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.distributed.impl;
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.UUID;
  import java.util.concurrent.Future;
  import java.util.function.BiConsumer;
  
  import com.google.common.collect.Iterators;
  
  import accord.utils.Invariants;
  import org.apache.cassandra.cql3.CQLStatement;
  import org.apache.cassandra.cql3.QueryOptions;
  import org.apache.cassandra.cql3.QueryProcessor;
  import org.apache.cassandra.cql3.statements.SelectStatement;
  import org.apache.cassandra.distributed.api.ConsistencyLevel;
  import org.apache.cassandra.distributed.api.ICoordinator;
  import org.apache.cassandra.distributed.api.IInstance;
  import org.apache.cassandra.distributed.api.QueryResult;
  import org.apache.cassandra.distributed.api.QueryResults;
  import org.apache.cassandra.distributed.api.SimpleQueryResult;
  import org.apache.cassandra.service.ClientState;
  import org.apache.cassandra.service.QueryState;
  import org.apache.cassandra.tracing.Tracing;
  import org.apache.cassandra.transport.Dispatcher;
  import org.apache.cassandra.transport.ProtocolVersion;
  import org.apache.cassandra.transport.messages.ResultMessage;
  import org.apache.cassandra.utils.ByteBufferUtil;
  import org.apache.cassandra.utils.TimeUUID;
  
  public class Coordinator implements ICoordinator
  {
      final Instance instance;
      public Coordinator(Instance instance)
      {
          this.instance = instance;
      }
  
      @Override
      public SimpleQueryResult executeWithResult(String query, ConsistencyLevel consistencyLevel, Object... boundValues)
      {
          return instance().sync(() -> unsafeExecuteInternal(query, consistencyLevel, boundValues)).call();
      }
  
      @Override
      public Future<?> executeWithResult(BiConsumer<SimpleQueryResult, Throwable> callback, String query, ConsistencyLevel consistencyLevel, Object... boundValues)
      {
          return executeWithResult(callback, query, null, consistencyLevel, boundValues);
      }
  
      @Override
      public Future<?> executeWithResult(BiConsumer<SimpleQueryResult, Throwable> callback, String query, ConsistencyLevel serialConsistencyLevel, ConsistencyLevel commitConsistencyLevel, Object... boundValues)
      {
          return instance().async(cb -> {
              SimpleQueryResult result;
              try
              {
                  result = CoordinatorHelper.unsafeExecuteInternal(query, serialConsistencyLevel, commitConsistencyLevel, boundValues);
              }
              catch (Throwable t)
              {
                  callback.accept(null, t);
                  return;
              }
              callback.accept(result, null);
          }).apply(callback);
      }
  
      public Future<SimpleQueryResult> asyncExecuteWithTracingWithResult(UUID sessionId, String query, ConsistencyLevel consistencyLevelOrigin, Object... boundValues)
      {
          return instance.async(() -> {
              try
              {
                  Tracing.instance.newSession(TimeUUID.fromUuid(sessionId), Collections.emptyMap());
                  return unsafeExecuteInternal(query, consistencyLevelOrigin, boundValues);
              }
              finally
              {
                  Tracing.instance.stopSession();
              }
          }).call();
      }
  
      @Override
      public Future<SimpleQueryResult> asyncExecuteWithResult(String query, ConsistencyLevel consistencyLevelOrigin, Object... boundValues)
      {
          return instance.async(() -> unsafeExecuteInternal(query, consistencyLevelOrigin, boundValues)).call();
      }
  
      public static org.apache.cassandra.db.ConsistencyLevel toCassandraCL(ConsistencyLevel cl)
      {
          try
          {
              return org.apache.cassandra.db.ConsistencyLevel.fromCode(cl.code);
          }
          catch (NoSuchFieldError e)
          {
              return org.apache.cassandra.db.ConsistencyLevel.fromCode(cl.ordinal());
          }
      }
  
  
      public static SimpleQueryResult unsafeExecuteInternal(String query, ConsistencyLevel consistencyLevel, Object[] boundValues)
      {
          return CoordinatorHelper.unsafeExecuteInternal(query, null, consistencyLevel, boundValues);
      }
  
  
      public Object[][] executeWithTracing(UUID sessionId, String query, ConsistencyLevel consistencyLevelOrigin, Object... boundValues)
      {
          return IsolatedExecutor.waitOn(asyncExecuteWithTracing(sessionId, query, consistencyLevelOrigin, boundValues));
      }
  
      public IInstance instance()
      {
          return instance;
      }
  
      @Override
      public SimpleQueryResult executeWithResult(String query, ConsistencyLevel serialConsistencyLevel, ConsistencyLevel commitConsistencyLevel, Object... boundValues)
      {
          return instance.sync(() -> CoordinatorHelper.unsafeExecuteInternal(query, serialConsistencyLevel, commitConsistencyLevel, boundValues)).call();
      }
  
      @Override
      public QueryResult executeWithPagingWithResult(String query, ConsistencyLevel consistencyLevelOrigin, int pageSize, Object... boundValues)
      {
          if (pageSize <= 0)
              throw new IllegalArgumentException("Page size should be strictly positive but was " + pageSize);
  
          return instance.sync(() -> {
              ClientState clientState = CoordinatorHelper.makeFakeClientState();
              ConsistencyLevel consistencyLevel = ConsistencyLevel.valueOf(consistencyLevelOrigin.name());
              CQLStatement prepared = QueryProcessor.getStatement(query, clientState);
              final List<ByteBuffer> boundBBValues = new ArrayList<>();
              for (Object boundValue : boundValues)
                  boundBBValues.add(ByteBufferUtil.objectToBytes(boundValue));
  
              prepared.validate(clientState);
              Invariants.require(prepared instanceof SelectStatement, "Only SELECT statements can be executed with paging %s", prepared);
  
              Dispatcher.RequestTime requestTime = Dispatcher.RequestTime.forImmediateExecution();
              SelectStatement selectStatement = (SelectStatement) prepared;
  
              QueryState queryState = new QueryState(clientState);
              QueryOptions initialOptions = QueryOptions.create(toCassandraCL(consistencyLevel),
                                                                boundBBValues,
                                                                false,
                                                                pageSize,
                                                                null,
                                                                null,
                                                                ProtocolVersion.CURRENT,
                                                                selectStatement.keyspace());
  
  
              ResultMessage.Rows initialRows = selectStatement.execute(queryState, initialOptions, requestTime);
              Iterator<Object[]> iter = new Iterator<Object[]>() {
                  ResultMessage.Rows rows = initialRows;
                  Iterator<Object[]> iter = RowUtil.toIter(rows);
  
                  public boolean hasNext()
                  {
                      if (iter.hasNext())
                          return true;
  
                      if (rows.result.metadata.getPagingState() == null)
                          return false;
  
                      QueryOptions nextOptions = QueryOptions.create(toCassandraCL(consistencyLevel),
                                                                     boundBBValues,
                                                                     true,
                                                                     pageSize,
                                                                     rows.result.metadata.getPagingState(),
                                                                     null,
                                                                     ProtocolVersion.CURRENT,
                                                                     selectStatement.keyspace());
  
                      rows = selectStatement.execute(queryState, nextOptions, requestTime);
                      iter = Iterators.forArray(RowUtil.toObjects(initialRows.result.metadata.names, rows.result.rows));
  
                      return hasNext();
                  }
  
                  public Object[] next()
                  {
                      return iter.next();
                  }
              };
  
              return QueryResults.fromObjectArrayIterator(RowUtil.getColumnNames(initialRows.result.metadata.names), iter);
          }).call();
      }
  
  }
  