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changed parsing of numerics [#CONV-7793]

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This commit is contained in:
Vyacheslav Alipov 2013-06-11 12:31:08 +00:00
parent 32dbd3d02a
commit b75d025580
1 changed files with 17 additions and 195 deletions
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212
dbms/include/DB/Functions/FunctionsVisitParam.h
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@ -34,170 +34,6 @@
namespace DB
{
/// Прочитать беззнаковое целое в простом формате из не-0-terminated строки.
static UInt64 readUIntText(const UInt8 * buf, const UInt8 * end)
{
UInt64 x = 0;
if (buf != end && *buf == '"')
++buf;
while (buf != end)
{
switch (*buf)
{
case '+':
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
x *= 10;
x += *buf - '0';
break;
default:
return x;
}
++buf;
}
return x;
}
/// Прочитать знаковое целое в простом формате из не-0-terminated строки.
static Int64 readIntText(const UInt8 * buf, const UInt8 * end)
{
bool negative = false;
Int64 x = 0;
if (buf != end && *buf == '"')
++buf;
while (buf != end)
{
switch (*buf)
{
case '+':
break;
case '-':
negative = true;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
x *= 10;
x += *buf - '0';
break;
default:
return x;
}
++buf;
}
if (negative)
x = -x;
return x;
}
/// Прочитать число с плавающей запятой в простом формате, с грубым округлением, из не-0-terminated строки.
static double readFloatText(const UInt8 * buf, const UInt8 * end)
{
bool negative = false;
double x = 0;
bool after_point = false;
double power_of_ten = 1;
if (buf != end && *buf == '"')
++buf;
while (buf != end)
{
switch (*buf)
{
case '+':
break;
case '-':
negative = true;
break;
case '.':
after_point = true;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (after_point)
{
power_of_ten /= 10;
x += (*buf - '0') * power_of_ten;
}
else
{
x *= 10;
x += *buf - '0';
}
break;
case 'e':
case 'E':
{
++buf;
Int32 exponent = readIntText(buf, end);
if (exponent == 0)
{
if (negative)
x = -x;
return x;
}
else if (exponent > 0)
{
for (Int32 i = 0; i < exponent; ++i)
x *= 10;
if (negative)
x = -x;
return x;
}
else
{
for (Int32 i = 0; i < exponent; ++i)
x /= 10;
if (negative)
x = -x;
return x;
}
}
default:
return x;
}
++buf;
}
if (negative)
x = -x;
return x;
}
struct HasParam
{
@ -209,40 +45,26 @@ struct HasParam
}
};
struct ExtractUInt
template<typename NumericType>
struct ExtractNumericType
{
typedef UInt64 ResultType;
typedef NumericType ResultType;
static UInt64 extract(const UInt8 * pos, const UInt8 * end)
static ResultType extract(const UInt8 * pos, const UInt8 * end)
{
return readUIntText(pos, end);
ReadBuffer in(const_cast<char *>(reinterpret_cast<const char *>(pos)), end - pos, 0);
/// Учимся читать числа в двойных кавычках
if (!in.eof() && *in.position() == '"')
++in.position();
ResultType x = 0;
if (!in.eof())
readText(x, in);
return x;
}
};
struct ExtractInt
{
typedef Int64 ResultType;
static Int64 extract(const UInt8 * pos, const UInt8 * end)
{
return readIntText(pos, end);
}
};
struct ExtractFloat
{
typedef Float64 ResultType;
static Float64 extract(const UInt8 * pos, const UInt8 * end)
{
return readFloatText(pos, end);
}
};
struct ExtractBool
{
typedef UInt8 ResultType;
@ -329,9 +151,9 @@ struct NameVisitParamExtractBool { static const char * get() { return "visitPara
typedef FunctionsStringSearch<ExtractParamImpl<HasParam>, NameVisitParamHas> FunctionVisitParamHas;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractUInt>, NameVisitParamExtractUInt> FunctionVisitParamExtractUInt;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractInt>, NameVisitParamExtractInt> FunctionVisitParamExtractInt;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractFloat>, NameVisitParamExtractFloat> FunctionVisitParamExtractFloat;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractNumericType<UInt64> >, NameVisitParamExtractUInt> FunctionVisitParamExtractUInt;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractNumericType<Int64> >, NameVisitParamExtractInt> FunctionVisitParamExtractInt;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractNumericType<Float64> >, NameVisitParamExtractFloat> FunctionVisitParamExtractFloat;
typedef FunctionsStringSearch<ExtractParamImpl<ExtractBool>, NameVisitParamExtractBool> FunctionVisitParamExtractBool;
}