Cleanup cycling and configuration of page swappers

Build page cache factory only page cache is actually created.
Move configure to PageSwapper and remove ConfigurablePageSwapperFactory.

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/Configuration.java

@@ -33,4 +33,17 @@ public interface Configuration
      * of the given property.
      */
     <T> T get( Setting<T> setting );
+
+    /**
+     * Empty configuration without any settings.
+     */
+    Configuration EMPTY = new Configuration()
+    {
+        @Override
+        public <T> T get( Setting<T> setting )
+        {
+            return null;
+        }
+    };
+
 }

community/io/pom.xml

@@ -64,6 +64,11 @@ the relevant Commercial Agreement.
       <groupId>org.apache.commons</groupId>
       <artifactId>commons-lang3</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.neo4j</groupId>
+      <artifactId>neo4j-graphdb-api</artifactId>
+      <version>${project.version}</version>
+    </dependency>
 
     <!-- Test dependencies -->
     <dependency>

community/io/src/main/java/org/neo4j/io/pagecache/PageSwapperFactory.java

@@ -24,6 +24,7 @@
 import java.nio.file.NoSuchFileException;
 import java.util.stream.Stream;
 
+import org.neo4j.graphdb.config.Configuration;
 import org.neo4j.io.fs.FileSystemAbstraction;
 
 /**
@@ -33,17 +34,27 @@
  * <p>
  * The PageSwapperFactory presumably knows about what file system to use.
  * <p>
+ * To be able to create PageSwapper factory need to be configured first using appropriate configure call.
  * Note that this API is <em>only</em> intended to be used by a {@link PageCache} implementation.
  * It should never be used directly by user code.
  */
 public interface PageSwapperFactory
 {
     /**
-     * Configure the FileSystemAbstraction to use.
-     * <p>
-     * This must be called before the first PageSwapper is created.
+     * Configure page swapper factory with filesystem and config
+     * @param fs file system to use in page swappers
+     * @param config custom page swapper configuration
+     */
+    void configure( FileSystemAbstraction fs, Configuration config );
+
+    /**
+     * Configure swapper with filesystem to use.
+     * @param fs file system to use in page swappers
      */
-    void setFileSystemAbstraction( FileSystemAbstraction fs );
+    default void configure( FileSystemAbstraction fs )
+    {
+        this.configure( fs, Configuration.EMPTY );
+    }
 
     /**
      * Get the name of this PageSwapperFactory implementation, for configuration purpose.

community/io/src/main/java/org/neo4j/io/pagecache/impl/SingleFilePageSwapperFactory.java

@@ -27,6 +27,7 @@
 import java.util.List;
 import java.util.stream.Stream;
 
+import org.neo4j.graphdb.config.Configuration;
 import org.neo4j.io.fs.FileSystemAbstraction;
 import org.neo4j.io.pagecache.FileHandle;
 import org.neo4j.io.pagecache.PageEvictionCallback;
@@ -45,7 +46,7 @@ public class SingleFilePageSwapperFactory implements PageSwapperFactory
     private FileSystemAbstraction fs;
 
     @Override
-    public void setFileSystemAbstraction( FileSystemAbstraction fs )
+    public void configure( FileSystemAbstraction fs, Configuration config )
     {
         this.fs = fs;
     }

community/io/src/main/java/org/neo4j/io/pagecache/impl/muninn/StandalonePageCacheFactory.java

@@ -54,7 +54,7 @@ public static PageCache createPageCache( FileSystemAbstraction fileSystem, Integ
             PageCacheTracer tracer, PageCursorTracerSupplier cursorTracerSupplier )
     {
         SingleFilePageSwapperFactory factory = new SingleFilePageSwapperFactory();
-        factory.setFileSystemAbstraction( fileSystem );
+        factory.configure( fileSystem );
 
         int cachePageSize = pageSize != null ? pageSize : factory.getCachePageSizeHint();
         long pageCacheMemory = ByteUnit.mebiBytes( 8 );

community/io/src/test/java/org/neo4j/io/pagecache/PageCacheTest.java

@@ -3744,7 +3744,7 @@ public void force() throws IOException
                 };
             }
         };
-        factory.setFileSystemAbstraction( fs );
+        factory.configure( fs );
         return factory;
     }
 

