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79 lines
2.4 KiB
C++
79 lines
2.4 KiB
C++
#pragma once
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#include <Core/Block.h>
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#include <Interpreters/Context.h>
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#include <Dictionaries/IDictionarySource.h>
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#include <Dictionaries/DictionaryStructure.h>
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#include <Processors/Sources/ShellCommandSource.h>
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namespace DB
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{
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/** ExecutablePoolDictionarySource allows loading data from pool of processes.
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* When client requests ids or keys source get process from ProcessPool
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* and create stream based on source format from process stdout.
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* It is important that stream format will expect only rows that were requested.
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* When stream is finished process is returned back to the ProcessPool.
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* If there are no processes in pool during request client will be blocked
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* until some process will be returned to pool.
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*/
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class ExecutablePoolDictionarySource final : public IDictionarySource
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{
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public:
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struct Configuration
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{
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String command;
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std::vector<String> command_arguments;
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bool implicit_key;
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};
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ExecutablePoolDictionarySource(
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const DictionaryStructure & dict_struct_,
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const Configuration & configuration_,
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Block & sample_block_,
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std::shared_ptr<ShellCommandSourceCoordinator> coordinator_,
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ContextPtr context_);
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ExecutablePoolDictionarySource(const ExecutablePoolDictionarySource & other);
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ExecutablePoolDictionarySource & operator=(const ExecutablePoolDictionarySource &) = delete;
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QueryPipeline loadAll() override;
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/** The logic of this method is flawed, absolutely incorrect and ignorant.
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* It may lead to skipping some values due to clock sync or timezone changes.
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* The intended usage of "update_field" is totally different.
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*/
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QueryPipeline loadUpdatedAll() override;
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QueryPipeline loadIds(const std::vector<UInt64> & ids) override;
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QueryPipeline loadKeys(const Columns & key_columns, const std::vector<size_t> & requested_rows) override;
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bool isModified() const override;
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bool supportsSelectiveLoad() const override;
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bool hasUpdateField() const override;
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DictionarySourcePtr clone() const override;
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std::string toString() const override;
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QueryPipeline getStreamForBlock(const Block & block);
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private:
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const DictionaryStructure dict_struct;
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const Configuration configuration;
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Block sample_block;
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std::shared_ptr<ShellCommandSourceCoordinator> coordinator;
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ContextPtr context;
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LoggerPtr log;
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};
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}
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