 1.20 690 */ 691 final public function quickMove( array $params ) { 692 return $this->doQuickOperation( array( 'op' => 'move' ) + $params ); 693 } 694 695 /** 696 * Performs a single quick delete operation. 697 * This sets $params['op'] to 'delete' and passes it to doQuickOperation(). 698 * 699 * @see FileBackend::doQuickOperation() 700 * 701 * @param array $params Operation parameters 702 * @return Status 703 * @since 1.20 704 */ 705 final public function quickDelete( array $params ) { 706 return $this->doQuickOperation( array( 'op' => 'delete' ) + $params ); 707 } 708 709 /** 710 * Performs a single quick describe operation. 711 * This sets $params['op'] to 'describe' and passes it to doQuickOperation(). 712 * 713 * @see FileBackend::doQuickOperation() 714 * 715 * @param array $params Operation parameters 716 * @return Status 717 * @since 1.21 718 */ 719 final public function quickDescribe( array $params ) { 720 return $this->doQuickOperation( array( 'op' => 'describe' ) + $params ); 721 } 722 723 /** 724 * Concatenate a list of storage files into a single file system file. 725 * The target path should refer to a file that is already locked or 726 * otherwise safe from modification from other processes. Normally, 727 * the file will be a new temp file, which should be adequate. 728 * 729 * @param array $params Operation parameters, include: 730 * - srcs : ordered source storage paths (e.g. chunk1, chunk2, ...) 731 * - dst : file system path to 0-byte temp file 732 * - parallelize : try to do operations in parallel when possible 733 * @return Status 734 */ 735 abstract public function concatenate( array $params ); 736 737 /** 738 * Prepare a storage directory for usage. 739 * This will create any required containers and parent directories. 740 * Backends using key/value stores only need to create the container. 741 * 742 * The 'noAccess' and 'noListing' parameters works the same as in secure(), 743 * except they are only applied *if* the directory/container had to be created. 744 * These flags should always be set for directories that have private files. 745 * However, setting them is not guaranteed to actually do anything. 746 * Additional server configuration may be needed to achieve the desired effect. 747 * 748 * @param array $params Parameters include: 749 * - dir : storage directory 750 * - noAccess : try to deny file access (since 1.20) 751 * - noListing : try to deny file listing (since 1.20) 752 * - bypassReadOnly : allow writes in read-only mode (since 1.20) 753 * @return Status 754 */ 755 final public function prepare( array $params ) { 756 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) { 757 return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly ); 758 } 759 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts 760 return $this->doPrepare( $params ); 761 } 762 763 /** 764 * @see FileBackend::prepare() 765 */ 766 abstract protected function doPrepare( array $params ); 767 768 /** 769 * Take measures to block web access to a storage directory and 770 * the container it belongs to. FS backends might add .htaccess 771 * files whereas key/value store backends might revoke container 772 * access to the storage user representing end-users in web requests. 773 * 774 * This is not guaranteed to actually make files or listings publically hidden. 775 * Additional server configuration may be needed to achieve the desired effect. 776 * 777 * @param array $params Parameters include: 778 * - dir : storage directory 779 * - noAccess : try to deny file access 780 * - noListing : try to deny file listing 781 * - bypassReadOnly : allow writes in read-only mode (since 1.20) 782 * @return Status 783 */ 784 final public function secure( array $params ) { 785 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) { 786 return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly ); 787 } 788 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts 789 return $this->doSecure( $params ); 790 } 791 792 /** 793 * @see FileBackend::secure() 794 */ 795 abstract protected function doSecure( array $params ); 796 797 /** 798 * Remove measures to block web access to a storage directory and 799 * the container it belongs to. FS backends might remove .htaccess 800 * files whereas key/value store backends might grant container 801 * access to the storage user representing end-users in web requests. 