[MCR] NameTableStore

General purpose cached store for things like:
 - content_models (id,name)
 - slot_roles (id,name)
And in the future possibly namespaces & content_formats
as mentioned at:
https://www.mediawiki.org/wiki/Multi-Content_Revisions/Schema_Migration#Name_tables

Bug: T188518
Change-Id: Ia550ef7fe30af25ac3fee5ac8a89d032544563bf

autoload.php

@@ -953,6 +953,8 @@ $wgAutoloadLocalClasses = [
 	'MediaWiki\\Storage\\IncompleteRevisionException' => __DIR__ . '/includes/Storage/IncompleteRevisionException.php',
 	'MediaWiki\\Storage\\MutableRevisionRecord' => __DIR__ . '/includes/Storage/MutableRevisionRecord.php',
 	'MediaWiki\\Storage\\MutableRevisionSlots' => __DIR__ . '/includes/Storage/MutableRevisionSlots.php',
+	'MediaWiki\\Storage\\NameTableAccessException' => __DIR__ . '/includes/Storage/NameTableAccessException.php',
+	'MediaWiki\\Storage\\NameTableStore' => __DIR__ . '/includes/Storage/NameTableStore.php',
 	'MediaWiki\\Storage\\RevisionAccessException' => __DIR__ . '/includes/Storage/RevisionAccessException.php',
 	'MediaWiki\\Storage\\RevisionArchiveRecord' => __DIR__ . '/includes/Storage/RevisionArchiveRecord.php',
 	'MediaWiki\\Storage\\RevisionFactory' => __DIR__ . '/includes/Storage/RevisionFactory.php',

includes/MediaWikiServices.php

@@ -16,6 +16,7 @@ use MediaWiki\Preferences\PreferencesFactory;
 use MediaWiki\Shell\CommandFactory;
 use MediaWiki\Storage\BlobStore;
 use MediaWiki\Storage\BlobStoreFactory;
+use MediaWiki\Storage\NameTableStore;
 use MediaWiki\Storage\RevisionFactory;
 use MediaWiki\Storage\RevisionLookup;
 use MediaWiki\Storage\RevisionStore;
@@ -770,6 +771,22 @@ class MediaWikiServices extends ServiceContainer {
 		return $this->getService( 'RevisionFactory' );
 	}
 
+	/**
+	 * @since 1.31
+	 * @return NameTableStore
+	 */
+	public function getContentModelStore() {
+		return $this->getService( 'ContentModelStore' );
+	}
+
+	/**
+	 * @since 1.31
+	 * @return NameTableStore
+	 */
+	public function getSlotRoleStore() {
+		return $this->getService( 'SlotRoleStore' );
+	}
+
 	/**
 	 * @since 1.31
 	 * @return PreferencesFactory

includes/ServiceWiring.php

@@ -45,6 +45,7 @@ use MediaWiki\MediaWikiServices;
 use MediaWiki\Preferences\DefaultPreferencesFactory;
 use MediaWiki\Shell\CommandFactory;
 use MediaWiki\Storage\BlobStoreFactory;
+use MediaWiki\Storage\NameTableStore;
 use MediaWiki\Storage\RevisionStore;
 use MediaWiki\Storage\SqlBlobStore;
 use Wikimedia\ObjectFactory;
@@ -539,6 +540,35 @@ return [
 		return $services->getBlobStoreFactory()->newSqlBlobStore();
 	},
 
+	'ContentModelStore' => function ( MediaWikiServices $services ) {
+		return new NameTableStore(
+			$services->getDBLoadBalancer(),
+			$services->getMainWANObjectCache(),
+			LoggerFactory::getInstance( 'NameTableSqlStore' ),
+			'content_models',
+			'model_id',
+			'model_name'
+			/**
+			 * No strtolower normalization is added to the service as there are examples of
+			 * extensions that do not stick to this assumption.
+			 * - extensions/examples/DataPages define( 'CONTENT_MODEL_XML_DATA','XML_DATA' );
+			 * - extensions/Scribunto define( 'CONTENT_MODEL_SCRIBUNTO', 'Scribunto' );
+			 */
+		);
+	},
+
+	'SlotRoleStore' => function ( MediaWikiServices $services ) {
+		return new NameTableStore(
+			$services->getDBLoadBalancer(),
+			$services->getMainWANObjectCache(),
+			LoggerFactory::getInstance( 'NameTableSqlStore' ),
+			'slot_roles',
+			'role_id',
+			'role_name',
+			'strtolower'
+		);
+	},
+
 	'PreferencesFactory' => function ( MediaWikiServices $services ) {
 		global $wgContLang;
 		$authManager = AuthManager::singleton();

