Fixes #1810: Removes a CompassReader once the world is unloaded.

This should no longer keep a reference to a World around and potentially
keep them loaded.
Also added a finalize() to CompassRegion to ensure the file is closed on a
GC.

Some cleanup regarding member order, final, etc

src/main/java/appeng/services/CompassService.java

@@ -27,7 +27,6 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
-
 import javax.annotation.Nonnull;
 
 import com.google.common.base.Preconditions;
@@ -35,10 +34,14 @@ import com.google.common.base.Preconditions;
 import net.minecraft.block.Block;
 import net.minecraft.world.World;
 import net.minecraft.world.chunk.Chunk;
+import net.minecraftforge.event.world.WorldEvent;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+
 import appeng.api.AEApi;
 import appeng.api.util.DimensionalCoord;
 import appeng.services.compass.CompassReader;
 import appeng.services.compass.ICompassCallback;
+import appeng.util.Platform;
 
 
 public final class CompassService
@@ -70,6 +73,22 @@ public final class CompassService
 		return this.executor.submit( new CMDirectionRequest( coord, maxRange, cc ) );
 	}
 
+	/**
+	 * Ensure the a compass service is removed once a world gets unloaded by forge.
+	 *
+	 * @param event the event containing the unloaded world.
+	 */
+	@SubscribeEvent
+	public void unloadWorld( WorldEvent.Unload event )
+	{
+		if( Platform.isServer() && this.worldSet.containsKey( event.world ) )
+		{
+			final CompassReader compassReader = this.worldSet.remove( event.world );
+
+			compassReader.close();
+		}
+	}
+
 	public int jobSize()
 	{
 		return this.jobSize;
@@ -77,7 +96,7 @@ public final class CompassService
 
 	public void cleanUp()
 	{
-		for( CompassReader cr : this.worldSet.values() )
+		for( final CompassReader cr : this.worldSet.values() )
 		{
 			cr.close();
 		}
@@ -85,8 +104,8 @@ public final class CompassService
 
 	public void updateArea( World w, int chunkX, int chunkZ )
 	{
-		int x = chunkX << 4;
+		final int x = chunkX << 4;
-		int z = chunkZ << 4;
+		final int z = chunkZ << 4;
 
 		this.updateArea( w, x, CHUNK_SIZE, z );
 		this.updateArea( w, x, CHUNK_SIZE + 32, z );
@@ -103,17 +122,17 @@ public final class CompassService
 	{
 		this.jobSize++;
 
-		int cx = x >> 4;
+		final int cx = x >> 4;
-		int cdy = y >> 5;
+		final int cdy = y >> 5;
-		int cz = z >> 4;
+		final int cz = z >> 4;
 
-		int low_y = cdy << 5;
+		final int low_y = cdy << 5;
-		int hi_y = low_y + 32;
+		final int hi_y = low_y + 32;
 
 		// lower level...
-		Chunk c = w.getChunkFromChunkCoords( cx, cz );
+		final Chunk c = w.getChunkFromChunkCoords( cx, cz );
 
-		for( Block skyStoneBlock : AEApi.instance().definitions().blocks().skyStone().maybeBlock().asSet() )
+		for( final Block skyStoneBlock : AEApi.instance().definitions().blocks().skyStone().maybeBlock().asSet() )
 		{
 			for( int i = 0; i < CHUNK_SIZE; i++ )
 			{
@@ -134,6 +153,28 @@ public final class CompassService
 		return this.executor.submit( new CMUpdatePost( w, cx, cz, cdy, false ) );
 	}
 
+	public void kill()
+	{
+		this.executor.shutdown();
+
+		try
+		{
+			this.executor.awaitTermination( 6, TimeUnit.MINUTES );
+			this.jobSize = 0;
+
+			for( final CompassReader cr : this.worldSet.values() )
+			{
+				cr.close();
+			}
+
+			this.worldSet.clear();
+		}
+		catch( final InterruptedException e )
+		{
+			// wrap this up..
+		}
+	}
+
 	private CompassReader getReader( World w )
 	{
 		CompassReader cr = this.worldSet.get( w );
@@ -149,42 +190,20 @@ public final class CompassService
 
 	private int dist( int ax, int az, int bx, int bz )
 	{
-		int up = ( bz - az ) * CHUNK_SIZE;
+		final int up = ( bz - az ) * CHUNK_SIZE;
-		int side = ( bx - ax ) * CHUNK_SIZE;
+		final int side = ( bx - ax ) * CHUNK_SIZE;
 
 		return up * up + side * side;
 	}
 
 	private double rad( int ax, int az, int bx, int bz )
 	{
-		int up = bz - az;
+		final int up = bz - az;
-		int side = bx - ax;
+		final int side = bx - ax;
 
 		return Math.atan2( -up, side ) - Math.PI / 2.0;
 	}
 
-	public void kill()
-	{
-		this.executor.shutdown();
-
-		try
-		{
-			this.executor.awaitTermination( 6, TimeUnit.MINUTES );
-			this.jobSize = 0;
-
-			for( CompassReader cr : this.worldSet.values() )
-			{
-				cr.close();
-			}
-
-			this.worldSet.clear();
-		}
-		catch( InterruptedException e )
-		{
-			// wrap this up..
-		}
-	}
-
 	private class CMUpdatePost implements Runnable
 	{
 
