data-source-scan-node.h

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// Copyright 2014 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_DATA_SOURCE_SCAN_NODE_H_
#define IMPALA_EXEC_DATA_SOURCE_SCAN_NODE_H_

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

#include "exec/scan-node.h"
#include "exec/external-data-source-executor.h"
#include "runtime/descriptors.h"
#include "runtime/mem-pool.h"

#include "gen-cpp/ExternalDataSource_types.h"

namespace impala {

class Tuple;

class DataSourceScanNode : public ScanNode {
 public:
  DataSourceScanNode(ObjectPool* pool, const TPlanNode& tnode, const DescriptorTbl& descs);

  ~DataSourceScanNode();

  virtual Status Prepare(RuntimeState* state);

  virtual Status Open(RuntimeState* state);

  virtual Status GetNext(RuntimeState* state, RowBatch* row_batch, bool* eos);

  virtual Status Reset(RuntimeState* state);

  virtual void Close(RuntimeState* state);

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

 private:
  boost::scoped_ptr<ExternalDataSourceExecutor> data_source_executor_;

  const TDataSourceScanNode data_src_node_;

  const TupleDescriptor* tuple_desc_;

  int tuple_idx_;

  Tuple* tuple_;

  std::vector<SlotDescriptor*> materialized_slots_;

  std::string scan_handle_;

  boost::scoped_ptr<extdatasource::TGetNextResult> input_batch_;

  int num_rows_;

  size_t next_row_idx_;

  std::vector<int> cols_next_val_idx_;

  Status MaterializeNextRow(MemPool* mem_pool);

  Status GetNextInputBatch();

  Status ValidateRowBatchSize();

  bool InputBatchHasNext() {
    if (!input_batch_->__isset.rows) return false;
    return next_row_idx_ < num_rows_;
  }
};

}

#endif