AWebsocket.h

/*
 * AUI Framework - Declarative UI toolkit for modern C++20
 * Copyright (C) 2020-2024 Alex2772 and Contributors
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 
//
// Created by alex2772 on 9/5/22.
//
 
#pragma once
 
 
#include "ACurl.h"
#include "AUI/Common/AByteBufferView.h"
#include "AUI/Common/AOptional.h"
#include "AUI/Common/AString.h"
#include "AUI/IO/ADynamicPipe.h"

class API_AUI_CURL AWebsocket: public ACurl, public IOutputStream {
    friend class WebsocketTest_Receive1_Test;
    friend class WebsocketTest_Receive2_Test;
public:
    AWebsocket(const AString& url, AString key = generateKeyString());
    void write(const char* src, size_t size) override;
 
    void close() override;
 
    enum class Opcode {
        CONTINUATION = 0x0,
        TEXT = 0x1,
        BINARY = 0x2,
        CLOSE = 0x8,
        PING = 0x9,
        PONG = 0xa,
    };
 
private:
    AString mKey;
    ADynamicPipe mRead;
    bool mAccepted = false;

    struct Header {
        /* first byte: fin + opcode */
        uint8_t opcode: 4;
        uint8_t rsv: 3;
        uint8_t fin: 1;
 
        /* second byte: mask + payload length */
        uint8_t payload_len: 7; /* if 126, uses extra 2 bytes (uint16_t)
                                 * if 127, uses extra 8 bytes (uint64_t)
                                 * if <=125 is self-contained
                                 */
        uint8_t mask: 1; /* if 1, uses 4 extra bytes */
    };
 
    static AString generateKeyString();
 
    void writeRaw(const char* src, size_t size);
    void writeRawMasked(const std::uint8_t mask[4], AByteBufferView message);
    void writeMessage(Opcode opcode, AByteBufferView message);
 
    std::size_t onDataReceived(AByteBufferView data);
    std::size_t decodeOnePacket(AByteBufferView data);
    std::size_t onDataSend(char* dst, std::size_t maxLen);
 
    AWebsocket(): ACurl(ACurl::Builder("localhost")) {} // for tests
 
    AOptional<AByteBuffer> mTrailingBuffer;
 
signals:
    emits<> connected;
    emits<AByteBuffer> received;
    emits<AString /* message */> websocketClosed;
};
 
AUI_ENUM_VALUES(AWebsocket::Opcode,
                AWebsocket::Opcode::CONTINUATION,
                AWebsocket::Opcode::TEXT,
                AWebsocket::Opcode::BINARY,
                AWebsocket::Opcode::CLOSE,
                AWebsocket::Opcode::PING,
                AWebsocket::Opcode::PONG
)