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.beam.runners.dataflow.worker;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.fail;
  import static org.mockito.Mockito.doThrow;
  import static org.mockito.Mockito.verify;
  
  import java.io.IOException;
  import java.util.concurrent.TimeUnit;
  import org.apache.beam.sdk.io.UnboundedSource;
  import org.apache.beam.vendor.grpc.v1p69p0.com.google.protobuf.ByteString;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Stopwatch;
  import org.joda.time.Duration;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  import org.mockito.Mock;
  import org.mockito.MockitoAnnotations;
  
  /** Tests for {@link ReaderCache}. */
  @RunWith(JUnit4.class)
  public class ReaderCacheTest {
  
    private static final String C_ID = "computationId";
    private static final String C_ID_1 = "computationId_1";
  
    private static final ByteString KEY_1 = ByteString.copyFromUtf8("0000000000000001");
    private static final ByteString KEY_2 = ByteString.copyFromUtf8("0000000000000002");
    private static final ByteString KEY_3 = ByteString.copyFromUtf8("0000000000000003");
  
    private static final long SHARDING_KEY = 12345;
    private static final long SHARDING_KEY_1 = 54321;
  
    private ReaderCache readerCache = null;
  
    @Mock private UnboundedSource.UnboundedReader<?> reader1;
    @Mock private UnboundedSource.UnboundedReader<?> reader2;
    @Mock private UnboundedSource.UnboundedReader<?> reader3;
  
    @Before
    public void setUp() {
      readerCache = new ReaderCache(Duration.standardMinutes(1), Runnable::run);
      MockitoAnnotations.initMocks(this);
    }
  
    @Test
    public void testReaderCache() throws IOException {
      // Test basic caching expectations
  
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 0, reader1);
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY), 2, 0, reader2);
  
      assertEquals(
          reader1,
          readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 1));
      assertNull(
          readerCache.acquireReader(
              WindmillComputationKey.create(C_ID_1, KEY_1, SHARDING_KEY), 1, 1));
      assertNull(
          readerCache.acquireReader(
              WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY_1), 1, 1));
  
      // Trying to override existing reader should throw
      try {
        readerCache.cacheReader(
            WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY), 2, 2, reader1);
        fail("Exception should have been thrown");
      } catch (RuntimeException expected) {
        // expected
      }
  
      // And it should not have overwritten the old value
      assertEquals(
          reader2,
          readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY), 2, 3));
  
      assertNull(
          "acquireReader(WindmillComputationKey.create() should remove matching entry",
          readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY), 2, 4));
  
      // Make sure computationId is part of the cache key
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID_1, KEY_1, SHARDING_KEY), 1, 5, reader2);
      assertEquals(
          reader2,
          readerCache.acquireReader(
              WindmillComputationKey.create(C_ID_1, KEY_1, SHARDING_KEY), 1, 6));
  
      // Make sure sharding key is part of the cache key
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY_1), 1, 0, reader3);
      assertEquals(
          reader3,
          readerCache.acquireReader(
              WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY_1), 1, 1));
    }
  
    @Test
    public void testInvalidation() throws IOException {
  
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 0, reader1);
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY), 2, 0, reader2);
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY_1), 2, 0, reader3);
  
      readerCache.invalidateReader(WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY));
      verify(reader1).close();
  
      // Verify IOException during close is not thrown (it is logged).
      doThrow(new IOException("swallowed")).when(reader2).close();
      readerCache.invalidateReader(WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY));
  
      // Make sure a runtime exception is not swallowed
      doThrow(new RuntimeException("expected")).when(reader3).close();
      try {
        readerCache.invalidateReader(WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY_1));
        fail("Exception should have been thrown");
      } catch (RuntimeException e) {
        assertEquals("expected", e.getMessage());
      }
    }
  
    @Test
    public void testReaderCacheExpiration() throws IOException, InterruptedException {
      // Make sure cache closes the reader soon after expiry (as long as readerCache is accessed).
      Duration cacheDuration = Duration.millis(10);
  
      // Create a cache with short expiry period.
      ReaderCache readerCache = new ReaderCache(cacheDuration, Runnable::run);
  
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 0, reader1);
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_2, SHARDING_KEY), 2, 0, reader2);
  
      Stopwatch stopwatch = Stopwatch.createStarted();
      while (stopwatch.elapsed(TimeUnit.MILLISECONDS) < 2 * cacheDuration.getMillis()) {
        Thread.sleep(1);
      }
  
      // Trigger clean up with a lookup, non-existing key is ok.
      readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_3, SHARDING_KEY), 3, 0);
  
      verify(reader1).close();
    }
  
    @Test
    public void testReaderCacheRetries() throws IOException, InterruptedException {
      ReaderCache readerCache = new ReaderCache(Duration.standardMinutes(1), Runnable::run);
  
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 1, reader1);
      // Same cache token should not recover the reader from the cache.
      assertNull(
          readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 1));
  
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 1, reader2);
      assertEquals(
          reader2,
          readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 20));
      readerCache.cacheReader(
          WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 20, reader2);
      // Stale cache token should not recover the reader from the cache.
      assertNull(
          readerCache.acquireReader(WindmillComputationKey.create(C_ID, KEY_1, SHARDING_KEY), 1, 3));
  
      verify(reader1).close();
      verify(reader2).close();
    }
  }
  