mirror of https://gitee.com/bigwinds/arangodb
84 lines
2.9 KiB
C++
84 lines
2.9 KiB
C++
////////////////////////////////////////////////////////////////////////////////
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/// DISCLAIMER
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///
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/// Copyright 2018 ArangoDB GmbH, Cologne, Germany
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///
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/// Licensed under the Apache License, Version 2.0 (the "License");
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/// you may not use this file except in compliance with the License.
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/// You may obtain a copy of the License at
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///
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/// http://www.apache.org/licenses/LICENSE-2.0
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///
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/// Unless required by applicable law or agreed to in writing, software
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/// distributed under the License is distributed on an "AS IS" BASIS,
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/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/// See the License for the specific language governing permissions and
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/// limitations under the License.
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///
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/// Copyright holder is ArangoDB GmbH, Cologne, Germany
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///
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/// @author Tobias Gödderz
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/// @author Michael Hackstein
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/// @author Heiko Kernbach
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/// @author Jan Christoph Uhde
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////////////////////////////////////////////////////////////////////////////////
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#include "SingleRowFetcher.h"
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#include "Aql/AqlItemBlock.h"
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#include "Aql/DependencyProxy.h"
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#include "Aql/ExecutionBlock.h"
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#include "Aql/ExecutionState.h"
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#include "Aql/InputAqlItemRow.h"
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using namespace arangodb;
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using namespace arangodb::aql;
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template <bool passBlocksThrough>
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SingleRowFetcher<passBlocksThrough>::SingleRowFetcher(DependencyProxy<passBlocksThrough>& executionBlock)
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: _dependencyProxy(&executionBlock),
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_upstreamState(ExecutionState::HASMORE),
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_rowIndex(0),
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_currentRow{CreateInvalidInputRowHint{}} {}
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template <bool passBlocksThrough>
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std::pair<ExecutionState, SharedAqlItemBlockPtr> SingleRowFetcher<passBlocksThrough>::fetchBlock(size_t atMost) {
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atMost = (std::min)(atMost, ExecutionBlock::DefaultBatchSize());
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// There are still some blocks left that ask their parent even after they got
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// DONE the last time, and I don't currently have time to track them down.
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// Thus the following assert is commented out.
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// TRI_ASSERT(_upstreamState != ExecutionState::DONE);
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auto res = _dependencyProxy->fetchBlock(atMost);
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_upstreamState = res.first;
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return res;
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}
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template <bool passBlocksThrough>
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SingleRowFetcher<passBlocksThrough>::SingleRowFetcher()
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: _dependencyProxy(nullptr), _rowIndex(0), _currentRow{CreateInvalidInputRowHint{}} {}
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template <bool passBlocksThrough>
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std::pair<ExecutionState, SharedAqlItemBlockPtr>
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SingleRowFetcher<passBlocksThrough>::fetchBlockForPassthrough(size_t atMost) {
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return _dependencyProxy->fetchBlockForPassthrough(atMost);
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}
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template <bool passBlocksThrough>
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std::pair<ExecutionState, size_t> SingleRowFetcher<passBlocksThrough>::skipRows(size_t atMost) {
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TRI_ASSERT(!_currentRow.isInitialized() || _currentRow.isLastRowInBlock());
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TRI_ASSERT(!indexIsValid());
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auto res = _dependencyProxy->skipSome(atMost);
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_upstreamState = res.first;
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TRI_ASSERT(res.second <= atMost);
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return res;
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}
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template class ::arangodb::aql::SingleRowFetcher<false>;
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template class ::arangodb::aql::SingleRowFetcher<true>;
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