includes/Storage/NameTableAccessException.php

@@ -0,0 +1,45 @@
+<?php
+/**
+ * Exception representing a failure to look up a row from a name table.
+ *
+ * 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
+ */
+
+namespace MediaWiki\Storage;
+
+use RuntimeException;
+
+/**
+ * Exception representing a failure to look up a row from a name table.
+ *
+ * @since 1.31
+ */
+class NameTableAccessException extends RuntimeException {
+
+	/**
+	 * @param string $tableName
+	 * @param string $accessType
+	 * @param string|int $accessValue
+	 * @return NameTableAccessException
+	 */
+	public static function newFromDetails( $tableName, $accessType, $accessValue ) {
+		$message = "Failed to access name from ${tableName} using ${accessType} = ${accessValue}";
+		return new self( $message );
+	}
+
+}

includes/Storage/NameTableStore.php

@@ -0,0 +1,365 @@
+<?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
+ */
+
+namespace MediaWiki\Storage;
+
+use IExpiringStore;
+use Psr\Log\LoggerInterface;
+use WANObjectCache;
+use Wikimedia\Assert\Assert;
+use Wikimedia\Rdbms\Database;
+use Wikimedia\Rdbms\IDatabase;
+use Wikimedia\Rdbms\LoadBalancer;
+
+/**
+ * @author Addshore
+ * @since 1.31
+ */
+class NameTableStore {
+
+	/** @var LoadBalancer */
+	private $loadBalancer;
+
+	/** @var WANObjectCache */
+	private $cache;
+
+	/** @var LoggerInterface */
+	private $logger;
+
+	/** @var string[] */
+	private $tableCache = null;
+
+	/** @var bool|string */
+	private $wikiId = false;
+
+	/** @var int */
+	private $cacheTTL;
+
+	/** @var string */
+	private $table;
+	/** @var string */
+	private $idField;
+	/** @var string */
+	private $nameField;
+	/** @var null|callable */
+	private $normalizationCallback = null;
+
+	/**
+	 * @param LoadBalancer $dbLoadBalancer A load balancer for acquiring database connections
+	 * @param WANObjectCache $cache A cache manager for caching data
+	 * @param LoggerInterface $logger
+	 * @param string $table
+	 * @param string $idField
+	 * @param string $nameField
+	 * @param callable $normalizationCallback Normalization to be applied to names before being
+	 * saved or queried. This should be a callback that accepts and returns a single string.
+	 * @param bool|string $wikiId The ID of the target wiki database. Use false for the local wiki.
+	 */
+	public function __construct(
+		LoadBalancer $dbLoadBalancer,
+		WANObjectCache $cache,
+		LoggerInterface $logger,
+		$table,
+		$idField,
+		$nameField,
+		callable $normalizationCallback = null,
+		$wikiId = false
+	) {
+		$this->loadBalancer = $dbLoadBalancer;
+		$this->cache = $cache;
+		$this->logger = $logger;
+		$this->table = $table;
+		$this->idField = $idField;
+		$this->nameField = $nameField;
+		$this->normalizationCallback = $normalizationCallback;
+		$this->wikiId = $wikiId;
+		$this->cacheTTL = IExpiringStore::TTL_MONTH;
+	}
+
+	/**
+	 * @param int $index A database index, like DB_MASTER or DB_REPLICA
+	 * @param int $flags Database connection flags
+	 *
+	 * @return IDatabase
+	 */
+	private function getDBConnection( $index, $flags = 0 ) {
+		return $this->loadBalancer->getConnection( $index, [], $this->wikiId, $flags );
+	}
+
+	private function getCacheKey() {
+		return $this->cache->makeKey( 'NameTableSqlStore', $this->table, $this->wikiId );
+	}
+
+	/**
+	 * @param string $name
+	 * @return string
+	 */
+	private function normalizeName( $name ) {
+		if ( $this->normalizationCallback === null ) {
+			return $name;
+		}