community/io/src/test/java/org/neo4j/io/pagecache/PageCacheTestSupport.java

@@ -42,8 +42,8 @@
 import org.neo4j.io.fs.StoreChannel;
 import org.neo4j.io.pagecache.impl.SingleFilePageSwapperFactory;
 import org.neo4j.io.pagecache.tracing.PageCacheTracer;
-import org.neo4j.test.rule.RepeatRule;
 import org.neo4j.io.pagecache.tracing.cursor.PageCursorTracerSupplier;
+import org.neo4j.test.rule.RepeatRule;
 
 import static org.junit.Assert.assertThat;
 import static org.neo4j.test.matchers.ByteArrayMatcher.byteArray;
@@ -117,7 +117,7 @@ protected T createPageCache( FileSystemAbstraction fs, int maxPages, int pageSiz
             PageCursorTracerSupplier cursorTracerSupplier )
     {
         PageSwapperFactory swapperFactory = new SingleFilePageSwapperFactory();
-        swapperFactory.setFileSystemAbstraction( fs );
+        swapperFactory.configure( fs );
         return createPageCache( swapperFactory, maxPages, pageSize, tracer, cursorTracerSupplier );
     }
 

community/io/src/test/java/org/neo4j/io/pagecache/impl/SingleFilePageSwapperTest.java

@@ -38,6 +38,7 @@
 
 import org.neo4j.adversaries.RandomAdversary;
 import org.neo4j.adversaries.fs.AdversarialFileSystemAbstraction;
+import org.neo4j.graphdb.config.Configuration;
 import org.neo4j.graphdb.mockfs.DelegatingFileSystemAbstraction;
 import org.neo4j.graphdb.mockfs.DelegatingStoreChannel;
 import org.neo4j.graphdb.mockfs.EphemeralFileSystemAbstraction;
@@ -81,7 +82,7 @@ public void tearDown() throws Exception
     protected PageSwapperFactory swapperFactory()
     {
         SingleFilePageSwapperFactory factory = new SingleFilePageSwapperFactory();
-        factory.setFileSystemAbstraction( getFs() );
+        factory.configure( getFs(), Configuration.EMPTY );
         return factory;
     }
 
@@ -235,7 +236,7 @@ public void creatingSwapperForFileMustTakeLockOnFile() throws Exception
         assumeFalse( "No file locking on Windows", SystemUtils.IS_OS_WINDOWS );
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( fileSystem );
+        factory.configure( fileSystem );
         File file = testDir.file( "file" );
         fileSystem.create( file ).close();
 
@@ -259,7 +260,7 @@ public void creatingSwapperForInternallyLockedFileMustThrow() throws Exception
         assumeFalse( "No file locking on Windows", SystemUtils.IS_OS_WINDOWS ); // no file locking on Windows.
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( fileSystem );
+        factory.configure( fileSystem );
         File file = testDir.file( "file" );
 
         StoreFileChannel channel = fileSystem.create( file );
@@ -278,7 +279,7 @@ public void creatingSwapperForExternallyLockedFileMustThrow() throws Exception
         assumeFalse( "No file locking on Windows", SystemUtils.IS_OS_WINDOWS ); // no file locking on Windows.
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( fileSystem );
+        factory.configure( fileSystem );
         File file = testDir.file( "file" );
 
         fileSystem.create( file ).close();
@@ -312,7 +313,7 @@ public void mustUnlockFileWhenThePageSwapperIsClosed() throws Exception
         assumeFalse( "No file locking on Windows", SystemUtils.IS_OS_WINDOWS ); // no file locking on Windows.
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( fileSystem );
+        factory.configure( fileSystem );
         File file = testDir.file( "file" );
         fileSystem.create( file ).close();
 
@@ -331,7 +332,7 @@ public void fileMustRemainLockedEvenIfChannelIsClosedByStrayInterrupt() throws E
         assumeFalse( "No file locking on Windows", SystemUtils.IS_OS_WINDOWS ); // no file locking on Windows.
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( fileSystem );
+        factory.configure( fileSystem );
         File file = testDir.file( "file" );
         fileSystem.create( file ).close();
 
