BagOStuffTest.php

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<?php

use Wikimedia\ScopedCallback;

class BagOStuffTest extends MediaWikiTestCase {
    private $cache;

    protected function setUp() {
        parent::setUp();

        // type defined through parameter
        if ( $this->getCliArg( 'use-bagostuff' ) ) {
            $name = $this->getCliArg( 'use-bagostuff' );

            $this->cache = ObjectCache::newFromId( $name );
        } else {
            // no type defined - use simple hash
            $this->cache = new HashBagOStuff;
        }

        $this->cache->delete( wfMemcKey( 'test' ) );
    }

    public function testMakeKey() {
        $cache = ObjectCache::newFromId( 'hash' );

        $localKey = $cache->makeKey( 'first', 'second', 'third' );
        $globalKey = $cache->makeGlobalKey( 'first', 'second', 'third' );

        $this->assertStringMatchesFormat(
            '%Sfirst%Ssecond%Sthird%S',
            $localKey,
            'Local key interpolates parameters'
        );

        $this->assertStringMatchesFormat(
            'global%Sfirst%Ssecond%Sthird%S',
            $globalKey,
            'Global key interpolates parameters and contains global prefix'
        );

        $this->assertNotEquals(
            $localKey,
            $globalKey,
            'Local key and global key with same parameters should not be equal'
        );

        $this->assertNotEquals(
            $cache->makeKeyInternal( 'prefix', [ 'a', 'bc:', 'de' ] ),
            $cache->makeKeyInternal( 'prefix', [ 'a', 'bc', ':de' ] )
        );
    }

    public function testMerge() {
        $key = wfMemcKey( 'test' );

        $usleep = 0;

        $callback = function ( BagOStuff $cache, $key, $existingValue ) use ( &$usleep ) {
            // let's pretend this is an expensive callback to test concurrent merge attempts
            usleep( $usleep );

            if ( $existingValue === false ) {
                return 'merged';
            }

            return $existingValue . 'merged';
        };

        // merge on non-existing value
        $merged = $this->cache->merge( $key, $callback, 0 );
        $this->assertTrue( $merged );
        $this->assertEquals( $this->cache->get( $key ), 'merged' );

        // merge on existing value
        $merged = $this->cache->merge( $key, $callback, 0 );
        $this->assertTrue( $merged );
        $this->assertEquals( $this->cache->get( $key ), 'mergedmerged' );

        /*
         * Test concurrent merges by forking this process, if:
         * - not manually called with --use-bagostuff
         * - pcntl_fork is supported by the system
         * - cache type will correctly support calls over forks
         */
        $fork = (bool)$this->getCliArg( 'use-bagostuff' );
        $fork &= function_exists( 'pcntl_fork' );
        $fork &= !$this->cache instanceof HashBagOStuff;
        $fork &= !$this->cache instanceof EmptyBagOStuff;
        $fork &= !$this->cache instanceof MultiWriteBagOStuff;
        if ( $fork ) {
            // callback should take awhile now so that we can test concurrent merge attempts
            $pid = pcntl_fork();
            if ( $pid == -1 ) {
                // can't fork, ignore this test...
            } elseif ( $pid ) {
                // wait a little, making sure that the child process is calling merge
                usleep( 3000 );

                // attempt a merge - this should fail
                $merged = $this->cache->merge( $key, $callback, 0, 1 );

                // merge has failed because child process was merging (and we only attempted once)
                $this->assertFalse( $merged );

                // make sure the child's merge is completed and verify
                usleep( 3000 );
                $this->assertEquals( $this->cache->get( $key ), 'mergedmergedmerged' );
            } else {
                $this->cache->merge( $key, $callback, 0, 1 );

                // Note: I'm not even going to check if the merge worked, I'll
                // compare values in the parent process to test if this merge worked.
                // I'm just going to exit this child process, since I don't want the
                // child to output any test results (would be rather confusing to
                // have test output twice)
                exit;
            }
        }
    }

    public function testChangeTTL() {
        $key = wfMemcKey( 'test' );
        $value = 'meow';

        $this->cache->add( $key, $value );
        $this->assertTrue( $this->cache->changeTTL( $key, 5 ) );
        $this->assertEquals( $this->cache->get( $key ), $value );
        $this->cache->delete( $key );
        $this->assertFalse( $this->cache->changeTTL( $key, 5 ) );
    }

    public function testAdd() {
        $key = wfMemcKey( 'test' );
        $this->assertTrue( $this->cache->add( $key, 'test' ) );
    }

    public function testGet() {
        $value = [ 'this' => 'is', 'a' => 'test' ];