802 * This essentially can undo the result of secure() calls. 803 * 804 * This is not guaranteed to actually make files or listings publically viewable. 805 * Additional server configuration may be needed to achieve the desired effect. 806 * 807 * @param array $params Parameters include: 808 * - dir : storage directory 809 * - access : try to allow file access 810 * - listing : try to allow file listing 811 * - bypassReadOnly : allow writes in read-only mode (since 1.20) 812 * @return Status 813 * @since 1.20 814 */ 815 final public function publish( array $params ) { 816 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) { 817 return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly ); 818 } 819 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts 820 return $this->doPublish( $params ); 821 } 822 823 /** 824 * @see FileBackend::publish() 825 */ 826 abstract protected function doPublish( array $params ); 827 828 /** 829 * Delete a storage directory if it is empty. 830 * Backends using key/value stores may do nothing unless the directory 831 * is that of an empty container, in which case it will be deleted. 832 * 833 * @param array $params Parameters include: 834 * - dir : storage directory 835 * - recursive : recursively delete empty subdirectories first (since 1.20) 836 * - bypassReadOnly : allow writes in read-only mode (since 1.20) 837 * @return Status 838 */ 839 final public function clean( array $params ) { 840 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) { 841 return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly ); 842 } 843 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts 844 return $this->doClean( $params ); 845 } 846 847 /** 848 * @see FileBackend::clean() 849 */ 850 abstract protected function doClean( array $params ); 851 852 /** 853 * Enter file operation scope. 854 * This just makes PHP ignore user aborts/disconnects until the return 855 * value leaves scope. This returns null and does nothing in CLI mode. 856 * 857 * @return ScopedCallback|null 858 */ 859 final protected function getScopedPHPBehaviorForOps() { 860 if ( PHP_SAPI != 'cli' ) { // http://bugs.php.net/bug.php?id=47540 861 $old = ignore_user_abort( true ); // avoid half-finished operations 862 return new ScopedCallback( function () use ( $old ) { 863 ignore_user_abort( $old ); 864 } ); 865 } 866 867 return null; 868 } 869 870 /** 871 * Check if a file exists at a storage path in the backend. 872 * This returns false if only a directory exists at the path. 873 * 874 * @param array $params Parameters include: 875 * - src : source storage path 876 * - latest : use the latest available data 877 * @return bool|null Returns null on failure 878 */ 879 abstract public function fileExists( array $params ); 880 881 /** 882 * Get the last-modified timestamp of the file at a storage path. 883 * 884 * @param array $params Parameters include: 885 * - src : source storage path 886 * - latest : use the latest available data 887 * @return string|bool TS_MW timestamp or false on failure 888 */ 889 abstract public function getFileTimestamp( array $params ); 890 891 /** 892 * Get the contents of a file at a storage path in the backend. 893 * This should be avoided for potentially large files. 894 * 895 * @param array $params Parameters include: 896 * - src : source storage path 897 * - latest : use the latest available data 898 * @return string|bool Returns false on failure 899 */ 900 final public function getFileContents( array $params ) { 901 $contents = $this->getFileContentsMulti( 902 array( 'srcs' => array( $params['src'] ) ) + $params ); 903 904 return $contents[$params['src']]; 905 } 906 907 /** 908 * Like getFileContents() except it takes an array of storage paths 909 * and returns a map of storage paths to strings (or null on failure). 910 * The map keys (paths) are in the same order as the provided list of paths. 911 * 912 * @see FileBackend::getFileContents() 913 * 914 * @param array $params Parameters include: 915 * - srcs : list of source storage paths 916 * - latest : use the latest available data 917 * - parallelize : try to do operations in parallel when possible 918 * @return array Map of (path name => string or false on failure) 919 * @since 1.20 920 */ 921 abstract public function getFileContentsMulti( array $params ); 922 923 /** 924 * Get metadata about a file at a storage path in the backend. 