From ea874ad1c53b4b4a27ae610eb3baf71a1488bcef Mon Sep 17 00:00:00 2001
From: Michael Kolupaev <mkolupaev@yandex-team.ru>
Date: Mon, 24 Dec 2012 08:16:25 +0000
Subject: [PATCH] clickhouse: added missing file [#CONV-6318].

---
 dbms/include/DB/Functions/FunctionsRound.h | 99 ++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 dbms/include/DB/Functions/FunctionsRound.h

diff --git a/dbms/include/DB/Functions/FunctionsRound.h b/dbms/include/DB/Functions/FunctionsRound.h
new file mode 100644
index 00000000000..a487824c048
--- /dev/null
+++ b/dbms/include/DB/Functions/FunctionsRound.h
@@ -0,0 +1,99 @@
+#pragma once
+
+#include <DB/Functions/FunctionsArithmetic.h>
+#include <cmath>	// log2()
+
+
+namespace DB
+{
+	
+	/** Функции округления:
+	 * roundToExp2 - вниз до ближайшей степени двойки;
+	 * roundDuration - вниз до ближайшего из: 0, 1, 10, 30, 60, 120, 180, 240, 300, 600, 1200, 1800, 3600, 7200, 18000, 36000;
+	 * roundAge - вниз до ближайшего из: 0, 18, 25, 35, 45.
+	 */
+	
+	template<typename A>
+	struct RoundToExp2Impl
+	{
+		typedef A ResultType;
+		
+		static inline A apply(A x)
+		{
+			return x <= 0 ? static_cast<A>(0) : (static_cast<A>(1) << static_cast<UInt64>(log2(static_cast<double>(x))));
+		}
+	};
+	
+	template<>
+	struct RoundToExp2Impl<Float32>
+	{
+		typedef Float32 ResultType;
+		
+		static inline Float32 apply(Float32 x)
+		{
+			return static_cast<Float32>(x < 1 ? 0. : pow(2., floor(log2(x))));
+		}
+	};
+	
+	template<>
+	struct RoundToExp2Impl<Float64>
+	{
+		typedef Float64 ResultType;
+		
+		static inline Float64 apply(Float64 x)
+		{
+			return x < 1 ? 0. : pow(2., floor(log2(x)));
+		}
+	};
+	
+	template<typename A>
+	struct RoundDurationImpl
+	{
+		typedef UInt16 ResultType;
+		
+		static inline ResultType apply(A x)
+		{
+			return x < 1 ? 0
+				: (x < 10 ? 1
+				: (x < 30 ? 10
+				: (x < 60 ? 30
+				: (x < 120 ? 60
+				: (x < 180 ? 120
+				: (x < 240 ? 180
+				: (x < 300 ? 240
+				: (x < 600 ? 300
+				: (x < 1200 ? 600
+				: (x < 1800 ? 1200
+				: (x < 3600 ? 1800
+				: (x < 7200 ? 3600
+				: (x < 18000 ? 7200
+				: (x < 36000 ? 18000
+				: 36000))))))))))))));
+		}
+	};
+	
+	template<typename A>
+	struct RoundAgeImpl
+	{
+		typedef UInt8 ResultType;
+		
+		static inline ResultType apply(A x)
+		{
+			return x < 18 ? 0
+				: (x < 25 ? 18
+				: (x < 35 ? 25
+				: (x < 45 ? 35
+				: 45)));
+		}
+	};
+	
+	
+	struct NameRoundToExp2		{ static const char * get() { return "roundToExp"; } };
+	struct NameRoundDuration	{ static const char * get() { return "roundDuration"; } };
+	struct NameRoundAge 		{ static const char * get() { return "roundAge"; } };
+	
+	typedef FunctionUnaryArithmetic<RoundToExp2Impl,	NameRoundToExp2> 	FunctionRoundToExp2;
+	typedef FunctionUnaryArithmetic<RoundDurationImpl,	NameRoundDuration>	FunctionRoundDuration;
+	typedef FunctionUnaryArithmetic<RoundAgeImpl,		NameRoundAge>		FunctionRoundAge;
+	
+}