Simplified logging in LuceneLabelScanStore

Currently LuceneLabelScanStore uses monitor to log messages about things like
initialization and rebuild. This logging, while being always valuable, could be
suppressed by passing in other monitor.

This commit makes log statements explicit and removes the logging monitor.

community/lucene-index/src/main/java/org/neo4j/index/lucene/LuceneLabelScanStoreBuilder.java

@@ -32,8 +32,6 @@
 import org.neo4j.kernel.impl.api.scan.LabelScanStoreProvider.FullStoreChangeStream;
 import org.neo4j.logging.LogProvider;
 
-import static org.neo4j.kernel.impl.api.scan.LabelScanStoreProvider.fullStoreLabelUpdateStream;
-
 /**
  * Means of obtaining a {@link LabelScanStore}, independent of the {@link org.neo4j.kernel.extension.KernelExtensions}
  * mechanism, when you need to access the store without running a full database. This is used during consistency
@@ -48,7 +46,7 @@ public class LuceneLabelScanStoreBuilder
     private final FileSystemAbstraction fileSystem;
     private final LogProvider logProvider;
 
-    private LuceneLabelScanStore labelScanStore = null;
+    private LuceneLabelScanStore labelScanStore;
 
     public LuceneLabelScanStoreBuilder( File storeDir, FullStoreChangeStream fullStoreStream,
             FileSystemAbstraction fileSystem, LogProvider logProvider )
@@ -68,8 +66,8 @@ public LabelScanStore build()
                     LabelScanStoreProvider.getStoreDirectory( storeDir ),
                     LuceneLabelScanStore.INDEX_IDENTIFIER );
             LuceneLabelScanIndex index = new LuceneLabelScanIndex( indexStorage );
-            labelScanStore = new LuceneLabelScanStore( index, fullStoreStream,
-                    LuceneLabelScanStore.loggerMonitor( logProvider ) );
+            labelScanStore = new LuceneLabelScanStore( index, fullStoreStream, logProvider,
+                    LuceneLabelScanStore.Monitor.EMPTY );
 
             try
             {

community/lucene-index/src/main/java/org/neo4j/kernel/api/impl/index/LuceneLabelScanStore.java

@@ -42,75 +42,65 @@ public class LuceneLabelScanStore implements LabelScanStore
     private final LuceneLabelScanIndex luceneIndex;
     // We get in a full store stream here in case we need to fully rebuild the store if it's missing or corrupted.
     private final FullStoreChangeStream fullStoreStream;
+    private final Log log;
     private final Monitor monitor;
     private boolean needsRebuild;
     private final Lock lock = new ReentrantLock( true );
 
     public interface Monitor
     {
-        void init();
-
-        void noIndex();
-
-        void lockedIndex( LockObtainFailedException e );
-
-        void corruptIndex( IOException e );
-
-        void rebuilding();
-
-        void rebuilt( long roughNodeCount );
-    }
-
-    // todo: WAT?
-    public static Monitor loggerMonitor( LogProvider logProvider )
-    {
-        final Log log = logProvider.getLog( LuceneLabelScanStore.class );
-        return new Monitor()
+        Monitor EMPTY = new Monitor()
         {
             @Override
             public void init()
-            {   // Don't log anything here
+            {
             }
 
             @Override
             public void noIndex()
             {
-                log.info( "No lucene scan store index found, this might just be first use. " +
-                             "Preparing to rebuild." );
             }
 
             @Override
             public void lockedIndex( LockObtainFailedException e )
             {
-                log.warn( "Index is locked by another process or database", e );
             }
 
             @Override
-            public void corruptIndex( IOException corruptionException )
+            public void corruptIndex( IOException e )
             {
-                log.warn( "Lucene scan store index could not be read. Preparing to rebuild.",
-                        corruptionException );
             }
 
             @Override
             public void rebuilding()
             {
-                log.info( "Rebuilding lucene scan store, this may take a while" );
             }
 
             @Override
-            public void rebuilt( long highNodeId )
+            public void rebuilt( long roughNodeCount )
             {
-                log.info( "Lucene scan store rebuilt (roughly " + highNodeId + " nodes)" );
             }
         };
+
+        void init();
+
+        void noIndex();
+
+        void lockedIndex( LockObtainFailedException e );
+
+        void corruptIndex( IOException e );
+
+        void rebuilding();
+
+        void rebuilt( long roughNodeCount );
     }
 
     public LuceneLabelScanStore( LuceneLabelScanIndex luceneIndex, FullStoreChangeStream fullStoreStream,
-            Monitor monitor )
+            LogProvider logProvider, Monitor monitor )
     {
         this.luceneIndex = luceneIndex;
         this.fullStoreStream = fullStoreStream;
+        this.log = logProvider.getLog( getClass() );
         this.monitor = monitor;
     }
 