925 * If the file does not exist, then this returns false. 926 * Otherwise, the result is an associative array that includes: 927 * - headers : map of HTTP headers used for GET/HEAD requests (name => value) 928 * - metadata : map of file metadata (name => value) 929 * Metadata keys and headers names will be returned in all lower-case. 930 * Additional values may be included for internal use only. 931 * 932 * Use FileBackend::hasFeatures() to check how well this is supported. 933 * 934 * @param array $params 935 * $params include: 936 * - src : source storage path 937 * - latest : use the latest available data 938 * @return array|bool Returns false on failure 939 * @since 1.23 940 */ 941 abstract public function getFileXAttributes( array $params ); 942 943 /** 944 * Get the size (bytes) of a file at a storage path in the backend. 945 * 946 * @param array $params Parameters include: 947 * - src : source storage path 948 * - latest : use the latest available data 949 * @return int|bool Returns false on failure 950 */ 951 abstract public function getFileSize( array $params ); 952 953 /** 954 * Get quick information about a file at a storage path in the backend. 955 * If the file does not exist, then this returns false. 956 * Otherwise, the result is an associative array that includes: 957 * - mtime : the last-modified timestamp (TS_MW) 958 * - size : the file size (bytes) 959 * Additional values may be included for internal use only. 960 * 961 * @param array $params Parameters include: 962 * - src : source storage path 963 * - latest : use the latest available data 964 * @return array|bool|null Returns null on failure 965 */ 966 abstract public function getFileStat( array $params ); 967 968 /** 969 * Get a SHA-1 hash of the file at a storage path in the backend. 970 * 971 * @param array $params Parameters include: 972 * - src : source storage path 973 * - latest : use the latest available data 974 * @return string|bool Hash string or false on failure 975 */ 976 abstract public function getFileSha1Base36( array $params ); 977 978 /** 979 * Get the properties of the file at a storage path in the backend. 980 * This gives the result of FSFile::getProps() on a local copy of the file. 981 * 982 * @param array $params Parameters include: 983 * - src : source storage path 984 * - latest : use the latest available data 985 * @return array Returns FSFile::placeholderProps() on failure 986 */ 987 abstract public function getFileProps( array $params ); 988 989 /** 990 * Stream the file at a storage path in the backend. 991 * If the file does not exists, an HTTP 404 error will be given. 992 * Appropriate HTTP headers (Status, Content-Type, Content-Length) 993 * will be sent if streaming began, while none will be sent otherwise. 994 * Implementations should flush the output buffer before sending data. 995 * 996 * @param array $params Parameters include: 997 * - src : source storage path 998 * - headers : list of additional HTTP headers to send on success 999 * - latest : use the latest available data 1000 * @return Status 1001 */ 1002 abstract public function streamFile( array $params ); 1003 1004 /** 1005 * Returns a file system file, identical to the file at a storage path. 1006 * The file returned is either: 1007 * - a) A local copy of the file at a storage path in the backend. 1008 * The temporary copy will have the same extension as the source. 1009 * - b) An original of the file at a storage path in the backend. 1010 * Temporary files may be purged when the file object falls out of scope. 1011 * 1012 * Write operations should *never* be done on this file as some backends 1013 * may do internal tracking or may be instances of FileBackendMultiWrite. 1014 * In that later case, there are copies of the file that must stay in sync. 1015 * Additionally, further calls to this function may return the same file. 1016 * 1017 * @param array $params Parameters include: 1018 * - src : source storage path 1019 * - latest : use the latest available data 1020 * @return FSFile|null Returns null on failure 1021 */ 1022 final public function getLocalReference( array $params ) { 1023 $fsFiles = $this->getLocalReferenceMulti( 1024 array( 'srcs' => array( $params['src'] ) ) + $params ); 1025 1026 return $fsFiles[$params['src']]; 1027 } 1028 1029 /** 1030 * Like getLocalReference() except it takes an array of storage paths 1031 * and returns a map of storage paths to FSFile objects (or null on failure). 