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45 lines
1.0 KiB
C++
45 lines
1.0 KiB
C++
#pragma once
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#include <DataStreams/IBlockInputStream.h>
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namespace DB
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{
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/** A stream of blocks from which you can read the next block from an explicitly provided list.
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* Also see OneBlockInputStream.
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*/
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class BlocksListBlockInputStream : public IBlockInputStream
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{
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public:
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/// Acquires the ownership of the block list.
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BlocksListBlockInputStream(BlocksList && list_)
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: list(std::move(list_)), it(list.begin()), end(list.end()) {}
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/// Uses a list of blocks lying somewhere else.
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BlocksListBlockInputStream(BlocksList::iterator & begin_, BlocksList::iterator & end_)
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: it(begin_), end(end_) {}
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String getName() const override { return "BlocksList"; }
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protected:
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Block getHeader() const override { return list.empty() ? Block() : *list.begin(); }
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Block readImpl() override
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{
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if (it == end)
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return Block();
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Block res = *it;
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++it;
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return res;
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}
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private:
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BlocksList list;
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BlocksList::iterator it;
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const BlocksList::iterator end;
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};
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}
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