diff options
Diffstat (limited to 'includes/filerepo/backend/FileOp.php')
| -rw-r--r-- | includes/filerepo/backend/FileOp.php | 697 |
1 files changed, 0 insertions, 697 deletions
diff --git a/includes/filerepo/backend/FileOp.php b/includes/filerepo/backend/FileOp.php deleted file mode 100644 index 5844c9f2..00000000 --- a/includes/filerepo/backend/FileOp.php +++ /dev/null @@ -1,697 +0,0 @@ -<?php -/** - * @file - * @ingroup FileBackend - * @author Aaron Schulz - */ - -/** - * Helper class for representing operations with transaction support. - * Do not use this class from places outside FileBackend. - * - * Methods called from attemptBatch() should avoid throwing exceptions at all costs. - * FileOp objects should be lightweight in order to support large arrays in memory. - * - * @ingroup FileBackend - * @since 1.19 - */ -abstract class FileOp { - /** @var Array */ - protected $params = array(); - /** @var FileBackendStore */ - protected $backend; - - protected $state = self::STATE_NEW; // integer - protected $failed = false; // boolean - protected $useLatest = true; // boolean - - protected $sourceSha1; // string - protected $destSameAsSource; // boolean - - /* Object life-cycle */ - const STATE_NEW = 1; - const STATE_CHECKED = 2; - const STATE_ATTEMPTED = 3; - - /* Timeout related parameters */ - const MAX_BATCH_SIZE = 1000; - const TIME_LIMIT_SEC = 300; // 5 minutes - - /** - * Build a new file operation transaction - * - * @params $backend FileBackendStore - * @params $params Array - * @throws MWException - */ - final public function __construct( FileBackendStore $backend, array $params ) { - $this->backend = $backend; - list( $required, $optional ) = $this->allowedParams(); - foreach ( $required as $name ) { - if ( isset( $params[$name] ) ) { - $this->params[$name] = $params[$name]; - } else { - throw new MWException( "File operation missing parameter '$name'." ); - } - } - foreach ( $optional as $name ) { - if ( isset( $params[$name] ) ) { - $this->params[$name] = $params[$name]; - } - } - $this->params = $params; - } - - /** - * Allow stale data for file reads and existence checks - * - * @return void - */ - final protected function allowStaleReads() { - $this->useLatest = false; - } - - /** - * Attempt a series of file operations. - * Callers are responsible for handling file locking. - * - * $opts is an array of options, including: - * 'force' : Errors that would normally cause a rollback do not. - * The remaining operations are still attempted if any fail. - * 'allowStale' : Don't require the latest available data. - * This can increase performance for non-critical writes. - * This has no effect unless the 'force' flag is set. - * - * The resulting Status will be "OK" unless: - * a) unexpected operation errors occurred (network partitions, disk full...) - * b) significant operation errors occured and 'force' was not set - * - * @param $performOps Array List of FileOp operations - * @param $opts Array Batch operation options - * @return Status - */ - final public static function attemptBatch( array $performOps, array $opts ) { - $status = Status::newGood(); - - $allowStale = !empty( $opts['allowStale'] ); - $ignoreErrors = !empty( $opts['force'] ); - - $n = count( $performOps ); - if ( $n > self::MAX_BATCH_SIZE ) { - $status->fatal( 'backend-fail-batchsize', $n, self::MAX_BATCH_SIZE ); - return $status; - } - - $predicates = FileOp::newPredicates(); // account for previous op in prechecks - // Do pre-checks for each operation; abort on failure... - foreach ( $performOps as $index => $fileOp ) { - if ( $allowStale ) { - $fileOp->allowStaleReads(); // allow potentially stale reads - } - $subStatus = $fileOp->precheck( $predicates ); - $status->merge( $subStatus ); - if ( !$subStatus->isOK() ) { // operation failed? - $status->success[$index] = false; - ++$status->failCount; - if ( !