1032 * The map keys (paths) are in the same order as the provided list of paths. 1033 * 1034 * @see FileBackend::getLocalReference() 1035 * 1036 * @param array $params Parameters include: 1037 * - srcs : list of source storage paths 1038 * - latest : use the latest available data 1039 * - parallelize : try to do operations in parallel when possible 1040 * @return array Map of (path name => FSFile or null on failure) 1041 * @since 1.20 1042 */ 1043 abstract public function getLocalReferenceMulti( array $params ); 1044 1045 /** 1046 * Get a local copy on disk of the file at a storage path in the backend. 1047 * The temporary copy will have the same file extension as the source. 1048 * Temporary files may be purged when the file object falls out of scope. 1049 * 1050 * @param array $params Parameters include: 1051 * - src : source storage path 1052 * - latest : use the latest available data 1053 * @return TempFSFile|null Returns null on failure 1054 */ 1055 final public function getLocalCopy( array $params ) { 1056 $tmpFiles = $this->getLocalCopyMulti( 1057 array( 'srcs' => array( $params['src'] ) ) + $params ); 1058 1059 return $tmpFiles[$params['src']]; 1060 } 1061 1062 /** 1063 * Like getLocalCopy() except it takes an array of storage paths and 1064 * returns a map of storage paths to TempFSFile objects (or null on failure). 1065 * The map keys (paths) are in the same order as the provided list of paths. 1066 * 1067 * @see FileBackend::getLocalCopy() 1068 * 1069 * @param array $params Parameters include: 1070 * - srcs : list of source storage paths 1071 * - latest : use the latest available data 1072 * - parallelize : try to do operations in parallel when possible 1073 * @return array Map of (path name => TempFSFile or null on failure) 1074 * @since 1.20 1075 */ 1076 abstract public function getLocalCopyMulti( array $params ); 1077 1078 /** 1079 * Return an HTTP URL to a given file that requires no authentication to use. 1080 * The URL may be pre-authenticated (via some token in the URL) and temporary. 1081 * This will return null if the backend cannot make an HTTP URL for the file. 1082 * 1083 * This is useful for key/value stores when using scripts that seek around 1084 * large files and those scripts (and the backend) support HTTP Range headers. 1085 * Otherwise, one would need to use getLocalReference(), which involves loading 1086 * the entire file on to local disk. 1087 * 1088 * @param array $params Parameters include: 1089 * - src : source storage path 1090 * - ttl : lifetime (seconds) if pre-authenticated; default is 1 day 1091 * @return string|null 1092 * @since 1.21 1093 */ 1094 abstract public function getFileHttpUrl( array $params ); 1095 1096 /** 1097 * Check if a directory exists at a given storage path. 1098 * Backends using key/value stores will check if the path is a 1099 * virtual directory, meaning there are files under the given directory. 1100 * 1101 * Storage backends with eventual consistency might return stale data. 1102 * 1103 * @param array $params Parameters include: 1104 * - dir : storage directory 1105 * @return bool|null Returns null on failure 1106 * @since 1.20 1107 */ 1108 abstract public function directoryExists( array $params ); 1109 1110 /** 1111 * Get an iterator to list *all* directories under a storage directory. 1112 * If the directory is of the form "mwstore://backend/container", 1113 * then all directories in the container will be listed. 1114 * If the directory is of form "mwstore://backend/container/dir", 1115 * then all directories directly under that directory will be listed. 1116 * Results will be storage directories relative to the given directory. 1117 * 1118 * Storage backends with eventual consistency might return stale data. 1119 * 1120 * Failures during iteration can result in FileBackendError exceptions (since 1.22). 1121 * 1122 * @param array $params Parameters include: 1123 * - dir : storage directory 1124 * - topOnly : only return direct child dirs of the directory 1125 * @return Traversable|array|null Returns null on failure 1126 * @since 1.20 1127 */ 1128 abstract public function getDirectoryList( array $params ); 1129 1130 /** 1131 * Same as FileBackend::getDirectoryList() except only lists 1132 * directories that are immediately under the given directory. 