QGIS/external/lazperf/Inserter.hpp

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#pragma once

#include <cstring>

#include "portable_endian.hpp"

namespace lazperf
{

class LeInserter
{
public:
    LeInserter(unsigned char *buf, std::size_t size) : m_pbase((char *)buf),
        m_epptr((char *)buf + size), m_pptr((char *)buf)
    {}
    LeInserter(char *buf, std::size_t size) : m_pbase(buf),
        m_epptr(buf + size), m_pptr(buf)
    {}

private:
    // Base pointer - start of buffer (names taken from std::streambuf).
    char *m_pbase;
    // End pointer.
    char *m_epptr;
    // Current position.
    char *m_pptr;

public:
    operator bool() const
        { return good(); }
    bool good() const
        { return m_pptr < m_epptr; }
    void seek(std::size_t pos)
        { m_pptr = m_pbase + pos; }
    void put(const std::string& s)
        { put(s, s.size()); }
    void put(std::string s, size_t len)
    {
        s.resize(len);
        put(s.data(), len);
    }
    void put(const char *c, size_t len)
    {
        memcpy(m_pptr, c, len);
        m_pptr += len;
    }
    void put(const unsigned char *c, size_t len)
    {
        memcpy(m_pptr, c, len);
        m_pptr += len;
    }
    std::size_t position() const
        { return m_pptr - m_pbase; }

    LeInserter& operator << (uint8_t v)
    {
        *m_pptr++ = (char)v;
        return *this;
    }

    LeInserter& operator << (int8_t v)
    {
        *m_pptr++ = v;
        return *this;
    }

    LeInserter& operator << (uint16_t v)
    {
        v = htole16(v);
        memcpy(m_pptr, &v, sizeof(v));
        m_pptr += sizeof(v);
        return *this;
    }

    LeInserter& operator << (int16_t v)
    {
        v = (int16_t)htole16((uint16_t)v);
        memcpy(m_pptr, &v, sizeof(v));
        m_pptr += sizeof(v);
        return *this;
    }

    LeInserter& operator << (uint32_t v)
    {
        v = htole32(v);
        memcpy(m_pptr, &v, sizeof(v));
        m_pptr += sizeof(v);
        return *this;
    }

    LeInserter& operator << (int32_t v)
    {
        v = (int32_t)htole32((uint32_t)v);
        memcpy(m_pptr, &v, sizeof(v));
        m_pptr += sizeof(v);
        return *this;
    }

    LeInserter& operator << (uint64_t v)
    {
        v = htole64(v);
        memcpy(m_pptr, &v, sizeof(v));
        m_pptr += sizeof(v);
        return *this;
    }

    LeInserter& operator << (int64_t v)
    {
        v = (int64_t)htole64((uint64_t)v);
        memcpy(m_pptr, &v, sizeof(v));
        m_pptr += sizeof(v);
        return *this;
    }

    LeInserter& operator << (float v)
    {
        union
        {
            float f;
            uint32_t u;
        } uu;

        uu.f = v;
        uu.u = htole32(uu.u);
        memcpy(m_pptr, &uu.f, sizeof(uu.f));
        m_pptr += sizeof(uu.f);
        return *this;
    }

    LeInserter& operator << (double v)
    {
        union
        {
            double d;
            uint64_t u;
        } uu;

        uu.d = v;
        uu.u = htole64(uu.u);
        memcpy(m_pptr, &uu.d, sizeof(uu.d));
        m_pptr += sizeof(uu.d);
        return *this;
    }
};

} // namespace lazperf