@@ -147,7 +137,9 @@ public void init() throws IOException
         {
             if ( !luceneIndex.exists() )
             {
+                log.info( "No lucene scan store index found, this might just be first use. Preparing to rebuild." );
                 monitor.noIndex();
+
                 luceneIndex.create();
                 needsRebuild = true;
             }
@@ -158,6 +150,8 @@ else if ( !luceneIndex.isValid() )
 //                luceneIndex.create();
 //                needsRebuild = true;
 
+                log.warn( "Lucene scan store index could not be read. Preparing to rebuild." );
+
                 throw new IOException( "Label scan store could not be read, and needs to be rebuilt. " +
                                        "To trigger a rebuild, ensure the database is stopped, delete the files in '" +
                                        luceneIndex + "', and then start the database again." );
@@ -169,6 +163,7 @@ else if ( !luceneIndex.isValid() )
         catch ( LockObtainFailedException e )
         {
             luceneIndex.close();
+            log.error( "Index is locked by another process or database", e );
             monitor.lockedIndex( e );
             throw e;
         }
@@ -181,8 +176,10 @@ public void start() throws IOException
         {   // we saw in init() that we need to rebuild the index, so do it here after the
             // neostore has been properly started.
             monitor.rebuilding();
+            log.info( "Rebuilding lucene scan store, this may take a while" );
             long numberOfNodes = rebuild();
             monitor.rebuilt( numberOfNodes );
+            log.info( "Lucene scan store rebuilt (roughly " + numberOfNodes + " nodes)" );
             needsRebuild = false;
         }
     }

community/lucene-index/src/main/java/org/neo4j/kernel/api/impl/index/LuceneLabelScanStoreExtension.java

@@ -36,7 +36,6 @@
 import org.neo4j.kernel.lifecycle.Lifecycle;
 
 import static org.neo4j.kernel.api.impl.index.LuceneKernelExtensions.directoryFactory;
-import static org.neo4j.kernel.api.impl.index.LuceneLabelScanStore.loggerMonitor;
 import static org.neo4j.kernel.impl.api.scan.LabelScanStoreProvider.fullStoreLabelUpdateStream;
 
 @Service.Implementation(KernelExtensionFactory.class)
@@ -69,7 +68,7 @@ public LuceneLabelScanStoreExtension()
     {
         super( "lucene-scan-store");
         this.priority = priority;
-        this.monitor = monitor;
+        this.monitor = (monitor == null) ? Monitor.EMPTY : monitor;
     }
 
     @Override
@@ -80,7 +79,9 @@ public LabelScanStoreProvider newInstance( KernelContext context, Dependencies d
 
         LuceneLabelScanIndex index = getLuceneIndex( context, directoryFactory );
         LuceneLabelScanStore scanStore = new LuceneLabelScanStore( index,
-                fullStoreLabelUpdateStream( dependencies.indexStoreView() ), getMonitor( dependencies ) );
+                fullStoreLabelUpdateStream( dependencies.indexStoreView() ),
+                dependencies.getLogService().getInternalLogProvider(), monitor );
+
 
         return new LabelScanStoreProvider( scanStore, priority );
     }
@@ -93,8 +94,4 @@ private LuceneLabelScanIndex getLuceneIndex( KernelContext context, DirectoryFac
         return new LuceneLabelScanIndex( indexStorage );
     }
 
-    private Monitor getMonitor( Dependencies dependencies )
-    {
-        return monitor != null ? monitor : loggerMonitor( dependencies.getLogService().getInternalLogProvider() );
-    }
 }

community/lucene-index/src/test/java/org/neo4j/kernel/api/impl/index/LuceneLabelScanStoreTest.java

@@ -52,6 +52,7 @@
 import org.neo4j.kernel.impl.api.scan.LabelScanStoreProvider.FullStoreChangeStream;
 import org.neo4j.kernel.lifecycle.LifeSupport;
 import org.neo4j.kernel.lifecycle.LifecycleException;
+import org.neo4j.logging.NullLogProvider;
 import org.neo4j.storageengine.api.schema.BoundedIterable;
 import org.neo4j.storageengine.api.schema.LabelScanReader;
 import org.neo4j.storageengine.api.schema.NodeLabelRange;
@@ -459,7 +460,8 @@ private void start( List<NodeLabelUpdate> existingData )
                 LuceneLabelScanStore.INDEX_IDENTIFIER );
 
         LuceneLabelScanIndex index = new LuceneLabelScanIndex( documentFormat, indexStorage );
-        store = life.add( new LuceneLabelScanStore( index, asStream( existingData ), monitor ) );
+        store = new LuceneLabelScanStore( index, asStream( existingData ), NullLogProvider.getInstance(), monitor );
+        life.add( store );
 
         life.start();
         assertTrue( monitor.initCalled );