1133 * 1134 * Storage backends with eventual consistency might return stale data. 1135 * 1136 * Failures during iteration can result in FileBackendError exceptions (since 1.22). 1137 * 1138 * @param array $params Parameters include: 1139 * - dir : storage directory 1140 * @return Traversable|array|null Returns null on failure 1141 * @since 1.20 1142 */ 1143 final public function getTopDirectoryList( array $params ) { 1144 return $this->getDirectoryList( array( 'topOnly' => true ) + $params ); 1145 } 1146 1147 /** 1148 * Get an iterator to list *all* stored files under a storage directory. 1149 * If the directory is of the form "mwstore://backend/container", 1150 * then all files in the container will be listed. 1151 * If the directory is of form "mwstore://backend/container/dir", 1152 * then all files under that directory will be listed. 1153 * Results will be storage paths relative to the given directory. 1154 * 1155 * Storage backends with eventual consistency might return stale data. 1156 * 1157 * Failures during iteration can result in FileBackendError exceptions (since 1.22). 1158 * 1159 * @param array $params Parameters include: 1160 * - dir : storage directory 1161 * - topOnly : only return direct child files of the directory (since 1.20) 1162 * - adviseStat : set to true if stat requests will be made on the files (since 1.22) 1163 * @return Traversable|array|null Returns null on failure 1164 */ 1165 abstract public function getFileList( array $params ); 1166 1167 /** 1168 * Same as FileBackend::getFileList() except only lists 1169 * files that are immediately under the given directory. 1170 * 1171 * Storage backends with eventual consistency might return stale data. 1172 * 1173 * Failures during iteration can result in FileBackendError exceptions (since 1.22). 1174 * 1175 * @param array $params Parameters include: 1176 * - dir : storage directory 1177 * - adviseStat : set to true if stat requests will be made on the files (since 1.22) 1178 * @return Traversable|array|null Returns null on failure 1179 * @since 1.20 1180 */ 1181 final public function getTopFileList( array $params ) { 1182 return $this->getFileList( array( 'topOnly' => true ) + $params ); 1183 } 1184 1185 /** 1186 * Preload persistent file stat cache and property cache into in-process cache. 1187 * This should be used when stat calls will be made on a known list of a many files. 1188 * 1189 * @see FileBackend::getFileStat() 1190 * 1191 * @param array $paths Storage paths 1192 */ 1193 abstract public function preloadCache( array $paths ); 1194 1195 /** 1196 * Invalidate any in-process file stat and property cache. 1197 * If $paths is given, then only the cache for those files will be cleared. 1198 * 1199 * @see FileBackend::getFileStat() 1200 * 1201 * @param array $paths Storage paths (optional) 1202 */ 1203 abstract public function clearCache( array $paths = null ); 1204 1205 /** 1206 * Preload file stat information (concurrently if possible) into in-process cache. 1207 * This should be used when stat calls will be made on a known list of a many files. 1208 * 1209 * @see FileBackend::getFileStat() 1210 * 1211 * @param array $params Parameters include: 1212 * - srcs : list of source storage paths 1213 * - latest : use the latest available data 1214 * @return bool All requests proceeded without I/O errors (since 1.24) 1215 * @since 1.23 1216 */ 1217 abstract public function preloadFileStat( array $params ); 1218 1219 /** 1220 * Lock the files at the given storage paths in the backend. 1221 * This will either lock all the files or none (on failure). 1222 * 1223 * Callers should consider using getScopedFileLocks() instead. 1224 * 1225 * @param array $paths Storage paths 1226 * @param int $type LockManager::LOCK_* constant 1227 * @param int $timeout Timeout in seconds (0 means non-blocking) (since 1.24) 1228 * @return Status 1229 */ 1230 final public function lockFiles( array $paths, $type, $timeout = 0 ) { 1231 $paths = array_map( 'FileBackend::normalizeStoragePath', $paths ); 1232 1233 return $this->lockManager->lock( $paths, $type, $timeout ); 1234 } 1235 1236 /** 1237 * Unlock the files at the given storage paths in the backend. 