GEOT-3315 Memory leak in ContentEntry.state

modules/library/data/src/main/java/org/geotools/data/store/ContentEntry.java

@@ -174,6 +174,16 @@ public void dispose() {
         }
     }
 
+    /**
+     * Removes a closed transaction from the state cache.
+     * @param transaction
+     */
+    public void clearTransaction(Transaction transaction) {
+        if (state.containsKey(transaction)) {
+            state.remove(transaction);
+        }
+    }
+
     public String toString() {
         return getTypeName();
     }

modules/library/data/src/main/java/org/geotools/data/store/DiffTransactionState.java

@@ -71,6 +71,10 @@ public Diff getDiff() {
      * the transaction is correct.
      */
     public synchronized void setTransaction(Transaction transaction) {
+        if (this.transaction != null && transaction == null) {
+            // clear ContentEntry transaction to fix GEOT-3315
+            state.getEntry().clearTransaction(this.transaction);
+        }
         this.transaction = transaction;
     }
 

modules/library/data/src/test/java/org/geotools/data/store/ContentEntryTest.java

@@ -0,0 +1,81 @@
+/*
+ *    GeoTools - The Open Source Java GIS Toolkit
+ *    http://geotools.org
+ * 
+ *    (C) 2011, Open Source Geospatial Foundation (OSGeo)
+ *    
+ *    This library is free software; you can redistribute it and/or
+ *    modify it under the terms of the GNU Lesser General Public
+ *    License as published by the Free Software Foundation;
+ *    version 2.1 of the License.
+ *
+ *    This library is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *    Lesser General Public License for more details.
+ */
+package org.geotools.data.store;
+
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.geotools.data.DefaultTransaction;
+import org.geotools.data.Transaction;
+import org.geotools.feature.NameImpl;
+import org.junit.Test;
+import org.opengis.feature.type.Name;
+
+/**
+ * Test the behaviour of {@link ContentEntry}.
+ * @author Mauro Bartolomeoli (mauro.bartolomeoli@geo-solutions.it)
+ */
+public class ContentEntryTest {
+
+    /**
+     * Test that the a Transaction is removed from state when the Transaction is
+     * closed.
+     */
+    @Test
+    public void transactionCacheClearedOnTransactionClose() {
+        ContentDataStore dataStore = new ContentDataStore() {
+
+            @Override
+            protected List<Name> createTypeNames() throws IOException {                
+                return null;
+            }
+
+            @Override
+            protected ContentFeatureSource createFeatureSource(ContentEntry entry)
+                    throws IOException {
+                return null;
+            }
+        };
+
+        Transaction transaction = new DefaultTransaction();
+
+        ContentEntry entry = new ContentEntry(dataStore, new NameImpl("test"));
+        ContentState state = entry.getState(transaction);
+        new DiffTransactionState(state);
+
+        // state is extracted from state cache
+        assertSame(state, entry.getState(transaction));
+        // and contains our transaction
+        assertSame(state.getTransaction(), transaction);
+
+        try {
+            transaction.close();
+
+            // after transaction closing, the old state has been cleared, so 
+            // a new one is built and returned
+            ContentState stateForClosedTransaction = entry.getState(transaction);
+            assertNotSame(stateForClosedTransaction, state);
+        } catch (IOException e) {
+            fail("Cannot close transaction: " + e.getLocalizedMessage());
+        }
+    }
+
+}

modules/library/main/src/main/java/org/geotools/data/DefaultTransaction.java

@@ -88,6 +88,9 @@ public DefaultTransaction(String handle) {
      *      org.geotools.data.Transaction.State)
      */
     public void putState(Object key, State state) {
+        if (stateLookup == null) {
+            return;
+        }
         if (stateLookup.containsKey(key)) {
             State current = (State) stateLookup.get(key);