filebackend: improve internal use of FileBackend constants
authorAaron Schulz <aschulz@wikimedia.org>
Fri, 30 Aug 2019 07:01:29 +0000 (00:01 -0700)
committerAaron Schulz <aschulz@wikimedia.org>
Wed, 4 Sep 2019 02:31:17 +0000 (19:31 -0700)
Add more result constants and split up FileBackend::UNKNOWN for
clarity. This follows up 5719815f3b, which added that constant.

Make internal FileBackendStore::doGet* methods distinguish I/O errors
from missing files; the return types of public FileBackend methods are
unchanged. Avoid process caching any mtime/size/sha1 values in the
case of I/O errors. Use error constants consistently for stat methods
when given invalid paths.

Also:
* Factor out FileBackendStore::processCacheAndPersistStatEntries() method
  to reduce significant code duplication.
* Consolidate duplicated isPathUsable() checks in FileOp subclasses to
  FileOp::precheck().
* Remove null process cache value check from FileBackend::getFileStat()
  as null values are never stored in the process cache to begin with.
* Reformat some oddly wrapped lines to look cleaner.

Change-Id: Id0e4b0da0bb2ed3184847b35142d587c7f3d953d

14 files changed:
includes/libs/filebackend/FSFileBackend.php
includes/libs/filebackend/FileBackend.php
includes/libs/filebackend/FileBackendMultiWrite.php
includes/libs/filebackend/FileBackendStore.php
includes/libs/filebackend/MemoryFileBackend.php
includes/libs/filebackend/SwiftFileBackend.php
includes/libs/filebackend/fileop/CopyFileOp.php
includes/libs/filebackend/fileop/CreateFileOp.php
includes/libs/filebackend/fileop/DeleteFileOp.php
includes/libs/filebackend/fileop/DescribeFileOp.php
includes/libs/filebackend/fileop/FileOp.php
includes/libs/filebackend/fileop/MoveFileOp.php
includes/libs/filebackend/fileop/StoreFileOp.php
tests/phpunit/includes/filebackend/FileBackendTest.php

index c1a796f..c333a5e 100644 (file)
@@ -137,7 +137,7 @@ class FSFileBackend extends FileBackendStore {
                        }
                }
 
-               return null;
+               return null; // invalid
        }
 
        /**
@@ -576,25 +576,23 @@ class FSFileBackend extends FileBackendStore {
        protected function doGetFileStat( array $params ) {
                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
-                       return false; // invalid storage path
+                       return self::$RES_ERROR; // invalid storage path
                }
 
                $this->trapWarnings(); // don't trust 'false' if there were errors
                $stat = is_file( $source ) ? stat( $source ) : false; // regular files only
                $hadError = $this->untrapWarnings();
 
-               if ( $stat ) {
+               if ( is_array( $stat ) ) {
                        $ct = new ConvertibleTimestamp( $stat['mtime'] );
 
                        return [
                                'mtime' => $ct->getTimestamp( TS_MW ),
                                'size' => $stat['size']
                        ];
-               } elseif ( !$hadError ) {
-                       return false; // file does not exist
-               } else {
-                       return self::UNKNOWN; // failure
                }
+
+               return $hadError ? self::$RES_ERROR : self::$RES_ABSENT;
        }
 
        protected function doClearCache( array $paths = null ) {
@@ -610,7 +608,7 @@ class FSFileBackend extends FileBackendStore {
                $exists = is_dir( $dir );
                $hadError = $this->untrapWarnings();
 
-               return $hadError ? self::UNKNOWN : $exists;
+               return $hadError ? self::$RES_ERROR : $exists;
        }
 
        /**
@@ -624,18 +622,27 @@ class FSFileBackend extends FileBackendStore {
                list( , $shortCont, ) = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
+
+               $this->trapWarnings(); // don't trust 'false' if there were errors
                $exists = is_dir( $dir );
-               if ( !$exists ) {
-                       $this->logger->warning( __METHOD__ . "() given directory does not exist: '$dir'\n" );
+               $isReadable = $exists ? is_readable( $dir ) : false;
+               $hadError = $this->untrapWarnings();
 
-                       return []; // nothing under this dir
-               } elseif ( !is_readable( $dir ) ) {
-                       $this->logger->warning( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
+               if ( $isReadable ) {
+                       return new FSFileBackendDirList( $dir, $params );
+               } elseif ( $exists ) {
+                       $this->logger->warning( __METHOD__ . ": given directory is unreadable: '$dir'" );
 
-                       return self::UNKNOWN; // bad permissions?
-               }
+                       return self::$RES_ERROR; // bad permissions?
+               } elseif ( $hadError ) {
+                       $this->logger->warning( __METHOD__ . ": given directory was unreachable: '$dir'" );
+
+                       return self::$RES_ERROR;
+               } else {
+                       $this->logger->info( __METHOD__ . ": given directory does not exist: '$dir'" );
 
-               return new FSFileBackendDirList( $dir, $params );
+                       return []; // nothing under this dir
+               }
        }
 
        /**
@@ -649,18 +656,27 @@ class FSFileBackend extends FileBackendStore {
                list( , $shortCont, ) = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
+
+               $this->trapWarnings(); // don't trust 'false' if there were errors
                $exists = is_dir( $dir );
-               if ( !$exists ) {
-                       $this->logger->warning( __METHOD__ . "() given directory does not exist: '$dir'\n" );
+               $isReadable = $exists ? is_readable( $dir ) : false;
+               $hadError = $this->untrapWarnings();
 
-                       return []; // nothing under this dir
-               } elseif ( !is_readable( $dir ) ) {
-                       $this->logger->warning( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
+               if ( $exists && $isReadable ) {
+                       return new FSFileBackendFileList( $dir, $params );
+               } elseif ( $exists ) {
+                       $this->logger->warning( __METHOD__ . ": given directory is unreadable: '$dir'\n" );
 
-                       return self::UNKNOWN; // bad permissions?
-               }
+                       return self::$RES_ERROR; // bad permissions?
+               } elseif ( $hadError ) {
+                       $this->logger->warning( __METHOD__ . ": given directory was unreachable: '$dir'\n" );
 
-               return new FSFileBackendFileList( $dir, $params );
+                       return self::$RES_ERROR;
+               } else {
+                       $this->logger->info( __METHOD__ . ": given directory does not exist: '$dir'\n" );
+
+                       return []; // nothing under this dir
+               }
        }
 
        protected function doGetLocalReferenceMulti( array $params ) {
@@ -668,10 +684,21 @@ class FSFileBackend extends FileBackendStore {
 
                foreach ( $params['srcs'] as $src ) {
                        $source = $this->resolveToFSPath( $src );
-                       if ( $source === null || !is_file( $source ) ) {
-                               $fsFiles[$src] = null; // invalid path or file does not exist
-                       } else {
+                       if ( $source === null ) {
+                               $fsFiles[$src] = self::$RES_ERROR; // invalid path
+                               continue;
+                       }
+
+                       $this->trapWarnings(); // don't trust 'false' if there were errors
+                       $isFile = is_file( $source ); // regular files only
+                       $hadError = $this->untrapWarnings();
+
+                       if ( $isFile ) {
                                $fsFiles[$src] = new FSFile( $source );
+                       } elseif ( $hadError ) {
+                               $fsFiles[$src] = self::$RES_ERROR;
+                       } else {
+                               $fsFiles[$src] = self::$RES_ABSENT;
                        }
                }
 
@@ -684,26 +711,31 @@ class FSFileBackend extends FileBackendStore {
                foreach ( $params['srcs'] as $src ) {
                        $source = $this->resolveToFSPath( $src );
                        if ( $source === null ) {
-                               $tmpFiles[$src] = null; // invalid path
+                               $tmpFiles[$src] = self::$RES_ERROR; // invalid path
+                               continue;
+                       }
+                       // Create a new temporary file with the same extension...
+                       $ext = FileBackend::extensionFromPath( $src );
+                       $tmpFile = $this->tmpFileFactory->newTempFSFile( 'localcopy_', $ext );
+                       if ( !$tmpFile ) {
+                               $tmpFiles[$src] = self::$RES_ERROR;
+                               continue;
+                       }
+
+                       $tmpPath = $tmpFile->getPath();
+                       // Copy the source file over the temp file
+                       $this->trapWarnings();
+                       $isFile = is_file( $source ); // regular files only
+                       $copySuccess = $isFile ? copy( $source, $tmpPath ) : false;
+                       $hadError = $this->untrapWarnings();
+
+                       if ( $copySuccess ) {
+                               $this->chmod( $tmpPath );
+                               $tmpFiles[$src] = $tmpFile;
+                       } elseif ( $hadError ) {
+                               $tmpFiles[$src] = self::$RES_ERROR; // copy failed
                        } else {
-                               // Create a new temporary file with the same extension...
-                               $ext = FileBackend::extensionFromPath( $src );
-                               $tmpFile = $this->tmpFileFactory->newTempFSFile( 'localcopy_', $ext );
-                               if ( !$tmpFile ) {
-                                       $tmpFiles[$src] = null;
-                               } else {
-                                       $tmpPath = $tmpFile->getPath();
-                                       // Copy the source file over the temp file
-                                       $this->trapWarnings();
-                                       $ok = copy( $source, $tmpPath );
-                                       $this->untrapWarnings();
-                                       if ( !$ok ) {
-                                               $tmpFiles[$src] = null;
-                                       } else {
-                                               $this->chmod( $tmpPath );
-                                               $tmpFiles[$src] = $tmpFile;
-                                       }
-                               }
+                               $tmpFiles[$src] = self::$RES_ABSENT;
                        }
                }
 
index 428fec6..6ab1707 100644 (file)
@@ -131,8 +131,28 @@ abstract class FileBackend implements LoggerAwareInterface {
        const ATTR_METADATA = 2; // files can be stored with metadata key/values
        const ATTR_UNICODE_PATHS = 4; // files can have Unicode paths (not just ASCII)
 
-       /** @var null Idiom for "could not determine due to I/O errors" */
-       const UNKNOWN = null;
+       /** @var false Idiom for "no info; non-existant file" (since 1.34) */
+       const STAT_ABSENT = false;
+
+       /** @var null Idiom for "no info; I/O errors" (since 1.34) */
+       const STAT_ERROR = null;
+       /** @var null Idiom for "no file/directory list; I/O errors" (since 1.34) */
+       const LIST_ERROR = null;
+       /** @var null Idiom for "no temp URL; not supported or I/O errors" (since 1.34) */
+       const TEMPURL_ERROR = null;
+       /** @var null Idiom for "existence unknown; I/O errors" (since 1.34) */
+       const EXISTENCE_ERROR = null;
+
+       /** @var false Idiom for "no timestamp; missing file or I/O errors" (since 1.34) */
+       const TIMESTAMP_FAIL = false;
+       /** @var false Idiom for "no content; missing file or I/O errors" (since 1.34) */
+       const CONTENT_FAIL = false;
+       /** @var false Idiom for "no metadata; missing file or I/O errors" (since 1.34) */
+       const XATTRS_FAIL = false;
+       /** @var false Idiom for "no size; missing file or I/O errors" (since 1.34) */
+       const SIZE_FAIL = false;
+       /** @var false Idiom for "no SHA1 hash; missing file or I/O errors" (since 1.34) */
+       const SHA1_FAIL = false;
 
        /**
         * Create a new backend instance from configuration.
@@ -157,9 +177,9 @@ abstract class FileBackend implements LoggerAwareInterface {
         *      Allowed values are "implicit", "explicit" and "off".
         *   - concurrency : How many file operations can be done in parallel.
         *   - tmpDirectory : Directory to use for temporary files.
-        *   - tmpFileFactory : Optional TempFSFileFactory object. Only has an effect if tmpDirectory is
-        *      not set. If both are unset or null, then the backend will try to discover a usable
-        *      temporary directory.
+        *   - tmpFileFactory : Optional TempFSFileFactory object. Only has an effect if
+        *      tmpDirectory is not set. If both are unset or null, then the backend will
+        *      try to discover a usable temporary directory.
         *   - obResetFunc : alternative callback to clear the output buffer
         *   - streamMimeFunc : alternative method to determine the content type from the path
         *   - logger : Optional PSR logger object.
@@ -946,20 +966,29 @@ abstract class FileBackend implements LoggerAwareInterface {
         * Check if a file exists at a storage path in the backend.
         * This returns false if only a directory exists at the path.
         *
+        * Callers that only care if a file is readily accessible can use non-strict
+        * comparisons on the result. If "does not exist" and "existence is unknown"
+        * must be distinguished, then strict comparisons to true/null should be used.
+        *
+        * @see FileBackend::EXISTENCE_ERROR
+        * @see FileBackend::directoryExists()
+        *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return bool|null Returns null on failure
+        * @return bool|null Whether the file exists or null (I/O error)
         */
        abstract public function fileExists( array $params );
 
        /**
         * Get the last-modified timestamp of the file at a storage path.
         *
+        * @see FileBackend::TIMESTAMP_FAIL
+        *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return string|bool TS_MW timestamp or false on failure
+        * @return string|false TS_MW timestamp or false (missing file or I/O error)
         */
        abstract public function getFileTimestamp( array $params );
 