$ignoreErrors ) { - return $status; // abort - } - } - } - - if ( $ignoreErrors ) { - # Treat all precheck() fatals as merely warnings - $status->setResult( true, $status->value ); - } - - // Restart PHP's execution timer and set the timeout to safe amount. - // This handles cases where the operations take a long time or where we are - // already running low on time left. The old timeout is restored afterwards. - # @TODO: re-enable this for when the number of batches is high. - #$scopedTimeLimit = new FileOpScopedPHPTimeout( self::TIME_LIMIT_SEC ); - - // Attempt each operation... - foreach ( $performOps as $index => $fileOp ) { - if ( $fileOp->failed() ) { - continue; // nothing to do - } - $subStatus = $fileOp->attempt(); - $status->merge( $subStatus ); - if ( $subStatus->isOK() ) { - $status->success[$index] = true; - ++$status->successCount; - } else { - $status->success[$index] = false; - ++$status->failCount; - // We can't continue (even with $ignoreErrors) as $predicates is wrong. - // Log the remaining ops as failed for recovery... - for ( $i = ($index + 1); $i < count( $performOps ); $i++ ) { - $performOps[$i]->logFailure( 'attempt_aborted' ); - } - return $status; // bail out - } - } - - return $status; - } - - /** - * Get the value of the parameter with the given name - * - * @param $name string - * @return mixed Returns null if the parameter is not set - */ - final public function getParam( $name ) { - return isset( $this->params[$name] ) ? $this->params[$name] : null; - } - - /** - * Check if this operation failed precheck() or attempt() - * - * @return bool - */ - final public function failed() { - return $this->failed; - } - - /** - * Get a new empty predicates array for precheck() - * - * @return Array - */ - final public static function newPredicates() { - return array( 'exists' => array(), 'sha1' => array() ); - } - - /** - * Check preconditions of the operation without writing anything - * - * @param $predicates Array - * @return Status - */ - final public function precheck( array &$predicates ) { - if ( $this->state !== self::STATE_NEW ) { - return Status::newFatal( 'fileop-fail-state', self::STATE_NEW, $this->state ); - } - $this->state = self::STATE_CHECKED; - $status = $this->doPrecheck( $predicates ); - if ( !$status->isOK() ) { - $this->failed = true; - } - return $status; - } - - /** - * Attempt the operation, backing up files as needed; this must be reversible - * - * @return Status - */ - final public function attempt() { - if ( $this->state !== self::STATE_CHECKED ) { - return Status::newFatal( 'fileop-fail-state', self::STATE_CHECKED, $this->state ); - } elseif ( $this->failed ) { // failed precheck - return Status::newFatal( 'fileop-fail-attempt-precheck' ); - } - $this->state = self::STATE_ATTEMPTED; - $status = $this->doAttempt(); - if ( !$status->isOK() ) { - $this->failed = true; - $this->logFailure( 'attempt' ); - } - return $status; - } - - /** - * Get the file operation parameters - * - * @return Array (required params list, optional params list) - */ - protected function allowedParams() { - return array( array(), array() ); - } - - /** - * Get a list of storage paths read from for this operation - * - * @return Array - */ - public function storagePathsRead() { - return array(); - } - - /** - * Get a list of storage paths written to for this operation - * - * @return Array - */ - public function storagePathsChanged() { - return array(); - } - - /** - * @return Status - */ - protected function doPrecheck( array &$predicates ) { - return Status::newGood(); - } - - /** - * @return Status - */ - protected function doAttempt() { - return Status::newGood(); - } - - /** - * Check for errors with regards to the destination file already existing. - * This also updates the destSameAsSource and sourceSha1 member variables. - * A bad status will be returned if there is no chance it can be overwritten. - * - * @param $predicates Array - * @return Status - */ - protected function precheckDestExistence( array $predicates ) { - $status = Status::newGood(); - // Get hash of source file/string and the destination file - $this->sourceSha1 = $this->getSourceSha1Base36(); // FS file or data string - if ( $this->sourceSha1 === null ) { // file in storage? - $this->sourceSha1 = $this->fileSha1( $this->params['src'], $predicates ); - } - $this->destSameAsSource = false; - if ( $this->fileExists( $this->params['dst'], $predicates ) ) { - if ( $this->getParam( 'overwrite' ) ) { - return $status; // OK - } elseif ( $this->getParam( 'overwriteSame' ) ) { - $dhash = $this->fileSha1( $this->params['dst'], $predicates ); - // Check if hashes are valid and match each other... - if ( !strlen( $this->sourceSha1 ) || !strlen( $dhash ) ) { - $status->fatal( 'backend-fail-hashes' ); - } elseif ( $this->sourceSha1 !