Fixed a bug in the MappedFileBuffer + added test case for exposing the bug.

sandbox/sandbox-common/src/main/java/com/twelvemonkeys/image/MappedFileBuffer.java

@@ -52,7 +52,7 @@ public abstract class MappedFileBuffer extends DataBuffer {
     private final Buffer buffer;
 
     private MappedFileBuffer(final int type, final int size, final int numBanks) throws IOException {
-        super(type, Validate.isTrue(size >= 0, size, "Integer overflow for size: %d"), numBanks);
+        super(type, Validate.isTrue(size >= 0, size, "Integer overflow for size: %d"), Validate.isTrue(numBanks >= 0, numBanks, "Number of banks must be positive"));
 
         int componentSize = DataBuffer.getDataTypeSize(type) / 8;
 
@@ -125,7 +125,7 @@ public abstract class MappedFileBuffer extends DataBuffer {
 
         @Override
         public int getElem(int bank, int i) {
-            return buffer.get(bank * size + i);
+            return buffer.get(bank * size + i) & 0xff;
         }
 
         @Override
@@ -144,12 +144,12 @@ public abstract class MappedFileBuffer extends DataBuffer {
 
         @Override
         public int getElem(int bank, int i) {
-            return buffer.get(bank * size + i);
+            return buffer.get(bank * size + i) & 0xffff;
         }
 
         @Override
         public void setElem(int bank, int i, int val) {
-            buffer.put(bank * size + i, (short) (val & 0xffff));
+            buffer.put(bank * size + i, (short) val);
         }
     }
 

sandbox/sandbox-common/src/test/java/com/twlevemonkeys/image/MappedFileBufferTest.java

@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2012, Harald Kuhr
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name "TwelveMonkeys" nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.twlevemonkeys.image;
+
+import com.twelvemonkeys.image.MappedFileBuffer;
+import org.junit.Test;
+
+import java.awt.image.DataBuffer;
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * MappedFileBufferTest
+ *
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
+ * @author last modified by $Author: haraldk$
+ * @version $Id: MappedFileBufferTest.java,v 1.0 01.06.12 14:23 haraldk Exp$
+ */
+public class MappedFileBufferTest {
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateInvalidType() throws IOException {
+        MappedFileBuffer.create(-1, 1, 1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateInvalidSize() throws IOException {
+        MappedFileBuffer.create(DataBuffer.TYPE_USHORT, -1, 1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateInvalidBands() throws IOException {
+        MappedFileBuffer.create(DataBuffer.TYPE_BYTE, 1, -1);
+    }
+
+    @Test
+    public void testCreateByte() throws IOException {
+        DataBuffer buffer = MappedFileBuffer.create(DataBuffer.TYPE_BYTE, 256, 3);
+        assertNotNull(buffer);
+
+        assertEquals(DataBuffer.TYPE_BYTE, buffer.getDataType());
+        assertEquals(256, buffer.getSize());
+        assertEquals(3, buffer.getNumBanks());
+    }
+
+    @Test
+    public void testSetGetElemByte() throws IOException {
+        final int size = 256;
+        DataBuffer buffer = MappedFileBuffer.create(DataBuffer.TYPE_BYTE, size, 3);
+        assertNotNull(buffer);
+
+        for (int b = 0; b < 3; b++) {
+            for (int i = 0; i < size; i++) {
+                buffer.setElem(b, i, i);
+
+                assertEquals(i, buffer.getElem(b, i));
+            }
+        }
+    }
+
+    @Test
+    public void testCreateUShort() throws IOException {
+        DataBuffer buffer = MappedFileBuffer.create(DataBuffer.TYPE_USHORT, 256, 3);
+        assertNotNull(buffer);
+
+        assertEquals(DataBuffer.TYPE_USHORT, buffer.getDataType());
+        assertEquals(256, buffer.getSize());
+        assertEquals(3, buffer.getNumBanks());
+    }
+
+    @Test
+    public void testSetGetElemUShort() throws IOException {
+        final int size = (Short.MAX_VALUE + 1) * 2;
+        DataBuffer buffer = MappedFileBuffer.create(DataBuffer.TYPE_USHORT, size, 3);
+        assertNotNull(buffer);
+
+        for (int b = 0; b < 3; b++) {
+            for (int i = 0; i < size; i++) {
+                buffer.setElem(b, i, i);
+
+                assertEquals(i, buffer.getElem(b, i));
+            }
+        }
+    }
+
+    @Test
+    public void testCreateInt() throws IOException {
+        DataBuffer buffer = MappedFileBuffer.create(DataBuffer.TYPE_INT, 256, 3);
+        assertNotNull(buffer);
+
+        assertEquals(DataBuffer.TYPE_INT, buffer.getDataType());
+        assertEquals(256, buffer.getSize());
+        assertEquals(3, buffer.getNumBanks());
+    }
+
+    @Test
+    public void testSetGetElemInt() throws IOException {
+        final int size = (Short.MAX_VALUE + 1) * 2;
+        DataBuffer buffer = MappedFileBuffer.create(DataBuffer.TYPE_INT, size, 3);
+        assertNotNull(buffer);
+
+        for (int b = 0; b < 3; b++) {
+            for (int i = 0; i < size; i++) {
+                buffer.setElem(b, i, i * i);
+
+                assertEquals(i * i, buffer.getElem(b, i));
+            }
+        }
+    }
+}