2017-07-12 16:59:36 +00:00
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#pragma once
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#include <DataStreams/IProfilingBlockInputStream.h>
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namespace DB
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{
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/** Removes the specified columns from the block.
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*/
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class RemoveColumnsBlockInputStream : public IProfilingBlockInputStream
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{
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public:
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RemoveColumnsBlockInputStream(
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BlockInputStreamPtr input_,
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const Names & columns_to_remove_)
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: columns_to_remove(columns_to_remove_)
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{
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children.push_back(input_);
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}
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String getName() const override { return "RemoveColumns"; }
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2018-02-18 03:23:48 +00:00
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Block getHeader() const override
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2018-01-06 18:10:44 +00:00
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{
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Block res = children.back()->getHeader();
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for (const auto & it : columns_to_remove)
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if (res.has(it))
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res.erase(it);
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return res;
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}
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2017-07-12 16:59:36 +00:00
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protected:
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Block readImpl() override
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{
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Block res = children.back()->read();
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if (!res)
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return res;
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for (const auto & it : columns_to_remove)
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if (res.has(it))
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res.erase(it);
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return res;
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}
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private:
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Names columns_to_remove;
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};
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}
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