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.bookkeeper.bookie.datainteg;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.equalTo;
  import static org.hamcrest.Matchers.instanceOf;
  
  import com.google.common.collect.Lists;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.TimeUnit;
  import org.apache.bookkeeper.client.BKException;
  import org.apache.bookkeeper.client.LedgerMetadataBuilder;
  import org.apache.bookkeeper.client.api.DigestType;
  import org.apache.bookkeeper.client.api.LedgerMetadata;
  import org.apache.bookkeeper.common.concurrent.FutureUtils;
  import org.apache.bookkeeper.meta.LedgerManager;
  import org.apache.bookkeeper.meta.MockLedgerManager;
  import org.apache.bookkeeper.net.BookieId;
  import org.apache.bookkeeper.versioning.Versioned;
  import org.junit.Assert;
  import org.junit.Test;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Tests for MetadataAsyncIterator.
   */
  public class MetadataAsyncIteratorTest {
      private static Logger log = LoggerFactory.getLogger(MetadataAsyncIteratorTest.class);
  
      private LedgerMetadata newRandomMetadata(long randBit) throws Exception {
          return LedgerMetadataBuilder.create()
              .withId(1)
              .withPassword(new byte[0])
              .withDigestType(DigestType.CRC32C)
              .withEnsembleSize(1)
              .withWriteQuorumSize(1)
              .withAckQuorumSize(1)
              .newEnsembleEntry(0, Lists.newArrayList(
                                        BookieId.parse("foobar-" + randBit + ":3181")))
              .build();
      }
  
      private ConcurrentHashMap<Long, LedgerMetadata> addLedgers(LedgerManager lm, int count)
              throws Exception {
          ConcurrentHashMap<Long, LedgerMetadata> added = new ConcurrentHashMap<>();
          for (long i = 0; i < count; i++) {
              LedgerMetadata metadata = newRandomMetadata(i);
              lm.createLedgerMetadata(i, metadata).get();
              added.put(i, metadata);
          }
          return added;
      }
  
      private static CompletableFuture<Void> removeFromMap(
              ConcurrentHashMap<Long, LedgerMetadata> map,
              long ledgerId, LedgerMetadata metadata) {
          if (log.isDebugEnabled()) {
              log.debug("removing ledger {}", ledgerId);
          }
          if (map.remove(ledgerId, metadata)) {
              return CompletableFuture.completedFuture(null);
          } else {
              if (log.isDebugEnabled()) {
                  log.debug("ledger {} already removed", ledgerId);
              }
              return FutureUtils.exception(new Exception("ledger already removed"));
          }
      }
  
      @Test
      public void testIteratorOverAll() throws Exception {
          MockLedgerManager lm = new MockLedgerManager();
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, 10000);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          iterator.forEach((ledgerId, metadata) -> removeFromMap(added, ledgerId, metadata))
              .get(10, TimeUnit.SECONDS);
          assertThat(added.isEmpty(), equalTo(true));
      }
  
      @Test
      public void testSingleLedger() throws Exception {
          MockLedgerManager lm = new MockLedgerManager();
          LedgerMetadata single = newRandomMetadata(0xdeadbeef);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          iterator.forEach((ledgerId, metadata) -> {
                  if (ledgerId == 0xdeadbeef && metadata.equals(single)) {
                      return CompletableFuture.completedFuture(null);
                  } else {
                      return FutureUtils.exception(new Exception("Unexpected metadata"));
                  }
              }).get(10, TimeUnit.SECONDS);
      }
  
      @Test
      public void testEmptyRange() throws Exception {
          MockLedgerManager lm = new MockLedgerManager();
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          iterator.forEach((ledgerId, metadata) -> FutureUtils.exception(new Exception("Should be empty")))
              .get(10, TimeUnit.SECONDS);
      }
  
      @Test
      public void testOneLedgerErrorsOnRead() throws Exception {
          MockLedgerManager lm = new MockLedgerManager() {
                  @Override
                  public CompletableFuture<Versioned<LedgerMetadata>> readLedgerMetadata(long ledgerId) {
                      if (ledgerId == 403) {
                          return FutureUtils.exception(new BKException.ZKException());
                      } else {
                          return super.readLedgerMetadata(ledgerId);
                      }
                  }
              };
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, 10000);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          try {
              iterator.forEach((ledgerId, metadata) -> removeFromMap(added, ledgerId, metadata))
                  .get(10, TimeUnit.SECONDS);
          } catch (ExecutionException ee) {
              assertThat(ee.getCause(), instanceOf(BKException.ZKException.class));
          }
      }
  
      @Test
      public void testOneLedgerErrorsOnProcessing() throws Exception {
          MockLedgerManager lm = new MockLedgerManager();
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, 10000);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          try {
              iterator.forEach((ledgerId, metadata) -> {
                      if (ledgerId == 403) {
                          log.info("IKDEBUG erroring");
                          return FutureUtils.exception(new Exception("foobar"));
                      } else {
                          return CompletableFuture.completedFuture(null);
                      }
                  }).get(10, TimeUnit.SECONDS);
              Assert.fail("shouldn't succeed");
          } catch (ExecutionException ee) {
              assertThat(ee.getCause().getMessage(), equalTo("foobar"));
          }
      }
  
