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38 lines
901 B
C++
38 lines
901 B
C++
#pragma once
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#include <Parsers/IAST.h>
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namespace DB
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{
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/** Sampling factor in the form 0.1 or 1/10.
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* It's important to save it as a rational number without converting it to IEEE-754.
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*/
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class ASTSampleRatio : public IAST
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{
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public:
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using BigNum = __uint128_t; /// Must contain the result of multiplying two UInt64.
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struct Rational
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{
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BigNum numerator = 0;
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BigNum denominator = 1;
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};
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Rational ratio;
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explicit ASTSampleRatio(const Rational & ratio_) : ratio(ratio_) {}
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String getID(char delim) const override { return "SampleRatio" + (delim + toString(ratio)); }
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ASTPtr clone() const override { return std::make_shared<ASTSampleRatio>(*this); }
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static String toString(BigNum num);
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static String toString(Rational ratio);
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void formatImpl(const FormatSettings & settings, FormatState &, FormatStateStacked) const override;
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};
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}
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