file: Move json metadata storage out of LocalFile

So ArchivedFile could use it as well

Bug: T298417
Bug: T298398
Change-Id: Idd258437d9f91824195ed0c12b5694841cb365b0

4 files changed, 173 insertions, 98 deletions

diff --git a/autoload.php b/autoload.php
index 43549820c972..f6566a043e23 100644
--- a/autoload.php
+++ b/autoload.php
@@ -1131,6 +1131,7 @@ $wgAutoloadLocalClasses = [
 	'MessageContent' => __DIR__ . '/includes/content/MessageContent.php',
 	'MessageLocalizer' => __DIR__ . '/includes/language/MessageLocalizer.php',
 	'MessageSpecifier' => __DIR__ . '/includes/libs/MessageSpecifier.php',
+	'MetadataStorageHelper' => __DIR__ . '/includes/filerepo/file/MetadataStorageHelper.php',
 	'MigrateActors' => __DIR__ . '/maintenance/includes/MigrateActors.php',
 	'MigrateArchiveText' => __DIR__ . '/maintenance/migrateArchiveText.php',
 	'MigrateComments' => __DIR__ . '/maintenance/migrateComments.php',
diff --git a/includes/filerepo/file/LocalFile.php b/includes/filerepo/file/LocalFile.php
index 6ba0ea93e7ff..9ca0a6a5b95e 100644
--- a/includes/filerepo/file/LocalFile.php
+++ b/includes/filerepo/file/LocalFile.php
@@ -26,7 +26,6 @@ use MediaWiki\Logger\LoggerFactory;
 use MediaWiki\MediaWikiServices;
 use MediaWiki\Permissions\Authority;
 use MediaWiki\Revision\RevisionRecord;
-use MediaWiki\Storage\BlobStore;
 use MediaWiki\User\UserIdentity;
 use MediaWiki\User\UserIdentityValue;
 use Wikimedia\Rdbms\Blob;
@@ -174,6 +173,9 @@ class LocalFile extends File {
 	/** @var bool True if file is not present in file system. Not to be cached in memcached */
 	private $missing;
 
+	/** @var MetadataStorageHelper */
+	private $metadataStorageHelper;
+
 	// @note: higher than IDBAccessObject constants
 	private const LOAD_ALL = 16; // integer; load all the lazy fields too (like metadata)
 
@@ -188,7 +190,7 @@ class LocalFile extends File {
 	 * @stable to override
 	 *
 	 * @param Title $title
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 * @param null $unused
 	 *
 	 * @return static
@@ -204,7 +206,7 @@ class LocalFile extends File {
 	 * @stable to override
 	 *
 	 * @param stdClass $row
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 *
 	 * @return static
 	 */
@@ -310,10 +312,11 @@ class LocalFile extends File {
 	 * @stable to call
 	 *
 	 * @param Title $title
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 */
 	public function __construct( $title, $repo ) {
 		parent::__construct( $title, $repo );
+		$this->metadataStorageHelper = new MetadataStorageHelper( $repo );
 
 		$this->assertRepoDefined();
 		$this->assertTitleDefined();
@@ -1090,25 +1093,13 @@ class LocalFile extends File {
 				$addresses[$itemName] = $this->unloadedMetadataBlobs[$itemName];
 			}
 		}
+
 		if ( $addresses ) {
-			$blobStore = $this->repo->getBlobStore();
-			if ( !$blobStore ) {
-				LoggerFactory::getInstance( 'LocalFile' )->warning(
-					"Unable to load metadata: repo has no blob store" );
-				return $result;
-			}
-			$status = $blobStore->getBlobBatch( $addresses );
-			if ( !$status->isGood() ) {
-				$msg = Status::wrap( $status )->getWikiText(
-					false, false, 'en' );
-				LoggerFactory::getInstance( 'LocalFile' )->warning(
-					"Error loading metadata from BlobStore: $msg" );
-			}
+			$resultFromBlob = $this->metadataStorageHelper->getMetadataFromBlobStore( $addresses );
 			foreach ( $addresses as $itemName => $address ) {
 				unset( $this->unloadedMetadataBlobs[$itemName] );
-				$json = $status->getValue()[$address] ?? null;
-				if ( $json !== null ) {
-					$value = $this->jsonDecode( $json );
+				$value = $resultFromBlob[$itemName] ?? null;
+				if ( $value !== null ) {
 					$result[$itemName] = $value;
 					$this->metadataArray[$itemName] = $value;
 				}
@@ -1118,42 +1109,6 @@ class LocalFile extends File {
 	}
 