@@ -967,22 +996,22 @@ abstract class FileBackend implements LoggerAwareInterface {
         * Get the contents of a file at a storage path in the backend.
         * This should be avoided for potentially large files.
         *
+        * @see FileBackend::CONTENT_FAIL
+        *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return string|bool Returns false on failure
+        * @return string|false Content string or false (missing file or I/O error)
         */
        final public function getFileContents( array $params ) {
-               $contents = $this->getFileContentsMulti(
-                       [ 'srcs' => [ $params['src'] ] ] + $params );
+               $contents = $this->getFileContentsMulti( [ 'srcs' => [ $params['src'] ] ] + $params );
 
                return $contents[$params['src']];
        }
 
        /**
         * Like getFileContents() except it takes an array of storage paths
-        * and returns a map of storage paths to strings (or null on failure).
-        * The map keys (paths) are in the same order as the provided list of paths.
+        * and returns an order preserved map of storage paths to their content.
         *
         * @see FileBackend::getFileContents()
         *
@@ -990,7 +1019,7 @@ abstract class FileBackend implements LoggerAwareInterface {
         *   - srcs        : list of source storage paths
         *   - latest      : use the latest available data
         *   - parallelize : try to do operations in parallel when possible
-        * @return array Map of (path name => string or false on failure)
+        * @return string[]|false[] Map of (path name => file content or false on failure)
         * @since 1.20
         */
        abstract public function getFileContentsMulti( array $params );
@@ -1006,11 +1035,13 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * Use FileBackend::hasFeatures() to check how well this is supported.
         *
+        * @see FileBackend::XATTRS_FAIL
+        *
         * @param array $params
         * $params include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return array|bool Returns false on failure
+        * @return array|false File metadata array or false (missing file or I/O error)
         * @since 1.23
         */
        abstract public function getFileXAttributes( array $params );
@@ -1018,10 +1049,12 @@ abstract class FileBackend implements LoggerAwareInterface {
        /**
         * Get the size (bytes) of a file at a storage path in the backend.
         *
+        * @see FileBackend::SIZE_FAIL
+        *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return int|bool Returns false on failure
+        * @return int|false File size in bytes or false (missing file or I/O error)
         */
        abstract public function getFileSize( array $params );
 
@@ -1033,36 +1066,41 @@ abstract class FileBackend implements LoggerAwareInterface {
         *   - size   : the file size (bytes)
         * Additional values may be included for internal use only.
         *
+        * @see FileBackend::STAT_ABSENT
+        * @see FileBackend::STAT_ERROR
+        *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return array|bool|null Returns null on failure
+        * @return array|false|null Attribute map, false (missing file), or null (I/O error)
         */
        abstract public function getFileStat( array $params );
 
        /**
-        * Get a SHA-1 hash of the file at a storage path in the backend.
+        * Get a SHA-1 hash of the content of the file at a storage path in the backend.
+        *
+        * @see FileBackend::SHA1_FAIL
         *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return string|bool Hash string or false on failure
+        * @return string|false Hash string or false (missing file or I/O error)
         */
        abstract public function getFileSha1Base36( array $params );
 
        /**
-        * Get the properties of the file at a storage path in the backend.
+        * Get the properties of the content of the file at a storage path in the backend.
         * This gives the result of FSFile::getProps() on a local copy of the file.
         *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return array Returns FSFile::placeholderProps() on failure
+        * @return array Properties map; FSFile::placeholderProps() if file missing or on I/O error
         */
        abstract public function getFileProps( array $params );
 
        /**
-        * Stream the file at a storage path in the backend.
+        * Stream the content of the file at a storage path in the backend.
         *
         * If the file does not exists, an HTTP 404 error will be given.
         * Appropriate HTTP headers (Status, Content-Type, Content-Length)
@@ -1083,34 +1121,36 @@ abstract class FileBackend implements LoggerAwareInterface {
        abstract public function streamFile( array $params );
 
        /**
-        * Returns a file system file, identical to the file at a storage path.
+        * Returns a file system file, identical in content to the file at a storage path.
         * The file returned is either:
-        *   - a) A local copy of the file at a storage path in the backend.
+        *   - a) A TempFSFile local copy of the file at a storage path in the backend.
         *        The temporary copy will have the same extension as the source.
-        *   - b) An original of the file at a storage path in the backend.
-        * Temporary files may be purged when the file object falls out of scope.
+        *        Temporary files may be purged when the file object falls out of scope.
+        *   - b) An FSFile pointing to the original file at a storage path in the backend.
+        *        This is applicable for backends layered directly on top of file systems.
         *
-        * Write operations should *never* be done on this file as some backends
-        * may do internal tracking or may be instances of FileBackendMultiWrite.
-        * In that latter case, there are copies of the file that must stay in sync.
-        * Additionally, further calls to this function may return the same file.
+        * Never modify the returned file since it might be the original, it might be shared
+        * among multiple callers of this method, or the backend might internally keep FSFile
+        * references for deferred operations.
         *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return FSFile|null Returns null on failure
+        * @return FSFile|null Local file copy or null (missing file or I/O error)
         */
        final public function getLocalReference( array $params ) {
-               $fsFiles = $this->getLocalReferenceMulti(
-                       [ 'srcs' => [ $params['src'] ] ] + $params );
+               $fsFiles = $this->getLocalReferenceMulti( [ 'srcs' => [ $params['src'] ] ] + $params );
 
                return $fsFiles[$params['src']];
        }
 
        /**
-        * Like getLocalReference() except it takes an array of storage paths
-        * and returns a map of storage paths to FSFile objects (or null on failure).
-        * The map keys (paths) are in the same order as the provided list of paths.
+        * Like getLocalReference() except it takes an array of storage paths and
+        * yields an order-preserved map of storage paths to temporary local file copies.
+        *
+        * Never modify the returned files since they might be originals, they might be shared
+        * among multiple callers of this method, or the backend might internally keep FSFile
+        * references for deferred operations.
         *
         * @see FileBackend::getLocalReference()
         *
@@ -1128,22 +1168,24 @@ abstract class FileBackend implements LoggerAwareInterface {
         * The temporary copy will have the same file extension as the source.
         * Temporary files may be purged when the file object falls out of scope.
         *
+        * Multiple calls to this method for the same path will create new copies.
+        *
         * @param array $params Parameters include:
         *   - src    : source storage path
         *   - latest : use the latest available data
-        * @return TempFSFile|null Returns null on failure
+        * @return TempFSFile|null Temporary local file copy or null (missing file or I/O error)
         */
        final public function getLocalCopy( array $params ) {
-               $tmpFiles = $this->getLocalCopyMulti(
-                       [ 'srcs' => [ $params['src'] ] ] + $params );
+               $tmpFiles = $this->getLocalCopyMulti( [ 'srcs' => [ $params['src'] ] ] + $params );
 
                return $tmpFiles[$params['src']];
        }
 
        /**
-        * Like getLocalCopy() except it takes an array of storage paths and
-        * returns a map of storage paths to TempFSFile objects (or null on failure).
-        * The map keys (paths) are in the same order as the provided list of paths.
+        * Like getLocalCopy() except it takes an array of storage paths and yields
+        * an order preserved-map of storage paths to temporary local file copies.
+        *
+        * Multiple calls to this method for the same path will create new copies.
         *
         * @see FileBackend::getLocalCopy()
         *
@@ -1166,10 +1208,12 @@ abstract class FileBackend implements LoggerAwareInterface {
         * Otherwise, one would need to use getLocalReference(), which involves loading
         * the entire file on to local disk.
         *
+        * @see FileBackend::TEMPURL_ERROR
+        *
         * @param array $params Parameters include:
         *   - src : source storage path
         *   - ttl : lifetime (seconds) if pre-authenticated; default is 1 day
-        * @return string|null
+        * @return string|null URL or null (not supported or I/O error)
         * @since 1.21
         */
        abstract public function getFileHttpUrl( array $params );
@@ -1191,11 +1235,12 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * Storage backends with eventual consistency might return stale data.
         *
+        * @see FileBackend::EXISTENCE_ERROR
         * @see FileBackend::clean()
         *
         * @param array $params Parameters include:
         *   - dir : storage directory
-        * @return bool|null Whether a directory exists or null on failure
+        * @return bool|null Whether a directory exists or null (I/O error)
         * @since 1.20
         */
        abstract public function directoryExists( array $params );
@@ -1213,12 +1258,13 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * Failures during iteration can result in FileBackendError exceptions (since 1.22).
         *
+        * @see FileBackend::LIST_ERROR
         * @see FileBackend::directoryExists()
         *
         * @param array $params Parameters include:
         *   - dir     : storage directory
         *   - topOnly : only return direct child dirs of the directory
-        * @return Traversable|array|null Directory list enumerator null on failure
+        * @return Traversable|array|null Directory list enumerator or null (initial I/O error)
         * @since 1.20
         */
        abstract public function getDirectoryList( array $params );
@@ -1231,11 +1277,12 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * Failures during iteration can result in FileBackendError exceptions (since 1.22).
         *
+        * @see FileBackend::LIST_ERROR
         * @see FileBackend::directoryExists()
         *
         * @param array $params Parameters include:
         *   - dir : storage directory
-        * @return Traversable|array|null Directory list enumerator or null on failure
+        * @return Traversable|array|null Directory list enumerator or null (initial I/O error)
         * @since 1.20
         */
        final public function getTopDirectoryList( array $params ) {
@@ -1254,11 +1301,13 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * Failures during iteration can result in FileBackendError exceptions (since 1.22).
         *
+        * @see FileBackend::LIST_ERROR
+        *
         * @param array $params Parameters include:
         *   - dir        : storage directory
         *   - topOnly    : only return direct child files of the directory (since 1.20)
         *   - adviseStat : set to true if stat requests will be made on the files (since 1.22)
-        * @return Traversable|array|null File list enumerator or null on failure
+        * @return Traversable|array|null File list enumerator or null (initial I/O error)
         */
        abstract public function getFileList( array $params );
 
@@ -1270,6 +1319,8 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * Failures during iteration can result in FileBackendError exceptions (since 1.22).
         *
+        * @see FileBackend::LIST_ERROR
+        *
         * @param array $params Parameters include:
         *   - dir        : storage directory
         *   - adviseStat : set to true if stat requests will be made on the files (since 1.22)
@@ -1360,7 +1411,7 @@ abstract class FileBackend implements LoggerAwareInterface {
         * @param int|string $type LockManager::LOCK_* constant or "mixed"
         * @param StatusValue $status StatusValue to update on lock/unlock
         * @param int $timeout Timeout in seconds (0 means non-blocking) (since 1.24)
-        * @return ScopedLock|null Returns null on failure
+        * @return ScopedLock|null RAII-style self-unlocking lock or null on failure
         */
        final public function getScopedFileLocks(
                array $paths, $type, StatusValue $status, $timeout = 0
@@ -1389,7 +1440,7 @@ abstract class FileBackend implements LoggerAwareInterface {
         *
         * @param array $ops List of file operations to FileBackend::doOperations()
         * @param StatusValue $status StatusValue to update on lock/unlock
-        * @return ScopedLock|null
+        * @return ScopedLock|null RAII-style self-unlocking lock or null on failure
         * @since 1.20
         */
        abstract public function getScopedLocksForOps( array $ops, StatusValue $status );
@@ -1487,7 +1538,7 @@ abstract class FileBackend implements LoggerAwareInterface {
         * Returns null if the path is not of the format of a valid storage path.
         *
         * @param string $storagePath
-        * @return string|null
+        * @return string|null Normalized storage path or null on failure
         */
        final public static function normalizeStoragePath( $storagePath ) {
                list( $backend, $container, $relPath ) = self::splitStoragePath( $storagePath );
@@ -1509,7 +1560,7 @@ abstract class FileBackend implements LoggerAwareInterface {
         * "mwstore://backend/container/...", or null if there is no parent.
         *
         * @param string $storagePath
-        * @return string|null
+        * @return string|null Parent storage path or null on failure
         */
        final public static function parentStoragePath( $storagePath ) {
                $storagePath = dirname( $storagePath );
@@ -1582,7 +1633,7 @@ abstract class FileBackend implements LoggerAwareInterface {
         * This uses the same traversal protection as Title::secureAndSplit().
         *
         * @param string $path Storage path relative to a container
-        * @return string|null
+        * @return string|null Normalized container path or null on failure
         */
        final protected static function normalizeContainerPath( $path ) {
                // Normalize directory separators
index 9bfb5c5..cbfd76e 100644 (file)
@@ -248,7 +248,7 @@ class FileBackendMultiWrite extends FileBackend {
                        $masterBackend = $this->backends[$this->masterIndex];
                        $masterParams = $this->substOpPaths( $params, $masterBackend );
                        $masterStat = $masterBackend->getFileStat( $masterParams );
-                       if ( $masterStat === self::UNKNOWN ) {
+                       if ( $masterStat === self::STAT_ERROR ) {
                                $status->fatal( 'backend-fail-stat', $path );
                                continue;
                        }
@@ -357,7 +357,7 @@ class FileBackendMultiWrite extends FileBackend {
                        $masterParams = $this->substOpPaths( $params, $masterBackend );
                        $masterPath = $masterParams['src'];
                        $masterStat = $masterBackend->getFileStat( $masterParams );
-                       if ( $masterStat === self::UNKNOWN ) {
+                       if ( $masterStat === self::STAT_ERROR ) {
                                $status->fatal( 'backend-fail-stat', $path );
                                $this->logger->error( "$fname: file '$masterPath' is not available" );
                                continue;
@@ -379,7 +379,7 @@ class FileBackendMultiWrite extends FileBackend {
                                $cloneParams = $this->substOpPaths( $params, $cloneBackend );
                                $clonePath = $cloneParams['src'];
                                $cloneStat = $cloneBackend->getFileStat( $cloneParams );
-                               if ( $cloneStat === self::UNKNOWN ) {
+                               if ( $cloneStat === self::STAT_ERROR ) {
                                        $status->fatal( 'backend-fail-stat', $path );
                                        $this->logger->error( "$fname: file '$clonePath' is not available" );
                                        continue;
@@ -501,7 +501,7 @@ class FileBackendMultiWrite extends FileBackend {
         *
         * @param array|string $paths List of paths or single string path
         * @param FileBackendStore $backend
-        * @return array|string
+        * @return string[]|string
         */
        protected function substPaths( $paths, FileBackendStore $backend ) {
                return preg_replace(
@@ -515,12 +515,13 @@ class FileBackendMultiWrite extends FileBackend {
         * Substitute the backend of internal storage paths with the proxy backend's name
         *
         * @param array|string $paths List of paths or single string path
-        * @return array|string
+        * @param FileBackendStore $backend internal storage backend
+        * @return string[]|string
         */
-       protected function unsubstPaths( $paths ) {
+       protected function unsubstPaths( $paths, FileBackendStore $backend ) {
                return preg_replace(
-                       '!^mwstore://([^/]+)!',
-                       StringUtils::escapeRegexReplacement( "mwstore://{$this->name}" ),
+                       '!^mwstore://' . preg_quote( $backend->getName(), '!' ) . '/!',
+                       StringUtils::escapeRegexReplacement( "mwstore://{$this->name}/" ),
                        $paths // string or array
                );
        }
@@ -674,7 +675,7 @@ class FileBackendMultiWrite extends FileBackend {
 
