duckdb::NumericHelper Class Reference

NumericHelper is a static class that holds helper functions for integers/doubles. More...

Public Member Functions
template<>
int	UnsignedLength (uint8_t value)
template<>
int	UnsignedLength (uint16_t value)
template<>
int	UnsignedLength (uint32_t value)
template<>
int	UnsignedLength (uint64_t value)
template<>
int	UnsignedLength (hugeint_t value)
template<>
char *	FormatUnsigned (hugeint_t value, char *ptr)
template<>
std::string	ToString (hugeint_t value)
template<>
std::string	ToString (uhugeint_t value)
template<>
string_t	FormatSigned (hugeint_t value, Vector &vector)

Static Public Member Functions
template<class T >
static int	UnsignedLength (T value)
template<class SIGNED , class UNSIGNED >
static int	SignedLength (SIGNED value)
template<class T >
static char *	FormatUnsigned (T value, char *ptr)
template<class T >
static string_t	FormatSigned (T value, Vector &vector)
template<class T >
static std::string	ToString (T value)

Static Public Attributes
static constexpr uint8_t	CACHED_POWERS_OF_TEN = 19
static const int64_t	POWERS_OF_TEN [CACHED_POWERS_OF_TEN]
static const double	DOUBLE_POWERS_OF_TEN [40]

Detailed Description

NumericHelper is a static class that holds helper functions for integers/doubles.

Member Function Documentation

SignedLength()

template<class SIGNED , class UNSIGNED >

static int duckdb::NumericHelper::SignedLength ( SIGNED  value )

inlinestatic

                                          {
        int sign = -(value < 0);
        UNSIGNED unsigned_value = UnsafeNumericCast<UNSIGNED>((value ^ sign) - sign);
        return UnsignedLength(unsigned_value) - sign;
    }

FormatUnsigned()

template<class T >

static char * duckdb::NumericHelper::FormatUnsigned ( T  value, char *  ptr  )

inlinestatic

                                                    {
        while (value >= 100) {
            // Integer division is slow so do it for a group of two digits instead
            // of for every digit. The idea comes from the talk by Alexandrescu
            // "Three Optimization Tips for C++".
            auto index = NumericCast<unsigned>((value % 100) * 2);
            value /= 100;
            *--ptr = duckdb_fmt::internal::data::digits[index + 1];
            *--ptr = duckdb_fmt::internal::data::digits[index];
        }
        if (value < 10) {
            *--ptr = NumericCast<char>('0' + value);
            return ptr;
        }
        auto index = NumericCast<unsigned>(value * 2);
        *--ptr = duckdb_fmt::internal::data::digits[index + 1];
        *--ptr = duckdb_fmt::internal::data::digits[index];
        return ptr;
    }

FormatSigned()

template<class T >

static string_t duckdb::NumericHelper::FormatSigned ( T  value, Vector &  vector  )

inlinestatic

                                                          {
        typedef typename MakeUnsigned<T>::type unsigned_t;
        int8_t sign = -(value < 0);
        unsigned_t unsigned_value = unsigned_t(value ^ T(sign)) + unsigned_t(AbsValue(sign));
        auto length = UnsafeNumericCast<idx_t>(UnsignedLength<unsigned_t>(unsigned_value) + AbsValue(sign));
        string_t result = StringVector::EmptyString(vector, length);
        auto dataptr = result.GetDataWriteable();
        auto endptr = dataptr + length;
        endptr = FormatUnsigned(unsigned_value, endptr);
        if (sign) {
            *--endptr = '-';
        }
        result.Finalize();
        return result;
    }

ToString()

template<class T >

static std::string duckdb::NumericHelper::ToString ( T  value )

inlinestatic

                                       {
        return std::to_string(value);
    }

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The documentation for this class was generated from the following file:

• external/duckdb/duckdb.cpp