 	/**
-	 * Do JSON encoding with local flags. Throw an exception if the data cannot be
-	 * serialized.
-	 *
-	 * @throws MWException
-	 * @param mixed $data
-	 * @return string
-	 */
-	private function jsonEncode( $data ): string {
-		$s = json_encode( $data,
-			JSON_INVALID_UTF8_IGNORE |
-			JSON_UNESCAPED_SLASHES |
-			JSON_UNESCAPED_UNICODE );
-		if ( $s === false ) {
-			throw new MWException( __METHOD__ . ': metadata is not JSON-serializable ' .
-				'(type = ' . $this->getMimeType() . ')' );
-		}
-		return $s;
-	}
-
-	/**
-	 * Do JSON decoding with local flags.
-	 *
-	 * This doesn't use JsonCodec because JsonCodec can construct objects,
-	 * which we don't want.
-	 *
-	 * Does not throw. Returns false on failure.
-	 *
-	 * @param string $s
-	 * @return mixed The decoded value, or false on failure
-	 */
-	private function jsonDecode( string $s ) {
-		// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
-		return @json_decode( $s, true, 512, JSON_INVALID_UTF8_IGNORE );
-	}
-
-	/**
 	 * Serialize the metadata array for insertion into img_metadata, oi_metadata
 	 * or fa_metadata.
 	 *
@@ -1196,42 +1151,7 @@ class LocalFile extends File {
 			$envelope['blobs'] = $this->metadataBlobs;
 		}
 
-		// Try encoding
-		$s = $this->jsonEncode( $envelope );
-
-		// Decide whether to try splitting the metadata.
-		// Return early if it's not going to happen.
-		if ( !$this->repo->isSplitMetadataEnabled()
-			|| !$this->getHandler()
-			|| !$this->getHandler()->useSplitMetadata()
-		) {
-			return $s;
-		}
-		$threshold = $this->repo->getSplitMetadataThreshold();
-		if ( !$threshold || strlen( $s ) <= $threshold ) {
-			return $s;
-		}
-		$blobStore = $this->repo->getBlobStore();
-		if ( !$blobStore ) {
-			return $s;
-		}
-
-		// The data as a whole is above the item threshold. Look for
-		// large items that can be split out.
-		$blobAddresses = [];
-		foreach ( $envelope['data'] as $name => $value ) {
-			$encoded = $this->jsonEncode( $value );
-			if ( strlen( $encoded ) > $threshold ) {
-				$blobAddresses[$name] = $blobStore->storeBlob(
-					$encoded,
-					[ BlobStore::IMAGE_HINT => $this->getName() ]
-				);
-			}
-		}
-		// Remove any items that were split out
-		$envelope['data'] = array_diff_key( $envelope['data'], $blobAddresses );
-		$envelope['blobs'] = $blobAddresses;
-		$s = $this->jsonEncode( $envelope );
+		list( $s, $blobAddresses ) = $this->metadataStorageHelper->getJsonMetadata( $this, $envelope );
 