                $contents = []; // (path => FSFile) mapping using the proxy backend's name
                foreach ( $contentsM as $path => $data ) {
-                       $contents[$this->unsubstPaths( $path )] = $data;
+                       $contents[$this->unsubstPaths( $path, $this->backends[$index] )] = $data;
                }
 
                return $contents;
@@ -709,7 +710,7 @@ class FileBackendMultiWrite extends FileBackend {
 
                $fsFiles = []; // (path => FSFile) mapping using the proxy backend's name
                foreach ( $fsFilesM as $path => $fsFile ) {
-                       $fsFiles[$this->unsubstPaths( $path )] = $fsFile;
+                       $fsFiles[$this->unsubstPaths( $path, $this->backends[$index] )] = $fsFile;
                }
 
                return $fsFiles;
@@ -723,7 +724,7 @@ class FileBackendMultiWrite extends FileBackend {
 
                $tempFiles = []; // (path => TempFSFile) mapping using the proxy backend's name
                foreach ( $tempFilesM as $path => $tempFile ) {
-                       $tempFiles[$this->unsubstPaths( $path )] = $tempFile;
+                       $tempFiles[$this->unsubstPaths( $path, $this->backends[$index] )] = $tempFile;
                }
 
                return $tempFiles;
@@ -784,8 +785,14 @@ class FileBackendMultiWrite extends FileBackend {
                $paths = $this->backends[$this->masterIndex]->getPathsToLockForOpsInternal( $fileOps );
                // Get the paths under the proxy backend's name
                $pbPaths = [
-                       LockManager::LOCK_UW => $this->unsubstPaths( $paths[LockManager::LOCK_UW] ),
-                       LockManager::LOCK_EX => $this->unsubstPaths( $paths[LockManager::LOCK_EX] )
+                       LockManager::LOCK_UW => $this->unsubstPaths(
+                               $paths[LockManager::LOCK_UW],
+                               $this->backends[$this->masterIndex]
+                       ),
+                       LockManager::LOCK_EX => $this->unsubstPaths(
+                               $paths[LockManager::LOCK_EX],
+                               $this->backends[$this->masterIndex]
+                       )
                ];
 
                // Actually acquire the locks
index e637565..f2c07e8 100644 (file)
@@ -59,6 +59,16 @@ abstract class FileBackendStore extends FileBackend {
        const CACHE_CHEAP_SIZE = 500; // integer; max entries in "cheap cache"
        const CACHE_EXPENSIVE_SIZE = 5; // integer; max entries in "expensive cache"
 
+       /** @var false Idiom for "no result due to missing file" (since 1.34) */
+       protected static $RES_ABSENT = false;
+       /** @var null Idiom for "no result due to I/O errors" (since 1.34) */
+       protected static $RES_ERROR = null;
+
+       /** @var string File does not exist according to a normal stat query */
+       protected static $ABSENT_NORMAL = 'FNE-N';
+       /** @var string File does not exist according to a "latest"-mode stat query */
+       protected static $ABSENT_LATEST = 'FNE-L';
+
        /**
         * @see FileBackend::__construct()
         * Additional $config params include:
@@ -91,9 +101,10 @@ abstract class FileBackendStore extends FileBackend {
        }
 
        /**
-        * Check if a file can be created or changed at a given storage path.
-        * FS backends should check if the parent directory exists, files can be
-        * written under it, and that any file already there is writable.
+        * Check if a file can be created or changed at a given storage path in the backend
+        *
+        * FS backends should check that the parent directory exists, files can be written
+        * under it, and that any file already there is both readable and writable.
         * Backends using key/value stores should check if the container exists.
         *
         * @param string $storagePath
@@ -122,6 +133,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function createInternal( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                if ( strlen( $params['content'] ) > $this->maxFileSizeInternal() ) {
                        $status = $this->newStatus( 'backend-fail-maxsize',
                                $params['dst'], $this->maxFileSizeInternal() );
@@ -164,6 +176,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function storeInternal( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                if ( filesize( $params['src'] ) > $this->maxFileSizeInternal() ) {
                        $status = $this->newStatus( 'backend-fail-maxsize',
                                $params['dst'], $this->maxFileSizeInternal() );
@@ -207,6 +220,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function copyInternal( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $status = $this->doCopyInternal( $params );
                $this->clearCache( [ $params['dst'] ] );
                if ( !isset( $params['dstExists'] ) || $params['dstExists'] ) {
@@ -240,6 +254,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function deleteInternal( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $status = $this->doDeleteInternal( $params );
                $this->clearCache( [ $params['src'] ] );
                $this->deleteFileCache( $params['src'] ); // persistent cache
@@ -275,6 +290,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function moveInternal( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $status = $this->doMoveInternal( $params );
                $this->clearCache( [ $params['src'], $params['dst'] ] );
                $this->deleteFileCache( $params['src'] ); // persistent cache
@@ -322,6 +338,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function describeInternal( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                if ( count( $params['headers'] ) ) {
                        $status = $this->doDescribeInternal( $params );
                        $this->clearCache( [ $params['src'] ] );
@@ -617,54 +634,71 @@ abstract class FileBackendStore extends FileBackend {
        final public function fileExists( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $stat = $this->getFileStat( $params );
+               if ( is_array( $stat ) ) {
+                       return true;
+               }
 
-               return ( $stat === self::UNKNOWN ) ? self::UNKNOWN : (bool)$stat;
+               return ( $stat === self::$RES_ABSENT ) ? false : self::EXISTENCE_ERROR;
        }
 
        final public function getFileTimestamp( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $stat = $this->getFileStat( $params );
+               if ( is_array( $stat ) ) {
+                       return $stat['mtime'];
+               }
 
-               return $stat ? $stat['mtime'] : false;
+               return self::TIMESTAMP_FAIL; // all failure cases
        }
 
        final public function getFileSize( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $stat = $this->getFileStat( $params );
+               if ( is_array( $stat ) ) {
+                       return $stat['size'];
+               }
 
-               return $stat ? $stat['size'] : false;
+               return self::SIZE_FAIL; // all failure cases
        }
 
        final public function getFileStat( array $params ) {
+               /** @noinspection PhpUnusedLocalVariableInspection */
+               $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $path = self::normalizeStoragePath( $params['src'] );
                if ( $path === null ) {
-                       return false; // invalid storage path
+                       return self::STAT_ERROR; // invalid storage path
                }
-               /** @noinspection PhpUnusedLocalVariableInspection */
-               $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
 
-               $latest = !empty( $params['latest'] ); // use latest data?
-               $requireSHA1 = !empty( $params['requireSHA1'] ); // require SHA-1 if file exists?
+               // Whether to bypass cache except for process cache entries loaded directly from
+               // high consistency backend queries (caller handles any cache flushing and locking)
+               $latest = !empty( $params['latest'] );
+               // Whether to ignore cache entries missing the SHA-1 field for existing files
+               $requireSHA1 = !empty( $params['requireSHA1'] );
 
+               $stat = $this->cheapCache->getField( $path, 'stat', self::CACHE_TTL );
+               // Load the persistent stat cache into process cache if needed
                if ( !$latest ) {
-                       $stat = $this->cheapCache->getField( $path, 'stat', self::CACHE_TTL );
-                       // Note that some backends, like SwiftFileBackend, sometimes set file stat process
-                       // cache entries from mass object listings that do not include the SHA-1. In that
-                       // case, loading the persistent stat cache will likely yield the SHA-1.
                        if (
-                               $stat === self::UNKNOWN ||
+                               // File stat is not in process cache
+                               $stat === null ||
+                               // Key/value store backends might opportunistically set file stat process
+                               // cache entries from object listings that do not include the SHA-1. In that
+                               // case, loading the persistent stat cache will likely yield the SHA-1.
                                ( $requireSHA1 && is_array( $stat ) && !isset( $stat['sha1'] ) )
                        ) {
-                               $this->primeFileCache( [ $path ] ); // check persistent cache
+                               $this->primeFileCache( [ $path ] );
+                               // Get any newly process-cached entry
+                               $stat = $this->cheapCache->getField( $path, 'stat', self::CACHE_TTL );
                        }
                }
 
-               $stat = $this->cheapCache->getField( $path, 'stat', self::CACHE_TTL );
-               // If we want the latest data, check that this cached
-               // value was in fact fetched with the latest available data.
                if ( is_array( $stat ) ) {
                        if (
                                ( !$latest || $stat['latest'] ) &&
@@ -672,42 +706,90 @@ abstract class FileBackendStore extends FileBackend {
                        ) {
                                return $stat;
                        }
-               } elseif ( in_array( $stat, [ 'NOT_EXIST', 'NOT_EXIST_LATEST' ], true ) ) {
-                       if ( !$latest || $stat === 'NOT_EXIST_LATEST' ) {
-                               return false;
+               } elseif ( $stat === self::$ABSENT_LATEST ) {
+                       return self::STAT_ABSENT;
+               } elseif ( $stat === self::$ABSENT_NORMAL ) {
+                       if ( !$latest ) {
+                               return self::STAT_ABSENT;
                        }
                }
 
+               // Load the file stat from the backend and update caches
                $stat = $this->doGetFileStat( $params );
+               $this->ingestFreshFileStats( [ $path => $stat ], $latest );
 
-               if ( is_array( $stat ) ) { // file exists
-                       // Strongly consistent backends can automatically set "latest"
-                       $stat['latest'] = $stat['latest'] ?? $latest;
-                       $this->cheapCache->setField( $path, 'stat', $stat );
-                       $this->setFileCache( $path, $stat ); // update persistent cache
-                       if ( isset( $stat['sha1'] ) ) { // some backends store SHA-1 as metadata
-                               $this->cheapCache->setField( $path, 'sha1',
-                                       [ 'hash' => $stat['sha1'], 'latest' => $latest ] );
-                       }
-                       if ( isset( $stat['xattr'] ) ) { // some backends store headers/metadata
-                               $stat['xattr'] = self::normalizeXAttributes( $stat['xattr'] );
-                               $this->cheapCache->setField( $path, 'xattr',
-                                       [ 'map' => $stat['xattr'], 'latest' => $latest ] );
+               if ( is_array( $stat ) ) {
+                       return $stat;
+               }
+
+               return ( $stat === self::$RES_ERROR ) ? self::STAT_ERROR : self::STAT_ABSENT;
+       }
+
+       /**
+        * Ingest file stat entries that just came from querying the backend (not cache)
+        *
+        * @param array[]|bool[]|null[] $stats Map of (path => doGetFileStat() stype result)
+        * @param bool $latest Whether doGetFileStat()/doGetFileStatMulti() had the 'latest' flag
+        * @return bool Whether all files have non-error stat replies
+        */
+       final protected function ingestFreshFileStats( array $stats, $latest ) {
+               $success = true;
+
+               foreach ( $stats as $path => $stat ) {
+                       if ( is_array( $stat ) ) {
+                               // Strongly consistent backends might automatically set this flag
+                               $stat['latest'] = $stat['latest'] ?? $latest;
+
+                               $this->cheapCache->setField( $path, 'stat', $stat );
+                               if ( isset( $stat['sha1'] ) ) {
+                                       // Some backends store the SHA-1 hash as metadata
+                                       $this->cheapCache->setField(
+                                               $path,
+                                               'sha1',
+                                               [ 'hash' => $stat['sha1'], 'latest' => $latest ]
+                                       );
+                               }
+                               if ( isset( $stat['xattr'] ) ) {
+                                       // Some backends store custom headers/metadata
+                                       $stat['xattr'] = self::normalizeXAttributes( $stat['xattr'] );
+                                       $this->cheapCache->setField(
+                                               $path,
+                                               'xattr',
+                                               [ 'map' => $stat['xattr'], 'latest' => $latest ]
+                                       );
+                               }
+                               // Update persistent cache (@TODO: set all entries in one batch)
+                               $this->setFileCache( $path, $stat );
+                       } elseif ( $stat === self::$RES_ABSENT ) {
+                               $this->cheapCache->setField(
+                                       $path,
+                                       'stat',
+                                       $latest ? self::$ABSENT_LATEST : self::$ABSENT_NORMAL
+                               );
+                               $this->cheapCache->setField(
+                                       $path,
+                                       'xattr',
+                                       [ 'map' => self::XATTRS_FAIL, 'latest' => $latest ]
+                               );
+                               $this->cheapCache->setField(
+                                       $path,
+                                       'sha1',
+                                       [ 'hash' => self::SHA1_FAIL, 'latest' => $latest ]
+                               );
+                               $this->logger->debug(
+                                       __METHOD__ . ': File {path} does not exist',
+                                       [ 'path' => $path ]
+                               );
+                       } else {
+                               $success = false;
+                               $this->logger->error(
+                                       __METHOD__ . ': Could not stat file {path}',
+                                       [ 'path' => $path ]
+                               );
                        }
-               } elseif ( $stat === false ) { // file does not exist
-                       $this->cheapCache->setField( $path, 'stat', $latest ? 'NOT_EXIST_LATEST' : 'NOT_EXIST' );
-                       $this->cheapCache->setField( $path, 'xattr', [ 'map' => false, 'latest' => $latest ] );
-                       $this->cheapCache->setField( $path, 'sha1', [ 'hash' => false, 'latest' => $latest ] );
-                       $this->logger->debug( __METHOD__ . ': File {path} does not exist', [
-                               'path' => $path,
-                       ] );
-               } else { // an error occurred
-                       $this->logger->warning( __METHOD__ . ': Could not stat file {path}', [
-                               'path' => $path,
-                       ] );
                }
 