== $dhash ) { - // Give an error if the files are not identical - $status->fatal( 'backend-fail-notsame', $this->params['dst'] ); - } else { - $this->destSameAsSource = true; // OK - } - return $status; // do nothing; either OK or bad status - } else { - $status->fatal( 'backend-fail-alreadyexists', $this->params['dst'] ); - return $status; - } - } - return $status; - } - - /** - * precheckDestExistence() helper function to get the source file SHA-1. - * Subclasses should overwride this iff the source is not in storage. - * - * @return string|false Returns false on failure - */ - protected function getSourceSha1Base36() { - return null; // N/A - } - - /** - * Check if a file will exist in storage when this operation is attempted - * - * @param $source string Storage path - * @param $predicates Array - * @return bool - */ - final protected function fileExists( $source, array $predicates ) { - if ( isset( $predicates['exists'][$source] ) ) { - return $predicates['exists'][$source]; // previous op assures this - } else { - $params = array( 'src' => $source, 'latest' => $this->useLatest ); - return $this->backend->fileExists( $params ); - } - } - - /** - * Get the SHA-1 of a file in storage when this operation is attempted - * - * @param $source string Storage path - * @param $predicates Array - * @return string|false - */ - final protected function fileSha1( $source, array $predicates ) { - if ( isset( $predicates['sha1'][$source] ) ) { - return $predicates['sha1'][$source]; // previous op assures this - } else { - $params = array( 'src' => $source, 'latest' => $this->useLatest ); - return $this->backend->getFileSha1Base36( $params ); - } - } - - /** - * Log a file operation failure and preserve any temp files - * - * @param $action string - * @return void - */ - final protected function logFailure( $action ) { - $params = $this->params; - $params['failedAction'] = $action; - try { - wfDebugLog( 'FileOperation', - get_class( $this ) . ' failed:' . serialize( $params ) ); - } catch ( Exception $e ) { - // bad config? debug log error? - } - } -} - -/** - * FileOp helper class to expand PHP execution time for a function. - * On construction, set_time_limit() is called and set to $seconds. - * When the object goes out of scope, the timer is restarted, with - * the original time limit minus the time the object existed. - */ -class FileOpScopedPHPTimeout { - protected $startTime; // float; seconds - protected $oldTimeout; // integer; seconds - - protected static $stackDepth = 0; // integer - protected static $totalCalls = 0; // integer - protected static $totalElapsed = 0; // float; seconds - - /* Prevent callers in infinite loops from running forever */ - const MAX_TOTAL_CALLS = 1000000; - const MAX_TOTAL_TIME = 300; // seconds - - /** - * @param $seconds integer - */ - public function __construct( $seconds ) { - if ( ini_get( 'max_execution_time' ) > 0 ) { // CLI uses 0 - if ( self::$totalCalls >= self::MAX_TOTAL_CALLS ) { - trigger_error( "Maximum invocations of " . __CLASS__ . " exceeded." ); - } elseif ( self::$totalElapsed >= self::MAX_TOTAL_TIME ) { - trigger_error( "Time limit within invocations of " . __CLASS__ . " exceeded." ); - } elseif ( self::$stackDepth > 0 ) { // recursion guard - trigger_error( "Resursive invocation of " . __CLASS__ . " attempted." ); - } else { - $this->oldTimeout = ini_set( 'max_execution_time', $seconds ); - $this->startTime = microtime( true ); - ++self::$stackDepth; - ++self::$totalCalls; // proof against < 1us scopes - } - } - } - - /** - * Restore the original timeout. - * This does not account for the timer value on __construct(). - */ - public function __destruct() { - if ( $this->oldTimeout ) { - $elapsed = microtime( true ) - $this->startTime; - // Note: a limit of 0 is treated as "forever" - set_time_limit( max( 1, $this->oldTimeout - (int)$elapsed ) ); - // If each scoped timeout is for less than one second, we end up - // restoring the original timeout without any decrease in value. - // Thus web scripts in an infinite loop can run forever unless we - // take some measures to prevent this. Track total time and calls. - self::$totalElapsed += $elapsed; - --self::$stackDepth; - } - } -} - -/** - * Store a file into the backend from a file on the file system. - * Parameters similar to FileBackendStore::storeInternal(), which include: - * src : source path on file system - * dst : destination storage path - * overwrite : do nothing and pass if an identical file exists at destination - * overwriteSame : override any existing file at destination - */ -class StoreFileOp extends FileOp { - protected function allowedParams() { - return array( array( 'src', 'dst' ), array( 'overwrite', 'overwriteSame' ) ); - } - - protected