+		return call_user_func( $this->normalizationCallback, $name );
+	}
+
+	/**
+	 * Acquire the id of the given name.
+	 * This creates a row in the table if it doesn't already exist.
+	 *
+	 * @param string $name
+	 * @throws NameTableAccessException
+	 * @return int
+	 */
+	public function acquireId( $name ) {
+		Assert::parameterType( 'string', $name, '$name' );
+		$name = $this->normalizeName( $name );
+
+		$table = $this->getTableFromCachesOrReplica();
+		$searchResult = array_search( $name, $table, true );
+		if ( $searchResult === false ) {
+			$id = $this->store( $name );
+			if ( $id === null ) {
+				// RACE: $name was already in the db, probably just inserted, so load from master
+				// Use DBO_TRX to avoid missing inserts due to other threads or REPEATABLE-READs
+				$table = $this->loadTable(
+					$this->getDBConnection( DB_MASTER, LoadBalancer::CONN_TRX_AUTO )
+				);
+				$searchResult = array_search( $name, $table, true );
+				if ( $searchResult === false ) {
+					// Insert failed due to IGNORE flag, but DB_MASTER didn't give us the data
+					$m = "No insert possible but master didn't give us a record for " .
+						"'{$name}' in '{$this->table}'";
+					$this->logger->error( $m );
+					throw new NameTableAccessException( $m );
+				}
+				$this->purgeWANCache(
+					function () {
+						$this->cache->reap( $this->getCacheKey(), INF );
+					}
+				);
+			} else {
+				$table[$id] = $name;
+				$searchResult = $id;
+				// As store returned an ID we know we inserted so delete from WAN cache
+				$this->purgeWANCache(
+					function () {
+						$this->cache->delete( $this->getCacheKey() );
+					}
+				);
+			}
+			$this->tableCache = $table;
+		}
+
+		return $searchResult;
+	}
+
+	/**
+	 * Get the id of the given name.
+	 * If the name doesn't exist this will throw.
+	 * This should be used in cases where we believe the name already exists or want to check for
+	 * existence.
+	 *
+	 * @param string $name
+	 * @throws NameTableAccessException The name does not exist
+	 * @return int Id
+	 */
+	public function getId( $name ) {
+		Assert::parameterType( 'string', $name, '$name' );
+		$name = $this->normalizeName( $name );
+
+		$table = $this->getTableFromCachesOrReplica();
+		$searchResult = array_search( $name, $table, true );
+
+		if ( $searchResult !== false ) {
+			return $searchResult;
+		}
+
+		throw NameTableAccessException::newFromDetails( $this->table, 'name', $name );
+	}
+
+	/**
+	 * Get the name of the given id.
+	 * If the id doesn't exist this will throw.
+	 * This should be used in cases where we believe the id already exists.
+	 *
+	 * Note: Calls to this method will result in a master select for non existing IDs.
+	 *
+	 * @param int $id
+	 * @throws NameTableAccessException The id does not exist
+	 * @return string name
+	 */
+	public function getName( $id ) {
+		Assert::parameterType( 'integer', $id, '$id' );
+
+		$table = $this->getTableFromCachesOrReplica();
+		if ( array_key_exists( $id, $table ) ) {
+			return $table[$id];
+		}
+
+		$table = $this->cache->getWithSetCallback(
+			$this->getCacheKey(),
+			$this->cacheTTL,
+			function ( $oldValue, &$ttl, &$setOpts ) use ( $id ) {
+				// Check if cached value is up-to-date enough to have $id
+				if ( is_array( $oldValue ) && array_key_exists( $id, $oldValue ) ) {
+					// Completely leave the cache key alone
+					$ttl = WANObjectCache::TTL_UNCACHEABLE;
+					// Use the old value
+					return $oldValue;
+				}
+				// Regenerate from replica DB, and master DB if needed