-               return $stat;
+               return $success;
        }
 
        /**
@@ -722,6 +804,11 @@ abstract class FileBackendStore extends FileBackend {
 
                $params = $this->setConcurrencyFlags( $params );
                $contents = $this->doGetFileContentsMulti( $params );
+               foreach ( $contents as $path => $content ) {
+                       if ( !is_string( $content ) ) {
+                               $contents[$path] = self::CONTENT_FAIL; // used for all failure cases
+                       }
+               }
 
                return $contents;
        }
@@ -729,26 +816,34 @@ abstract class FileBackendStore extends FileBackend {
        /**
         * @see FileBackendStore::getFileContentsMulti()
         * @param array $params
-        * @return array
+        * @return string[]|bool[]|null[] Map of (path => string, false (missing), or null (error))
         */
        protected function doGetFileContentsMulti( array $params ) {
                $contents = [];
                foreach ( $this->doGetLocalReferenceMulti( $params ) as $path => $fsFile ) {
-                       AtEase::suppressWarnings();
-                       $contents[$path] = $fsFile ? file_get_contents( $fsFile->getPath() ) : false;
-                       AtEase::restoreWarnings();
+                       if ( $fsFile instanceof FSFile ) {
+                               AtEase::suppressWarnings();
+                               $content = file_get_contents( $fsFile->getPath() );
+                               AtEase::restoreWarnings();
+                               $contents[$path] = is_string( $content ) ? $content : self::$RES_ERROR;
+                       } elseif ( $fsFile === self::$RES_ABSENT ) {
+                               $contents[$path] = self::$RES_ABSENT;
+                       } else {
+                               $contents[$path] = self::$RES_ERROR;
+                       }
                }
 
                return $contents;
        }
 
        final public function getFileXAttributes( array $params ) {
+               /** @noinspection PhpUnusedLocalVariableInspection */
+               $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $path = self::normalizeStoragePath( $params['src'] );
                if ( $path === null ) {
-                       return false; // invalid storage path
+                       return self::XATTRS_FAIL; // invalid storage path
                }
-               /** @noinspection PhpUnusedLocalVariableInspection */
-               $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
                $latest = !empty( $params['latest'] ); // use latest data?
                if ( $this->cheapCache->hasField( $path, 'xattr', self::CACHE_TTL ) ) {
                        $stat = $this->cheapCache->getField( $path, 'xattr' );
@@ -759,8 +854,22 @@ abstract class FileBackendStore extends FileBackend {
                        }
                }
                $fields = $this->doGetFileXAttributes( $params );
-               $fields = is_array( $fields ) ? self::normalizeXAttributes( $fields ) : false;
-               $this->cheapCache->setField( $path, 'xattr', [ 'map' => $fields, 'latest' => $latest ] );
+               if ( is_array( $fields ) ) {
+                       $fields = self::normalizeXAttributes( $fields );
+                       $this->cheapCache->setField(
+                               $path,
+                               'xattr',
+                               [ 'map' => $fields, 'latest' => $latest ]
+                       );
+               } elseif ( $fields === self::$RES_ABSENT ) {
+                       $this->cheapCache->setField(
+                               $path,
+                               'xattr',
+                               [ 'map' => self::XATTRS_FAIL, 'latest' => $latest ]
+                       );
+               } else {
+                       $fields = self::XATTRS_FAIL; // used for all failure cases
+               }
 
                return $fields;
        }
@@ -768,19 +877,20 @@ abstract class FileBackendStore extends FileBackend {
        /**
         * @see FileBackendStore::getFileXAttributes()
         * @param array $params
-        * @return array[][]|false
+        * @return array[][]|false|null Attributes, false (missing file), or null (error)
         */
        protected function doGetFileXAttributes( array $params ) {
                return [ 'headers' => [], 'metadata' => [] ]; // not supported
        }
 
        final public function getFileSha1Base36( array $params ) {
+               /** @noinspection PhpUnusedLocalVariableInspection */
+               $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $path = self::normalizeStoragePath( $params['src'] );
                if ( $path === null ) {
-                       return false; // invalid storage path
+                       return self::SHA1_FAIL; // invalid storage path
                }
-               /** @noinspection PhpUnusedLocalVariableInspection */
-               $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
                $latest = !empty( $params['latest'] ); // use latest data?
                if ( $this->cheapCache->hasField( $path, 'sha1', self::CACHE_TTL ) ) {
                        $stat = $this->cheapCache->getField( $path, 'sha1' );
@@ -790,33 +900,49 @@ abstract class FileBackendStore extends FileBackend {
                                return $stat['hash'];
                        }
                }
-               $hash = $this->doGetFileSha1Base36( $params );
-               $this->cheapCache->setField( $path, 'sha1', [ 'hash' => $hash, 'latest' => $latest ] );
+               $sha1 = $this->doGetFileSha1Base36( $params );
+               if ( is_string( $sha1 ) ) {
+                       $this->cheapCache->setField(
+                               $path,
+                               'sha1',
+                               [ 'hash' => $sha1, 'latest' => $latest ]
+                       );
+               } elseif ( $sha1 === self::$RES_ABSENT ) {
+                       $this->cheapCache->setField(
+                               $path,
+                               'sha1',
+                               [ 'hash' => self::SHA1_FAIL, 'latest' => $latest ]
+                       );
+               } else {
+                       $sha1 = self::SHA1_FAIL; // used for all failure cases
+               }
 
-               return $hash;
+               return $sha1;
        }
 
        /**
         * @see FileBackendStore::getFileSha1Base36()
         * @param array $params
-        * @return bool|string
+        * @return bool|string|null SHA1, false (missing file), or null (error)
         */
        protected function doGetFileSha1Base36( array $params ) {
                $fsFile = $this->getLocalReference( $params );
-               if ( !$fsFile ) {
-                       return false;
-               } else {
-                       return $fsFile->getSha1Base36();
+               if ( $fsFile instanceof FSFile ) {
+                       $sha1 = $fsFile->getSha1Base36();
+
+                       return is_string( $sha1 ) ? $sha1 : self::$RES_ERROR;
                }
+
+               return ( $fsFile === self::$RES_ERROR ) ? self::$RES_ERROR : self::$RES_ABSENT;
        }
 
        final public function getFileProps( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
+
                $fsFile = $this->getLocalReference( $params );
-               $props = $fsFile ? $fsFile->getProps() : FSFile::placeholderProps();
 
-               return $props;
+               return $fsFile ? $fsFile->getProps() : FSFile::placeholderProps();
        }
 
        final public function getLocalReferenceMulti( array $params ) {
@@ -844,10 +970,15 @@ abstract class FileBackendStore extends FileBackend {
                // Fetch local references of any remaning files...
                $params['srcs'] = array_diff( $params['srcs'], array_keys( $fsFiles ) );
                foreach ( $this->doGetLocalReferenceMulti( $params ) as $path => $fsFile ) {
-                       $fsFiles[$path] = $fsFile;
-                       if ( $fsFile ) { // update the process cache...
-                               $this->expensiveCache->setField( $path, 'localRef',
-                                       [ 'object' => $fsFile, 'latest' => $latest ] );
+                       if ( $fsFile instanceof FSFile ) {
+                               $fsFiles[$path] = $fsFile;
+                               $this->expensiveCache->setField(
+                                       $path,
+                                       'localRef',
+                                       [ 'object' => $fsFile, 'latest' => $latest ]
+                               );
+                       } else {
+                               $fsFiles[$path] = null; // used for all failure cases
                        }
                }
 
@@ -857,7 +988,7 @@ abstract class FileBackendStore extends FileBackend {
        /**
         * @see FileBackendStore::getLocalReferenceMulti()
         * @param array $params
-        * @return array
+        * @return string[]|bool[]|null[] Map of (path => FSFile, false (missing), or null (error))
         */
        protected function doGetLocalReferenceMulti( array $params ) {
                return $this->doGetLocalCopyMulti( $params );
@@ -869,6 +1000,11 @@ abstract class FileBackendStore extends FileBackend {
 
                $params = $this->setConcurrencyFlags( $params );
                $tmpFiles = $this->doGetLocalCopyMulti( $params );
+               foreach ( $tmpFiles as $path => $tmpFile ) {
+                       if ( !$tmpFile ) {
+                               $tmpFiles[$path] = null; // used for all failure cases
+                       }
+               }
 
                return $tmpFiles;
        }
@@ -876,7 +1012,7 @@ abstract class FileBackendStore extends FileBackend {
        /**
         * @see FileBackendStore::getLocalCopyMulti()
         * @param array $params
-        * @return array
+        * @return string[]|bool[]|null[] Map of (path => TempFSFile, false (missing), or null (error))
         */
        abstract protected function doGetLocalCopyMulti( array $params );
 
@@ -886,7 +1022,7 @@ abstract class FileBackendStore extends FileBackend {
         * @return string|null
         */
        public function getFileHttpUrl( array $params ) {
-               return null; // not supported
+               return self::TEMPURL_ERROR; // not supported
        }
 
        final public function streamFile( array $params ) {
@@ -947,7 +1083,7 @@ abstract class FileBackendStore extends FileBackend {
        final public function directoryExists( array $params ) {
                list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
                if ( $dir === null ) {
-                       return false; // invalid storage path
+                       return self::EXISTENCE_ERROR; // invalid storage path
                }
                if ( $shard !== null ) { // confined to a single container/shard
                        return $this->doDirectoryExists( $fullCont, $dir, $params );
@@ -957,11 +1093,11 @@ abstract class FileBackendStore extends FileBackend {
                        $res = false; // response
                        foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
                                $exists = $this->doDirectoryExists( "{$fullCont}{$suffix}", $dir, $params );
-                               if ( $exists ) {
+                               if ( $exists === true ) {
                                        $res = true;
                                        break; // found one!
-                               } elseif ( $exists === null ) { // error?
-                                       $res = self::UNKNOWN; // if we don't find anything, it is indeterminate
+                               } elseif ( $exists === self::$RES_ERROR ) {
+                                       $res = self::EXISTENCE_ERROR;
                                }
                        }
 
@@ -981,8 +1117,8 @@ abstract class FileBackendStore extends FileBackend {
 
        final public function getDirectoryList( array $params ) {
                list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-               if ( $dir === null ) { // invalid storage path
-                       return self::UNKNOWN;
+               if ( $dir === null ) {
+                       return self::EXISTENCE_ERROR; // invalid storage path
                }
                if ( $shard !== null ) {
                        // File listing is confined to a single container/shard
@@ -1005,14 +1141,14 @@ abstract class FileBackendStore extends FileBackend {
         * @param string $container Resolved container name
         * @param string $dir Resolved path relative to container
         * @param array $params
-        * @return Traversable|array|null Returns null on failure
+        * @return Traversable|array|null Iterable list or null (error)
         */
        abstract public function getDirectoryListInternal( $container, $dir, array $params );
 
        final public function getFileList( array $params ) {
                list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-               if ( $dir === null ) { // invalid storage path
-                       return self::UNKNOWN;
+               if ( $dir === null ) {
+                       return self::LIST_ERROR; // invalid storage path
                }
                if ( $shard !== null ) {
                        // File listing is confined to a single container/shard
@@ -1035,7 +1171,7 @@ abstract class FileBackendStore extends FileBackend {
         * @param string $container Resolved container name
         * @param string $dir Resolved path relative to container
         * @param array $params
-        * @return Traversable|string[]|null Returns null on failure
+        * @return Traversable|string[]|null Iterable list or null (error)
         */
        abstract public function getFileListInternal( $container, $dir, array $params );
 
@@ -1356,7 +1492,6 @@ abstract class FileBackendStore extends FileBackend {
        final public function preloadFileStat( array $params ) {
                /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-               $success = true; // no network errors
 
                $params['concurrency'] = ( $this->parallelize !== 'off' ) ? $this->concurrency : 1;
                $stats = $this->doGetFileStatMulti( $params );
@@ -1364,45 +1499,10 @@ abstract class FileBackendStore extends FileBackend {
                        return true; // not supported
                }
 
-               $latest = !empty( $params['latest'] ); // use latest data?
-               foreach ( $stats as $path => $stat ) {
-                       $path = FileBackend::normalizeStoragePath( $path );
-                       if ( $path === null ) {
-                               continue; // this shouldn't happen
-                       }
-                       if ( is_array( $stat ) ) { // file exists
-                               // Strongly consistent backends can automatically set "latest"
-                               $stat['latest'] = $stat['latest'] ?? $latest;
-                               $this->cheapCache->setField( $path, 'stat', $stat );
-                               $this->setFileCache( $path, $stat ); // update persistent cache
-                               if ( isset( $stat['sha1'] ) ) { // some backends store SHA-1 as metadata
-                                       $this->cheapCache->setField( $path, 'sha1',
-                                               [ 'hash' => $stat['sha1'], 'latest' => $latest ] );
-                               }
-                               if ( isset( $stat['xattr'] ) ) { // some backends store headers/metadata
-                                       $stat['xattr'] = self::normalizeXAttributes( $stat['xattr'] );
-                                       $this->cheapCache->setField( $path, 'xattr',
-                                               [ 'map' => $stat['xattr'], 'latest' => $latest ] );
-                               }
-                       } elseif ( $stat === false ) { // file does not exist
-                               $this->cheapCache->setField( $path, 'stat',
-                                       $latest ? 'NOT_EXIST_LATEST' : 'NOT_EXIST' );
-                               $this->cheapCache->setField( $path, 'xattr',
-                                       [ 'map' => false, 'latest' => $latest ] );
-                               $this->cheapCache->setField( $path, 'sha1',
-                                       [ 'hash' => false, 'latest' => $latest ] );
-                               $this->logger->debug( __METHOD__ . ': File {path} does not exist', [
-                                       'path' => $path,
-                               ] );
-                       } else { // an error occurred
-                               $success = false;
-                               $this->logger->warning( __METHOD__ . ': Could not stat file {path}', [
-                                       'path' => $path,
-                               ] );
-                       }
-               }
+               // Whether this queried the backend in high consistency mode
+               $latest = !empty( $params['latest'] );
 
-               return $success;
+               return $this->ingestFreshFileStats( $stats, $latest );
        }
 