1238 * 1239 * @param array $paths Storage paths 1240 * @param int $type LockManager::LOCK_* constant 1241 * @return Status 1242 */ 1243 final public function unlockFiles( array $paths, $type ) { 1244 $paths = array_map( 'FileBackend::normalizeStoragePath', $paths ); 1245 1246 return $this->lockManager->unlock( $paths, $type ); 1247 } 1248 1249 /** 1250 * Lock the files at the given storage paths in the backend. 1251 * This will either lock all the files or none (on failure). 1252 * On failure, the status object will be updated with errors. 1253 * 1254 * Once the return value goes out scope, the locks will be released and 1255 * the status updated. Unlock fatals will not change the status "OK" value. 1256 * 1257 * @see ScopedLock::factory() 1258 * 1259 * @param array $paths List of storage paths or map of lock types to path lists 1260 * @param int|string $type LockManager::LOCK_* constant or "mixed" 1261 * @param Status $status Status to update on lock/unlock 1262 * @param int $timeout Timeout in seconds (0 means non-blocking) (since 1.24) 1263 * @return ScopedLock|null Returns null on failure 1264 */ 1265 final public function getScopedFileLocks( array $paths, $type, Status $status, $timeout = 0 ) { 1266 if ( $type === 'mixed' ) { 1267 foreach ( $paths as &$typePaths ) { 1268 $typePaths = array_map( 'FileBackend::normalizeStoragePath', $typePaths ); 1269 } 1270 } else { 1271 $paths = array_map( 'FileBackend::normalizeStoragePath', $paths ); 1272 } 1273 1274 return ScopedLock::factory( $this->lockManager, $paths, $type, $status, $timeout ); 1275 } 1276 1277 /** 1278 * Get an array of scoped locks needed for a batch of file operations. 1279 * 1280 * Normally, FileBackend::doOperations() handles locking, unless 1281 * the 'nonLocking' param is passed in. This function is useful if you 1282 * want the files to be locked for a broader scope than just when the 1283 * files are changing. For example, if you need to update DB metadata, 1284 * you may want to keep the files locked until finished. 1285 * 1286 * @see FileBackend::doOperations() 1287 * 1288 * @param array $ops List of file operations to FileBackend::doOperations() 1289 * @param Status $status Status to update on lock/unlock 1290 * @return array List of ScopedFileLocks or null values 1291 * @since 1.20 1292 */ 1293 abstract public function getScopedLocksForOps( array $ops, Status $status ); 1294 1295 /** 1296 * Get the root storage path of this backend. 1297 * All container paths are "subdirectories" of this path. 1298 * 1299 * @return string Storage path 1300 * @since 1.20 1301 */ 1302 final public function getRootStoragePath() { 1303 return "mwstore://{$this->name}"; 1304 } 1305 1306 /** 1307 * Get the storage path for the given container for this backend 1308 * 1309 * @param string $container Container name 1310 * @return string Storage path 1311 * @since 1.21 1312 */ 1313 final public function getContainerStoragePath( $container ) { 1314 return $this->getRootStoragePath() . "/{$container}"; 1315 } 1316 1317 /** 1318 * Get the file journal object for this backend 1319 * 1320 * @return FileJournal 1321 */ 1322 final public function getJournal() { 1323 return $this->fileJournal; 1324 } 1325 1326 /** 1327 * Check if a given path is a "mwstore://" path. 1328 * This does not do any further validation or any existence checks. 1329 * 1330 * @param string $path 1331 * @return bool 1332 */ 1333 final public static function isStoragePath( $path ) { 1334 return ( strpos( $path, 'mwstore://' ) === 0 ); 1335 } 1336 1337 /** 1338 * Split a storage path into a backend name, a container name, 1339 * and a relative file path. The relative path may be the empty string. 1340 * This does not do any path normalization or traversal checks. 1341 * 1342 * @param string $storagePath 1343 * @return array (backend, container, rel object) or (null, null, null) 1344 */ 1345 final public static function splitStoragePath( $storagePath ) { 1346 if ( self::isStoragePath( $storagePath ) ) { 1347 // Remove the "mwstore://" prefix and split the path 1348 $parts = explode( '/', substr( $storagePath, 10 ), 3 ); 1349 if ( count( $parts ) >= 2 && $parts[0] != '' && $parts[1] != '' ) { 1350 if ( count( $parts ) == 3 ) { 1351 return $parts; // e.g. "backend/container/path" 1352 } else { 1353 return array( $parts[0], $parts[1], '' ); // e.g. "backend/container" 1354 } 1355 } 1356 } 1357 1358 return array( null, null, null ); 1359 } 1360 1361 /** 1362 * Normalize a storage path by cleaning up directory separators. 