+				foreach ( [ DB_REPLICA, DB_MASTER ] as $source ) {
+					// Log a fallback to master
+					if ( $source === DB_MASTER ) {
+						$this->logger->info(
+							__METHOD__ . 'falling back to master select from ' .
+							$this->table . ' with id ' . $id
+						);
+					}
+					$db = $this->getDBConnection( $source );
+					$cacheSetOpts = Database::getCacheSetOptions( $db );
+					$table = $this->loadTable( $db );
+					if ( array_key_exists( $id, $table ) ) {
+						break; // found it
+					}
+				}
+				// Use the value from last source checked
+				$setOpts += $cacheSetOpts;
+
+				return $table;
+			},
+			[ 'minAsOf' => INF ] // force callback run
+		);
+
+		$this->tableCache = $table;
+
+		if ( array_key_exists( $id, $table ) ) {
+			return $table[$id];
+		}
+
+		throw NameTableAccessException::newFromDetails( $this->table, 'id', $id );
+	}
+
+	/**
+	 * Get the whole table, in no particular order as a map of ids to names.
+	 * This method could be subject to DB or cache lag.
+	 *
+	 * @return string[] keys are the name ids, values are the names themselves
+	 *  Example: [ 1 => 'foo', 3 => 'bar' ]
+	 */
+	public function getMap() {
+		return $this->getTableFromCachesOrReplica();
+	}
+
+	/**
+	 * @return string[]
+	 */
+	private function getTableFromCachesOrReplica() {
+		if ( $this->tableCache !== null ) {
+			return $this->tableCache;
+		}
+
+		$table = $this->cache->getWithSetCallback(
+			$this->getCacheKey(),
+			$this->cacheTTL,
+			function ( $oldValue, &$ttl, &$setOpts ) {
+				$dbr = $this->getDBConnection( DB_REPLICA );
+				$setOpts += Database::getCacheSetOptions( $dbr );
+				return $this->loadTable( $dbr );
+			}
+		);
+
+		$this->tableCache = $table;
+
+		return $table;
+	}
+
+	/**
+	 * Reap the WANCache entry for this table.
+	 *
+	 * @param callable $purgeCallback callback to 'purge' the WAN cache
+	 */
+	private function purgeWANCache( $purgeCallback ) {
+		// If the LB has no DB changes don't both with onTransactionPreCommitOrIdle
+		if ( !$this->loadBalancer->hasOrMadeRecentMasterChanges() ) {
+			$purgeCallback();
+			return;
+		}
+
+		$this->getDBConnection( DB_MASTER )
+			->onTransactionPreCommitOrIdle( $purgeCallback, __METHOD__ );
+	}
+
+	/**
+	 * Gets the table from the db
+	 *
+	 * @param IDatabase $db
+	 *
+	 * @return string[]
+	 */
+	private function loadTable( IDatabase $db ) {
+		$result = $db->select(
+			$this->table,
+			[
+				'id' => $this->idField,
+				'name' => $this->nameField
+			],
+			[],
+			__METHOD__
+		);
+
+		$assocArray = [];
+		foreach ( $result as $row ) {
+			$assocArray[$row->id] = $row->name;
+		}
+
+		return $assocArray;
+	}
+
+	/**
+	 * Stores the given name in the DB, returning the ID when an insert occurs.
+	 *
+	 * @param string $name
+	 * @return int|null int if we know the ID, null if we don't
+	 */
+	private function store( $name ) {
+		Assert::parameterType( 'string', $name, '$name' );
+		Assert::parameter( $name !== '', '$name', 'should not be an empty string' );
+		// Note: this is only called internally so normalization of $name has already occurred.
+
+		$dbw = $this->getDBConnection( DB_MASTER );
+
+		$dbw->insert(
+			$this->table,
+			[ $this->nameField => $name ],
+			__METHOD__,
+			[ 'IGNORE' ]
+		);
+
+		if ( $dbw->affectedRows() === 0 ) {
+			$this->logger->info(
+				'Tried to insert name into table ' . $this->table . ', but value already existed.'
+			);
+			return null;
+		}
+
+		return $dbw->insertId();
+	}
+
+}