        /**
@@ -1810,7 +1910,7 @@ abstract class FileBackendStore extends FileBackend {
                                $paths[] = FileBackend::normalizeStoragePath( $item );
                        }
                }
-               // Get rid of any paths that failed normalization...
+               // Get rid of any paths that failed normalization
                $paths = array_filter( $paths, 'strlen' ); // remove nulls
                // Get all the corresponding cache keys for paths...
                foreach ( $paths as $path ) {
@@ -1819,22 +1919,33 @@ abstract class FileBackendStore extends FileBackend {
                                $pathNames[$this->fileCacheKey( $path )] = $path;
                        }
                }
-               // Get all cache entries for these file cache keys...
+               // Get all cache entries for these file cache keys.
+               // Note that negatives are not cached by getFileStat()/preloadFileStat().
                $values = $this->memCache->getMulti( array_keys( $pathNames ) );
-               foreach ( $values as $cacheKey => $val ) {
+               // Load all of the results into process cache...
+               foreach ( array_filter( $values, 'is_array' ) as $cacheKey => $stat ) {
                        $path = $pathNames[$cacheKey];
-                       if ( is_array( $val ) ) {
-                               $val['latest'] = false; // never completely trust cache
-                               $this->cheapCache->setField( $path, 'stat', $val );
-                               if ( isset( $val['sha1'] ) ) { // some backends store SHA-1 as metadata
-                                       $this->cheapCache->setField( $path, 'sha1',
-                                               [ 'hash' => $val['sha1'], 'latest' => false ] );
-                               }
-                               if ( isset( $val['xattr'] ) ) { // some backends store headers/metadata
-                                       $val['xattr'] = self::normalizeXAttributes( $val['xattr'] );
-                                       $this->cheapCache->setField( $path, 'xattr',
-                                               [ 'map' => $val['xattr'], 'latest' => false ] );
-                               }
+                       // Sanity; this flag only applies to stat info loaded directly
+                       // from a high consistency backend query to the process cache
+                       unset( $stat['latest'] );
+
+                       $this->cheapCache->setField( $path, 'stat', $stat );
+                       if ( isset( $stat['sha1'] ) && strlen( $stat['sha1'] ) == 31 ) {
+                               // Some backends store SHA-1 as metadata
+                               $this->cheapCache->setField(
+                                       $path,
+                                       'sha1',
+                                       [ 'hash' => $stat['sha1'], 'latest' => false ]
+                               );
+                       }
+                       if ( isset( $stat['xattr'] ) && is_array( $stat['xattr'] ) ) {
+                               // Some backends store custom headers/metadata
+                               $stat['xattr'] = self::normalizeXAttributes( $stat['xattr'] );
+                               $this->cheapCache->setField(
+                                       $path,
+                                       'xattr',
+                                       [ 'map' => $stat['xattr'], 'latest' => false ]
+                               );
                        }
                }
        }
index 88b281e..f3bbecb 100644 (file)
@@ -41,7 +41,7 @@ class MemoryFileBackend extends FileBackendStore {
        }
 
        public function isPathUsableInternal( $storagePath ) {
-               return true;
+               return ( $this->resolveHashKey( $storagePath ) !== null );
        }
 
        protected function doCreateInternal( array $params ) {
@@ -148,7 +148,7 @@ class MemoryFileBackend extends FileBackendStore {
        protected function doGetFileStat( array $params ) {
                $src = $this->resolveHashKey( $params['src'] );
                if ( $src === null ) {
-                       return false; // invalid path
+                       return self::$RES_ERROR; // invalid path
                }
 
                if ( isset( $this->files[$src] ) ) {
@@ -158,15 +158,17 @@ class MemoryFileBackend extends FileBackendStore {
                        ];
                }
 
-               return false;
+               return self::$RES_ABSENT;
        }
 
        protected function doGetLocalCopyMulti( array $params ) {
                $tmpFiles = []; // (path => TempFSFile)
                foreach ( $params['srcs'] as $srcPath ) {
                        $src = $this->resolveHashKey( $srcPath );
-                       if ( $src === null || !isset( $this->files[$src] ) ) {
-                               $fsFile = null;
+                       if ( $src === null ) {
+                               $fsFile = self::$RES_ERROR;
+                       } elseif ( !isset( $this->files[$src] ) ) {
+                               $fsFile = self::$RES_ABSENT;
                        } else {
                                // Create a new temporary file with the same extension...
                                $ext = FileBackend::extensionFromPath( $src );
@@ -174,7 +176,7 @@ class MemoryFileBackend extends FileBackendStore {
                                if ( $fsFile ) {
                                        $bytes = file_put_contents( $fsFile->getPath(), $this->files[$src]['data'] );
                                        if ( $bytes !== strlen( $this->files[$src]['data'] ) ) {
-                                               $fsFile = null;
+                                               $fsFile = self::$RES_ERROR;
                                        }
                                }
                        }
index 6d6451e..56a2177 100644 (file)
@@ -145,8 +145,11 @@ class SwiftFileBackend extends FileBackendStore {
        }
 
        public function getFeatures() {
-               return ( FileBackend::ATTR_UNICODE_PATHS |
-                       FileBackend::ATTR_HEADERS | FileBackend::ATTR_METADATA );
+               return (
+                       FileBackend::ATTR_UNICODE_PATHS |
+                       FileBackend::ATTR_HEADERS |
+                       FileBackend::ATTR_METADATA
+               );
        }
 
        protected function resolveContainerPath( $container, $relStoragePath ) {
@@ -593,7 +596,7 @@ class SwiftFileBackend extends FileBackendStore {
                $stat = $this->getContainerStat( $fullCont );
                if ( is_array( $stat ) ) {
                        return $status; // already there
-               } elseif ( $stat === self::UNKNOWN ) {
+               } elseif ( $stat === self::$RES_ERROR ) {
                        $status->fatal( 'backend-fail-internal', $this->name );
                        $this->logger->error( __METHOD__ . ': cannot get container stat' );
 
@@ -777,8 +780,6 @@ class SwiftFileBackend extends FileBackendStore {
        }
 
        protected function doGetFileContentsMulti( array $params ) {
-               $contents = [];
-
                $auth = $this->getAuthentication();
 
                $ep = array_diff_key( $params, [ 'srcs' => 1 ] ); // for error logging
@@ -786,11 +787,12 @@ class SwiftFileBackend extends FileBackendStore {
                // if the file does not exist. Do not waste time doing file stats here.
                $reqs = []; // (path => op)
 
+               // Initial dummy values to preserve path order
+               $contents = array_fill_keys( $params['srcs'], self::$RES_ERROR );
                foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
                        list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
                        if ( $srcRel === null || !$auth ) {
-                               $contents[$path] = false;
-                               continue;
+                               continue; // invalid storage path or auth error
                        }
                        // Create a new temporary memory file...
                        $handle = fopen( 'php://temp', 'wb' );
@@ -803,7 +805,6 @@ class SwiftFileBackend extends FileBackendStore {
                                        'stream'  => $handle,
                                ];
                        }
-                       $contents[$path] = false;
                }
 
                $opts = [ 'maxConnsPerHost' => $params['concurrency'] ];
@@ -812,10 +813,21 @@ class SwiftFileBackend extends FileBackendStore {
                        list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
                        if ( $rcode >= 200 && $rcode <= 299 ) {
                                rewind( $op['stream'] ); // start from the beginning
-                               $contents[$path] = stream_get_contents( $op['stream'] );
+                               $content = (string)stream_get_contents( $op['stream'] );
+                               $size = strlen( $content );
+                               // Make sure that stream finished
+                               if ( $size === (int)$rhdrs['content-length'] ) {
+                                       $contents[$path] = $content;
+                               } else {
+                                       $contents[$path] = self::$RES_ERROR;
+                                       $rerr = "Got {$size}/{$rhdrs['content-length']} bytes";
+                                       $this->onError( null, __METHOD__,
+                                               [ 'src' => $path ] + $ep, $rerr, $rcode, $rdesc );
+                               }
                        } elseif ( $rcode === 404 ) {
-                               $contents[$path] = false;
+                               $contents[$path] = self::$RES_ABSENT;
                        } else {
+                               $contents[$path] = self::$RES_ERROR;
                                $this->onError( null, __METHOD__,
                                        [ 'src' => $path ] + $ep, $rerr, $rcode, $rdesc );
                        }
@@ -832,7 +844,7 @@ class SwiftFileBackend extends FileBackendStore {
                        return ( count( $status->value ) ) > 0;
                }
 
-               return self::UNKNOWN; // error
+               return self::$RES_ERROR;
        }
 
        /**
@@ -874,6 +886,7 @@ class SwiftFileBackend extends FileBackendStore {
                        return $dirs; // nothing more
                }
 
+               /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
 
                $prefix = ( $dir == '' ) ? null : "{$dir}/";
@@ -956,10 +969,11 @@ class SwiftFileBackend extends FileBackendStore {
                        return $files; // nothing more
                }
 
+               /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
 
                $prefix = ( $dir == '' ) ? null : "{$dir}/";
-               // $objects will contain a list of unfiltered names or CF_Object items
+               // $objects will contain a list of unfiltered names or stdClass items
                // Non-recursive: only list files right under $dir
                if ( !empty( $params['topOnly'] ) ) {
                        if ( !empty( $params['adviseStat'] ) ) {
@@ -982,7 +996,7 @@ class SwiftFileBackend extends FileBackendStore {
                }
 
                $objects = $status->value;
-               $files = $this->buildFileObjectListing( $params, $dir, $objects );
+               $files = $this->buildFileObjectListing( $objects );
 
                // Page on the unfiltered object listing (what is returned may be filtered)
                if ( count( $objects ) < $limit ) {
@@ -997,14 +1011,12 @@ class SwiftFileBackend extends FileBackendStore {
 
        /**
         * Build a list of file objects, filtering out any directories
-        * and extracting any stat info if provided in $objects (for CF_Objects)
+        * and extracting any stat info if provided in $objects
         *
-        * @param array $params Parameters for getDirectoryList()
-        * @param string $dir Resolved container directory path
-        * @param array $objects List of CF_Object items or object names
+        * @param stdClass[]|string[] $objects List of stdClass items or object names
         * @return array List of (names,stat array or null) entries
         */
-       private function buildFileObjectListing( array $params, $dir, array $objects ) {
+       private function buildFileObjectListing( array $objects ) {
                $names = [];
                foreach ( $objects as $object ) {
                        if ( is_object( $object ) ) {
@@ -1042,18 +1054,17 @@ class SwiftFileBackend extends FileBackendStore {
 
        protected function doGetFileXAttributes( array $params ) {
                $stat = $this->getFileStat( $params );
-               if ( $stat ) {
-                       if ( !isset( $stat['xattr'] ) ) {
-                               // Stat entries filled by file listings don't include metadata/headers
-                               $this->clearCache( [ $params['src'] ] );
-                               $stat = $this->getFileStat( $params );
-                       }
+               // Stat entries filled by file listings don't include metadata/headers
+               if ( is_array( $stat ) && !isset( $stat['xattr'] ) ) {
+                       $this->clearCache( [ $params['src'] ] );
+                       $stat = $this->getFileStat( $params );
+               }
 
-                       // @phan-suppress-next-line PhanTypeArraySuspiciousNullable
+               if ( is_array( $stat ) ) {
                        return $stat['xattr'];
-               } else {
-                       return false;
                }
+
+               return ( $stat === self::$RES_ERROR ) ? self::$RES_ERROR : self::$RES_ABSENT;
        }
 
        protected function doGetFileSha1base36( array $params ) {
@@ -1062,11 +1073,11 @@ class SwiftFileBackend extends FileBackendStore {
                $params['requireSHA1'] = true;
 
                $stat = $this->getFileStat( $params );
-               if ( $stat ) {
+               if ( is_array( $stat ) ) {
                        return $stat['sha1'];
-               } else {
-                       return false;
                }
+
+               return ( $stat === self::$RES_ERROR ) ? self::$RES_ERROR : self::$RES_ABSENT;
        }
 
        protected function doStreamFile( array $params ) {
@@ -1136,9 +1147,6 @@ class SwiftFileBackend extends FileBackendStore {
        }
 
        protected function doGetLocalCopyMulti( array $params ) {
-               /** @var TempFSFile[] $tmpFiles */
-               $tmpFiles = [];
-
                $auth = $this->getAuthentication();
 
                $ep = array_diff_key( $params, [ 'srcs' => 1 ] ); // for error logging
@@ -1146,56 +1154,62 @@ class SwiftFileBackend extends FileBackendStore {
                // if the file does not exist. Do not waste time doing file stats here.
                $reqs = []; // (path => op)
 
+               // Initial dummy values to preserve path order
+               $tmpFiles = array_fill_keys( $params['srcs'], self::$RES_ERROR );
                foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
                        list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
                        if ( $srcRel === null || !$auth ) {
-                               $tmpFiles[$path] = null;
-                               continue;
+                               continue; // invalid storage path or auth error
                        }
                        // Get source file extension
                        $ext = FileBackend::extensionFromPath( $path );
                        // Create a new temporary file...
                        $tmpFile = $this->tmpFileFactory->newTempFSFile( 'localcopy_', $ext );
-                       if ( $tmpFile ) {
-                               $handle = fopen( $tmpFile->getPath(), 'wb' );
-                               if ( $handle ) {
-                                       $reqs[$path] = [
-                                               'method'  => 'GET',
-                                               'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
-                                               'headers' => $this->authTokenHeaders( $auth )
-                                                       + $this->headersFromParams( $params ),
-                                               'stream'  => $handle,
-                                       ];
-                               } else {
-                                       $tmpFile = null;
-                               }
+                       $handle = $tmpFile ? fopen( $tmpFile->getPath(), 'wb' ) : false;
+                       if ( $handle ) {
+                               $reqs[$path] = [
+                                       'method'  => 'GET',
+                                       'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
+                                       'headers' => $this->authTokenHeaders( $auth )
+                                               + $this->headersFromParams( $params ),
+                                       'stream'  => $handle,
+                               ];
+                               $tmpFiles[$path] = $tmpFile;
                        }
-                       $tmpFiles[$path] = $tmpFile;
                }
 
