ClickHouse/base/mysqlxx/Value.cpp

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#include <mysqlxx/Value.h>
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#include <mysqlxx/ResultBase.h>
#include <mysqlxx/Query.h>
#include <mysqlxx/Exception.h>
namespace mysqlxx
{
UInt64 Value::readUIntText(const char * buf, size_t length) const
{
UInt64 x = 0;
const char * end = buf + length;
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:
throwException("Cannot parse unsigned integer");
}
++buf;
}
return x;
}
Int64 Value::readIntText(const char * buf, size_t length) const
{
bool negative = false;
UInt64 x = 0;
const char * end = buf + length;
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:
throwException("Cannot parse signed integer");
}
++buf;
}
return negative ? -x : x;
}
double Value::readFloatText(const char * buf, size_t length) const
{
bool negative = false;
double x = 0;
bool after_point = false;
double power_of_ten = 1;
const char * end = buf + length;
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 - buf);
x *= preciseExp10(exponent);
if (negative)
x = -x;
return x;
}
case 'i':
case 'I':
x = std::numeric_limits<double>::infinity();
if (negative)
x = -x;
return x;
case 'n':
case 'N':
x = std::numeric_limits<double>::quiet_NaN();
return x;
default:
throwException("Cannot parse floating point number");
}
++buf;
}
if (negative)
x = -x;
return x;
}
void Value::throwException(const char * text) const
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{
static constexpr size_t preview_length = 1000;
std::stringstream info;
info << text;
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if (!isNull())
{
info << ": ";
info.write(m_data, m_length);
}
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if (res && res->getQuery())
info << ", query: " << res->getQuery()->str().substr(0, preview_length);
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throw CannotParseValue(info.str());
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}
}