      @Test
      public void testAllLedgersErrorOnRead() throws Exception {
          MockLedgerManager lm = new MockLedgerManager() {
                  @Override
                  public CompletableFuture<Versioned<LedgerMetadata>> readLedgerMetadata(long ledgerId) {
                      CompletableFuture<Versioned<LedgerMetadata>> promise = new CompletableFuture<>();
                      promise.completeExceptionally(new BKException.ZKException());
                      return promise;
                  }
              };
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, 10000);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          try {
              iterator.forEach((ledgerId, metadata) -> CompletableFuture.completedFuture(null))
                  .get(10, TimeUnit.SECONDS);
          } catch (ExecutionException ee) {
              assertThat(ee.getCause(), instanceOf(BKException.ZKException.class));
          }
      }
  
      @Test
      public void testAllLedgersErrorOnProcessing() throws Exception {
          MockLedgerManager lm = new MockLedgerManager();
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, 10000);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          try {
              iterator.forEach((ledgerId, metadata) -> FutureUtils.exception(new Exception("foobar")))
                  .get(10, TimeUnit.SECONDS);
              Assert.fail("shouldn't succeed");
          } catch (ExecutionException ee) {
              assertThat(ee.getCause().getMessage(), equalTo("foobar"));
          }
      }
  
      @Test
      public void testOneLedgerDisappearsBetweenListAndRead() throws Exception {
          MockLedgerManager lm = new MockLedgerManager() {
                  @Override
                  public CompletableFuture<Versioned<LedgerMetadata>> readLedgerMetadata(long ledgerId) {
                      if (ledgerId == 501) {
                          CompletableFuture<Versioned<LedgerMetadata>> promise = new CompletableFuture<>();
                          promise.completeExceptionally(new BKException.BKNoSuchLedgerExistsOnMetadataServerException());
                          return promise;
                      } else {
                          return super.readLedgerMetadata(ledgerId);
                      }
                  }
              };
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, 10000);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100 /* inflight */,
                                                                     3 /* timeout */, TimeUnit.SECONDS);
          iterator.forEach((ledgerId, metadata) -> removeFromMap(added, ledgerId, metadata))
              .get(10, TimeUnit.SECONDS);
          assertThat(added.size(), equalTo(1));
          log.info("IKDEBUG {} {}", added, added.containsKey(5L));
          assertThat(added.containsKey(501L), equalTo(true));
      }
  
      @Test
      public void testEverySecondLedgerDisappearsBetweenListAndRead() throws Exception {
          MockLedgerManager lm = new MockLedgerManager() {
                  @Override
                  public CompletableFuture<Versioned<LedgerMetadata>> readLedgerMetadata(long ledgerId) {
                      if (ledgerId % 2 == 0) {
                          return FutureUtils.exception(
                                  new BKException.BKNoSuchLedgerExistsOnMetadataServerException());
                      } else {
                          return super.readLedgerMetadata(ledgerId);
                      }
                  }
              };
          int numLedgers = 10000;
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, numLedgers);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100,
                                                                     3, TimeUnit.SECONDS);
          iterator.forEach((ledgerId, metadata) -> removeFromMap(added, ledgerId, metadata))
              .get(10, TimeUnit.SECONDS);
          assertThat(added.size(), equalTo(numLedgers / 2));
          assertThat(added.keySet().stream().allMatch(k -> k % 2 == 0), equalTo(true));
          assertThat(added.keySet().stream().noneMatch(k -> k % 2 == 1), equalTo(true));
      }
  
      @Test
      public void testEveryLedgerDisappearsBetweenListAndRead() throws Exception {
          MockLedgerManager lm = new MockLedgerManager() {
                  @Override
                  public CompletableFuture<Versioned<LedgerMetadata>> readLedgerMetadata(long ledgerId) {
                      return FutureUtils.exception(
                              new BKException.BKNoSuchLedgerExistsOnMetadataServerException());
                  }
              };
          int numLedgers = 10000;
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, numLedgers);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 100,
                                                                     3, TimeUnit.SECONDS);
          iterator.forEach((ledgerId, metadata) -> removeFromMap(added, ledgerId, metadata))
              .get(10, TimeUnit.SECONDS);
          assertThat(added.size(), equalTo(numLedgers));
      }
  
      @Test
      public void testMaxOutInFlight() throws Exception {
          MockLedgerManager lm = new MockLedgerManager();
          int numLedgers = 1000;
          ConcurrentHashMap<Long, LedgerMetadata> added = addLedgers(lm, numLedgers);
          MetadataAsyncIterator iterator = new MetadataAsyncIterator(Schedulers.io(),
                                                                     lm, 10,
                                                                     3, TimeUnit.SECONDS);
          CompletableFuture<Void> blocker = new CompletableFuture<>();
          CompletableFuture<Void> iterFuture = iterator.forEach(
                  (ledgerId, metadata) ->
                  blocker.thenCompose(ignore -> removeFromMap(added, ledgerId, metadata)));
          assertThat(iterFuture.isDone(), equalTo(false));
          blocker.complete(null);
          iterFuture.get(10, TimeUnit.SECONDS);
          assertThat(added.isEmpty(), equalTo(true));
      }
  
  }
  