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arangodb/arangod/Aql/CountCollectExecutor.cpp

112 lines
3.9 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2018 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 Goedderz
/// @author Michael Hackstein
/// @author Heiko Kernbach
/// @author Jan Christoph Uhde
////////////////////////////////////////////////////////////////////////////////
#include "CountCollectExecutor.h"
#include "Aql/AqlValue.h"
#include "Aql/ExecutorInfos.h"
#include "Aql/InputAqlItemRow.h"
#include "Aql/OutputAqlItemRow.h"
#include "Aql/SingleRowFetcher.h"
#include "Aql/Stats.h"
#include <utility>
using namespace arangodb;
using namespace arangodb::aql;
constexpr bool CountCollectExecutor::Properties::preservesOrder;
constexpr BlockPassthrough CountCollectExecutor::Properties::allowsBlockPassthrough;
constexpr bool CountCollectExecutor::Properties::inputSizeRestrictsOutputSize;
CountCollectExecutorInfos::CountCollectExecutorInfos(
RegisterId collectRegister, RegisterId nrInputRegisters, RegisterId nrOutputRegisters,
// cppcheck-suppress passedByValue
std::unordered_set<RegisterId> registersToClear,
// cppcheck-suppress passedByValue
std::unordered_set<RegisterId> registersToKeep)
: ExecutorInfos(std::make_shared<std::unordered_set<RegisterId>>(),
make_shared_unordered_set({collectRegister}),
nrInputRegisters, nrOutputRegisters,
std::move(registersToClear), std::move(registersToKeep)),
_collectRegister(collectRegister) {}
RegisterId CountCollectExecutorInfos::getOutputRegisterId() const {
return _collectRegister;
}
CountCollectExecutor::CountCollectExecutor(Fetcher& fetcher, Infos& infos)
: _infos(infos), _fetcher(fetcher), _state(ExecutionState::HASMORE), _count(0) {}
std::pair<ExecutionState, NoStats> CountCollectExecutor::produceRows(OutputAqlItemRow& output) {
TRI_IF_FAILURE("CountCollectExecutor::produceRows") {
THROW_ARANGO_EXCEPTION(TRI_ERROR_DEBUG);
}
if (_state == ExecutionState::DONE) {
return {_state, NoStats{}};
}
while (_state != ExecutionState::DONE) {
size_t skipped;
std::tie(_state, skipped) = _fetcher.skipRows(ExecutionBlock::SkipAllSize());
if (_state == ExecutionState::WAITING) {
TRI_ASSERT(skipped == 0);
return {_state, NoStats{}};
}
TRI_ASSERT(skipped != 0 || _state == ExecutionState::DONE);
incrCountBy(skipped);
}
// In general, we do not have an input row. In fact, we never fetch one.
output.setAllowSourceRowUninitialized();
// We must produce exactly one output row.
output.cloneValueInto(_infos.getOutputRegisterId(),
InputAqlItemRow{CreateInvalidInputRowHint{}},
AqlValue(AqlValueHintUInt(getCount())));
return {_state, NoStats{}};
}
void CountCollectExecutor::incrCountBy(size_t incr) noexcept { _count += incr; }
uint64_t CountCollectExecutor::getCount() noexcept { return _count; }
std::pair<ExecutionState, size_t> CountCollectExecutor::expectedNumberOfRows(size_t) const {
if (_state == ExecutionState::DONE) {
return {ExecutionState::DONE, 0};
}
return {ExecutionState::HASMORE, 1};
}
const CountCollectExecutor::Infos& CountCollectExecutor::infos() const noexcept {
return _infos;
}
CountCollectExecutor::~CountCollectExecutor() = default;