Communication API Description

The external communication APIs are necessary for the proper running of the video stream engine. These APIs are implemented by secondary developers and provided as a DLL. The following shows an API calling example.

// The function prototype declaration is implemented by users.
using OnNewConnectionCallback = void (*)(int connection);
using RegConnectionCBFunc = int (*)(OnNewConnectionCallback newConnCb);
using CloseConnectionFunc = int (*)(int connection);
using SendFullyFunc = ssize_t (*)(int connection, uint8_t *buf, size_t len); 
using RecvFunc = ssize_t (*)(int connection, uint8_t *buf, size_t len);
const char *soPath = "./libCommunication.so";

// The callback function notifies the server that a new connection has been established, which is implemented by the cloud phone engine.
// The input parameter connection indicates the valid handle to the new connection.
static void OnNewConnection(int conn);

void Test()  
{
    // Function symbol for dynamically loading the dynamic communication library
    void *handle = dlopen(soPath, RTLD_GLOBAL | RTLD_LAZY | RTLD_NODELETE);
    RegConnectionCBFunc regConnection = (RegConnectionCBFunc)dlsym(handle, "RegConnectionCB");
    CloseConnectionFunc closeConnection = (CloseConnectionFunc)dlsym(handle, "CloseConnection");
    SendFullyFunc sendFully = (SendFullyFunc)dlsym(handle, "SendFully");
    RecvFunc recvData = (RecvFunc)dlsym(handle, "Recv");
    size_t bufSize = 1024; 
    uint8_t *data = malloc(bufSize); 
    // Create a connection to the server.
    int connRet = regConnection(OnNewConnection);  
   // Send data.
    ssize_t ret = sendFully(conn, data, bufSize); 
    // Receive data.
    ret = recvData(conn, data, bufSize);
    // Release resources.
    free(data); 
    closeConnection(conn);
    dlclose(handle);
}

For details about the APIs, see RegConnectionCB to Recv.