@@ -360,7 +361,7 @@ public void mustCloseFilesIfTakingFileLockThrows() throws Exception
 
         final AtomicInteger openFilesCounter = new AtomicInteger();
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( new DelegatingFileSystemAbstraction( fileSystem )
+        factory.configure( new DelegatingFileSystemAbstraction( fileSystem )
         {
             @Override
             public StoreChannel open( File fileName, String mode ) throws IOException
@@ -421,7 +422,7 @@ public void mustHandleMischiefInPositionedRead() throws Exception
         ThreadLocalRandom.current().nextBytes( data );
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( getFs() );
+        factory.configure( getFs() );
         File file = getFile();
         PageSwapper swapper = createSwapper( factory, file, bytesTotal, NO_CALLBACK, true );
         try
@@ -434,7 +435,7 @@ public void mustHandleMischiefInPositionedRead() throws Exception
         }
 
         RandomAdversary adversary = new RandomAdversary( 0.5, 0.0, 0.0 );
-        factory.setFileSystemAbstraction( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
+        factory.configure( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
         swapper = createSwapper( factory, file, bytesTotal, NO_CALLBACK, false );
 
         ByteBufferPage page = createPage( bytesTotal );
@@ -466,7 +467,7 @@ public void mustHandleMischiefInPositionedWrite() throws Exception
         File file = getFile();
         PageSwapperFactory factory = createSwapperFactory();
         RandomAdversary adversary = new RandomAdversary( 0.5, 0.0, 0.0 );
-        factory.setFileSystemAbstraction( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
+        factory.configure( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
         PageSwapper swapper = createSwapper( factory, file, bytesTotal, NO_CALLBACK, true );
 
         ByteBufferPage page = createPage( bytesTotal );
@@ -502,7 +503,7 @@ public void mustHandleMischiefInPositionedVectoredRead() throws Exception
         ThreadLocalRandom.current().nextBytes( data );
 
         PageSwapperFactory factory = createSwapperFactory();
-        factory.setFileSystemAbstraction( getFs() );
+        factory.configure( getFs() );
         File file = getFile();
         PageSwapper swapper = createSwapper( factory, file, bytesTotal, NO_CALLBACK, true );
         try
@@ -515,7 +516,7 @@ public void mustHandleMischiefInPositionedVectoredRead() throws Exception
         }
 
         RandomAdversary adversary = new RandomAdversary( 0.5, 0.0, 0.0 );
-        factory.setFileSystemAbstraction( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
+        factory.configure( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
         swapper = createSwapper( factory, file, bytesPerPage, NO_CALLBACK, false );
 
         ByteBufferPage[] pages = new ByteBufferPage[pageCount];
@@ -561,7 +562,7 @@ public void mustHandleMischiefInPositionedVectoredWrite() throws Exception
         File file = getFile();
         PageSwapperFactory factory = createSwapperFactory();
         RandomAdversary adversary = new RandomAdversary( 0.5, 0.0, 0.0 );
-        factory.setFileSystemAbstraction( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
+        factory.configure( new AdversarialFileSystemAbstraction( adversary, getFs() ) );
         PageSwapper swapper = createSwapper( factory, file, bytesPerPage, NO_CALLBACK, true );
 
         ByteBufferPage[] writePages = new ByteBufferPage[pageCount];

community/io/src/test/java/org/neo4j/io/pagecache/randomharness/RandomPageCacheTestHarness.java

@@ -382,7 +382,7 @@ private void runIteration( long timeout, TimeUnit unit ) throws Exception
         }
 
         PageSwapperFactory swapperFactory = new SingleFilePageSwapperFactory();
-        swapperFactory.setFileSystemAbstraction( fs );
+        swapperFactory.configure( fs );
         MuninnPageCache cache = new MuninnPageCache( swapperFactory, cachePageCount, cachePageSize, tracer,
                 cursorTracerSupplier );
         cache.setPrintExceptionsOnClose( false );

community/io/src/test/java/org/neo4j/io/pagecache/stress/PageCacheStressTest.java

