mco_iot_comm_register_callback

此函数为通信器 comm 在 ARF（物联网）运行时注册一个回调函数结构体 iot_comm_callback_t 。

请注意，对于所有当前处于活动状态的回调，上下文必须是唯一的；也就是说，无法注册两个具有相同上下文的回调。

    MCO_RET mco_iot_comm_register_callback(
    	mco_iot_comm_h comm, 
        iot_comm_callback_t *callback, 
        void *context
    );

有关概述，请参阅主动复制结构页面。

参数

comm

mco_iot_comm_h

要注册回调函数的通信器对象。

callback

iot_comm_callback_t

带有已初始化函数指针的回调结构体 iot_comm_callback_t。

context

void

用户定义的上下文（指向包含应用程序特定数据的结构的指针）。

返回

MCO_S_OK

回调函数已成功注册。

MCO_E_ILLEGAL_PARAM

参数中的值无效/不合适。

MCO_E_NOMEM

无法为回调描述符分配内存。

MCO_E_IOT_DUPLICATE_CALLBACK

具有相同上下文的回调函数已注册（请参阅上面的注释）。

示例

下面的代码片段定义了 5 个回调函数，初始化 ARF（物联网）运行时环境，在打开并连接数据库之后，创建通信器，然后注册这些回调函数：

    int iot_on_connect(mco_iot_connection_h iotc, void *context)
    {
        mco_iot_connection_stat_t iotc_stat;
        char address[MCO_NET_INETADDR_STRING_LEN];
        mco_iot_conn_get_stat(iotc, &iotc_stat);
        mco_net_ntoa(&iotc_stat.inetaddr, address);
        printf("Agent %llu connected. Address %s:%d\n", mco_iot_conn_get_agent_id(iotc), address, iotc_stat.port);
        return IOT_CALLBACK_OK;
    }
 
    int iot_on_receive(mco_iot_connection_h iotc, mco_iot_read_stream_t *stream, void *context)
    {
        printf("DATA received from agent %llu\n", mco_iot_conn_get_agent_id(iotc));
        return IOT_CALLBACK_OK;
    }
 
    int iot_on_ack(mco_iot_connection_h iotc, const iot_ack_t *ack, void *context)
    {
        printf("ACK  received from agent %llu : %llu->%llu, ts=%llu, errcode=%d (%s)\n", mco_iot_conn_get_agent_id(iotc),
        ack->sender_agent_id, ack->receiver_agent_id, ack->timestamp, ack->error_code, mco_strerror(ack->error_code));
        return IOT_CALLBACK_OK;
    }
 
    int iot_on_disconnect(mco_iot_connection_h iotc, void *context)
    {
        mco_iot_connection_stat_t iotc_stat;
        mco_iot_conn_get_stat(iotc, &iotc_stat);
        printf("Agent %llu disconnected. Bytes sent %llu, recevied %llu\n", mco_iot_conn_get_agent_id(iotc),
        iotc_stat.sent_bytes, iotc_stat.recv_bytes);
        return IOT_CALLBACK_OK;
    }
 
    int iot_on_destroy(mco_iot_connection_h iotc, void *context)
    {
        printf("Agent connection %llu destroyed\n", mco_iot_conn_get_agent_id(iotc));
        return IOT_CALLBACK_OK;
    }
     
    int main(int argc, char *argv[])
    {
        mco_db_params_t db_params;
        mco_device_t dev;
        mco_db_h db;
        mco_iot_replicator_params_t repl_params;
        mco_iot_comm_params_t comm_params;
        mco_iot_replicator_h repl;
        mco_iot_comm_h comm;
        const char *conn_string = (argc > 1) ? argv[1] : "127.0.0.1:15000";
        iot_comm_callback_t iot_callbacks = {&iot_on_connect, &iot_on_receive, &iot_on_ack, &iot_on_disconnect, &iot_on_destroy};
        
 
        /* Initialize SmartEDB and IoT runtimes */
        mco_error_set_handler(&sample_errhandler);
        mco_runtime_start();
        mco_iot_init();
 
        /* Create database */
        dev.type       = MCO_MEMORY_CONV;
        dev.assignment = MCO_MEMORY_ASSIGN_DATABASE;
        dev.size       = DEVICE_DATABASE_SIZE;
        dev.dev.conv.ptr = (void*)malloc(dev.size);
        mco_db_params_init (&db_params);
        db_params.db_max_connections = 5;
 
        if (argc > 2) {
            db_params.iot_agent_id = atoi(argv[2]); /* Override the agent_id in the schema */
        }
        CHECK(mco_db_open_dev(db_name, iotdevice_get_dictionary(), &dev, 1, &db_params));
        CHECK(mco_db_connect(db_name, &db));
        mco_iot_comm_params_init(&comm_params);
        CHECK(mco_iot_comm_create(&comm_params, &comm));
        ...
        CHECK(mco_iot_comm_register_callback(comm, &iot_callbacks, comm));
    }

文件

• 头文件：mcoiot.h
• 源文件：mcoiotcomm.c
• 库：libmcoiotcomm.a