mem-patch

.gitignore

@@ -0,0 +1,3 @@
+/build/
+/.classpath
+/.project

demos/prefuse/demos/Congress.java

@@ -157,9 +157,9 @@ public Renderer getRenderer(VisualItem item) {
 
         // set up the actions
         AxisLayout xaxis = new AxisLayout(group, "State Code",
-                Constants.X_AXIS, VisiblePredicate.TRUE); 
+                Constants.X_AXIS, VisiblePredicate.getTruePredicate()); 
         AxisLayout yaxis = new AxisLayout(group, RECEIPTS,
-                Constants.Y_AXIS, VisiblePredicate.TRUE);
+                Constants.Y_AXIS, VisiblePredicate.getTruePredicate());
         //yaxis.setScale(Constants.LOG_SCALE);
         yaxis.setRangeModel(receiptsQ.getModel());
         receiptsQ.getNumberModel().setValueRange(0,65000000,0,65000000);

demos/prefuse/demos/ScatterPlot.java

@@ -61,11 +61,11 @@ public ScatterPlot(Table t, String xfield, String yfield, String sfield) {
 
         // set up the actions
         AxisLayout x_axis = new AxisLayout(group, xfield, 
-                Constants.X_AXIS, VisiblePredicate.TRUE);
+                Constants.X_AXIS, VisiblePredicate.getTruePredicate());
         m_vis.putAction("x", x_axis);
 
         AxisLayout y_axis = new AxisLayout(group, yfield, 
-                Constants.Y_AXIS, VisiblePredicate.TRUE);
+                Constants.Y_AXIS, VisiblePredicate.getTruePredicate());
         m_vis.putAction("y", y_axis);
 
         ColorAction color = new ColorAction(group, 

src/prefuse/Display.java

@@ -421,9 +421,9 @@ public void setPredicate(String expr) {
      */
     public synchronized void setPredicate(Predicate p) {
         if ( p == null ) {
-            m_predicate.set(VisiblePredicate.TRUE);
+            m_predicate.set(VisiblePredicate.getTruePredicate());
         } else {
-            m_predicate.set(new Predicate[] {p, VisiblePredicate.TRUE});
+            m_predicate.set(new Predicate[] {p, VisiblePredicate.getTruePredicate()});
         }
     }
 

src/prefuse/Visualization.java

@@ -936,7 +936,7 @@ public void invalidateAll() {
      * @return an iterator over all visible items.
      */
     public Iterator visibleItems() {
-        return items(VisiblePredicate.TRUE);
+        return items(VisiblePredicate.getTruePredicate());
     }
 
     /**
@@ -945,7 +945,7 @@ public Iterator visibleItems() {
      * @return an iterator over all visible items in the specified group
      */
     public Iterator visibleItems(String group) {
-        return items(group, VisiblePredicate.TRUE);
+        return items(group, VisiblePredicate.getTruePredicate());
     }
 
     /**

src/prefuse/action/ItemAction.java

@@ -60,7 +60,7 @@ public ItemAction(String group, Predicate filter) {
      * @param group the name of the group to process
      */
     public ItemAction(Visualization vis, String group) {
-        this(vis, group, VisiblePredicate.TRUE);
+        this(vis, group, VisiblePredicate.getTruePredicate());
     }
 
     /**

src/prefuse/action/filter/VisibilityFilter.java

@@ -56,7 +56,7 @@ public VisibilityFilter(Visualization vis, String group, Predicate p) {
      */
     protected void setPredicate(Predicate p) {
         m_predicate = p;
-        m_filter = new OrPredicate(p, VisiblePredicate.TRUE);
+        m_filter = new OrPredicate(p, VisiblePredicate.getTruePredicate());
     }
 
     /**

src/prefuse/util/display/RenderingQueue.java

@@ -33,7 +33,7 @@ public class RenderingQueue {
     // buffer queues for use in sorting, these prevent continual re-allocation
     transient static VisualItem[] items_buf;
     transient static int[]        scores_buf;
-    
+
     /**
      * Clear both rendering and picking queues.
      */
@@ -122,6 +122,9 @@ private void sort(VisualItem[] items, int[] scores, int size) {
         }
         // now sort
         ArrayLib.sort(scores, items, scores_buf, items_buf, 0, size);
+
+        // clean up the temp buffer from object references
+        Arrays.fill(items_buf, null);
     }
 
 } // end of class RenderingQueue

src/prefuse/visual/expression/VisiblePredicate.java

@@ -1,5 +1,7 @@
 package prefuse.visual.expression;
 
+import java.lang.ref.WeakReference;
+
 import prefuse.data.expression.ColumnExpression;
 import prefuse.data.expression.Expression;
 import prefuse.data.expression.Function;
@@ -12,15 +14,35 @@
  * 
  * @author <a href="http://jheer.org">jeffrey heer</a>
  */
-public class VisiblePredicate extends ColumnExpression
-    implements Predicate, Function
-{
-
-    /** Convenience instance for the visible == true case. */
-    public static final Predicate TRUE = new VisiblePredicate();
-    /** Convenience instance for the visible == false case. */
-    public static final Predicate FALSE = new NotPredicate(TRUE);
-
+public class VisiblePredicate extends ColumnExpression implements Predicate, Function {
+
+    private static WeakReference TRUE_REFERENCE;
+    private static WeakReference FALSE_REFERENCE;
+
+    public static synchronized Predicate getTruePredicate() {
+        if (TRUE_REFERENCE != null) {
+            Object item = TRUE_REFERENCE.get();
+            if (item instanceof Predicate) {
+                return (Predicate) item;
+            }
+        }
+        VisiblePredicate TRUE = new VisiblePredicate();
+        TRUE_REFERENCE = new WeakReference(TRUE);
+        return TRUE;
+    }
+
+    public static synchronized Predicate getFalsePredicate() {
+        if (FALSE_REFERENCE != null) {
+            Object item = FALSE_REFERENCE.get();
+            if (item instanceof Predicate) {
+                return (Predicate) item;
+            }
+        }
+        Predicate FALSE = new NotPredicate(getTruePredicate());
+        TRUE_REFERENCE = new WeakReference(FALSE);
+        return FALSE;
+    }
+
     /**
      * Create a new VisiblePredicate.
      */
@@ -48,12 +70,12 @@ public void addParameter(Expression e) {
     public int getParameterCount() {
         return 0;
     }
-    
+
     /**
      * @see java.lang.Object#toString()
      */
     public String toString() {
-        return getName()+"()";
+        return getName() + "()";
     }
 
 } // end of class VisiblePredicate