Packet.h

Go to the documentation of this file.

/****
 * Sming Framework Project - Open Source framework for high efficiency native ESP8266 development.
 * Created 2015 by Skurydin Alexey
 * http://github.com/SmingHub/Sming
 * All files of the Sming Core are provided under the LGPL v3 license.
 *
 * Packet.h
 *
 ****/
 
#pragma once
 
#include <WString.h>
 
struct Packet {
    uint8_t* data;
    mutable uint16_t pos;
 
    Packet(void* data, uint16_t pos = 0) : data(static_cast<uint8_t*>(data)), pos(pos)
    {
    }
 
    const uint8_t* ptr() const
    {
        return data + pos;
    }
 
    uint8_t* ptr()
    {
        return data + pos;
    }
 
    void skip(uint16_t len) const
    {
        pos += len;
    }
 
    uint8_t peek8() const
    {
        return data[pos];
    }
 
    uint8_t read8() const
    {
        return data[pos++];
    }
 
    void read(void* buffer, uint16_t len) const
    {
        memcpy(buffer, ptr(), len);
        pos += len;
    }
 
    String readString(uint16_t length) const
    {
        String s;
        if(s.setLength(length)) {
            read(s.begin(), length);
        } else {
            pos += length;
        }
        return s;
    }
 
    void write8(uint8_t value)
    {
        data[pos++] = value;
    }
 
    void write(const void* s, uint16_t len)
    {
        memcpy(ptr(), s, len);
        pos += len;
    }
};
 
struct NetworkPacket : public Packet {
    using Packet::Packet;
 
    uint16_t peek16() const
    {
        return (data[pos] << 8) | data[pos + 1];
    }
 
    uint16_t read16() const
    {
        return (read8() << 8) | read8();
    }
 
    uint32_t read32() const
    {
        return (read16() << 16) | read16();
    }
 
    void write16(uint16_t value)
    {
        write8(value >> 8);
        write8(value & 0xff);
    }
 
    void write32(uint32_t value)
    {
        write16(value >> 16);
        write16(value & 0xffff);
    }
};
 
struct HostPacket : public Packet {
    using Packet::Packet;
 
    uint16_t peek16() const
    {
        return data[pos] | (data[pos + 1] << 8);
    }
 
    uint16_t read16() const
    {
        return read8() | (read8() << 8);
    }
 
    uint32_t read32() const
    {
        return read16() | (read16() << 16);
    }
 
    void write16(uint16_t value)
    {
        write8(value & 0xff);
        write8(value >> 8);
    }
 
    void write32(uint32_t value)
    {
        write16(value & 0xffff);
        write16(value >> 16);
    }
};