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#pragma once
#include <library/cpp/int128/int128.h>
#include <util/system/defaults.h>
#include <util/generic/string.h>
#include <array>
namespace NYT::NDecimal {
////////////////////////////////////////////////////////////////////////////////
class TDecimal
{
public:
//! Both types defined below represent signed values. They are only intended
//! to be used for manipulating binary data, since they don't actually expose
//! any arithmetic operations. You should avoid dealing with individual parts.
struct TValue128
{
ui64 Low;
i64 High;
};
static_assert(sizeof(TValue128) == 2 * sizeof(ui64));
struct TValue256
{
std::array<ui32, 8> Parts;
};
static_assert(sizeof(TValue256) == 4 * sizeof(ui64));
public:
//! Maximum precision supported by YT.
static constexpr int MaxPrecision = 76;
static constexpr int MaxBinarySize = 32;
// NB. Sometimes we print values that exceed MaxPrecision (e.g. in error messages)
// MaxTextSize is chosen so we can print ANY i256 number as decimal.
static constexpr int MaxTextSize =
77 // length of 2^63 in decimal form
+ 1 // possible decimal point
+ 1; // possible minus sign
static void ValidatePrecisionAndScale(int precision, int scale);
static void ValidateBinaryValue(TStringBuf binaryValue, int precision, int scale);
static TString BinaryToText(TStringBuf binaryDecimal, int precision, int scale);
static TString TextToBinary(TStringBuf textDecimal, int precision, int scale);
// More efficient versions of conversion functions without allocations.
// `buffer` must be at least of size MaxTextSize / MaxBinarySize.
// Returned value is substring of buffer.
static TStringBuf BinaryToText(TStringBuf binaryDecimal, int precision, int scale, char* buffer, size_t bufferLength);
static TStringBuf TextToBinary(TStringBuf textDecimal, int precision, int scale, char* buffer, size_t bufferLength);
static int GetValueBinarySize(int precision);
static TStringBuf WriteBinary32(int precision, i32 value, char* buffer, size_t bufferLength);
static TStringBuf WriteBinary64(int precision, i64 value, char* buffer, size_t bufferLength);
static TStringBuf WriteBinary128(int precision, TValue128 value, char* buffer, size_t bufferLength);
static TStringBuf WriteBinary256(int precision, TValue256 value, char* buffer, size_t bufferLength);
// Writes either 32-bit, 64-bit or 128-bit binary value depending on precision, provided a TValue128.
static TStringBuf WriteBinary128Variadic(int precision, TValue128 value, char* buffer, size_t bufferLength);
static i32 ParseBinary32(int precision, TStringBuf buffer);
static i64 ParseBinary64(int precision, TStringBuf buffer);
static TValue128 ParseBinary128(int precision, TStringBuf buffer);
static TValue256 ParseBinary256(int precision, TStringBuf buffer);
};
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT::NDecimal
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