libwebsockets之简单服务器代码

#include #include #include #include #include #include #include //协议回调函数之 callback_httpstatic int callback_http(struct lws *wsi,    enum lws_callback_reasons reason, void *user,    void *in, size_t len){return 0;}static int websocket_write_back(struct lws *wsi_in, char *str, int str_size_in)   //此函数从别处借来，再此非常感谢{      if (str == NULL || wsi_in == NULL)          return -1;        int n;      int len;      unsigned char *out = NULL;        if (str_size_in < 1)           len = strlen(str);      else          len = str_size_in;        out = (unsigned char *)malloc(sizeof(unsigned char)*(LWS_SEND_BUFFER_PRE_PADDING + len + LWS_SEND_BUFFER_POST_PADDING));      //* setup the buffer*/      memcpy (out + LWS_SEND_BUFFER_PRE_PADDING, str, len );  //要发送的数据从此处拷贝    //* write out*/      n = lws_write(wsi_in, out + LWS_SEND_BUFFER_PRE_PADDING, len, LWS_WRITE_TEXT);  //lws的发送函数    //  printf("[websocket_write_back] %s\n", str);      //* free the buffer*/      free(out);        return n;  }  //callback_dumb_incrementstatic int callback_dumb_increment(struct lws *wsi,    enum lws_callback_reasons reason,    void *user, void *in, size_t len){int temp = 0;    switch (reason) {        case LWS_CALLBACK_ESTABLISHED:            printf("connection established\n");            break;        case LWS_CALLBACK_RECEIVE: {            printf("received data: %s\n", (char *) in);lws_close_reason(wsi, LWS_CLOSE_STATUS_GOINGAWAY,(unsigned char *)"seeya", 5);            }break;case LWS_CALLBACK_SERVER_WRITEABLE://此处会调用的前提是：lws_callback_on_writable_all_protocol(context,&protocols[1]);被循环调用，如本程序的最后面printf("writeable+45\n");websocket_write_back(wsi ,"shfjksahfhie",12);sleep(1);break;        default:            break;    }    return 0;}//注册协议,一种协议，对应一套处理方案（类似驱动中的设备树）static struct lws_protocols protocols[] = {/* first protocol must always be HTTP handler */{"http-only", /* name */callback_http,/* callback */// sizeof (struct per_session_data__http),/* per_session_data_size */0, /* max frame size / rx buffer */},{"dumb-increment-protocol",callback_dumb_increment,// sizeof(struct per_session_data__dumb_increment), （一帧数据包的大小，注释表示无限制，由实际发送的数据的大小来决定）10, /* rx buf size must be >= permessage-deflate rx size    * dumb-increment only sends very small packets, so we set    * this accordingly.  If your protocol will send bigger    * things, adjust this to match */},{ NULL, NULL, 0, 0 } /* terminator */};int main(void) {int port = 9988;//端口号 struct lws_context_creation_info info;//上下文对象的信息struct lws_context *context;//上下文对象指针int opts = 0;//本软件的额外功能选项volatile int force_exit = 0;unsigned int ms, oldms = 0;int n = 0;//设置info，填充info信息体memset(&info,0,sizeof(info));info.port = port;info.iface=NULL;info.protocols = protocols;info.extensions = NULL;info.ssl_cert_filepath = NULL;      info.ssl_private_key_filepath = NULL; info.ssl_ca_filepath = NULL;    info.gid = -1;      info.uid = -1;      info.options = opts;  info.ka_time = 0;info.ka_probes = 0;info.ka_interval = 0;context = lws_create_context(&info);//创建上下文对面，管理wsif (context == NULL) {          printf(" Websocket context create error.\n");          return -1;      }printf("starting server with thread: %d...\n", lws_get_count_threads(context));while(1){// struct timeval tv;// gettimeofday(&tv, NULL);/** This provokes the LWS_CALLBACK_SERVER_WRITEABLE for every* live websocket connection using the DUMB_INCREMENT protocol,* as soon as it can take more packets (usually immediately)*/// ms = (tv.tv_sec * 1000) + (tv.tv_usec / 1000);// if ((ms - oldms) > 50) {// lws_callback_on_writable_all_protocol(context,// &protocols[1]);// oldms = ms;// }lws_callback_on_writable_all_protocol(context,&protocols[1]);//激活 case LWS_CALLBACK_SERVER_WRITEABLE 分支,没有此句，则不能往外发送数据，只有写了此句，才能往客户端发送数据。lws_service(context, 50);//启动ws服务}usleep(10);lws_context_destroy(context);return 0;}