-               $isLatest = ( $this->isRGW || !empty( $params['latest'] ) );
+               // Ceph RADOS Gateway is in use (strong consistency) or X-Newest will be used
+               $latest = ( $this->isRGW || !empty( $params['latest'] ) );
+
                $opts = [ 'maxConnsPerHost' => $params['concurrency'] ];
                $reqs = $this->http->runMulti( $reqs, $opts );
                foreach ( $reqs as $path => $op ) {
                        list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
                        fclose( $op['stream'] ); // close open handle
                        if ( $rcode >= 200 && $rcode <= 299 ) {
-                               $size = $tmpFiles[$path] ? $tmpFiles[$path]->getSize() : 0;
-                               // Double check that the disk is not full/broken
-                               if ( $size != $rhdrs['content-length'] ) {
-                                       $tmpFiles[$path] = null;
+                               /** @var TempFSFile $tmpFile */
+                               $tmpFile = $tmpFiles[$path];
+                               // Make sure that the stream finished and fully wrote to disk
+                               $size = $tmpFile->getSize();
+                               if ( $size !== (int)$rhdrs['content-length'] ) {
+                                       $tmpFiles[$path] = self::$RES_ERROR;
                                        $rerr = "Got {$size}/{$rhdrs['content-length']} bytes";
                                        $this->onError( null, __METHOD__,
                                                [ 'src' => $path ] + $ep, $rerr, $rcode, $rdesc );
                                }
                                // Set the file stat process cache in passing
                                $stat = $this->getStatFromHeaders( $rhdrs );
-                               $stat['latest'] = $isLatest;
+                               $stat['latest'] = $latest;
                                $this->cheapCache->setField( $path, 'stat', $stat );
                        } elseif ( $rcode === 404 ) {
-                               $tmpFiles[$path] = false;
+                               $tmpFiles[$path] = self::$RES_ABSENT;
+                               $this->cheapCache->setField(
+                                       $path,
+                                       'stat',
+                                       $latest ? self::$ABSENT_LATEST : self::$ABSENT_NORMAL
+                               );
                        } else {
-                               $tmpFiles[$path] = null;
+                               $tmpFiles[$path] = self::$RES_ERROR;
                                $this->onError( null, __METHOD__,
                                        [ 'src' => $path ] + $ep, $rerr, $rcode, $rdesc );
                        }
@@ -1210,12 +1224,12 @@ class SwiftFileBackend extends FileBackendStore {
                ) {
                        list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
                        if ( $srcRel === null ) {
-                               return null; // invalid path
+                               return self::TEMPURL_ERROR; // invalid path
                        }
 
                        $auth = $this->getAuthentication();
                        if ( !$auth ) {
-                               return null;
+                               return self::TEMPURL_ERROR;
                        }
 
                        $ttl = $params['ttl'] ?? 86400;
@@ -1255,7 +1269,7 @@ class SwiftFileBackend extends FileBackendStore {
                        }
                }
 
-               return null;
+               return self::TEMPURL_ERROR;
        }
 
        protected function directoriesAreVirtual() {
@@ -1394,6 +1408,7 @@ class SwiftFileBackend extends FileBackendStore {
         * @return array|bool|null False on 404, null on failure
         */
        protected function getContainerStat( $container, $bypassCache = false ) {
+               /** @noinspection PhpUnusedLocalVariableInspection */
                $ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
 
                if ( $bypassCache ) { // purge cache
@@ -1404,7 +1419,7 @@ class SwiftFileBackend extends FileBackendStore {
                if ( !$this->containerStatCache->hasField( $container, 'stat' ) ) {
                        $auth = $this->getAuthentication();
                        if ( !$auth ) {
-                               return self::UNKNOWN;
+                               return self::$RES_ERROR;
                        }
 
                        list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( [
@@ -1425,12 +1440,12 @@ class SwiftFileBackend extends FileBackendStore {
                                        $this->setContainerCache( $container, $stat ); // update persistent cache
                                }
                        } elseif ( $rcode === 404 ) {
-                               return false;
+                               return self::$RES_ABSENT;
                        } else {
                                $this->onError( null, __METHOD__,
                                        [ 'cont' => $container ], $rerr, $rcode, $rdesc );
 
-                               return self::UNKNOWN;
+                               return self::$RES_ERROR;
                        }
                }
 
@@ -1595,24 +1610,21 @@ class SwiftFileBackend extends FileBackendStore {
 
                $auth = $this->getAuthentication();
 
-               $reqs = [];
+               $reqs = []; // (path => op)
+               // (a) Check the containers of the paths...
                foreach ( $params['srcs'] as $path ) {
                        list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
-                       if ( $srcRel === null ) {
-                               $stats[$path] = false;
-                               continue; // invalid storage path
-                       } elseif ( !$auth ) {
-                               $stats[$path] = self::UNKNOWN;
-                               continue;
+                       if ( $srcRel === null || !$auth ) {
+                               $stats[$path] = self::$RES_ERROR;
+                               continue; // invalid storage path or auth error
                        }
 
-                       // (a) Check the container
                        $cstat = $this->getContainerStat( $srcCont );
-                       if ( $cstat === false ) {
-                               $stats[$path] = false;
+                       if ( $cstat === self::$RES_ABSENT ) {
+                               $stats[$path] = self::$RES_ABSENT;
                                continue; // ok, nothing to do
                        } elseif ( !is_array( $cstat ) ) {
-                               $stats[$path] = self::UNKNOWN;
+                               $stats[$path] = self::$RES_ERROR;
                                continue;
                        }
 
@@ -1623,15 +1635,11 @@ class SwiftFileBackend extends FileBackendStore {
                        ];
                }
 
+               // (b) Check the files themselves...
                $opts = [ 'maxConnsPerHost' => $params['concurrency'] ];
                $reqs = $this->http->runMulti( $reqs, $opts );
-
-               foreach ( $params['srcs'] as $path ) {
-                       if ( array_key_exists( $path, $stats ) ) {
-                               continue; // some sort of failure above
-                       }
-                       // (b) Check the file
-                       list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $reqs[$path]['response'];
+               foreach ( $reqs as $path => $op ) {
+                       list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
                        if ( $rcode === 200 || $rcode === 204 ) {
                                // Update the object if it is missing some headers
                                if ( !empty( $params['requireSHA1'] ) ) {
@@ -1643,9 +1651,9 @@ class SwiftFileBackend extends FileBackendStore {
                                        $stat['latest'] = true; // strong consistency
                                }
                        } elseif ( $rcode === 404 ) {
-                               $stat = false;
+                               $stat = self::$RES_ABSENT;
                        } else {
-                               $stat = self::UNKNOWN;
+                               $stat = self::$RES_ERROR;
                                $this->onError( null, __METHOD__, $params, $rerr, $rcode, $rdesc );
                        }
                        $stats[$path] = $stat;
index 527de6a..59af944 100644 (file)
@@ -36,8 +36,10 @@ class CopyFileOp extends FileOp {
 
        protected function doPrecheck( array &$predicates ) {
                $status = StatusValue::newGood();
-               // Check if the source file exists
-               if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
+
+               // Check source file existence
+               $srcExists = $this->fileExists( $this->params['src'], $predicates );
+               if ( $srcExists === false ) {
                        if ( $this->getParam( 'ignoreMissingSource' ) ) {
                                $this->doOperation = false; // no-op
                                // Update file existence predicates (cache 404s)
@@ -50,10 +52,8 @@ class CopyFileOp extends FileOp {
 
                                return $status;
                        }
-                       // Check if a file can be placed/changed at the destination
-               } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-                       $status->fatal( 'backend-fail-usable', $this->params['dst'] );
-                       $status->fatal( 'backend-fail-copy', $this->params['src'], $this->params['dst'] );
+               } elseif ( $srcExists === FileBackend::EXISTENCE_ERROR ) {
+                       $status->fatal( 'backend-fail-stat', $this->params['src'] );
 
                        return $status;
                }
index f45b055..b68b98f 100644 (file)
@@ -34,21 +34,15 @@ class CreateFileOp extends FileOp {
 
        protected function doPrecheck( array &$predicates ) {
                $status = StatusValue::newGood();
-               // Check if the source data is too big
-               if ( strlen( $this->getParam( 'content' ) ) > $this->backend->maxFileSizeInternal() ) {
-                       $status->fatal( 'backend-fail-maxsize',
-                               $this->params['dst'], $this->backend->maxFileSizeInternal() );
-                       $status->fatal( 'backend-fail-create', $this->params['dst'] );
 
-                       return $status;
-                       // Check if a file can be placed/changed at the destination
-               } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-                       $status->fatal( 'backend-fail-usable', $this->params['dst'] );
-                       $status->fatal( 'backend-fail-create', $this->params['dst'] );
+               // Check if the source data is too big
+               $maxBytes = $this->backend->maxFileSizeInternal();
+               if ( strlen( $this->getParam( 'content' ) ) > $maxBytes ) {
+                       $status->fatal( 'backend-fail-maxsize', $this->params['dst'], $maxBytes );
 
                        return $status;
                }
-               // Check if destination file exists
+               // Check if an incompatible destination file exists
                $status->merge( $this->precheckDestExistence( $predicates ) );
                $this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
                if ( $status->isOK() ) {
@@ -61,12 +55,14 @@ class CreateFileOp extends FileOp {
        }
 
        protected function doAttempt() {
-               if ( !$this->overwriteSameCase ) {
+               if ( $this->overwriteSameCase ) {
+                       $status = StatusValue::newGood(); // nothing to do
+               } else {
                        // Create the file at the destination
-                       return $this->backend->createInternal( $this->setFlags( $this->params ) );
+                       $status = $this->backend->createInternal( $this->setFlags( $this->params ) );
                }
 
-               return StatusValue::newGood();
+               return $status;
        }
 
        protected function getSourceSha1Base36() {
index 1047a98..3b48881 100644 (file)
@@ -32,8 +32,10 @@ class DeleteFileOp extends FileOp {
 
        protected function doPrecheck( array &$predicates ) {
                $status = StatusValue::newGood();
-               // Check if the source file exists
-               if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
+
+               // Check source file existence
+               $srcExists = $this->fileExists( $this->params['src'], $predicates );
+               if ( $srcExists === false ) {
                        if ( $this->getParam( 'ignoreMissingSource' ) ) {
                                $this->doOperation = false; // no-op
                                // Update file existence predicates (cache 404s)
@@ -46,10 +48,8 @@ class DeleteFileOp extends FileOp {
 
                                return $status;
                        }
-                       // Check if a file can be placed/changed at the source
-               } elseif ( !$this->backend->isPathUsableInternal( $this->params['src'] ) ) {
-                       $status->fatal( 'backend-fail-usable', $this->params['src'] );
-                       $status->fatal( 'backend-fail-delete', $this->params['src'] );
+               } elseif ( $srcExists === FileBackend::EXISTENCE_ERROR ) {
+                       $status->fatal( 'backend-fail-stat', $this->params['src'] );
 
                        return $status;
                }
index 0d1e553..3604b26 100644 (file)
@@ -32,21 +32,20 @@ class DescribeFileOp extends FileOp {
 
        protected function doPrecheck( array &$predicates ) {
                $status = StatusValue::newGood();
-               // Check if the source file exists
-               if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
+
+               // Check source file existence
+               $srcExists = $this->fileExists( $this->params['src'], $predicates );
+               if ( $srcExists === false ) {
                        $status->fatal( 'backend-fail-notexists', $this->params['src'] );
 
                        return $status;
-                       // Check if a file can be placed/changed at the source
-               } elseif ( !$this->backend->isPathUsableInternal( $this->params['src'] ) ) {
-                       $status->fatal( 'backend-fail-usable', $this->params['src'] );
-                       $status->fatal( 'backend-fail-describe', $this->params['src'] );
+               } elseif ( $srcExists === FileBackend::EXISTENCE_ERROR ) {
+                       $status->fatal( 'backend-fail-stat', $this->params['src'] );
 
                        return $status;
                }
                // Update file existence predicates
-               $predicates['exists'][$this->params['src']] =
-                       $this->fileExists( $this->params['src'], $predicates );
+               $predicates['exists'][$this->params['src']] = $srcExists;
                $predicates['sha1'][$this->params['src']] =
                        $this->fileSha1( $this->params['src'], $predicates );
 
index 961fdb9..a046588 100644 (file)
@@ -255,6 +255,18 @@ abstract class FileOp {
                        return StatusValue::newFatal( 'fileop-fail-state', self::STATE_NEW, $this->state );
                }
                $this->state = self::STATE_CHECKED;
+
+               $status = StatusValue::newGood();
+               $storagePaths = array_merge( $this->storagePathsRead(), $this->storagePathsChanged() );
+               foreach ( array_unique( $storagePaths ) as $storagePath ) {
+                       if ( !$this->backend->isPathUsableInternal( $storagePath ) ) {
+                               $status->fatal( 'backend-fail-usable', $storagePath );
+                       }
+               }
+               if ( !$status->isOK() ) {
+                       return $status;
+               }
+
                $status = $this->doPrecheck( $predicates );
                if ( !$status->isOK() ) {
                        $this->failed = true;
@@ -391,6 +403,8 @@ abstract class FileOp {
 
                                return $status;
                        }
+               } elseif ( $this->destExists === FileBackend::EXISTENCE_ERROR ) {
+                       $status->fatal( 'backend-fail-stat', $this->params['dst'] );
                }
 
                return $status;
@@ -409,9 +423,12 @@ abstract class FileOp {
        /**
         * Check if a file will exist in storage when this operation is attempted
         *
+        * Ideally, the file stat entry should already be preloaded via preloadFileStat().
+        * Otherwise, this will query the backend.
+        *
         * @param string $source Storage path
         * @param array $predicates
-        * @return bool
+        * @return bool|null Whether the file will exist or null on error
         */
        final protected function fileExists( $source, array $predicates ) {
                if ( isset( $predicates['exists'][$source] ) ) {
@@ -424,11 +441,14 @@ abstract class FileOp {
        }
 