function doPrecheck( array &$predicates ) { - $status = Status::newGood(); - // Check if the source file exists on the file system - if ( !is_file( $this->params['src'] ) ) { - $status->fatal( 'backend-fail-notexists', $this->params['src'] ); - return $status; - // Check if the source file is too big - } elseif ( filesize( $this->params['src'] ) > $this->backend->maxFileSizeInternal() ) { - $status->fatal( 'backend-fail-store', $this->params['src'], $this->params['dst'] ); - return $status; - // Check if a file can be placed at the destination - } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) { - $status->fatal( 'backend-fail-store', $this->params['src'], $this->params['dst'] ); - return $status; - } - // Check if destination file exists - $status->merge( $this->precheckDestExistence( $predicates ) ); - if ( $status->isOK() ) { - // Update file existence predicates - $predicates['exists'][$this->params['dst']] = true; - $predicates['sha1'][$this->params['dst']] = $this->sourceSha1; - } - return $status; // safe to call attempt() - } - - protected function doAttempt() { - $status = Status::newGood(); - // Store the file at the destination - if ( !$this->destSameAsSource ) { - $status->merge( $this->backend->storeInternal( $this->params ) ); - } - return $status; - } - - protected function getSourceSha1Base36() { - wfSuppressWarnings(); - $hash = sha1_file( $this->params['src'] ); - wfRestoreWarnings(); - if ( $hash !== false ) { - $hash = wfBaseConvert( $hash, 16, 36, 31 ); - } - return $hash; - } - - public function storagePathsChanged() { - return array( $this->params['dst'] ); - } -} - -/** - * Create a file in the backend with the given content. - * Parameters similar to FileBackendStore::createInternal(), which include: - * content : the raw file contents - * dst : destination storage path - * overwrite : do nothing and pass if an identical file exists at destination - * overwriteSame : override any existing file at destination - */ -class CreateFileOp extends FileOp { - protected function allowedParams() { - return array( array( 'content', 'dst' ), array( 'overwrite', 'overwriteSame' ) ); - } - - protected function doPrecheck( array &$predicates ) { - $status = Status::newGood(); - // Check if the source data is too big - if ( strlen( $this->getParam( 'content' ) ) > $this->backend->maxFileSizeInternal() ) { - $status->fatal( 'backend-fail-create', $this->params['dst'] ); - return $status; - // Check if a file can be placed at the destination - } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) { - $status->fatal( 'backend-fail-create', $this->params['dst'] ); - return $status; - } - // Check if destination file exists - $status->merge( $this->precheckDestExistence( $predicates ) ); - if ( $status->isOK() ) { - // Update file existence predicates - $predicates['exists'][$this->params['dst']] = true; - $predicates['sha1'][$this->params['dst']] = $this->sourceSha1; - } - return $status; // safe to call attempt() - } - - protected function doAttempt() { - $status = Status::newGood(); - // Create the file at the destination - if ( !$this->destSameAsSource ) { - $status->merge( $this->backend->createInternal( $this->params ) ); - } - return $status; - } - - protected function getSourceSha1Base36() { - return wfBaseConvert( sha1( $this->params['content'] ), 16, 36, 31 ); - } - - public function storagePathsChanged() { - return array( $this->params['dst'] ); - } -} - -/** - * Copy a file from one storage path to another in the backend. - * Parameters similar to FileBackendStore::copyInternal(), which include: - * src : source storage path - * dst : destination storage path - * overwrite : do nothing and pass if an identical file exists at destination - * overwriteSame : override any existing file at destination - */ -class CopyFileOp extends FileOp { - protected function allowedParams() { - return array( array( 'src', 'dst' ), array( 'overwrite', 'overwriteSame' ) ); - } - - protected function doPrecheck( array &$predicates ) { - $status = Status::newGood(); - // Check if the source file exists - if ( !