| /** |
| * Copyright 2011-2015 Quickstep Technologies LLC. |
| * Copyright 2015 Pivotal Software, 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 QUICKSTEP_EXPRESSIONS_AGGREGATION_AGGREGATION_HANDLE_MAX_HPP_ |
| #define QUICKSTEP_EXPRESSIONS_AGGREGATION_AGGREGATION_HANDLE_MAX_HPP_ |
| |
| #include <cstddef> |
| #include <memory> |
| #include <utility> |
| #include <vector> |
| |
| #include "catalog/CatalogTypedefs.hpp" |
| #include "expressions/aggregation/AggregationHandle.hpp" |
| #include "storage/HashTableBase.hpp" |
| #include "threading/SpinMutex.hpp" |
| #include "types/Type.hpp" |
| #include "types/TypedValue.hpp" |
| #include "types/operations/comparisons/Comparison.hpp" |
| #include "utility/Macros.hpp" |
| |
| #include "glog/logging.h" |
| |
| namespace quickstep { |
| |
| class ColumnVector; |
| class StorageManager; |
| class ValueAccessor; |
| |
| /** \addtogroup Expressions |
| * @{ |
| */ |
| |
| /** |
| * @brief Aggregation state for max. |
| */ |
| class AggregationStateMax : public AggregationState { |
| public: |
| /** |
| * @brief Copy constructor (ignores mutex). |
| */ |
| AggregationStateMax(const AggregationStateMax &orig) |
| : max_(orig.max_) { |
| } |
| |
| /** |
| * @brief Destructor. |
| */ |
| ~AggregationStateMax() override {}; |
| |
| private: |
| friend class AggregationHandleMax; |
| |
| explicit AggregationStateMax(const Type &type) |
| : max_(type.getNullableVersion().makeNullValue()) { |
| } |
| |
| explicit AggregationStateMax(TypedValue &&value) |
| : max_(std::move(value)) { |
| } |
| |
| TypedValue max_; |
| SpinMutex mutex_; |
| }; |
| |
| /** |
| * @brief An aggregationhandle for max. |
| **/ |
| class AggregationHandleMax : public AggregationHandle { |
| public: |
| ~AggregationHandleMax() override { |
| } |
| |
| AggregationState* createInitialState() const override { |
| return new AggregationStateMax(type_); |
| } |
| |
| AggregationStateHashTableBase* createGroupByHashTable( |
| const HashTableImplType hash_table_impl, |
| const std::vector<const Type*> &group_by_types, |
| const std::size_t estimated_num_groups, |
| StorageManager *storage_manager) const override; |
| |
| /** |
| * @brief Iterate with max aggregation state. |
| */ |
| inline void iterateUnaryInl(AggregationStateMax *state, const TypedValue &value) const { |
| DCHECK(value.isPlausibleInstanceOf(type_.getSignature())); |
| compareAndUpdate(static_cast<AggregationStateMax*>(state), value); |
| } |
| |
| AggregationState* accumulateColumnVectors( |
| const std::vector<std::unique_ptr<ColumnVector>> &column_vectors) const override; |
| |
| #ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION |
| AggregationState* accumulateValueAccessor( |
| ValueAccessor *accessor, |
| const std::vector<attribute_id> &accessor_ids) const override; |
| #endif |
| |
| void aggregateValueAccessorIntoHashTable( |
| ValueAccessor *accessor, |
| const std::vector<attribute_id> &argument_ids, |
| const std::vector<attribute_id> &group_by_key_ids, |
| AggregationStateHashTableBase *hash_table) const override; |
| |
| void mergeStates(const AggregationState &source, |
| AggregationState *destination) const override; |
| |
| TypedValue finalize(const AggregationState &state) const override { |
| return TypedValue(static_cast<const AggregationStateMax&>(state).max_); |
| } |
| |
| inline TypedValue finalizeHashTableEntry(const AggregationState &state) const { |
| return TypedValue(static_cast<const AggregationStateMax&>(state).max_); |
| } |
| |
| ColumnVector* finalizeHashTable( |
| const AggregationStateHashTableBase &hash_table, |
| std::vector<std::vector<TypedValue>> *group_by_keys) const override; |
| |
| private: |
| friend class AggregateFunctionMax; |
| |
| /** |
| * @brief Constructor. |
| * |
| * @param type Type of the data set. |
| **/ |
| explicit AggregationHandleMax(const Type &type); |
| |
| /** |
| * @brief compare the value with max_ and update it if the value is larger than |
| * current maximum. NULLs are ignored. |
| * |
| * @param value A TypedValue to compare |
| **/ |
| inline void compareAndUpdate(AggregationStateMax *state, const TypedValue &value) const { |
| // TODO(chasseur): Avoid null-checks when aggregating a non-nullable Type. |
| if (value.isNull()) return; |
| |
| SpinMutexLock lock(state->mutex_); |
| if (state->max_.isNull() || fast_comparator_->compareTypedValues(value, state->max_)) { |
| state->max_ = value; |
| } |
| } |
| |
| const Type &type_; |
| std::unique_ptr<UncheckedComparator> fast_comparator_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AggregationHandleMax); |
| }; |
| |
| /** @} */ |
| |
| } // namespace quickstep |
| |
| #endif // QUICKSTEP_EXPRESSIONS_AGGREGATION_AGGREGATION_HANDLE_MAX_HPP_ |