        /**
-        * Get the SHA-1 of a file in storage when this operation is attempted
+        * Get the SHA-1 hash a file in storage will have when this operation is attempted
+        *
+        * Ideally, file the stat entry should already be preloaded via preloadFileStat() and
+        * the backend tracks hashes as extended attributes. Otherwise, this will query the backend.
         *
         * @param string $source Storage path
         * @param array $predicates
-        * @return string|bool False on failure
+        * @return string|bool The SHA-1 hash the file will have or false if non-existent or on error
         */
        final protected function fileSha1( $source, array $predicates ) {
                if ( isset( $predicates['sha1'][$source] ) ) {
index 55dca51..0a83370 100644 (file)
@@ -36,8 +36,10 @@ class MoveFileOp extends FileOp {
 
        protected function doPrecheck( array &$predicates ) {
                $status = StatusValue::newGood();
-               // Check if the source file exists
-               if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
+
+               // Check source file existence
+               $srcExists = $this->fileExists( $this->params['src'], $predicates );
+               if ( $srcExists === false ) {
                        if ( $this->getParam( 'ignoreMissingSource' ) ) {
                                $this->doOperation = false; // no-op
                                // Update file existence predicates (cache 404s)
@@ -50,14 +52,12 @@ class MoveFileOp extends FileOp {
 
                                return $status;
                        }
-                       // Check if a file can be placed/changed at the destination
-               } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-                       $status->fatal( 'backend-fail-usable', $this->params['dst'] );
-                       $status->fatal( 'backend-fail-move', $this->params['src'], $this->params['dst'] );
+               } elseif ( $srcExists === FileBackend::EXISTENCE_ERROR ) {
+                       $status->fatal( 'backend-fail-stat', $this->params['src'] );
 
                        return $status;
                }
-               // Check if destination file exists
+               // Check if an incompatible destination file exists
                $status->merge( $this->precheckDestExistence( $predicates ) );
                $this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
                if ( $status->isOK() ) {
index 5783a82..b8cfbf6 100644 (file)
@@ -38,26 +38,21 @@ class StoreFileOp extends FileOp {
 
        protected function doPrecheck( array &$predicates ) {
                $status = StatusValue::newGood();
-               // Check if the source file exists on the file system
+
+               // Check if the source file exists in the file system and is not too big
                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-maxsize',
-                               $this->params['dst'], $this->backend->maxFileSizeInternal() );
-                       $status->fatal( 'backend-fail-store', $this->params['src'], $this->params['dst'] );
-
-                       return $status;
-                       // Check if a file can be placed/changed at the destination
-               } elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-                       $status->fatal( 'backend-fail-usable', $this->params['dst'] );
-                       $status->fatal( 'backend-fail-store', $this->params['src'], $this->params['dst'] );
+               }
+               // Check if the source file is too big
+               $maxBytes = $this->backend->maxFileSizeInternal();
+               if ( filesize( $this->params['src'] ) > $maxBytes ) {
+                       $status->fatal( 'backend-fail-maxsize', $this->params['dst'], $maxBytes );
 
                        return $status;
                }
-               // Check if destination file exists
+               // Check if an incompatible destination file exists
                $status->merge( $this->precheckDestExistence( $predicates ) );
                $this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
                if ( $status->isOK() ) {
@@ -70,12 +65,14 @@ class StoreFileOp extends FileOp {
        }
 
        protected function doAttempt() {
-               if ( !$this->overwriteSameCase ) {
+               if ( $this->overwriteSameCase ) {
+                       $status = StatusValue::newGood(); // nothing to do
+               } else {
                        // Store the file at the destination
-                       return $this->backend->storeInternal( $this->setFlags( $this->params ) );
+                       $status = $this->backend->storeInternal( $this->setFlags( $this->params ) );
                }
 
-               return StatusValue::newGood();
+               return $status;
        }
 
        protected function getSourceSha1Base36() {
index bc3696d..062087d 100644 (file)
@@ -293,7 +293,7 @@ class FileBackendTest extends MediaWikiTestCase {
                $this->assertEquals( $props1, $props2,
                        "Source and destination have the same props ($backendName)." );
 
-               $this->assertBackendPathsConsistent( [ $dest ] );
+               $this->assertBackendPathsConsistent( [ $dest ], true );
        }
 
        public static function provider_testStore() {
@@ -318,19 +318,19 @@ class FileBackendTest extends MediaWikiTestCase {
        /**
         * @dataProvider provider_testCopy
         */
-       public function testCopy( $op ) {
+       public function testCopy( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus ) {
                $this->backend = $this->singleBackend;
                $this->tearDownFiles();
-               $this->doTestCopy( $op );
+               $this->doTestCopy( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus );
                $this->tearDownFiles();
 
                $this->backend = $this->multiBackend;
                $this->tearDownFiles();
-               $this->doTestCopy( $op );
+               $this->doTestCopy( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus );
                $this->tearDownFiles();
        }
 
-       private function doTestCopy( $op ) {
+       private function doTestCopy( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus ) {
                $backendName = $this->backendClass();
 
                $source = $op['src'];
@@ -338,99 +338,128 @@ class FileBackendTest extends MediaWikiTestCase {
                $this->prepare( [ 'dir' => dirname( $source ) ] );
                $this->prepare( [ 'dir' => dirname( $dest ) ] );
 
-               if ( isset( $op['ignoreMissingSource'] ) ) {
-                       $status = $this->backend->doOperation( $op );
-                       $this->assertGoodStatus( $status,
-                               "Move from $source to $dest succeeded without warnings ($backendName)." );
-                       $this->assertEquals( [ 0 => true ], $status->success,
-                               "Move from $source to $dest has proper 'success' field in Status ($backendName)." );
-                       $this->assertEquals( false, $this->backend->fileExists( [ 'src' => $source ] ),
-                               "Source file $source does not exist ($backendName)." );
-                       $this->assertEquals( false, $this->backend->fileExists( [ 'src' => $dest ] ),
-                               "Destination file $dest does not exist ($backendName)." );
-
-                       return;
+               if ( is_string( $srcContent ) ) {
+                       $status = $this->backend->create( [ 'content' => $srcContent, 'dst' => $source ] );
+                       $this->assertGoodStatus( $status, "Creation of $source succeeded ($backendName)." );
                }
-
-               $status = $this->backend->doOperation(
-                       [ 'op' => 'create', 'content' => 'blahblah', 'dst' => $source ] );
-               $this->assertGoodStatus( $status,
-                       "Creation of file at $source succeeded ($backendName)." );
-
-               if ( isset( $op['overwrite'] ) || isset( $op['overwriteSame'] ) ) {
-                       $this->backend->copy( $op );
+               if ( is_string( $dstContent ) ) {
+                       $status = $this->backend->create( [ 'content' => $dstContent, 'dst' => $dest ] );
+                       $this->assertGoodStatus( $status, "Creation of $dest succeeded ($backendName)." );
                }
 
                $status = $this->backend->doOperation( $op );
 
-               $this->assertGoodStatus( $status,
-                       "Copy from $source to $dest succeeded without warnings ($backendName)." );
-               $this->assertEquals( true, $status->isOK(),
-                       "Copy from $source to $dest succeeded ($backendName)." );
-               $this->assertEquals( [ 0 => true ], $status->success,
-                       "Copy from $source to $dest has proper 'success' field in Status ($backendName)." );
-               $this->assertEquals( true, $this->backend->fileExists( [ 'src' => $source ] ),
-                       "Source file $source still exists ($backendName)." );
-               $this->assertEquals( true, $this->backend->fileExists( [ 'src' => $dest ] ),
-                       "Destination file $dest exists after copy ($backendName)." );
-
-               $this->assertEquals(
-                       $this->backend->getFileSize( [ 'src' => $source ] ),
-                       $this->backend->getFileSize( [ 'src' => $dest ] ),
-                       "Destination file $dest has correct size ($backendName)." );
+               if ( $okStatus ) {
+                       $this->assertGoodStatus(
+                               $status,
+                               "Copy from $source to $dest succeeded without warnings ($backendName)." );
+                       $this->assertEquals( true, $status->isOK(),
+                               "Copy from $source to $dest succeeded ($backendName)." );
+                       $this->assertEquals( [ 0 => true ], $status->success,
+                               "Copy from $source to $dest has proper 'success' field in Status ($backendName)." );
+                       if ( !is_string( $srcContent ) ) {
+                               $this->assertSame(
+                                       is_string( $dstContent ),
+                                       $this->backend->fileExists( [ 'src' => $dest ] ),
+                                       "Destination file $dest unchanged after no-op copy ($backendName)." );
+                               $this->assertSame(
+                                       $dstContent,
+                                       $this->backend->getFileContents( [ 'src' => $dest ] ),
+                                       "Destination file $dest unchanged after no-op copy ($backendName)." );
+                       } else {
+                               $this->assertEquals(
+                                       $this->backend->getFileSize( [ 'src' => $source ] ),
+                                       $this->backend->getFileSize( [ 'src' => $dest ] ),
+                                       "Destination file $dest has correct size ($backendName)." );
+                               $props1 = $this->backend->getFileProps( [ 'src' => $source ] );
+                               $props2 = $this->backend->getFileProps( [ 'src' => $dest ] );
+                               $this->assertEquals(
+                                       $props1,
+                                       $props2,
+                                       "Source and destination have the same props ($backendName)." );
+                       }
+               } else {
+                       $this->assertBadStatus(
+                               $status,
+                               "Copy from $source to $dest fails ($backendName)." );
+                       $this->assertSame(
+                               is_string( $dstContent ),
+                               (bool)$this->backend->fileExists( [ 'src' => $dest ] ),
+                               "Destination file $dest unchanged after failed copy ($backendName)." );
+                       $this->assertSame(
+                               $dstContent,
+                               $this->backend->getFileContents( [ 'src' => $dest ] ),
+                               "Destination file $dest unchanged after failed copy ($backendName)." );
+               }
 
-               $props1 = $this->backend->getFileProps( [ 'src' => $source ] );
-               $props2 = $this->backend->getFileProps( [ 'src' => $dest ] );
-               $this->assertEquals( $props1, $props2,
-                       "Source and destination have the same props ($backendName)." );
+               $this->assertSame(
+                       is_string( $srcContent ),
+                       (bool)$this->backend->fileExists( [ 'src' => $source ] ),
+                       "Source file $source unchanged after copy ($backendName)."
+               );
+               $this->assertSame(
+                       $srcContent,
+                       $this->backend->getFileContents( [ 'src' => $source ] ),
+                       "Source file $source unchanged after copy ($backendName)."
+               );
+               if ( is_string( $dstContent ) ) {
+                       $this->assertTrue(
+                               (bool)$this->backend->fileExists( [ 'src' => $dest ] ),
+                               "Destination file $dest exists after copy ($backendName)." );
+               }
 
-               $this->assertBackendPathsConsistent( [ $source, $dest ] );
+               $this->assertBackendPathsConsistent( [ $source, $dest ], $okSyncStatus );
        }
 
+       /**
+        * @return array (op, source exists, dest exists, op succeeds, sync check succeeds)
+        */
        public static function provider_testCopy() {
                $cases = [];
 
                $source = self::baseStorePath() . '/unittest-cont1/e/file.txt';
-               $dest = self::baseStorePath() . '/unittest-cont2/a/fileMoved.txt';
+               $dest = self::baseStorePath() . '/unittest-cont2/a/fileCopied.txt';
+               $opBase = [ 'op' => 'copy', 'src' => $source, 'dst' => $dest ];
 
-               $op = [ 'op' => 'copy', 'src' => $source, 'dst' => $dest ];
-               $cases[] = [
-                       $op, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $cases[] = [ $op, 'yyy', false, true, true ];
 
-               $op2 = $op;
-               $op2['overwrite'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwrite'] = true;
+               $cases[] = [ $op, 'yyy', false, true, true ];
 
-               $op2 = $op;
-               $op2['overwriteSame'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwrite'] = true;
+               $cases[] = [ $op, 'yyy', 'xxx', true, true ];
 
-               $op2 = $op;
-               $op2['ignoreMissingSource'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwriteSame'] = true;
+               $cases[] = [ $op, 'yyy', false, true, true ];
 
-               $op2 = $op;
-               $op2['ignoreMissingSource'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       self::baseStorePath() . '/unittest-cont-bad/e/file.txt', // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwriteSame'] = true;
+               $cases[] = [ $op, 'yyy', 'yyy', true, true ];
+
+               $op = $opBase;
+               $op['overwriteSame'] = true;
+               $cases[] = [ $op, 'yyy', 'zzz', false, true ];
+
+               $op = $opBase;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, 'xxx', false, true, true ];
+
+               $op = $opBase;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, false, false, true, true ];
+
+               $op = $opBase;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, false, 'xxx', true, true ];
+
+               $op = $opBase;
+               $op['src'] = 'mwstore://wrongbackend/unittest-cont1/e/file.txt';
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, false, false, false, false ];
 
                return $cases;
        }
@@ -438,19 +467,19 @@ class FileBackendTest extends MediaWikiTestCase {
        /**
         * @dataProvider provider_testMove
         */
-       public function testMove( $op ) {
+       public function testMove( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus ) {
                $this->backend = $this->singleBackend;
                $this->tearDownFiles();
-               $this->doTestMove( $op );
+               $this->doTestMove( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus );
                $this->tearDownFiles();
 
                $this->backend = $this->multiBackend;
                $this->tearDownFiles();
-               $this->doTestMove( $op );
+               $this->doTestMove( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus );
                $this->tearDownFiles();
        }
 
-       private function doTestMove( $op ) {
+       private function doTestMove( $op, $srcContent, $dstContent, $okStatus, $okSyncStatus ) {
                $backendName = $this->backendClass();
 
                $source = $op['src'];
@@ -458,100 +487,128 @@ class FileBackendTest extends MediaWikiTestCase {
                $this->prepare( [ 'dir' => dirname( $source ) ] );
                $this->prepare( [ 'dir' => dirname( $dest ) ] );
 
