ClickHouse/dbms/src/Parsers/ASTSampleRatio.h
proller 1a8e22c37f Allow compile on 32bit systems (#1175)
* Trying compile under 32bit..

* PerformanceTest: use getMultiple*FromConfig, fix debug helpers

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* Fix boost 1.64 and gcc7+ compile errors

* More fixes

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* Fix arm build

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* Update MergeTreeSettings.h

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2017-09-01 20:21:03 +03:00

47 lines
1.2 KiB
C++

#pragma once
#include <Parsers/IAST.h>
namespace DB
{
/** Sampling factor in the form 0.1 or 1/10.
* It's important to save it as a rational number without converting it to IEEE-754.
*/
class ASTSampleRatio : public IAST
{
public:
#ifdef __SIZEOF_INT128__
using BigNum = __uint128_t; /// Must contain the result of multiplying two UInt64.
#else
// TODO: incomplete temporary fallback. change with boost::multiprecision
using BigNum = uint64_t;
#endif
struct Rational
{
BigNum numerator = 0;
BigNum denominator = 1;
};
Rational ratio;
ASTSampleRatio() = default;
ASTSampleRatio(const StringRange range_) : IAST(range_) {}
ASTSampleRatio(const StringRange range_, Rational & ratio_) : IAST(range_), ratio(ratio_) {}
String getID() const override { return "SampleRatio_" + toString(ratio); }
ASTPtr clone() const override { return std::make_shared<ASTSampleRatio>(*this); }
static String toString(BigNum num);
static String toString(Rational ratio);
void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override
{
settings.ostr << toString(ratio);
}
};
}