@@ -209,7 +228,7 @@ public final class CompassService
 		{
 			CompassService.this.jobSize--;
 
-			CompassReader cr = CompassService.this.getReader( this.world );
+			final CompassReader cr = CompassService.this.getReader( this.world );
 			cr.setHasBeacon( this.chunkX, this.chunkZ, this.doubleChunkY, this.value );
 
 			if( CompassService.this.jobSize() < 2 )
@@ -239,10 +258,10 @@ public final class CompassService
 		{
 			CompassService.this.jobSize--;
 
-			int cx = this.coord.x >> 4;
+			final int cx = this.coord.x >> 4;
-			int cz = this.coord.z >> 4;
+			final int cz = this.coord.z >> 4;
 
-			CompassReader cr = CompassService.this.getReader( this.coord.getWorld() );
+			final CompassReader cr = CompassService.this.getReader( this.coord.getWorld() );
 
 			// Am I standing on it?
 			if( cr.hasBeacon( cx, cz ) )
@@ -260,10 +279,10 @@ public final class CompassService
 			// spiral outward...
 			for( int offset = 1; offset < this.maxRange; offset++ )
 			{
-				int minX = cx - offset;
+				final int minX = cx - offset;
-				int minZ = cz - offset;
+				final int minZ = cz - offset;
-				int maxX = cx + offset;
+				final int maxX = cx + offset;
-				int maxZ = cz + offset;
+				final int maxZ = cz + offset;
 
 				int closest = Integer.MAX_VALUE;
 				int chosen_x = cx;
@@ -273,7 +292,7 @@ public final class CompassService
 				{
 					if( cr.hasBeacon( minX, z ) )
 					{
-						int closeness = CompassService.this.dist( cx, cz, minX, z );
+						final int closeness = CompassService.this.dist( cx, cz, minX, z );
 						if( closeness < closest )
 						{
 							closest = closeness;
@@ -284,7 +303,7 @@ public final class CompassService
 
 					if( cr.hasBeacon( maxX, z ) )
 					{
-						int closeness = CompassService.this.dist( cx, cz, maxX, z );
+						final int closeness = CompassService.this.dist( cx, cz, maxX, z );
 						if( closeness < closest )
 						{
 							closest = closeness;
@@ -298,7 +317,7 @@ public final class CompassService
 				{
 					if( cr.hasBeacon( x, minZ ) )
 					{
-						int closeness = CompassService.this.dist( cx, cz, x, minZ );
+						final int closeness = CompassService.this.dist( cx, cz, x, minZ );
 						if( closeness < closest )
 						{
 							closest = closeness;
@@ -309,7 +328,7 @@ public final class CompassService
 
 					if( cr.hasBeacon( x, maxZ ) )
 					{
-						int closeness = CompassService.this.dist( cx, cz, x, maxZ );
+						final int closeness = CompassService.this.dist( cx, cz, x, maxZ );
 						if( closeness < closest )
 						{
 							closest = closeness;

src/main/java/appeng/services/compass/CompassReader.java

@@ -55,10 +55,18 @@ public final class CompassReader
 
 	public void setHasBeacon( int cx, int cz, int cdy, boolean hasBeacon )
 	{
-		CompassRegion r = this.getRegion( cx, cz );
+		final CompassRegion r = this.getRegion( cx, cz );
+
 		r.setHasBeacon( cx, cz, cdy, hasBeacon );
 	}
 
+	public boolean hasBeacon( int cx, int cz )
+	{
+		final CompassRegion r = this.getRegion( cx, cz );
+
+		return r.hasBeacon( cx, cz );
+	}
+
 	private CompassRegion getRegion( int cx, int cz )
 	{
 		long pos = cx >> 10;
@@ -66,6 +74,7 @@ public final class CompassReader
 		pos |= ( cz >> 10 );
 