$this->fileExists( $this->params['src'], $predicates ) ) { - $status->fatal( 'backend-fail-notexists', $this->params['src'] ); - return $status; - // Check if a file can be placed at the destination - } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) { - $status->fatal( 'backend-fail-copy', $this->params['src'], $this->params['dst'] ); - return $status; - } - // Check if destination file exists - $status->merge( $this->precheckDestExistence( $predicates ) ); - if ( $status->isOK() ) { - // Update file existence predicates - $predicates['exists'][$this->params['dst']] = true; - $predicates['sha1'][$this->params['dst']] = $this->sourceSha1; - } - return $status; // safe to call attempt() - } - - protected function doAttempt() { - $status = Status::newGood(); - // Do nothing if the src/dst paths are the same - if ( $this->params['src'] !== $this->params['dst'] ) { - // Copy the file into the destination - if ( !$this->destSameAsSource ) { - $status->merge( $this->backend->copyInternal( $this->params ) ); - } - } - return $status; - } - - public function storagePathsRead() { - return array( $this->params['src'] ); - } - - public function storagePathsChanged() { - return array( $this->params['dst'] ); - } -} - -/** - * Move a file from one storage path to another in the backend. - * Parameters similar to FileBackendStore::moveInternal(), which include: - * src : source storage path - * dst : destination storage path - * overwrite : do nothing and pass if an identical file exists at destination - * overwriteSame : override any existing file at destination - */ -class MoveFileOp extends FileOp { - protected function allowedParams() { - return array( array( 'src', 'dst' ), array( 'overwrite', 'overwriteSame' ) ); - } - - protected function doPrecheck( array &$predicates ) { - $status = Status::newGood(); - // Check if the source file exists - if ( !$this->fileExists( $this->params['src'], $predicates ) ) { - $status->fatal( 'backend-fail-notexists', $this->params['src'] ); - return $status; - // Check if a file can be placed at the destination - } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) { - $status->fatal( 'backend-fail-move', $this->params['src'], $this->params['dst'] ); - return $status; - } - // Check if destination file exists - $status->merge( $this->precheckDestExistence( $predicates ) ); - if ( $status->isOK() ) { - // Update file existence predicates - $predicates['exists'][$this->params['src']] = false; - $predicates['sha1'][$this->params['src']] = false; - $predicates['exists'][$this->params['dst']] = true; - $predicates['sha1'][$this->params['dst']] = $this->sourceSha1; - } - return $status; // safe to call attempt() - } - - protected function doAttempt() { - $status = Status::newGood(); - // Do nothing if the src/dst paths are the same - if ( $this->params['src'] !== $this->params['dst'] ) { - if ( !$this->destSameAsSource ) { - // Move the file into the destination - $status->merge( $this->backend->moveInternal( $this->params ) ); - } else { - // Just delete source as the destination needs no changes - $params = array( 'src' => $this->params['src'] ); - $status->merge( $this->backend->deleteInternal( $params ) ); - } - } - return $status; - } - - public function storagePathsRead() { - return array( $this->params['src'] ); - } - - public function storagePathsChanged() { - return array( $this->params['dst'] ); - } -} - -/** - * Delete a file at the given storage path from the backend. - * Parameters similar to FileBackendStore::deleteInternal(), which include: - * src : source storage path - * ignoreMissingSource : don't return an error if the file does not exist - */ -class DeleteFileOp extends FileOp { - protected function allowedParams() { - return array( array( 'src' ), array( 'ignoreMissingSource' ) ); - } - - protected $needsDelete = true; - - protected function doPrecheck( array &$predicates ) { - $status = Status::newGood(); - // Check if the source file exists - if ( !$this->fileExists( $this->params['src'], $predicates ) ) { - if ( !$this->getParam( 'ignoreMissingSource' ) ) { - $status->fatal( 'backend-fail-notexists', $this->params['src'] ); - return $status; - } - $this->needsDelete = false; - } - // Update file existence predicates - $predicates['exists'][$this->params['src']] = false; - $predicates['sha1'][$this->params['src']] = false; - return $status; // safe to call attempt() - } - - protected function doAttempt() { - $status = Status::newGood(); - if ( $this->needsDelete ) { - // Delete the source file - $status->merge( $this->backend->deleteInternal( $this->params ) ); - } - return $status; - } - - public function storagePathsChanged() { - return array( $this->params['src'] ); - } -} - -/** - * Placeholder operation that has no params and does nothing - */ -class NullFileOp extends FileOp {} |