1363 * Returns null if the path is not of the format of a valid storage path. 1364 * 1365 * @param string $storagePath 1366 * @return string|null 1367 */ 1368 final public static function normalizeStoragePath( $storagePath ) { 1369 list( $backend, $container, $relPath ) = self::splitStoragePath( $storagePath ); 1370 if ( $relPath !== null ) { // must be for this backend 1371 $relPath = self::normalizeContainerPath( $relPath ); 1372 if ( $relPath !== null ) { 1373 return ( $relPath != '' ) 1374 ? "mwstore://{$backend}/{$container}/{$relPath}" 1375 : "mwstore://{$backend}/{$container}"; 1376 } 1377 } 1378 1379 return null; 1380 } 1381 1382 /** 1383 * Get the parent storage directory of a storage path. 1384 * This returns a path like "mwstore://backend/container", 1385 * "mwstore://backend/container/...", or null if there is no parent. 1386 * 1387 * @param string $storagePath 1388 * @return string|null 1389 */ 1390 final public static function parentStoragePath( $storagePath ) { 1391 $storagePath = dirname( $storagePath ); 1392 list( , , $rel ) = self::splitStoragePath( $storagePath ); 1393 1394 return ( $rel === null ) ? null : $storagePath; 1395 } 1396 1397 /** 1398 * Get the final extension from a storage or FS path 1399 * 1400 * @param string $path 1401 * @param string $case One of (rawcase, uppercase, lowercase) (since 1.24) 1402 * @return string 1403 */ 1404 final public static function extensionFromPath( $path, $case = 'lowercase' ) { 1405 $i = strrpos( $path, '.' ); 1406 $ext = $i ? substr( $path, $i + 1 ) : ''; 1407 1408 if ( $case === 'lowercase' ) { 1409 $ext = strtolower( $ext ); 1410 } elseif ( $case === 'uppercase' ) { 1411 $ext = strtoupper( $ext ); 1412 } 1413 1414 return $ext; 1415 } 1416 1417 /** 1418 * Check if a relative path has no directory traversals 1419 * 1420 * @param string $path 1421 * @return bool 1422 * @since 1.20 1423 */ 1424 final public static function isPathTraversalFree( $path ) { 1425 return ( self::normalizeContainerPath( $path ) !== null ); 1426 } 1427 1428 /** 1429 * Build a Content-Disposition header value per RFC 6266. 1430 * 1431 * @param string $type One of (attachment, inline) 1432 * @param string $filename Suggested file name (should not contain slashes) 1433 * @throws FileBackendError 1434 * @return string 1435 * @since 1.20 1436 */ 1437 final public static function makeContentDisposition( $type, $filename = '' ) { 1438 $parts = array(); 1439 1440 $type = strtolower( $type ); 1441 if ( !in_array( $type, array( 'inline', 'attachment' ) ) ) { 1442 throw new FileBackendError( "Invalid Content-Disposition type '$type'." ); 1443 } 1444 $parts[] = $type; 1445 1446 if ( strlen( $filename ) ) { 1447 $parts[] = "filename*=UTF-8''" . rawurlencode( basename( $filename ) ); 1448 } 1449 1450 return implode( ';', $parts ); 1451 } 1452 1453 /** 1454 * Validate and normalize a relative storage path. 1455 * Null is returned if the path involves directory traversal. 1456 * Traversal is insecure for FS backends and broken for others. 1457 * 1458 * This uses the same traversal protection as Title::secureAndSplit(). 1459 * 1460 * @param string $path Storage path relative to a container 1461 * @return string|null 1462 */ 1463 final protected static function normalizeContainerPath( $path ) { 1464 // Normalize directory separators 1465 $path = strtr( $path, '\\', '/' ); 1466 // Collapse any consecutive directory separators 1467 $path = preg_replace( '![/]{2,}!', '/', $path ); 1468 // Remove any leading directory separator 1469 $path = ltrim( $path, '/' ); 1470 // Use the same traversal protection as Title::secureAndSplit() 1471 if ( strpos( $path, '.' ) !== false ) { 1472 if ( 1473 $path === '.' || 1474 $path === '..' || 1475 strpos( $path, './' ) === 0 || 1476 strpos( $path, '../' ) === 0 || 1477 strpos( $path, '/./' ) !== false || 1478 strpos( $path, '/../' ) !== false 1479 ) { 1480 return null; 1481 } 1482 } 1483 1484 return $path; 1485 } 1486 } 1487 1488 /** 1489 * Generic file backend exception for checked and unexpected (e.g. config) exceptions 1490 * 1491 * @ingroup FileBackend 1492 * @since 1.23 1493 */ 1494 class FileBackendException extends MWException { 1495 } 1496 1497 /** 1498 * File backend exception for checked exceptions (e.g. I/O errors) 1499 * 1500 * @ingroup FileBackend 1501 * @since 1.22 1502 */ 1503 class FileBackendError extends FileBackendException { 1504 }
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