tests/phpunit/includes/Storage/NameTableStoreTest.php

@@ -0,0 +1,298 @@
+<?php
+
+namespace MediaWiki\Tests\Storage;
+
+use BagOStuff;
+use EmptyBagOStuff;
+use HashBagOStuff;
+use MediaWiki\Storage\NameTableAccessException;
+use MediaWiki\Storage\NameTableStore;
+use MediaWikiTestCase;
+use Psr\Log\NullLogger;
+use WANObjectCache;
+use Wikimedia\Rdbms\Database;
+use Wikimedia\Rdbms\LoadBalancer;
+use Wikimedia\TestingAccessWrapper;
+
+/**
+ * @author Addshore
+ * @group Database
+ * @covers \MediaWiki\Storage\NameTableStore
+ */
+class NameTableStoreTest extends MediaWikiTestCase {
+
+	public function setUp() {
+		$this->tablesUsed[] = 'slot_roles';
+		parent::setUp();
+	}
+
+	private function populateTable( $values ) {
+		$insertValues = [];
+		foreach ( $values as $name ) {
+			$insertValues[] = [ 'role_name' => $name ];
+		}
+		$this->db->insert( 'slot_roles', $insertValues );
+	}
+
+	private function getHashWANObjectCache( $cacheBag ) {
+		return new WANObjectCache( [ 'cache' => $cacheBag ] );
+	}
+
+	/**
+	 * @param $db
+	 * @return \PHPUnit_Framework_MockObject_MockObject|LoadBalancer
+	 */
+	private function getMockLoadBalancer( $db ) {
+		$mock = $this->getMockBuilder( LoadBalancer::class )
+			->disableOriginalConstructor()
+			->getMock();
+		$mock->expects( $this->any() )
+			->method( 'getConnection' )
+			->willReturn( $db );
+		return $mock;
+	}
+
+	private function getCallCheckingDb( $insertCalls, $selectCalls ) {
+		$mock = $this->getMockBuilder( Database::class )
+			->disableOriginalConstructor()
+			->getMock();
+		$mock->expects( $this->exactly( $insertCalls ) )
+			->method( 'insert' )
+			->willReturnCallback( function () {
+				return call_user_func_array( [ $this->db, 'insert' ], func_get_args() );
+			} );
+		$mock->expects( $this->exactly( $selectCalls ) )
+			->method( 'select' )
+			->willReturnCallback( function () {
+				return call_user_func_array( [ $this->db, 'select' ], func_get_args() );
+			} );
+		$mock->expects( $this->exactly( $insertCalls ) )
+			->method( 'affectedRows' )
+			->willReturnCallback( function () {
+				return call_user_func_array( [ $this->db, 'affectedRows' ], func_get_args() );
+			} );
+		$mock->expects( $this->any() )
+			->method( 'insertId' )
+			->willReturnCallback( function () {
+				return call_user_func_array( [ $this->db, 'insertId' ], func_get_args() );
+			} );
+		return $mock;
+	}
+
+	private function getNameTableSqlStore(
+		BagOStuff $cacheBag,
+		$insertCalls,
+		$selectCalls,
+		$normalizationCallback = null
+	) {
+		return new NameTableStore(
+			$this->getMockLoadBalancer( $this->getCallCheckingDb( $insertCalls, $selectCalls ) ),
+			$this->getHashWANObjectCache( $cacheBag ),
+			new NullLogger(),
+			'slot_roles', 'role_id', 'role_name',
+			$normalizationCallback
+		);
+	}
+
+	public function provideGetAndAcquireId() {
+		return [
+			'no wancache, empty table' =>
+				[ new EmptyBagOStuff(), true, 1, [], 'foo', 1 ],
+			'no wancache, one matching value' =>
+				[ new EmptyBagOStuff(), false, 1, [ 'foo' ], 'foo', 1 ],
+			'no wancache, one not matching value' =>
+				[ new EmptyBagOStuff(), true, 1, [ 'bar' ], 'foo', 2 ],
+			'no wancache, multiple, one matching value' =>
+				[ new EmptyBagOStuff(), false, 1, [ 'foo', 'bar' ], 'bar', 2 ],
+			'no wancache, multiple, no matching value' =>
+				[ new EmptyBagOStuff(), true, 1, [ 'foo', 'bar' ], 'baz', 3 ],
