child-query.h

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// Copyright 2012 Cloudera Inc.
//
// Licensed 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.

#ifndef IMPALA_SERVICE_CHILD_QUERY_H
#define IMPALA_SERVICE_CHILD_QUERY_H

#include <string>
#include <boost/thread.hpp>

#include "common/status.h"
#include "impala-server.h"
#include "gen-cpp/TCLIService_types.h"

namespace impala {

class ImpalaServer;

//
//
class ChildQuery {
 public:
  ChildQuery(const std::string& query, ImpalaServer::QueryExecState* parent_exec_state,
      ImpalaServer* parent_server)
    : query_(query),
      parent_exec_state_(parent_exec_state),
      parent_server_(parent_server),
      is_running_(false),
      is_cancelled_(false) {
    DCHECK(!query_.empty());
    DCHECK(parent_exec_state_ != NULL);
    DCHECK(parent_server_ != NULL);
  }

  ChildQuery(const ChildQuery& other)
    : query_(other.query_),
      parent_exec_state_(other.parent_exec_state_),
      parent_server_(other.parent_server_),
      is_running_(other.is_running_),
      is_cancelled_(other.is_cancelled_) {}

  ChildQuery& operator=(const ChildQuery& other) {
    query_ = other.query_;
    parent_exec_state_ = other.parent_exec_state_;
    parent_server_ = other.parent_server_;
    is_running_ = other.is_running_;
    is_cancelled_ = other.is_cancelled_;
    return *this;
  }

  Status ExecAndFetch();

  void Cancel();

  const apache::hive::service::cli::thrift::TTableSchema& result_schema() {
    return meta_resp_.schema;
  }

  const apache::hive::service::cli::thrift::TRowSet& result_data() {
    return fetch_resp_.results;
  }

  static const string PARENT_QUERY_OPT;

 private:
  void SetQueryOptions(const TQueryOptions& parent_options,
      apache::hive::service::cli::thrift::TExecuteStatementReq* exec_stmt_req);

  Status IsCancelled();

  std::string query_;

  ImpalaServer::QueryExecState* parent_exec_state_;

  ImpalaServer* parent_server_;

  apache::hive::service::cli::thrift::TGetResultSetMetadataResp meta_resp_;
  apache::hive::service::cli::thrift::TFetchResultsResp fetch_resp_;

  apache::hive::service::cli::thrift::TOperationHandle hs2_handle_;

  boost::mutex lock_;

  bool is_running_;

  bool is_cancelled_;
};

}

#endif