 		// Repeated calls to this function should not keep inserting more blobs
 		$this->metadataBlobs += $blobAddresses;
@@ -1252,7 +1172,7 @@ class LocalFile extends File {
 		$threshold = $this->repo->getSplitMetadataThreshold();
 		$directItems = array_diff_key( $this->metadataArray, $this->metadataBlobs );
 		foreach ( $directItems as $value ) {
-			if ( strlen( $this->jsonEncode( $value ) ) > $threshold ) {
+			if ( strlen( $this->metadataStorageHelper->jsonEncode( $value ) ) > $threshold ) {
 				return true;
 			}
 		}
@@ -1289,7 +1209,7 @@ class LocalFile extends File {
 			return;
 		}
 		if ( $metadataString[0] === '{' ) {
-			$envelope = $this->jsonDecode( $metadataString );
+			$envelope = $this->metadataStorageHelper->jsonDecode( $metadataString );
 			if ( !$envelope ) {
 				// Legacy error encoding
 				$this->metadataArray = [ '_error' => $metadataString ];
diff --git a/includes/filerepo/file/MetadataStorageHelper.php b/includes/filerepo/file/MetadataStorageHelper.php
new file mode 100644
index 000000000000..1c3282ae6bca
--- /dev/null
+++ b/includes/filerepo/file/MetadataStorageHelper.php
@@ -0,0 +1,154 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup FileAbstraction
+ */
+
+use MediaWiki\Logger\LoggerFactory;
+use MediaWiki\Storage\BlobStore;
+
+/**
+ * Helper for storage of metadata. Sharing the code between LocalFile and ArchivedFile
+ *
+ * @internal
+ * @ingroup FileAbstraction
+ */
+class MetadataStorageHelper {
+	/** @var LocalRepo */
+	private $repo;
+
+	public function __construct( LocalRepo $repo ) {
+		$this->repo = $repo;
+	}
+
+	/**
+	 * Get metadata in JSON format ready for DB insertion, optionally splitting
+	 * items out to BlobStore.
+	 *
+	 * @param LocalFile|ArchivedFile $file
+	 * @param array $envelope
+	 * @return array
+	 */
+	public function getJsonMetadata( $file, $envelope ) {
+		// Try encoding
+		$s = $this->jsonEncode( $envelope );
+
+		// Decide whether to try splitting the metadata.
+		// Return early if it's not going to happen.
+		if ( !$this->repo->isSplitMetadataEnabled()
+			|| !$file->getHandler()
+			|| !$file->getHandler()->useSplitMetadata()
+		) {
+			return [ $s, [] ];
+		}
+		$threshold = $this->repo->getSplitMetadataThreshold();
+		if ( !$threshold || strlen( $s ) <= $threshold ) {
+			return [ $s, [] ];
+		}
+		$blobStore = $this->repo->getBlobStore();
+		if ( !$blobStore ) {
+			return [ $s, [] ];
+		}
+
+		// The data as a whole is above the item threshold. Look for
+		// large items that can be split out.
+		$blobAddresses = [];
+		foreach ( $envelope['data'] as $name => $value ) {
+			$encoded = $this->jsonEncode( $value );
+			if ( strlen( $encoded ) > $threshold ) {
+				$blobAddresses[$name] = $blobStore->storeBlob(
+					$encoded,
+					[ BlobStore::IMAGE_HINT => $file->getName() ]
+				);
+			}
+		}
+		// Remove any items that were split out
+		$envelope['data'] = array_diff_key( $envelope['data'], $blobAddresses );
+		$envelope['blobs'] = $blobAddresses;
+		$s = $this->jsonEncode( $envelope );
+
+		return [ $s, $blobAddresses ];
+	}
+
+	/**
+	 * Do JSON encoding with local flags. Throw an exception if the data cannot be
+	 * serialized.
+	 *
+	 * @throws MWException
+	 * @param mixed $data
+	 * @return string
+	 */
+	public function jsonEncode( $data ): string {
+		$s = json_encode( $data,
+			JSON_INVALID_UTF8_IGNORE |
+			JSON_UNESCAPED_SLASHES |
+			JSON_UNESCAPED_UNICODE );
+		if ( $s === false ) {
+			throw new MWException( __METHOD__ . ': metadata is not JSON-serializable ' );
+		}
+		return $s;
+	}
+
+	/**
+	 * @param array $addresses
+	 * @return array
+	 */
+	public function getMetadataFromBlobStore( array $addresses ): array {
+		$result = [];
+		if ( $addresses ) {
+			$blobStore = $this->repo->getBlobStore();
+			if ( !$blobStore ) {
+				LoggerFactory::getInstance( 'LocalFile' )->warning(
+					"Unable to load metadata: repo has no blob store" );
+				return $result;
+			}
+			$status = $blobStore->getBlobBatch( $addresses );
+			if ( !$status->isGood() ) {
+				$msg = Status::wrap( $status )->getWikiText(
+					false, false, 'en' );
+				LoggerFactory::getInstance( 'LocalFile' )->warning(
+					"Error loading metadata from BlobStore: $msg" );
+			}
+			foreach ( $addresses as $itemName => $address ) {
+				$json = $status->getValue()[$address] ?? null;
+				if ( $json !== null ) {
+					$value = $this->jsonDecode( $json );
+					$result[$itemName] = $value;
+				}
+			}
+		}
+		return $result;
+	}
+
+	/**
+	 * Do JSON decoding with local flags.
+	 *
+	 * This doesn't use JsonCodec because JsonCodec can construct objects,
+	 * which we don't want.
+	 *
+	 * Does not throw. Returns false on failure.
+	 *
+	 * @param string $s
+	 * @return mixed The decoded value, or false on failure
+	 */
+	public function jsonDecode( string $s ) {
+		// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
+		return @json_decode( $s, true, 512, JSON_INVALID_UTF8_IGNORE );
+	}
+
+}
diff --git a/includes/filerepo/file/OldLocalFile.php b/includes/filerepo/file/OldLocalFile.php
index 7e6123faa46b..031fe4bd9a2c 100644
--- a/includes/filerepo/file/OldLocalFile.php
+++ b/includes/filerepo/file/OldLocalFile.php
@@ -44,7 +44,7 @@ class OldLocalFile extends LocalFile {
 	/**
 	 * @stable to override
 	 * @param Title $title
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 * @param string|int|null $time
 	 * @return static
 	 * @throws MWException
@@ -62,7 +62,7 @@ class OldLocalFile extends LocalFile {
 	 * @stable to override
 	 *
 	 * @param Title $title
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 * @param string $archiveName
 	 * @return static
 	 */
@@ -74,7 +74,7 @@ class OldLocalFile extends LocalFile {
 	 * @stable to override
 	 *
 	 * @param stdClass $row
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 * @return static
 	 */
 	public static function newFromRow( $row, $repo ) {
@@ -179,7 +179,7 @@ class OldLocalFile extends LocalFile {
 	 * @stable to call
 	 *
 	 * @param Title $title
-	 * @param FileRepo $repo
+	 * @param LocalRepo $repo
 	 * @param string|int|null $time Timestamp or null to load by archive name
 	 * @param string|null $archiveName Archive name or null to load by timestamp
 	 * @throws MWException