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40 lines
1.2 KiB
C++
40 lines
1.2 KiB
C++
#pragma once
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#include <Core/NamesAndTypes.h>
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#include <Storages/MergeTree/IMergeTreeReader.h>
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namespace DB
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{
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class MergeTreeDataPartInMemory;
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using DataPartInMemoryPtr = std::shared_ptr<const MergeTreeDataPartInMemory>;
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/// Reader for InMemory parts
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class MergeTreeReaderInMemory : public IMergeTreeReader
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{
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public:
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MergeTreeReaderInMemory(
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MergeTreeDataPartInfoForReaderPtr data_part_info_for_read_,
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DataPartInMemoryPtr data_part_,
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NamesAndTypesList columns_,
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const StorageMetadataPtr & metadata_snapshot_,
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MarkRanges mark_ranges_,
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MergeTreeReaderSettings settings_);
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/// Return the number of rows has been read or zero if there is no columns to read.
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/// If continue_reading is true, continue reading from last state, otherwise seek to from_mark
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size_t readRows(size_t from_mark, size_t current_tasl_last_mark,
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bool continue_reading, size_t max_rows_to_read, Columns & res_columns) override;
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bool canReadIncompleteGranules() const override { return true; }
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private:
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size_t total_rows_read = 0;
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DataPartInMemoryPtr part_in_memory;
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std::unordered_map<String, size_t> positions_for_offsets;
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};
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}
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