package it.com.atlassian.gzipfilter;
   
   import junit.framework.TestCase;
   import org.apache.commons.httpclient.Header;
   import org.apache.commons.httpclient.HttpClient;
   import org.apache.commons.httpclient.HttpMethod;
   import org.apache.commons.httpclient.methods.GetMethod;
   import org.junit.Test;
   import static org.junit.Assert.*;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.zip.GZIPInputStream;
  
  /**
   * Test to ensure that an out.flush() in a servlet results in bytes being send to the browser
   */
  public class TestFlushing
  {
  
      @Test
      public void testFlushingWithNoFilter() throws Exception {
          doTimingTest(null, null);
      }
      @Test
      public void testFlushingWithGzFilter() throws Exception {
          doTimingTest(IntegrationTestUtils.GZIP_RESPONSE_HEADER, IntegrationTestUtils.GZIP_ACCEPT_HEADER);
      }
  
      private void doTimingTest(Header expectedContentEncodoing, Header acceptHeader) throws IOException {
          long pause = 4000;
          HttpClient client = new HttpClient();
          HttpMethod method = new GetMethod(IntegrationTestUtils.URL + "flushing.html?delay=" + pause);
          if (acceptHeader != null) {
              method.addRequestHeader(acceptHeader);
          }
  
          long t0 = System.currentTimeMillis();
          int rc = client.executeMethod(method);
          long t1 = System.currentTimeMillis();
          assertEquals("Should return 200 - success", 200, rc);
          assertEquals(expectedContentEncodoing, method.getResponseHeader("Content-Encoding"));
          InputStream response = method.getResponseBodyAsStream();
          if (acceptHeader != null) {
              response = new GZIPInputStream(response, 1);
          }
  
          expect("first", response);
          long t2 = System.currentTimeMillis();
          expect("second", response);
          long t3 = System.currentTimeMillis();
          expect("last", response);
          long t4 = System.currentTimeMillis();
  
          assertTrue("read 'first' in response took: " + (t2 - t0), (t2 - t0) < 100); // should get "first" within 100ms of making the request
          assertTimeWithin(pause, t2, t3); // should get "second" within 4000 of "first"
          assertTimeWithin(pause, t3, t4); // should get "last" within 4000 of "second"
      }
  
      private static void assertTimeWithin(long expectedDelay, long t0, long t1) {
          assertEquals(expectedDelay, t1 - t0, 80);
      }
  
      private static void expect(String expected, InputStream in) throws IOException {
          for (int i = 0; i < expected.length(); i++) {
              int a = expected.charAt(i);
              int b = in.read();
              assertEquals(a, b);
          }
      }
  }