 		CompassRegion cr = this.regions.get( pos );
+
 		if( cr == null )
 		{
 			cr = new CompassRegion( cx, cz, this.dimensionId, this.worldCompassFolder );
@@ -74,10 +83,4 @@ public final class CompassReader
 
 		return cr;
 	}
-
-	public boolean hasBeacon( int cx, int cz )
-	{
-		CompassRegion r = this.getRegion( cx, cz );
-		return r.hasBeacon( cx, cz );
-	}
 }

src/main/java/appeng/services/compass/CompassRegion.java

@@ -52,8 +52,8 @@ public final class CompassRegion
 		this.worldCompassFolder = worldCompassFolder;
 		this.encoder = new MeteorDataNameEncoder( 0 );
 
-		int region_x = cx >> 10;
+		final int region_x = cx >> 10;
-		int region_z = cz >> 10;
+		final int region_z = cz >> 10;
 
 		this.lowX = region_x << 10;
 		this.lowZ = region_z << 10;
@@ -61,42 +61,6 @@ public final class CompassRegion
 		this.openFile( false );
 	}
 
-	private void openFile( boolean create )
-	{
-		if( this.hasFile )
-		{
-			return;
-		}
-
-		final File file = this.getFile();
-		if( create || this.isFileExistent( file ) )
-		{
-			try
-			{
-				this.raf = new RandomAccessFile( file, "rw" );
-				FileChannel fc = this.raf.getChannel();
-				this.buffer = fc.map( FileChannel.MapMode.READ_WRITE, 0, 0x400 * 0x400 );// fc.size() );
-				this.hasFile = true;
-			}
-			catch( Throwable t )
-			{
-				throw new CompassException( t );
-			}
-		}
-	}
-
-	private File getFile()
-	{
-		final String fileName = this.encoder.encode( this.world, this.lowX, this.lowZ);
-
-		return new File( this.worldCompassFolder, fileName );
-	}
-
-	private boolean isFileExistent( File file )
-	{
-		return file.exists() && file.isFile();
-	}
-
 	public void close()
 	{
 		try
@@ -122,7 +86,7 @@ public final class CompassRegion
 			cx &= 0x3FF;
 			cz &= 0x3FF;
 
-			int val = this.read( cx, cz );
+			final int val = this.read( cx, cz );
 			if( val != 0 )
 			{
 				return true;
@@ -132,6 +96,87 @@ public final class CompassRegion
 		return false;
 	}
 
+	public void setHasBeacon( int cx, int cz, int cdy, boolean hasBeacon )
+	{
+		cx &= 0x3FF;
+		cz &= 0x3FF;
+
+		this.openFile( hasBeacon );
+
+		if( this.hasFile )
+		{
+			int val = this.read( cx, cz );
+			final int originalVal = val;
+
+			if( hasBeacon )
+			{
+				val |= 1 << cdy;
+			}
+			else
+			{
+				val &= ~( 1 << cdy );
+			}
+
+			if( originalVal != val )
+			{
+				this.write( cx, cz, val );
+			}
+		}
+	}
+
+	@Override
+	protected void finalize() throws Throwable
+	{
+		try
+		{
+			if( this.raf != null )
+			{
+				this.raf.close();
+			}
+		}
+		finally
+		{
+			super.finalize();
+		}
+
+	}
+
+	private void openFile( boolean create )
+	{
+		if( this.hasFile )
+		{
+			return;
+		}
+
+		final File file = this.getFile();
+		if( create || this.isFileExistent( file ) )
+		{
+			try
+			{
+				this.raf = new RandomAccessFile( file, "rw" );
+				final FileChannel fc = this.raf.getChannel();
+				this.buffer = fc.map( FileChannel.MapMode.READ_WRITE, 0, 0x400 * 0x400 );// fc.size() );
+				this.hasFile = true;
+			}
+			catch( final Throwable t )
+			{
+				throw new CompassException( t );
+			}
+		}
+	}
+
+	private File getFile()
+	{
+		final String fileName = this.encoder.encode( this.world, this.lowX, this.lowZ );
+
+		return new File( this.worldCompassFolder, fileName );
+	}
+
+	private boolean isFileExistent( File file )
+	{
+		return file.exists() && file.isFile();
+	}
+
 	private int read( int cx, int cz )
 	{
 		try
@@ -150,34 +195,6 @@ public final class CompassRegion
 		}
 	}
 
-	public void setHasBeacon( int cx, int cz, int cdy, boolean hasBeacon )
-	{
-		cx &= 0x3FF;
-		cz &= 0x3FF;
-
-		this.openFile( hasBeacon );
-
-		if( this.hasFile )
-		{
-			int val = this.read( cx, cz );
-			int originalVal = val;
-
-			if( hasBeacon )
-			{
-				val |= 1 << cdy;
-			}
-			else
-			{
-				val &= ~( 1 << cdy );
-			}
-
-			if( originalVal != val )
-			{
-				this.write( cx, cz, val );
-			}
-		}
-	}
-
 	private void write( int cx, int cz, int val )
 	{
 		try