1
0
Fork 0
arangodb/arangod/Aql/AqlItemBlockInputRange.h

81 lines
2.5 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2019 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Tobias Gödderz
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_AQLITEMBLOCKINPUTITERATOR_H
#define ARANGOD_AQL_AQLITEMBLOCKINPUTITERATOR_H
#include "Aql/ExecutionState.h"
#include "Aql/InputAqlItemRow.h"
#include "Aql/SharedAqlItemBlockPtr.h"
namespace arangodb::aql {
class ShadowAqlItemRow;
class AqlItemBlockInputRange {
public:
explicit AqlItemBlockInputRange(ExecutorState state);
AqlItemBlockInputRange(ExecutorState, arangodb::aql::SharedAqlItemBlockPtr const&,
std::size_t startIndex, std::size_t endIndex);
AqlItemBlockInputRange(ExecutorState, arangodb::aql::SharedAqlItemBlockPtr&&,
std::size_t startIndex, std::size_t endIndex) noexcept;
bool hasMore() const noexcept;
ExecutorState state() const noexcept;
std::pair<ExecutorState, arangodb::aql::InputAqlItemRow> peek();
std::pair<ExecutorState, arangodb::aql::InputAqlItemRow> next();
std::size_t getRowIndex() noexcept { return _rowIndex; };
std::size_t getEndIndex() noexcept { return _endIndex; };
bool hasShadowRow() const noexcept;
std::pair<ExecutorState, arangodb::aql::ShadowAqlItemRow> peekShadowRow();
std::pair<ExecutorState, arangodb::aql::ShadowAqlItemRow> nextShadowRow();
private:
bool isIndexValid(std::size_t index) const noexcept;
bool isShadowRowAtIndex(std::size_t index) const noexcept;
enum LookAhead { NOW, NEXT };
enum RowType { DATA, SHADOW };
template <LookAhead doPeek, RowType type>
ExecutorState nextState() const noexcept;
private:
arangodb::aql::SharedAqlItemBlockPtr _block;
std::size_t _rowIndex;
std::size_t _endIndex;
ExecutorState _finalState;
};
} // namespace arangodb::aql
#endif // ARANGOD_AQL_AQLITEMBLOCKINPUTITERATOR_H