sorted-run-merger.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_RUNTIME_SORTED_RUN_MERGER_H_
#define IMPALA_RUNTIME_SORTED_RUN_MERGER_H_

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

#include "common/object-pool.h"
#include "util/tuple-row-compare.h"

namespace impala {

class RowBatch;
class RowDescriptor;
class RuntimeProfile;

//
class SortedRunMerger {
 public:
  typedef boost::function<Status (RowBatch**)> RunBatchSupplier;

  SortedRunMerger(const TupleRowComparator& compare_less_than, RowDescriptor* row_desc,
      RuntimeProfile* profile, bool deep_copy_input);

  Status Prepare(const std::vector<RunBatchSupplier>& input_runs);

  Status GetNext(RowBatch* output_batch, bool* eos);

  void TransferAllResources(RowBatch* transfer_resource_batch);

 private:
  class BatchedRowSupplier;

  void Heapify(int parent_index);

  std::vector<BatchedRowSupplier*> min_heap_;

  TupleRowComparator compare_less_than_;

  RowDescriptor* input_row_desc_;

  bool deep_copy_input_;

  ObjectPool pool_;

  RuntimeProfile::Counter* get_next_timer_;

  RuntimeProfile::Counter* get_next_batch_timer_;
};

}

#endif