old-nall/varint.hpp
Morten Delenk badedce822
v101r02
2016-08-09 20:27:40 +02:00

122 lines
3.6 KiB
C++

#pragma once
#include <nall/primitives.hpp>
#include <nall/serializer.hpp>
#include <nall/stdint.hpp>
namespace nall {
struct varint {
virtual auto read() -> uint8_t = 0;
virtual auto write(uint8_t) -> void = 0;
auto readvu() -> uintmax {
uintmax data = 0, shift = 1;
while(true) {
uint8_t x = read();
data += (x & 0x7f) * shift;
if(x & 0x80) break;
shift <<= 7;
data += shift;
}
return data;
}
auto readvs() -> intmax {
uintmax data = readvu();
bool negate = data & 1;
data >>= 1;
if(negate) data = ~data;
return data;
}
auto writevu(uintmax data) -> void {
while(true) {
uint8_t x = data & 0x7f;
data >>= 7;
if(data == 0) return write(0x80 | x);
write(x);
data--;
}
}
auto writevs(intmax data) -> void {
bool negate = data < 0;
if(negate) data = ~data;
data = (data << 1) | negate;
writevu(data);
}
};
struct VariadicNatural {
inline VariadicNatural() : mask(~0ull) { assign(0); }
template<typename T> inline VariadicNatural(const T& value) : mask(~0ull) { assign(value); }
inline operator uint64_t() const { return data; }
template<typename T> inline auto& operator=(const T& value) { return assign(value); }
inline auto operator++(int) { auto value = data; assign(data + 1); return value; }
inline auto operator--(int) { auto value = data; assign(data - 1); return value; }
inline auto& operator++() { return assign(data + 1); }
inline auto& operator--() { return assign(data - 1); }
inline auto& operator &=(const uint64_t value) { return assign(data & value); }
inline auto& operator |=(const uint64_t value) { return assign(data | value); }
inline auto& operator ^=(const uint64_t value) { return assign(data ^ value); }
inline auto& operator<<=(const uint64_t value) { return assign(data << value); }
inline auto& operator>>=(const uint64_t value) { return assign(data >> value); }
inline auto& operator +=(const uint64_t value) { return assign(data + value); }
inline auto& operator -=(const uint64_t value) { return assign(data - value); }
inline auto& operator *=(const uint64_t value) { return assign(data * value); }
inline auto& operator /=(const uint64_t value) { return assign(data / value); }
inline auto& operator %=(const uint64_t value) { return assign(data % value); }
inline auto resize(uint bits) {
assert(bits <= 64);
mask = ~0ull >> (64 - bits);
data &= mask;
}
inline auto serialize(serializer& s) {
s(data);
s(mask);
}
struct Reference {
inline Reference(VariadicNatural& self, uint lo, uint hi) : self(self), Lo(lo), Hi(hi) {}
inline operator uint64_t() const {
const uint64_t RangeBits = Hi - Lo + 1;
const uint64_t RangeMask = (((1ull << RangeBits) - 1) << Lo) & self.mask;
return (self & RangeMask) >> Lo;
}
inline auto& operator=(const uint64_t value) {
const uint64_t RangeBits = Hi - Lo + 1;
const uint64_t RangeMask = (((1ull << RangeBits) - 1) << Lo) & self.mask;
self.data = (self.data & ~RangeMask) | ((value << Lo) & RangeMask);
return *this;
}
private:
VariadicNatural& self;
const uint Lo;
const uint Hi;
};
inline auto bits(uint lo, uint hi) -> Reference { return {*this, lo < hi ? lo : hi, hi > lo ? hi : lo}; }
inline auto bit(uint index) -> Reference { return {*this, index, index}; }
inline auto byte(uint index) -> Reference { return {*this, index * 8 + 0, index * 8 + 7}; }
private:
auto assign(uint64_t value) -> VariadicNatural& {
data = value & mask;
return *this;
}
uint64_t data;
uint64_t mask;
};
}