nio/src/test/java/common/org/apache/harmony/nio/tests/java/nio/AbstractBufferTest.java

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.harmony.nio.tests.java.nio;

import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.InvalidMarkException;

import junit.framework.TestCase;

/**
 * Tests a java.nio.Buffer instance.
 */
public class AbstractBufferTest extends TestCase {
    
    protected Buffer baseBuf;
    
    protected void setUp() throws Exception{
    	super.setUp();
    	baseBuf = ByteBuffer.allocate(10);
    }
    
    protected void tearDown() throws Exception{
    	super.tearDown();
    }

    public void testCapacity() {
        assertTrue(0 <= baseBuf.position() && baseBuf.position() <= baseBuf.limit()
                && baseBuf.limit() <= baseBuf.capacity());
    }

    public void testClear() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        Buffer ret = baseBuf.clear();
        assertSame(ret, baseBuf);
        assertEquals(baseBuf.position(), 0);
        assertEquals(baseBuf.limit(), baseBuf.capacity());
        try {
            baseBuf.reset();
            fail("Should throw Exception"); //$NON-NLS-1$S
        } catch (InvalidMarkException e) {
            // expected
        }

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    public void testFlip() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        Buffer ret = baseBuf.flip();
        assertSame(ret, baseBuf);
        assertEquals(baseBuf.position(), 0);
        assertEquals(baseBuf.limit(), oldPosition);
        try {
            baseBuf.reset();
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (InvalidMarkException e) {
            // expected
        }

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    public void testHasRemaining() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        assertEquals(baseBuf.hasRemaining(), baseBuf.position() < baseBuf.limit());
        baseBuf.position(baseBuf.limit());
        assertFalse(baseBuf.hasRemaining());

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    public void testIsReadOnly() {
        baseBuf.isReadOnly();
    }

    /*
     * Class under test for int limit()
     */
    public void testLimit() {
        assertTrue(0 <= baseBuf.position() && baseBuf.position() <= baseBuf.limit()
                && baseBuf.limit() <= baseBuf.capacity());
    }

    /*
     * Class under test for Buffer limit(int)
     */
    public void testLimitint() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        Buffer ret = baseBuf.limit(baseBuf.limit());
        assertSame(ret, baseBuf);

        baseBuf.mark();
        baseBuf.limit(baseBuf.capacity());
        assertEquals(baseBuf.limit(), baseBuf.capacity());
        // position should not change
        assertEquals(baseBuf.position(), oldPosition);
        // mark should be valid
        baseBuf.reset();

        if (baseBuf.capacity() > 0) {
            baseBuf.limit(baseBuf.capacity());
            baseBuf.position(baseBuf.capacity());
            baseBuf.mark();
            baseBuf.limit(baseBuf.capacity() - 1);
            // position should be the new limit
            assertEquals(baseBuf.position(), baseBuf.limit());
            // mark should be invalid
            try {
                baseBuf.reset();
                fail("Should throw Exception"); //$NON-NLS-1$
            } catch (InvalidMarkException e) {
                // expected
            }
        }

        try {
            baseBuf.limit(-1);
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (IllegalArgumentException e) {
            // expected
        }
        try {
            baseBuf.limit(baseBuf.capacity() + 1);
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (IllegalArgumentException e) {
            // expected
        }

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    public void testMark() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        Buffer ret = baseBuf.mark();
        assertSame(ret, baseBuf);

        baseBuf.mark();
        baseBuf.position(baseBuf.limit());
        baseBuf.reset();
        assertEquals(baseBuf.position(), oldPosition);

        baseBuf.mark();
        baseBuf.position(baseBuf.limit());
        baseBuf.reset();
        assertEquals(baseBuf.position(), oldPosition);

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    /*
     * Class under test for int position()
     */
    public void testPosition() {
        assertTrue(0 <= baseBuf.position() && baseBuf.position() <= baseBuf.limit()
                && baseBuf.limit() <= baseBuf.capacity());
    }

    /*
     * Class under test for Buffer position(int)
     */
    public void testPositionint() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        try {
            baseBuf.position(-1);
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (IllegalArgumentException e) {
            // expected
        }
        try {
            baseBuf.position(baseBuf.limit() + 1);
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (IllegalArgumentException e) {
            // expected
        }

        baseBuf.mark();
        baseBuf.position(baseBuf.position());
        baseBuf.reset();
        assertEquals(baseBuf.position(), oldPosition);

        baseBuf.position(0);
        assertEquals(baseBuf.position(), 0);
        baseBuf.position(baseBuf.limit());
        assertEquals(baseBuf.position(), baseBuf.limit());

        if (baseBuf.capacity() > 0) {
            baseBuf.limit(baseBuf.capacity());
            baseBuf.position(baseBuf.limit());
            baseBuf.mark();
            baseBuf.position(baseBuf.limit() - 1);
            assertEquals(baseBuf.position(), baseBuf.limit() - 1);
            // mark should be invalid
            try {
                baseBuf.reset();
                fail("Should throw Exception"); //$NON-NLS-1$
            } catch (InvalidMarkException e) {
                // expected
            }
        }

        Buffer ret = baseBuf.position(0);
        assertSame(ret, baseBuf);

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    public void testRemaining() {
        assertEquals(baseBuf.remaining(), baseBuf.limit() - baseBuf.position());
    }

    public void testReset() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        baseBuf.mark();
        baseBuf.position(baseBuf.limit());
        baseBuf.reset();
        assertEquals(baseBuf.position(), oldPosition);

        baseBuf.mark();
        baseBuf.position(baseBuf.limit());
        baseBuf.reset();
        assertEquals(baseBuf.position(), oldPosition);

        Buffer ret = baseBuf.reset();
        assertSame(ret, baseBuf);

        baseBuf.clear();
        try {
            baseBuf.reset();
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (InvalidMarkException e) {
            // expected
        }

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }

    public void testRewind() {
        // save state
        int oldPosition = baseBuf.position();
        int oldLimit = baseBuf.limit();

        Buffer ret = baseBuf.rewind();
        assertEquals(baseBuf.position(), 0);
        assertSame(ret, baseBuf);
        try {
            baseBuf.reset();
            fail("Should throw Exception"); //$NON-NLS-1$
        } catch (InvalidMarkException e) {
            // expected
        }

        // restore state
        baseBuf.limit(oldLimit);
        baseBuf.position(oldPosition);
    }
}