Don't clear an empty table

neo4j · Dec 21, 2015 · b509ce1 · b509ce1
1 parent d4de728
commit b509ce1
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Showing 3 changed files with 38 additions and 7 deletions.
diff --git a/...ections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntArrayBasedKeyTable.java b/...ections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntArrayBasedKeyTable.java
@@ -163,7 +163,10 @@ protected int index( int index )
     @Override
     public void clear()
     {
-        clearTable();
+        if ( !isEmpty() )
+        {
+            clearTable();
+        }
         super.clear();
     }
 }
diff --git a/...itive-collections/src/main/java/org/neo4j/collection/primitive/hopscotch/UnsafeTable.java b/...itive-collections/src/main/java/org/neo4j/collection/primitive/hopscotch/UnsafeTable.java
@@ -39,13 +39,21 @@ protected UnsafeTable( int capacity, int bytesPerKey, VALUE valueMarker )
         this.valueMarker = valueMarker;
         this.dataSize = (long)this.capacity*bytesPerEntry;
         this.address = UnsafeUtil.allocateMemory( dataSize );
-        clear();
+        clearMemory();
     }
 
     @Override
     public void clear()
     {
+        if ( !isEmpty() )
+        {
+            clearMemory();
+        }
         super.clear();
+    }
+
+    private void clearMemory()
+    {
         UnsafeUtil.setMemory( address, dataSize, (byte)-1 );
     }
 

diff --git a/...ve-collections/src/test/java/org/neo4j/collection/primitive/hopscotch/BasicTableTest.java b/...ve-collections/src/test/java/org/neo4j/collection/primitive/hopscotch/BasicTableTest.java
@@ -192,9 +192,9 @@ public BasicTableTest( TableFactory factory )
     @Test
     public void shouldSetAndGetSmallKey() throws Exception
     {
-        // GIVEN
         try ( Table table = factory.newTable( Primitive.DEFAULT_HEAP_CAPACITY ) )
         {
+            // GIVEN
             long nullKey = table.nullKey();
             assertEquals( nullKey, table.key( 0 ) );
 
@@ -215,10 +215,10 @@ public void shouldSetAndGetSmallKey() throws Exception
     @Test
     public void shouldSetAndGetBigKey() throws Exception
     {
-        // GIVEN
         assumeTrue( factory.supportsLongs() );
         try ( Table table = factory.newTable( Primitive.DEFAULT_HEAP_CAPACITY ) )
         {
+            // GIVEN
             long nullKey = table.nullKey();
             assertEquals( nullKey, table.key( 0 ) );
 
@@ -235,10 +235,10 @@ public void shouldSetAndGetBigKey() throws Exception
     @Test
     public void shouldRemoveBigKey() throws Exception
     {
-        // GIVEN
         assumeTrue( factory.supportsLongs() );
         try ( Table table = factory.newTable( Primitive.DEFAULT_HEAP_CAPACITY ) )
         {
+            // GIVEN
             long nullKey = table.nullKey();
             long key = 0x24F1FF3FEL;
             int index = 5;
@@ -256,9 +256,9 @@ public void shouldRemoveBigKey() throws Exception
     @Test
     public void shouldSetHopBits() throws Exception
     {
-        // GIVEN
         try ( Table<?> table = factory.newTable( Primitive.DEFAULT_HEAP_CAPACITY ) )
         {
+            // GIVEN
             int index = 10;
             long hopBits = table.hopBits( index );
             assertEquals( 0L, hopBits );
@@ -275,9 +275,9 @@ public void shouldSetHopBits() throws Exception
     @Test
     public void shouldMoveHopBit() throws Exception
     {
-        // GIVEN
         try ( Table<?> table = factory.newTable( Primitive.DEFAULT_HEAP_CAPACITY ) )
         {
+            // GIVEN
             int index = 10;
             table.putHopBit( index, 2 );
             table.putHopBit( index, 11 );
@@ -290,6 +290,26 @@ public void shouldMoveHopBit() throws Exception
         }
     }
 
+    @Test
+    public void shouldClearTable() throws Exception
+    {
+        try ( Table table = factory.newTable( Primitive.DEFAULT_HEAP_CAPACITY ) )
+        {
+            // GIVEN
+            int index = 3;
+            long key = 123L;
+            Object value = factory.sampleValue();
+            table.put( index, key, value );
+            assertEquals( key, table.key( index ) );
+
+            // WHEN
+            table.clear();
+
+            // THEN
+            assertEquals( table.nullKey(), table.key( index ) );
+        }
+    }
+
     private interface TableFactory
     {
         Table newTable( int capacity );