blocking-join-node.h

Go to the documentation of this file.

// Copyright 2013 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_EXEC_BLOCKING_JOIN_NODE_H
#define IMPALA_EXEC_BLOCKING_JOIN_NODE_H

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

#include "exec/exec-node.h"
#include "util/promise.h"

#include "gen-cpp/PlanNodes_types.h"  // for TJoinOp

namespace impala {

class MemPool;
class RowBatch;
class TupleRow;

class BlockingJoinNode : public ExecNode {
 public:
  BlockingJoinNode(const std::string& node_name, const TJoinOp::type join_op,
      ObjectPool* pool, const TPlanNode& tnode, const DescriptorTbl& descs);

  virtual ~BlockingJoinNode();

  virtual Status Init(const TPlanNode& tnode);

  virtual Status Prepare(RuntimeState* state);

  virtual Status Open(RuntimeState* state);

  virtual Status Reset(RuntimeState* state);

  virtual void Close(RuntimeState* state);

  static const char* LLVM_CLASS_NAME;

 protected:
  const std::string node_name_;
  TJoinOp::type join_op_;
  bool eos_;  // if true, nothing left to return in GetNext()
  boost::scoped_ptr<MemPool> build_pool_;  // holds everything referenced from build side

  boost::scoped_ptr<RowBatch> probe_batch_;

  bool probe_side_eos_;  // if true, left child has no more rows to process

  int probe_batch_pos_;  // current scan pos in probe_batch_
  TupleRow* current_probe_row_;  // The row currently being probed
  bool matched_probe_;  // if true, the current probe row is matched

  int probe_tuple_row_size_;
  int build_tuple_row_size_;

  TupleRow* semi_join_staging_row_;

  bool can_add_probe_filters_;

  RuntimeProfile::Counter* build_timer_;   // time to prepare build side
  RuntimeProfile::Counter* probe_timer_;   // time to process the probe (left child) batch
  RuntimeProfile::Counter* build_row_counter_;   // num build rows
  RuntimeProfile::Counter* probe_row_counter_;   // num probe (left child) rows

  virtual Status InitGetNext(TupleRow* first_left_child_row) = 0;

  virtual Status ConstructBuildSide(RuntimeState* state) = 0;

  virtual void AddToDebugString(int indentation_level, std::stringstream* out) const {
  }

  virtual void DebugString(int indentation_level, std::stringstream* out) const;

  std::string GetLeftChildRowString(TupleRow* row);

  void CreateOutputRow(TupleRow* out_row, TupleRow* probe_row, TupleRow* build_row);

 private:
  void BuildSideThread(RuntimeState* state, Promise<Status>* status);
};

}

#endif