content: /*
   * 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.ambari.server.view;
  
  import java.util.concurrent.Semaphore;
  import java.util.concurrent.TimeUnit;
  
  import jakarta.servlet.FilterChain;
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  
  import org.apache.ambari.server.configuration.Configuration;
  import org.apache.ambari.server.state.stack.OsFamily;
  import org.easymock.EasyMock;
  import org.easymock.EasyMockSupport;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.powermock.api.mockito.PowerMockito;
  import org.powermock.core.classloader.annotations.PrepareForTest;
  import org.powermock.modules.junit4.PowerMockRunner;
  
  import com.google.inject.Binder;
  import com.google.inject.Guice;
  import com.google.inject.Injector;
  import com.google.inject.Module;
  
  /**
   * Tests the {@link ViewThrottleFilter}
   */
  @RunWith(PowerMockRunner.class)
  @PrepareForTest({ ViewThrottleFilter.class, Semaphore.class })
  public class ViewThrottleFilterTest extends EasyMockSupport {
  
    private Injector m_injector;
    private Semaphore m_mockSemaphore = createStrictMock(Semaphore.class);
  
    /**
     * @throws Exception
     */
    @Before
    public void setup() throws Exception {
      m_injector = Guice.createInjector(new MockModule());
      PowerMockito.whenNew(Semaphore.class).withAnyArguments().thenReturn(m_mockSemaphore);
    }
  
    /**
     * Tests that acquiring the {@link Semaphore} ensures that the
     * {@link FilterChain} is invoked and that the {@link Semaphore} is eventually
     * released.
     *
     * @throws Exception
     */
    @Test
    public void testAcquireInvokesFilterChain() throws Exception {
      Configuration configuration = m_injector.getInstance(Configuration.class);
      EasyMock.expect(configuration.getViewRequestThreadPoolMaxSize()).andReturn(1).atLeastOnce();
      EasyMock.expect(configuration.getViewRequestThreadPoolTimeout()).andReturn(2000).atLeastOnce();
      EasyMock.expect(configuration.getClientThreadPoolSize()).andReturn(25).atLeastOnce();
  
      // servlet mocks
      HttpServletRequest request = createNiceMock(HttpServletRequest.class);
      HttpServletResponse response = createStrictMock(HttpServletResponse.class);
      FilterChain filterChain = createStrictMock(FilterChain.class);
  
      // semaphore
      EasyMock.expect(m_mockSemaphore.tryAcquire(2000, TimeUnit.MILLISECONDS)).andReturn(true);
  
      // filter chain
      filterChain.doFilter(request, response);
      EasyMock.expectLastCall().once();
  
      // semaphore release
      m_mockSemaphore.release();
      EasyMock.expectLastCall().once();
  
      replayAll();
  
      ViewThrottleFilter filter = new ViewThrottleFilter();
      m_injector.injectMembers(filter);
      filter.init(null);
      filter.doFilter(request, response, filterChain);
  
      verifyAll();
    }
  
    /**
     * Tests that the failure to acquire the {@link Semaphore} stops the request
     * and returns a {@link HttpServletResponse#SC_SERVICE_UNAVAILABLE}.
     *
     * @throws Exception
     */
    @Test
    public void testSemaphorePreventsFilterChain() throws Exception {
      Configuration configuration = m_injector.getInstance(Configuration.class);
      EasyMock.expect(configuration.getViewRequestThreadPoolMaxSize()).andReturn(1).atLeastOnce();
      EasyMock.expect(configuration.getViewRequestThreadPoolTimeout()).andReturn(2000).atLeastOnce();
      EasyMock.expect(configuration.getClientThreadPoolSize()).andReturn(25).atLeastOnce();
  
      // servlet mocks
      HttpServletRequest request = createNiceMock(HttpServletRequest.class);
      HttpServletResponse response = createStrictMock(HttpServletResponse.class);
      FilterChain filterChain = createStrictMock(FilterChain.class);
  
      // semaphore
      EasyMock.expect(m_mockSemaphore.tryAcquire(2000, TimeUnit.MILLISECONDS)).andReturn(false);
  
      // response
      response.sendError(EasyMock.eq(HttpServletResponse.SC_SERVICE_UNAVAILABLE), EasyMock.anyString());
      EasyMock.expectLastCall().once();
  
      replayAll();
  
      ViewThrottleFilter filter = new ViewThrottleFilter();
      m_injector.injectMembers(filter);
      filter.init(null);
      filter.doFilter(request, response, filterChain);
  
      verifyAll();
    }
  
    /**
     *
     */
    private class MockModule implements Module {
      /**
      *
      */
      @Override
      public void configure(Binder binder) {
        binder.bind(Configuration.class).toInstance(createNiceMock(Configuration.class));
        binder.bind(OsFamily.class).toInstance(createNiceMock(OsFamily.class));
      }
    }
  }
  