LiteLoaderBDS-1.16.40/LiteLoader/include/llapi/utils/VarInt.h

#pragma once
#include "Bstream.h"
template <typename T>
struct VarInts {
    T v;
    operator T() {
        return v;
    }
    VarInts() {
    }
    VarInts(T x) {
        v = x;
    }
    template <typename _TP>
    void pack(WBStreamImpl<_TP>& ws) const {
        unsigned char buf[16];
        int ptr = 0;
        T enc = v;
        do {
            buf[ptr++] = enc & 0x7f;
            enc >>= 7;
        } while (enc);
        for (int i = 0; i < ptr - 1; ++i) {
            buf[i] |= 0x80;
        }
        ws.write(buf, ptr);
    }
    void unpack(RBStream& rs) {
        unsigned char buf[16];
        v = 0;
        int ptr = 0;
        for (; ptr < 16; ++ptr) {
            rs.apply(buf[ptr]);
            if (!(buf[ptr] & 0x80)) {
                ++ptr;
                break;
            }
            buf[ptr] &= 0x7f;
        }
        for (ptr = ptr - 1; ptr >= 0; --ptr) {
            v <<= 7;
            v |= buf[ptr];
        }
    }
};
using VarUInt = VarInts<unsigned int>;
using VarULong = VarInts<unsigned long long>;
using VarUShort = VarInts<unsigned short>;

struct MCString {
    std::string_view view;
    MCString() {
    }
    MCString(std::string_view sv)
    : view(sv) {
    }
    template <typename T>
    void pack(T& ws) const {
        ws.apply(VarUInt((unsigned int)view.size()));
        ws.write(view.data(), view.size());
    }
    void unpack(RBStream& rs) {
        VarUInt sz;
        rs.apply(sz);
        view = std::string_view((const char*)rs.data, sz.v);
        rs.data += sz.v;
    }
};