@@ -87,7 +87,7 @@ public void run() throws Exception
         try ( FileSystemAbstraction fs = new DefaultFileSystemAbstraction() )
         {
             PageSwapperFactory swapperFactory = new SingleFilePageSwapperFactory();
-            swapperFactory.setFileSystemAbstraction( fs );
+            swapperFactory.configure( fs );
 
             try ( PageCache pageCacheUnderTest = new MuninnPageCache( swapperFactory, numberOfCachePages, cachePageSize,
                     tracer, pageCursorTracerSupplier ) )

community/kernel/src/main/java/org/neo4j/kernel/impl/pagecache/ConfiguringPageCacheFactory.java

@@ -41,7 +41,8 @@
 public class ConfiguringPageCacheFactory
 {
     private static final int pageSize = getInteger( ConfiguringPageCacheFactory.class, "pageSize", 8192 );
-    private final PageSwapperFactory swapperFactory;
+    private PageSwapperFactory swapperFactory;
+    private final FileSystemAbstraction fs;
     private final Config config;
     private final PageCacheTracer pageCacheTracer;
     private final Log log;
@@ -60,46 +61,19 @@ public class ConfiguringPageCacheFactory
     public ConfiguringPageCacheFactory( FileSystemAbstraction fs, Config config, PageCacheTracer pageCacheTracer,
             PageCursorTracerSupplier pageCursorTracerSupplier, Log log )
     {
-        this.swapperFactory = createAndConfigureSwapperFactory( fs, config, log );
+        this.fs = fs;
         this.config = config;
         this.pageCacheTracer = pageCacheTracer;
         this.log = log;
         this.pageCursorTracerSupplier = pageCursorTracerSupplier;
     }
 
-    private PageSwapperFactory createAndConfigureSwapperFactory( FileSystemAbstraction fs, Config config, Log log )
-    {
-        String desiredImplementation = config.get( pagecache_swapper );
-
-        if ( desiredImplementation != null )
-        {
-            for ( PageSwapperFactory factory : Service.load( PageSwapperFactory.class ) )
-            {
-                if ( factory.implementationName().equals( desiredImplementation ) )
-                {
-                    factory.setFileSystemAbstraction( fs );
-                    if ( factory instanceof ConfigurablePageSwapperFactory )
-                    {
-                        ConfigurablePageSwapperFactory configurableFactory = (ConfigurablePageSwapperFactory) factory;
-                        configurableFactory.configure( config );
-                    }
-                    log.info( "Configured " + pagecache_swapper.name() + ": " + desiredImplementation );
-                    return factory;
-                }
-            }
-            throw new IllegalArgumentException( "Cannot find PageSwapperFactory: " + desiredImplementation );
-        }
-
-        SingleFilePageSwapperFactory factory = new SingleFilePageSwapperFactory();
-        factory.setFileSystemAbstraction( fs );
-        return factory;
-    }
-
     public synchronized PageCache getOrCreatePageCache()
     {
         if ( pageCache == null )
         {
-            pageCache = createPageCache();
+            this.swapperFactory = createAndConfigureSwapperFactory( fs, config, log );
+            this.pageCache = createPageCache();
         }
         return pageCache;
     }
@@ -218,4 +192,30 @@ public void dumpConfiguration()
 
         log.info( msg );
     }
+
+    private static PageSwapperFactory createAndConfigureSwapperFactory( FileSystemAbstraction fs, Config config, Log log )
+    {
+        PageSwapperFactory factory = getPageSwapperFactory( config, log );
+        factory.configure( fs, config );
+        return factory;
+    }
+
+    private static PageSwapperFactory getPageSwapperFactory( Config config, Log log )
+    {
+        String desiredImplementation = config.get( pagecache_swapper );
+        if ( desiredImplementation != null )
+        {
+            for ( PageSwapperFactory factory : Service.load( PageSwapperFactory.class ) )
+            {
+                if ( factory.implementationName().equals( desiredImplementation ) )
+                {
+                    log.info( "Configured " + pagecache_swapper.name() + ": " + desiredImplementation );
+                    return factory;
+                }
+            }
+            throw new IllegalArgumentException( "Cannot find PageSwapperFactory: " + desiredImplementation );
+        }
+        return new SingleFilePageSwapperFactory();
+    }
+
 }