cocos_lib/cocos/network/WebSocket.h

/****************************************************************************
 Copyright (c) 2010-2012 cocos2d-x.org
 Copyright (c) 2013-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2023 Xiamen Yaji Software Co., Ltd.

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#pragma once

#include "base/Macros.h"
#include "base/RefCounted.h"
#include "base/std/container/vector.h"
#include "platform/StdC.h"

#include <algorithm>
#include "base/std/container/string.h"
#ifndef OBJC_CLASS
    #ifdef __OBJC__
        #define OBJC_CLASS(name) @class name
    #else
        #define OBJC_CLASS(name) class name
    #endif
#endif // OBJC_CLASS

OBJC_CLASS(WebSocketImpl);

/**
 * @addtogroup network
 * @{
 */

namespace cc {

namespace network {

/**
 * WebSocket is wrapper of the libwebsockets-protocol, let the develop could call the websocket easily.
 * Please note that all public methods of WebSocket have to be invoked on Cocos Thread.
 */
class CC_DLL WebSocket : public RefCounted {
public:
    /**
     * Close all connections and wait for all websocket threads to exit
     * @note This method has to be invoked on Cocos Thread
     */
    static void closeAllConnections();

    /**
     * Constructor of WebSocket.
     *
     * @js ctor
     */
    WebSocket();

private:
    /**
     * Destructor of WebSocket.
     *
     * @js NA
     * @lua NA
     */
    ~WebSocket() override;

public:
    /**
     * Data structure for message
     */
    struct Data {
        Data() = default;
        char *bytes{nullptr};
        uint32_t len{0}, issued{0};
        bool isBinary{false};
        void *ext{nullptr};
        uint32_t getRemain() const { return std::max(static_cast<uint32_t>(0), len - issued); }
    };

    /**
     * ErrorCode enum used to represent the error in the websocket.
     */
    enum class ErrorCode {
        TIME_OUT,           /** &lt; value 0 */
        CONNECTION_FAILURE, /** &lt; value 1 */
        UNKNOWN,            /** &lt; value 2 */
    };

    /**
     *  State enum used to represent the Websocket state.
     */
    enum class State {
        CONNECTING, /** &lt; value 0 */
        OPEN,       /** &lt; value 1 */
        CLOSING,    /** &lt; value 2 */
        CLOSED,     /** &lt; value 3 */
    };

    /**
     * The delegate class is used to process websocket events.
     *
     * The most member function are pure virtual functions,they should be implemented the in subclass.
     * @lua NA
     */
    class Delegate {
    public:
        /** Destructor of Delegate. */
        virtual ~Delegate() = default;
        /**
         * This function to be called after the client connection complete a handshake with the remote server.
         * This means that the WebSocket connection is ready to send and receive data.
         *
         * @param ws The WebSocket object connected
         */
        virtual void onOpen(WebSocket *ws) = 0;
        /**
         * This function to be called when data has appeared from the server for the client connection.
         *
         * @param ws The WebSocket object connected.
         * @param data Data object for message.
         */
        virtual void onMessage(WebSocket *ws, const Data &data) = 0;
        /**
         * When the WebSocket object connected wants to close or the protocol won't get used at all and current _readyState is State::CLOSING,this function is to be called.
         *
         * @param ws The WebSocket object connected.
         */
        virtual void onClose(WebSocket *ws, uint16_t code, const ccstd::string &reason, bool wasClean) = 0;
        /**
         * This function is to be called in the following cases:
         * 1. client connection is failed.
         * 2. the request client connection has been unable to complete a handshake with the remote server.
         * 3. the protocol won't get used at all after this callback and current _readyState is State::CONNECTING.
         * 4. when a socket descriptor needs to be removed from an external polling array. in is again the struct libwebsocket_pollargs containing the fd member to be removed. If you are using the internal polling loop, you can just ignore it and current _readyState is State::CONNECTING.
         *
         * @param ws The WebSocket object connected.
         * @param error WebSocket::ErrorCode enum,would be ErrorCode::TIME_OUT or ErrorCode::CONNECTION_FAILURE.
         */
        virtual void onError(WebSocket *ws, const ErrorCode &error) = 0;
    };

    /**
     *  @brief The initialized method for websocket.
     *         It needs to be invoked right after websocket instance is allocated.
     *  @param delegate The delegate which want to receive event from websocket.
     *  @param url The URL of websocket server.
     *  @param protocols The websocket protocols that agree with websocket server
     *  @param caFilePath The ca file path for wss connection
     *  @return true: Success, false: Failure.
     *  @lua NA
     */
    bool init(const Delegate &delegate,
              const ccstd::string &url,
              const ccstd::vector<ccstd::string> *protocols = nullptr,
              const ccstd::string &caFilePath = "");

    /**
     *  @brief Sends string data to websocket server.
     *
     *  @param message string data.
     *  @lua sendstring
     */
    void send(const ccstd::string &message);

    /**
     *  @brief Sends binary data to websocket server.
     *
     *  @param binaryMsg binary string data.
     *  @param len the size of binary string data.
     *  @lua sendstring
     */
    void send(const unsigned char *binaryMsg, unsigned int len);

    /**
     *  @brief Closes the connection to server synchronously.
     *  @note It's a synchronous method, it will not return until websocket thread exits.
     */
    void close();

    /**
     *  @brief Closes the connection to server asynchronously.
     *  @note It's an asynchronous method, it just notifies websocket thread to exit and returns directly,
     *        If using 'closeAsync' to close websocket connection,
     *        be careful of not using destructed variables in the callback of 'onClose'.
     */
    void closeAsync();

    /**
    *  @brief Closes the connection to server asynchronously.
    *  @note It's an asynchronous method, it just notifies websocket thread to exit and returns directly,
    *        If using 'closeAsync' to close websocket connection,
    *        be careful of not using destructed variables in the callback of 'onClose'.
    *  @param code close reason
    *  @param reason reason text description
    */
    void closeAsync(int code, const ccstd::string &reason);

    /**
     *  @brief Gets current state of connection.
     *  @return State the state value could be State::CONNECTING, State::OPEN, State::CLOSING or State::CLOSED
     */
    State getReadyState() const;

    /**
     *  @brief Gets the URL of websocket connection.
     */
    const ccstd::string &getUrl() const;

    /**
    * @brief Returns the number of bytes of data that have been queued using calls to send() but not yet transmitted to the network.
    */
    size_t getBufferedAmount() const;

    /**
    * @brief Returns the extensions selected by the server.
    */
    ccstd::string getExtensions() const;

    /**
     *  @brief Gets the protocol selected by websocket server.
     */
    const ccstd::string &getProtocol() const;

    Delegate *getDelegate() const;

private:
    WebSocketImpl *_impl{nullptr};
};

} // namespace network

} // namespace cc

// end group
/// @}