NodeQueueTest.java

/**
 * Copyright 2009 the original author or authors.
 *
 * Licensed 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 net.sf.katta.protocol;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import static org.mockito.Matchers.endsWith;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.verify;
import net.sf.katta.AbstractZkTest;
import net.sf.katta.operation.node.NodeOperation;
import net.sf.katta.operation.node.OperationResult;

import org.I0Itec.zkclient.ZkClient;
import org.junit.Test;

public class NodeQueueTest extends AbstractZkTest {

  private String getRootPath() {
    // this path is cleaned up by ZkSystem!
    return _zk.getZkConf().getZkRootPath() + "/queue";
  }

  @Test(timeout = 15000)
  public void testResultMechanism() throws Exception {
    final NodeQueue queue = new NodeQueue(_zk.getZkClient(), getRootPath());
    NodeOperation nodeOperation = mock(NodeOperation.class);
    String elementId = queue.add(nodeOperation);

    assertNotNull(queue.peek());
    OperationResult result = new OperationResult("ndoe1");
    queue.complete(result);
    assertNotNull(queue.getResult(elementId, false));

    assertNotNull(queue.getResult(elementId, true));
    assertNull(queue.getResult(elementId, true));
  }

  @Test(timeout = 15000)
  public void testResultMechanism_DeletingOldResults() throws Exception {
    final NodeQueue queue = new NodeQueue(_zk.getZkClient(), getRootPath());
    String elementId = "operation-0000000000"; // cheat, we know the internals
    assertNull(queue.getResult(elementId, false));
    _zk.getZkClient().createPersistent(getRootPath() + "/results/" + elementId, "");
    assertNotNull(queue.getResult(elementId, false));

    NodeOperation nodeOperation = mock(NodeOperation.class);
    queue.add(nodeOperation);
    assertNull(queue.getResult(elementId, false));
  }

  @Test(timeout = 15000)
  public void testResultCleanup() throws Exception {
    ZkClient zkClientSpy = spy(_zk.getZkClient());
    NodeQueue queue = new NodeQueue(zkClientSpy, getRootPath());
    NodeOperation nodeOperation = mock(NodeOperation.class);
    String elementName = queue.add(nodeOperation);

    OperationResult result = new OperationResult("node1");
    // cause a unclean state
    doThrow(new IllegalStateException("test exception")).when(zkClientSpy).delete(endsWith(elementName));
    try {
      queue.complete(result);
      verify(zkClientSpy).createEphemeral(endsWith(elementName));
      fail("should throw exception");
    } catch (Exception e) {
      // expected
    }

    // we have now both, a operation and the operation for it
    assertEquals(1, queue.getResults().size());
    assertFalse(queue.isEmpty());

    // this should only be possible if zk connection fails so we try to cleanup
    // on queue initialization
    queue = new NodeQueue(_zk.getZkClient(), getRootPath());
    assertEquals(1, queue.getResults().size());
    assertTrue(queue.isEmpty());
  }
}