+			'wancache, empty table' =>
+				[ new HashBagOStuff(), true, 1, [], 'foo', 1 ],
+			'wancache, one matching value' =>
+				[ new HashBagOStuff(), false, 1, [ 'foo' ], 'foo', 1 ],
+			'wancache, one not matching value' =>
+				[ new HashBagOStuff(), true, 1, [ 'bar' ], 'foo', 2 ],
+			'wancache, multiple, one matching value' =>
+				[ new HashBagOStuff(), false, 1, [ 'foo', 'bar' ], 'bar', 2 ],
+			'wancache, multiple, no matching value' =>
+				[ new HashBagOStuff(), true, 1, [ 'foo', 'bar' ], 'baz', 3 ],
+		];
+	}
+
+	/**
+	 * @dataProvider provideGetAndAcquireId
+	 * @param BagOStuff $cacheBag to use in the WANObjectCache service
+	 * @param bool $needsInsert Does the value we are testing need to be inserted?
+	 * @param int $selectCalls Number of times the select DB method will be called
+	 * @param string[] $existingValues to be added to the db table
+	 * @param string $name name to acquire
+	 * @param int $expectedId the id we expect the name to have
+	 */
+	public function testGetAndAcquireId(
+		$cacheBag,
+		$needsInsert,
+		$selectCalls,
+		$existingValues,
+		$name,
+		$expectedId
+	) {
+		$this->populateTable( $existingValues );
+		$store = $this->getNameTableSqlStore( $cacheBag, (int)$needsInsert, $selectCalls );
+
+		// Some names will not initially exist
+		try {
+			$result = $store->getId( $name );
+			$this->assertSame( $expectedId, $result );
+		} catch ( NameTableAccessException $e ) {
+			if ( $needsInsert ) {
+				$this->assertTrue( true ); // Expected exception
+			} else {
+				$this->fail( 'Did not expect an exception, but got one: ' . $e->getMessage() );
+			}
+		}
+
+		// All names should return their id here
+		$this->assertSame( $expectedId, $store->acquireId( $name ) );
+
+		// acquireId inserted these names, so now everything should exist with getId
+		$this->assertSame( $expectedId, $store->getId( $name ) );
+
+		// calling getId again will also still work, and not result in more selects
+		$this->assertSame( $expectedId, $store->getId( $name ) );
+	}
+
+	public function provideTestGetAndAcquireIdNameNormalization() {
+		yield [ 'A', 'a', 'strtolower' ];
+		yield [ 'b', 'B', 'strtoupper' ];
+		yield [
+			'X',
+			'X',
+			function ( $name ) {
+				return $name;
+			}
+		];
+		yield [ 'ZZ', 'ZZ-a', __CLASS__ . '::appendDashAToString' ];
+	}
+
+	public static function appendDashAToString( $string ) {
+		return $string . '-a';
+	}
+
+	/**
+	 * @dataProvider provideTestGetAndAcquireIdNameNormalization
+	 */
+	public function testGetAndAcquireIdNameNormalization(
+		$nameIn,
+		$nameOut,
+		$normalizationCallback
+	) {
+		$store = $this->getNameTableSqlStore(
+			new EmptyBagOStuff(),
+			1,
+			1,
+			$normalizationCallback
+		);
+		$acquiredId = $store->acquireId( $nameIn );
+		$this->assertSame( $nameOut, $store->getName( $acquiredId ) );
+	}
+
+	public function provideGetName() {
+		return [
+			[ new HashBagOStuff(), 3, 3 ],
+			[ new EmptyBagOStuff(), 3, 3 ],
+		];
+	}
+
+	/**
+	 * @dataProvider provideGetName
+	 */
+	public function testGetName( $cacheBag, $insertCalls, $selectCalls ) {
+		$store = $this->getNameTableSqlStore( $cacheBag, $insertCalls, $selectCalls );
+
+		// Get 1 ID and make sure getName returns correctly
+		$fooId = $store->acquireId( 'foo' );
+		$this->assertSame( 'foo', $store->getName( $fooId ) );
+
