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.cassandra.db.commitlog;
  
  import java.io.ByteArrayOutputStream;
  import java.io.PrintStream;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.concurrent.ConcurrentLinkedQueue;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.junit.Assert;
  import org.junit.Test;
  
  import org.apache.cassandra.cql3.CQLTester;
  import org.apache.cassandra.cql3.QueryProcessor;
  import org.apache.cassandra.db.ColumnFamilyStore;
  import org.apache.cassandra.utils.FBUtilities;
  
  public class CommitLogCQLTest extends CQLTester
  {
      @Test
      public void testTruncateSegmentDiscard() throws Throwable
      {
          String otherTable = createTable("CREATE TABLE %s (idx INT, data TEXT, PRIMARY KEY(idx));");
  
          createTable("CREATE TABLE %s (idx INT, data TEXT, PRIMARY KEY(idx));");
          execute("INSERT INTO %s (idx, data) VALUES (?, ?)", 15, Integer.toString(15));
          flush();
  
          // We write something in different table to advance the commit log position. Current table remains clean.
          executeFormattedQuery(String.format("INSERT INTO %s.%s (idx, data) VALUES (?, ?)", keyspace(), otherTable), 16, Integer.toString(16));
  
          ColumnFamilyStore cfs = getCurrentColumnFamilyStore();
          assert cfs.getTracker().getView().getCurrentMemtable().isClean();
          // Calling switchMemtable directly applies Flush even though memtable is empty. This can happen with some races
          // (flush with recycling by segment manager). It should still tell commitlog that the memtable's region is clean.
          // CASSANDRA-12436
          cfs.switchMemtable(ColumnFamilyStore.FlushReason.UNIT_TESTS);
  
          execute("INSERT INTO %s (idx, data) VALUES (?, ?)", 15, Integer.toString(17));
  
          Collection<CommitLogSegment> active = new ArrayList<>(CommitLog.instance.segmentManager.getActiveSegments());
          CommitLog.instance.forceRecycleAllSegments();
  
          // If one of the previous segments remains, it wasn't clean.
          active.retainAll(CommitLog.instance.segmentManager.getActiveSegments());
          assert active.isEmpty();
      }
      
      @Test
      public void testSwitchMemtable() throws Throwable
      {
          createTable("CREATE TABLE %s (idx INT, data TEXT, PRIMARY KEY(idx));");
          ColumnFamilyStore cfs = getCurrentColumnFamilyStore();
          
          AtomicBoolean shouldStop = new AtomicBoolean(false);
          ConcurrentLinkedQueue<Throwable> errors = new ConcurrentLinkedQueue<>();
          List<Thread> threads = new ArrayList<>();
          
          final String stmt = String.format("INSERT INTO %s.%s (idx, data) VALUES(?, ?)", KEYSPACE, currentTable());
          for (int i = 0; i < 10; ++i)
          {
              threads.add(new Thread("" + i)
              {
                  public void run()
                  {
                      try
                      {
                          while (!shouldStop.get())
                          {
                              for (int i = 0; i < 50; i++)
                              {
                                  QueryProcessor.executeInternal(stmt, i, Integer.toString(i));
                              }
                              FBUtilities.waitOnFuture(cfs.dumpMemtable());
                          }
                      }
                      catch (Throwable t)
                      {
                          errors.add(t);
                          shouldStop.set(true);
                      }
                  }
              });
          }
  
          for (Thread t : threads)
              t.start();
  
          Thread.sleep(15_000);
          shouldStop.set(true);
          
          for (Thread t : threads)
              t.join();
  
          if (!errors.isEmpty())
          {
              StringBuilder sb = new StringBuilder();
              for(Throwable error: errors)
              {
                  sb.append("Got error during memtable switching:\n");
                  sb.append(error.getMessage() + "\n");
                  ByteArrayOutputStream os = new ByteArrayOutputStream();
                  PrintStream ps = new PrintStream(os);
                  error.printStackTrace(ps);
                  sb.append(os.toString("UTF-8"));
              }
              Assert.fail(sb.toString());
          }
      }
  }
  