-               if ( isset( $op['ignoreMissingSource'] ) ) {
-                       $status = $this->backend->doOperation( $op );
-                       $this->assertGoodStatus( $status,
-                               "Move from $source to $dest succeeded without warnings ($backendName)." );
-                       $this->assertEquals( [ 0 => true ], $status->success,
-                               "Move from $source to $dest has proper 'success' field in Status ($backendName)." );
-                       $this->assertEquals( false, $this->backend->fileExists( [ 'src' => $source ] ),
-                               "Source file $source does not exist ($backendName)." );
-                       $this->assertEquals( false, $this->backend->fileExists( [ 'src' => $dest ] ),
-                               "Destination file $dest does not exist ($backendName)." );
-
-                       return;
+               if ( is_string( $srcContent ) ) {
+                       $status = $this->backend->create( [ 'content' => $srcContent, 'dst' => $source ] );
+                       $this->assertGoodStatus( $status, "Creation of $source succeeded ($backendName)." );
                }
-
-               $status = $this->backend->doOperation(
-                       [ 'op' => 'create', 'content' => 'blahblah', 'dst' => $source ] );
-               $this->assertGoodStatus( $status,
-                       "Creation of file at $source succeeded ($backendName)." );
-
-               if ( isset( $op['overwrite'] ) || isset( $op['overwriteSame'] ) ) {
-                       $this->backend->copy( $op );
+               if ( is_string( $dstContent ) ) {
+                       $status = $this->backend->create( [ 'content' => $dstContent, 'dst' => $dest ] );
+                       $this->assertGoodStatus( $status, "Creation of $dest succeeded ($backendName)." );
                }
 
+               $oldSrcProps = $this->backend->getFileProps( [ 'src' => $source ] );
+
                $status = $this->backend->doOperation( $op );
-               $this->assertGoodStatus( $status,
-                       "Move from $source to $dest succeeded without warnings ($backendName)." );
-               $this->assertEquals( true, $status->isOK(),
-                       "Move from $source to $dest succeeded ($backendName)." );
-               $this->assertEquals( [ 0 => true ], $status->success,
-                       "Move from $source to $dest has proper 'success' field in Status ($backendName)." );
-               $this->assertEquals( false, $this->backend->fileExists( [ 'src' => $source ] ),
-                       "Source file $source does not still exists ($backendName)." );
-               $this->assertEquals( true, $this->backend->fileExists( [ 'src' => $dest ] ),
-                       "Destination file $dest exists after move ($backendName)." );
 
-               $this->assertNotEquals(
-                       $this->backend->getFileSize( [ 'src' => $source ] ),
-                       $this->backend->getFileSize( [ 'src' => $dest ] ),
-                       "Destination file $dest has correct size ($backendName)." );
+               if ( $okStatus ) {
+                       $this->assertGoodStatus(
+                               $status,
+                               "Move from $source to $dest succeeded without warnings ($backendName)." );
+                       $this->assertEquals( true, $status->isOK(),
+                               "Move from $source to $dest succeeded ($backendName)." );
+                       $this->assertEquals( [ 0 => true ], $status->success,
+                               "Move from $source to $dest has proper 'success' field in Status ($backendName)." );
+                       if ( !is_string( $srcContent ) ) {
+                               $this->assertSame(
+                                       is_string( $dstContent ),
+                                       $this->backend->fileExists( [ 'src' => $dest ] ),
+                                       "Destination file $dest unchanged after no-op move ($backendName)." );
+                               $this->assertSame(
+                                       $dstContent,
+                                       $this->backend->getFileContents( [ 'src' => $dest ] ),
+                                       "Destination file $dest unchanged after no-op move ($backendName)." );
+                       } else {
+                               $this->assertEquals(
+                                       $this->backend->getFileSize( [ 'src' => $dest ] ),
+                                       strlen( $srcContent ),
+                                       "Destination file $dest has correct size ($backendName)." );
+                               $this->assertEquals(
+                                       $oldSrcProps,
+                                       $this->backend->getFileProps( [ 'src' => $dest ] ),
+                                       "Source and destination have the same props ($backendName)." );
+                       }
+               } else {
+                       $this->assertBadStatus(
+                               $status,
+                               "Move from $source to $dest fails ($backendName)." );
+                       $this->assertSame(
+                               is_string( $dstContent ),
+                               (bool)$this->backend->fileExists( [ 'src' => $dest ] ),
+                               "Destination file $dest unchanged after failed move ($backendName)." );
+                       $this->assertSame(
+                               $dstContent,
+                               $this->backend->getFileContents( [ 'src' => $dest ] ),
+                               "Destination file $dest unchanged after failed move ($backendName)." );
+                       $this->assertSame(
+                               is_string( $srcContent ),
+                               (bool)$this->backend->fileExists( [ 'src' => $source ] ),
+                               "Source file $source unchanged after failed move ($backendName)."
+                       );
+                       $this->assertSame(
+                               $srcContent,
+                               $this->backend->getFileContents( [ 'src' => $source ] ),
+                               "Source file $source unchanged after failed move ($backendName)."
+                       );
+               }
 
-               $props1 = $this->backend->getFileProps( [ 'src' => $source ] );
-               $props2 = $this->backend->getFileProps( [ 'src' => $dest ] );
-               $this->assertEquals( false, $props1['fileExists'],
-                       "Source file does not exist accourding to props ($backendName)." );
-               $this->assertEquals( true, $props2['fileExists'],
-                       "Destination file exists accourding to props ($backendName)." );
+               if ( is_string( $dstContent ) ) {
+                       $this->assertTrue(
+                               (bool)$this->backend->fileExists( [ 'src' => $dest ] ),
+                               "Destination file $dest exists after move ($backendName)." );
+               }
 
-               $this->assertBackendPathsConsistent( [ $source, $dest ] );
+               $this->assertBackendPathsConsistent( [ $source, $dest ], $okSyncStatus );
        }
 
+       /**
+        * @return array (op, source exists, dest exists, op succeeds, sync check succeeds)
+        */
        public static function provider_testMove() {
                $cases = [];
 
                $source = self::baseStorePath() . '/unittest-cont1/e/file.txt';
                $dest = self::baseStorePath() . '/unittest-cont2/a/fileMoved.txt';
+               $opBase = [ 'op' => 'move', 'src' => $source, 'dst' => $dest ];
 
-               $op = [ 'op' => 'move', 'src' => $source, 'dst' => $dest ];
-               $cases[] = [
-                       $op, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $cases[] = [ $op, 'yyy', false, true, true ];
 
-               $op2 = $op;
-               $op2['overwrite'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwrite'] = true;
+               $cases[] = [ $op, 'yyy', false, true, true ];
 
-               $op2 = $op;
-               $op2['overwriteSame'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwrite'] = true;
+               $cases[] = [ $op, 'yyy', 'xxx', true, true ];
 
-               $op2 = $op;
-               $op2['ignoreMissingSource'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       $source, // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwriteSame'] = true;
+               $cases[] = [ $op, 'yyy', false, true, true ];
 
-               $op2 = $op;
-               $op2['ignoreMissingSource'] = true;
-               $cases[] = [
-                       $op2, // operation
-                       self::baseStorePath() . '/unittest-cont-bad/e/file.txt', // source
-                       $dest, // dest
-               ];
+               $op = $opBase;
+               $op['overwriteSame'] = true;
+               $cases[] = [ $op, 'yyy', 'yyy', true, true ];
+
+               $op = $opBase;
+               $op['overwriteSame'] = true;
+               $cases[] = [ $op, 'yyy', 'zzz', false, true ];
+
+               $op = $opBase;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, 'xxx', false, true, true ];
+
+               $op = $opBase;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, false, false, true, true ];
+
+               $op = $opBase;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, false, 'xxx', true, true ];
+
+               $op = $opBase;
+               $op['src'] = 'mwstore://wrongbackend/unittest-cont1/e/file.txt';
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, false, false, false, false ];
 
                return $cases;
        }
@@ -559,27 +616,27 @@ class FileBackendTest extends MediaWikiTestCase {
        /**
         * @dataProvider provider_testDelete
         */
-       public function testDelete( $op, $withSource, $okStatus ) {
+       public function testDelete( $op, $srcContent, $okStatus, $okSyncStatus ) {
                $this->backend = $this->singleBackend;
                $this->tearDownFiles();
-               $this->doTestDelete( $op, $withSource, $okStatus );
+               $this->doTestDelete( $op, $srcContent, $okStatus, $okSyncStatus );
                $this->tearDownFiles();
 
                $this->backend = $this->multiBackend;
                $this->tearDownFiles();
-               $this->doTestDelete( $op, $withSource, $okStatus );
+               $this->doTestDelete( $op, $srcContent, $okStatus, $okSyncStatus );
                $this->tearDownFiles();
        }
 
-       private function doTestDelete( $op, $withSource, $okStatus ) {
+       private function doTestDelete( $op, $srcContent, $okStatus, $okSyncStatus ) {
                $backendName = $this->backendClass();
 
                $source = $op['src'];
                $this->prepare( [ 'dir' => dirname( $source ) ] );
 
-               if ( $withSource ) {
+               if ( is_string( $srcContent ) ) {
                        $status = $this->backend->doOperation(
-                               [ 'op' => 'create', 'content' => 'blahblah', 'dst' => $source ] );
+                               [ 'op' => 'create', 'content' => $srcContent, 'dst' => $source ] );
                        $this->assertGoodStatus( $status,
                                "Creation of file at $source succeeded ($backendName)." );
                }
@@ -597,7 +654,8 @@ class FileBackendTest extends MediaWikiTestCase {
                                "Deletion of file at $source failed ($backendName)." );
                }
 
-               $this->assertEquals( false, $this->backend->fileExists( [ 'src' => $source ] ),
+               $this->assertFalse(
+                       (bool)$this->backend->fileExists( [ 'src' => $source ] ),
                        "Source file $source does not exist after move ($backendName)." );
 
                $this->assertFalse(
@@ -605,44 +663,40 @@ class FileBackendTest extends MediaWikiTestCase {
                        "Source file $source has correct size (false) ($backendName)." );
 
                $props1 = $this->backend->getFileProps( [ 'src' => $source ] );
-               $this->assertFalse( $props1['fileExists'],
+               $this->assertFalse(
+                       $props1['fileExists'],
                        "Source file $source does not exist according to props ($backendName)." );
 
-               $this->assertBackendPathsConsistent( [ $source ] );
+               $this->assertBackendPathsConsistent( [ $source ], $okSyncStatus );
        }
 
+       /**
+        * @return array (op, source content, op succeeds, sync check succeeds)
+        */
        public static function provider_testDelete() {
                $cases = [];
 
                $source = self::baseStorePath() . '/unittest-cont1/e/myfacefile.txt';
+               $baseOp = [ 'op' => 'delete', 'src' => $source ];
 
-               $op = [ 'op' => 'delete', 'src' => $source ];
-               $cases[] = [
-                       $op, // operation
-                       true, // with source
-                       true // succeeds
-               ];
+               $op = $baseOp;
+               $cases[] = [ $op, 'xxx', true, true ];
 
-               $cases[] = [
-                       $op, // operation
-                       false, // without source
-                       false // fails
-               ];
+               $op = $baseOp;
+               $op['ignoreMissingSource'] = true;
+               $cases[] = [ $op, 'xxx', true, true ];
+
+               $op = $baseOp;
+               $cases[] = [ $op, false, false, true ];
 
+               $op = $baseOp;
                $op['ignoreMissingSource'] = true;
-               $cases[] = [
-                       $op, // operation
-                       false, // without source
-                       true // succeeds
-               ];
+               $cases[] = [ $op, false, true, true ];
 
+               $op = $baseOp;
                $op['ignoreMissingSource'] = true;
-               $op['src'] = self::baseStorePath() . '/unittest-cont-bad/e/file.txt';
-               $cases[] = [
-                       $op, // operation
-                       false, // without source
-                       true // succeeds
-               ];
+               $op['src'] = 'mwstore://wrongbackend/unittest-cont1/e/file.txt';
+               $cases[] = [ $op, false, false, false ];
 
                return $cases;
        }
@@ -708,7 +762,7 @@ class FileBackendTest extends MediaWikiTestCase {
                                "Describe of file at $source failed ($backendName)." );
                }
 
-               $this->assertBackendPathsConsistent( [ $source ] );
+               $this->assertBackendPathsConsistent( [ $source ], true );
        }
 
        private function assertHasHeaders( array $headers, array $attr ) {
@@ -809,7 +863,7 @@ class FileBackendTest extends MediaWikiTestCase {
                                "Destination file $dest has original size according to props ($backendName)." );
                }
 
-               $this->assertBackendPathsConsistent( [ $dest ] );
+               $this->assertBackendPathsConsistent( [ $dest ], true );
        }
 
        /**
@@ -2608,7 +2662,7 @@ class FileBackendTest extends MediaWikiTestCase {
        }
 
        function tearDownFiles() {
-               $containers = [ 'unittest-cont1', 'unittest-cont2', 'unittest-cont-bad' ];
+               $containers = [ 'unittest-cont1', 'unittest-cont2' ];
                foreach ( $containers as $container ) {
                        $this->deleteFiles( $container );
                }
@@ -2627,14 +2681,24 @@ class FileBackendTest extends MediaWikiTestCase {
                $this->backend->clean( [ 'dir' => "$base/$container", 'recursive' => 1 ] );
        }
 
-       function assertBackendPathsConsistent( array $paths ) {
-               if ( $this->backend instanceof FileBackendMultiWrite ) {
-                       $status = $this->backend->consistencyCheck( $paths );
+       private function assertBackendPathsConsistent( array $paths, $okSyncStatus ) {
+               if ( !$this->backend instanceof FileBackendMultiWrite ) {
+                       return;
+               }
+
+               $status = $this->backend->consistencyCheck( $paths );
+               if ( $okSyncStatus ) {
                        $this->assertGoodStatus( $status, "Files synced: " . implode( ',', $paths ) );
+               } else {
+                       $this->assertBadStatus( $status, "Files not synced: " . implode( ',', $paths ) );
                }
        }
 
-       function assertGoodStatus( StatusValue $status, $msg ) {
+       private function assertGoodStatus( StatusValue $status, $msg ) {
                $this->assertEquals( print_r( [], 1 ), print_r( $status->getErrors(), 1 ), $msg );
        }
+
+       private function assertBadStatus( StatusValue $status, $msg ) {
+               $this->assertNotEquals( print_r( [], 1 ), print_r( $status->getErrors(), 1 ), $msg );
+       }
 }