mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-26 17:41:59 +00:00
d36f52502e
It's still hackish and dirty, but server and client compies. Server starts, but throwes meaningless exception on any query. Client seems to be working fine. Linux compilation might (but shouldn't) be broken (not tested).
47 lines
1.5 KiB
C++
47 lines
1.5 KiB
C++
#pragma once
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#include <DB/DataStreams/IBlockInputStream.h>
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#include <vector>
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namespace DB
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{
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class IDictionarySource;
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using DictionarySourcePtr = std::unique_ptr<IDictionarySource>;
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/** Data-provider interface for external dictionaries,
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* abstracts out the data source (file, MySQL, ClickHouse, external program, network request et cetera)
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* from the presentation and memory layout (the dictionary itself).
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*/
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class IDictionarySource
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{
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public:
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/// returns an input stream with all the data available from this source
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virtual BlockInputStreamPtr loadAll() = 0;
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/** Indicates whether this source supports "random access" loading of data
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* loadId and loadIds can only be used if this function returns true.
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*/
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virtual bool supportsSelectiveLoad() const = 0;
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/// returns an input stream with the data for a collection of identifiers
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virtual BlockInputStreamPtr loadIds(const std::vector<UInt64> & ids) = 0;
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/** returns an input stream with the data for a collection of composite keys.
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* `requested_rows` contains indices of all rows containing unique keys. */
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virtual BlockInputStreamPtr loadKeys(
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const ConstColumnPlainPtrs & key_columns, const std::vector<std::size_t> & requested_rows) = 0;
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/// indicates whether the source has been modified since last load* operation
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virtual bool isModified() const = 0;
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virtual DictionarySourcePtr clone() const = 0;
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/// returns an informal string describing the source
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virtual std::string toString() const = 0;
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virtual ~IDictionarySource() = default;
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};
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}
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