pooling for extra buffers

erh · erh · commit 8aeb408277c5 · 2010-05-05T13:11:15.000-04:00
diff --git a/src/main/com/mongodb/io/DBOutputBuffer.java b/src/main/com/mongodb/io/DBOutputBuffer.java
@@ -4,6 +4,7 @@
 
 import org.bson.*;
 import org.bson.io.*;
+import org.bson.util.*;
 
 import java.io.*;
 import java.util.*;
@@ -20,7 +21,8 @@ public void reset(){
         _cur.reset();
         _end.reset();
 
-        // TODO: pool
+        for ( int i=0; i<_fromPool.size(); i++ )
+            _extra.done( _fromPool.get(i) );
         _fromPool.clear();
     }
 
@@ -90,7 +92,7 @@ void _afterWrite(){
         if ( _end.y < BUF_SIZE )
             return;
         
-        _fromPool.add( new byte[BUF_SIZE] ); // TODO: pool
+        _fromPool.add( _extra.get() );
         _end.nextBuffer();
         _cur.reset( _end );
     }
@@ -180,5 +182,10 @@ public String toString(){
     
     private final Position _cur = new Position();
     private final Position _end = new Position();
-
+    
+    private static SimplePool<byte[]> _extra = new SimplePool<byte[]>( ( 1024 * 1024 * 10 ) / BUF_SIZE ){
+        protected byte[] createNew(){
+            return new byte[BUF_SIZE];
+        }
+    };
 }
diff --git a/src/main/org/bson/util/SimplePool.java b/src/main/org/bson/util/SimplePool.java
@@ -0,0 +1,43 @@
+// SimplePool.java
+
+package org.bson.util;
+
+import java.util.*;
+
+public abstract class SimplePool<T> {
+
+    public SimplePool( int max ){
+        _max = max;
+    }
+
+    public SimplePool(){
+        _max = 1000;
+    }
+    
+    protected abstract T createNew();
+
+    protected boolean ok( T t ){
+        return true;
+    }
+    
+    public T get(){
+        synchronized ( _stored ){
+            if ( _stored.size() > 0 ) 
+                return _stored.removeFirst();
+        }
+        return createNew();
+    }
+
+    public void done( T t ){
+        if ( ! ok( t ) )
+            return;
+        synchronized ( _stored ){
+            if ( _stored.size() > _max )
+                return;
+            _stored.addFirst( t );
+        }
+    }
+    
+    final int _max;
+    private LinkedList<T> _stored = new LinkedList<T>();
+}
