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.cql3;
  
  import java.util.Iterator;
  
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  import com.datastax.driver.core.Cluster;
  import com.datastax.driver.core.ResultSet;
  import com.datastax.driver.core.Row;
  import com.datastax.driver.core.Session;
  import com.datastax.driver.core.SimpleStatement;
  import com.datastax.driver.core.Statement;
  import org.apache.cassandra.ServerTestUtils;
  import org.apache.cassandra.config.DatabaseDescriptor;
  import org.apache.cassandra.locator.InetAddressAndPort;
  import org.apache.cassandra.locator.Replica;
  import org.apache.cassandra.locator.ReplicaCollection;
  import org.apache.cassandra.locator.NodeProximity;
  import org.apache.cassandra.locator.BaseProximity;
  import org.apache.cassandra.service.EmbeddedCassandraService;
  
  import static org.apache.cassandra.config.CassandraRelevantProperties.CASSANDRA_CONFIG;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  
  
  public class PagingTest
  {
      private static Cluster cluster;
      private static Session session;
  
      private static final String KEYSPACE = "paging_test";
      private static final String createKsStatement = "CREATE KEYSPACE " + KEYSPACE +
                                                      " WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 2 };";
  
      private static final String dropKsStatement = "DROP KEYSPACE IF EXISTS " + KEYSPACE;
      private static EmbeddedCassandraService cassandra;
  
      @BeforeClass
      public static void setup() throws Exception
      {
          CASSANDRA_CONFIG.setString("cassandra-murmur.yaml");
  
          cassandra = ServerTestUtils.startEmbeddedCassandraService();
  
          // Currently the native server start method return before the server is fully binded to the socket, so we need
          // to wait slightly before trying to connect to it. We should fix this but in the meantime using a sleep.
          Thread.sleep(500);
  
          cluster = Cluster.builder().addContactPoint("127.0.0.1")
                                     .withPort(DatabaseDescriptor.getNativeTransportPort())
                                     .build();
          session = cluster.connect();
  
          session.execute(dropKsStatement);
          session.execute(createKsStatement);
      }
  
      @AfterClass
      public static void tearDown()
      {
          if (cluster != null)
              cluster.close();
          if (cassandra != null)
              cassandra.stop();
      }
  
      /**
       * Makes sure that we don't drop any live rows when paging with DISTINCT queries
       *
       * * We need to have more rows than fetch_size
       * * The node must have a token within the first page (so that the range gets split up in StorageProxy#getRestrictedRanges)
       *   - This means that the second read in the second range will read back too many rows
       * * The extra rows are dropped (so that we only return fetch_size rows to client)
       * * This means that the last row recorded in AbstractQueryPager#recordLast is a non-live one
       * * For the next page, the first row returned will be the same non-live row as above
       * * The bug in CASSANDRA-14956 caused us to drop that non-live row + the first live row in the next page
       */
      @Test
      public void testPaging() throws InterruptedException
      {
          String table = KEYSPACE + ".paging";
          String createTableStatement = "CREATE TABLE IF NOT EXISTS " + table + " (id int, id2 int, id3 int, val text, PRIMARY KEY ((id, id2), id3));";
          String dropTableStatement = "DROP TABLE IF EXISTS " + table + ';';
  
          // custom proximity impl to avoid merging ranges back together after StorageProxy#getRestrictedRanges splits them up
          NodeProximity proximity = new BaseProximity()
          {
              private final NodeProximity oldProximity = DatabaseDescriptor.getNodeProximity();
              public int compareEndpoints(InetAddressAndPort target, Replica a1, Replica a2)
              {
                  return oldProximity.compareEndpoints(target, a1, a2);
              }
  
              @Override
              public boolean isWorthMergingForRangeQuery(ReplicaCollection merged, ReplicaCollection l1, ReplicaCollection l2)
              {
                  return false;
              }
          };
          DatabaseDescriptor.setNodeProximity(proximity);
          session.execute(createTableStatement);
  
          for (int i = 0; i < 110; i++)
          {
              // removing row with idx 10 causes the last row in the first page read to be empty
              String ttlClause = i == 10 ? "USING TTL 1" : "";
              session.execute(String.format("INSERT INTO %s (id, id2, id3, val) VALUES (%d, %d, %d, '%d') %s", table, i, i, i, i, ttlClause));
          }
          Thread.sleep(1500);
  
          Statement stmt = new SimpleStatement(String.format("SELECT DISTINCT token(id, id2), id, id2 FROM %s", table));
          stmt.setFetchSize(100);
          ResultSet res = session.execute(stmt);
          stmt.setFetchSize(200);
          ResultSet res2 = session.execute(stmt);
  
          Iterator<Row> iter1 = res.iterator();
          Iterator<Row> iter2 = res2.iterator();
  
          while (iter1.hasNext() && iter2.hasNext())
          {
              Row row1 = iter1.next();
              Row row2 = iter2.next();
              assertEquals(row1.getInt("id"), row2.getInt("id"));
          }
          assertFalse(iter1.hasNext());
          assertFalse(iter2.hasNext());
          session.execute(dropTableStatement);
      }
  }
  