        $key = wfMemcKey( 'test' );
        $this->cache->add( $key, $value );
        $this->assertEquals( $this->cache->get( $key ), $value );
    }

    public function testGetWithSetCallback() {
        $key = wfMemcKey( 'test' );
        $value = $this->cache->getWithSetCallback(
            $key,
            30,
            function () {
                return 'hello kitty';
            }
        );

        $this->assertEquals( 'hello kitty', $value );
        $this->assertEquals( $value, $this->cache->get( $key ) );
    }

    public function testIncr() {
        $key = wfMemcKey( 'test' );
        $this->cache->add( $key, 0 );
        $this->cache->incr( $key );
        $expectedValue = 1;
        $actualValue = $this->cache->get( $key );
        $this->assertEquals( $expectedValue, $actualValue, 'Value should be 1 after incrementing' );
    }

    public function testIncrWithInit() {
        $key = wfMemcKey( 'test' );
        $val = $this->cache->incrWithInit( $key, 0, 1, 3 );
        $this->assertEquals( 3, $val, "Correct init value" );

        $val = $this->cache->incrWithInit( $key, 0, 1, 3 );
        $this->assertEquals( 4, $val, "Correct init value" );
    }

    public function testGetMulti() {
        $value1 = [ 'this' => 'is', 'a' => 'test' ];
        $value2 = [ 'this' => 'is', 'another' => 'test' ];
        $value3 = [ 'testing a key that may be encoded when sent to cache backend' ];
        $value4 = [ 'another test where chars in key will be encoded' ];

        $key1 = wfMemcKey( 'test1' );
        $key2 = wfMemcKey( 'test2' );
        // internally, MemcachedBagOStuffs will encode to will-%25-encode
        $key3 = wfMemcKey( 'will-%-encode' );
        $key4 = wfMemcKey(
            'flowdb:flow_ref:wiki:by-source:v3:Parser\'s_"broken"_+_(page)_&_grill:testwiki:1:4.7'
        );

        $this->cache->add( $key1, $value1 );
        $this->cache->add( $key2, $value2 );
        $this->cache->add( $key3, $value3 );
        $this->cache->add( $key4, $value4 );

        $this->assertEquals(
            [ $key1 => $value1, $key2 => $value2, $key3 => $value3, $key4 => $value4 ],
            $this->cache->getMulti( [ $key1, $key2, $key3, $key4 ] )
        );

        // cleanup
        $this->cache->delete( $key1 );
        $this->cache->delete( $key2 );
        $this->cache->delete( $key3 );
        $this->cache->delete( $key4 );
    }

    public function testGetScopedLock() {
        $key = wfMemcKey( 'test' );
        $value1 = $this->cache->getScopedLock( $key, 0 );
        $value2 = $this->cache->getScopedLock( $key, 0 );

        $this->assertType( ScopedCallback::class, $value1, 'First call returned lock' );
        $this->assertNull( $value2, 'Duplicate call returned no lock' );

        unset( $value1 );

        $value3 = $this->cache->getScopedLock( $key, 0 );
        $this->assertType( ScopedCallback::class, $value3, 'Lock returned callback after release' );
        unset( $value3 );

        $value1 = $this->cache->getScopedLock( $key, 0, 5, 'reentry' );
        $value2 = $this->cache->getScopedLock( $key, 0, 5, 'reentry' );

        $this->assertType( ScopedCallback::class, $value1, 'First reentrant call returned lock' );
        $this->assertType( ScopedCallback::class, $value1, 'Second reentrant call returned lock' );
    }

    public function testReportDupes() {
        $logger = $this->getMock( 'Psr\Log\NullLogger' );
        $logger->expects( $this->once() )
            ->method( 'warning' )
            ->with( 'Duplicate get(): "{key}" fetched {count} times', [
                'key' => 'foo',
                'count' => 2,
            ] );

        $cache = new HashBagOStuff( [
            'reportDupes' => true,
            'asyncHandler' => 'DeferredUpdates::addCallableUpdate',
            'logger' => $logger,
        ] );
        $cache->get( 'foo' );
        $cache->get( 'bar' );
        $cache->get( 'foo' );

        DeferredUpdates::doUpdates();
    }
}