+		// Get another ID and make sure getName returns correctly
+		$barId = $store->acquireId( 'bar' );
+		$this->assertSame( 'bar', $store->getName( $barId ) );
+
+		// Blitz the cache and make sure it still returns
+		TestingAccessWrapper::newFromObject( $store )->tableCache = null;
+		$this->assertSame( 'foo', $store->getName( $fooId ) );
+		$this->assertSame( 'bar', $store->getName( $barId ) );
+
+		// Blitz the cache again and get another ID and make sure getName returns correctly
+		TestingAccessWrapper::newFromObject( $store )->tableCache = null;
+		$bazId = $store->acquireId( 'baz' );
+		$this->assertSame( 'baz', $store->getName( $bazId ) );
+		$this->assertSame( 'baz', $store->getName( $bazId ) );
+	}
+
+	public function testGetName_masterFallback() {
+		$store = $this->getNameTableSqlStore( new EmptyBagOStuff(), 1, 2 );
+
+		// Insert a new name
+		$fooId = $store->acquireId( 'foo' );
+
+		// Empty the process cache, getCachedTable() will now return this empty array
+		TestingAccessWrapper::newFromObject( $store )->tableCache = [];
+
+		// getName should fallback to master, which is why we assert 2 selectCalls above
+		$this->assertSame( 'foo', $store->getName( $fooId ) );
+	}
+
+	public function testGetMap_empty() {
+		$this->populateTable( [] );
+		$store = $this->getNameTableSqlStore( new HashBagOStuff(), 0, 1 );
+		$table = $store->getMap();
+		$this->assertSame( [], $table );
+	}
+
+	public function testGetMap_twoValues() {
+		$this->populateTable( [ 'foo', 'bar' ] );
+		$store = $this->getNameTableSqlStore( new HashBagOStuff(), 0, 1 );
+
+		// We are using a cache, so 2 calls should only result in 1 select on the db
+		$store->getMap();
+		$table = $store->getMap();
+
+		$expected = [ 2 => 'bar', 1 => 'foo' ];
+		$this->assertSame( $expected, $table );
+		// Make sure the table returned is the same as the cached table
+		$this->assertSame( $expected, TestingAccessWrapper::newFromObject( $store )->tableCache );
+	}
+
+	public function testCacheRaceCondition() {
+		$wanHashBag = new HashBagOStuff();
+		$store1 = $this->getNameTableSqlStore( $wanHashBag, 1, 1 );
+		$store2 = $this->getNameTableSqlStore( $wanHashBag, 1, 0 );
+		$store3 = $this->getNameTableSqlStore( $wanHashBag, 1, 1 );
+
+		// Cache the current table in the instances we will use
+		// This simulates multiple requests running simultaneously
+		$store1->getMap();
+		$store2->getMap();
+		$store3->getMap();
+
+		// Store 2 separate names using different instances
+		$fooId = $store1->acquireId( 'foo' );
+		$barId = $store2->acquireId( 'bar' );
+
+		// Each of these instances should be aware of what they have inserted
+		$this->assertSame( $fooId, $store1->acquireId( 'foo' ) );
+		$this->assertSame( $barId, $store2->acquireId( 'bar' ) );
+
+		// A new store should be able to get both of these new Ids
+		// Note: before there was a race condition here where acquireId( 'bar' ) would update the
+		//       cache with data missing the 'foo' key that it was not aware of
+		$store4 = $this->getNameTableSqlStore( $wanHashBag, 0, 1 );
+		$this->assertSame( $fooId, $store4->getId( 'foo' ) );
+		$this->assertSame( $barId, $store4->getId( 'bar' ) );
+
+		// If a store with old cached data tries to acquire these we will get the same ids.
+		$this->assertSame( $fooId, $store3->acquireId( 'foo' ) );
+		$this->assertSame( $barId, $store3->acquireId( 'bar' ) );
+	}
+
+}