[网络协议]高通 sensor see _2

// 随便　　记录下　　
sns_service_manager.c

sns_service_manager_init　函数

定义在　.data.sns 段里面…

static sns_fw_service_manager service_manager SNS_SECTION(".data.sns");

// init 流程.
service_manager　管理　各种　　service 。
１：　stream　service
2: attr_svc
3:event_service
4：　…

 service_manager.service.struct_len = sizeof(service_manager.service);
  service_manager.service.get_service = &get_service;

  service_manager.services[SNS_STREAM_SERVICE] = (sns_service*)sns_stream_service_init();
  service_manager.services[SNS_ATTRIBUTE_SERVICE] = (sns_service*)sns_attr_svc_init();
  //service_manager.services[SNS_DYNAMIC_BUFFER_SERVICE] = ;
  service_manager.services[SNS_EVENT_SERVICE] = (sns_service*)sns_event_service_init();
  service_manager.services[SNS_DIAG_SERVICE] = (sns_service *)sns_diag_service_init();
  service_manager.services[SNS_POWER_RAIL_SERVICE] = (sns_service*)sns_pwr_rail_service_init();
  service_manager.services[SNS_SYNC_COM_PORT_SERVICE] = (sns_service *)sns_sync_com_port_service_init();
  service_manager.services[SNS_GPIO_SERVICE] = (sns_service *)sns_gpio_service_init();
  service_manager.services[SNS_ISLAND_SERVICE] = (sns_service *)sns_island_service_init();
  return SNS_RC_SUCCESS;

再来看下　　get_service　函数.

SNS_SECTION(".text.sns") static sns_service*
get_service(struct sns_service_manager *svc_mngr, sns_service_type service)
{
1:framework service 获得..
  sns_fw_service_manager *this = (sns_fw_service_manager*)svc_mngr;
  if(service >= SNS_SERVICE_TYPE_LENGTH)
    return NULL;

2:Checks if a pointer can be safely dereferenced when in island mode. 如果　为　1,说明　在　island 模式下是安全的.这个不影响　流程.跳过.
  Consider NULL to be a valid island pointer  if(!sns_island_is_island_ptr((intptr_t)this->services[service]))
  {
    SNS_ISLAND_EXIT();
  }
3:返回　　具体的　service 
  return this->services[service];
}

这个　直接获得　　service_manager 的地址.

SNS_SECTION(".text.sns") sns_fw_service_manager*
sns_service_manager_ref(void)
{
  return &service_manager;
}

举个例子:
参考　:
https://blog.csdn.net/mjfh095215/article/details/113932106?spm=1001.2014.3001.5502

init_dependencies

static void init_dependencies(sns_sensor *const this)
{
  DBG_PRINTF_EX(LOW, this, "init_dependencies sensor");

  for(int i=0;i<ARR_SIZE(def_dependency);i++)
  {
    send_suid_req(this, def_dependency[i], strlen(def_dependency[i]));
  }
}

def_dependency :没看懂是　啥意思？

我们看下　　send_suid_req　这个函数

if(shared_state->suid_stream == NULL)
  {
    sns_service_manager *manager = this->cb->get_service_manager(this);
    sns_stream_service *stream_service =
      (sns_stream_service*)manager->get_service(manager, SNS_STREAM_SERVICE);
     stream_service->api->create_sensor_stream(stream_service, this, sns_get_suid_lookup(),
                                               &shared_state->suid_stream);
  }

this->cb->get_service_manager　
这个　函数　sns_sensor_init_fw　
执行的是　get_service_manager　函数

sensor_cb = (sns_sensor_cb)
  {
    .struct_len = sizeof(sensor_cb),
    .get_service_manager = &get_service_manager,

这个　函数　上面写了, 就是返回　service_manager　的地址.
这个　　this 　参数没有用上.

SNS_SECTION(".text.sns") static struct sns_service_manager*
get_service_manager(sns_sensor const *this)
{
  UNUSED_VAR(this);
  return (sns_service_manager*)sns_service_manager_ref();
}

当然　我们在　　sns_service_manager_init　中绑定了　get_service　函数

  service_manager.service.get_service = &get_service;

看下调用:
其实　就是获得了　这个　
service_manager.services[SNS_STREAM_SERVICE] = (sns_service*)sns_stream_service_init();

      (sns_stream_service*)manager->get_service(manager, SNS_STREAM_SERVICE);

在来看下　　这个　stream_service 的函数
stream_service_api 这个结构体的初始化　还是要看下,不然到后面真的是找不到了.

sns_fw_stream_service*
sns_stream_service_init(void)
{
  stream_service_api = (sns_stream_service_api)
  {
    .struct_len = sizeof(stream_service_api),
    .create_sensor_stream = &create_sensor_stream,
    .create_sensor_instance_stream = &create_sensor_instance_stream,
    .remove_stream = &remove_stream
  };

  stream_service.service.service.version = version;
  stream_service.service.service.type = SNS_STREAM_SERVICE;
  stream_service.service.api = &stream_service_api;

  return &stream_service;
}

继续回到　　send_suid_req　
这个就不在进去看了.看下注释　
Initialize a new stream to be used by a Sensor　
第一个参数：　stream 的服务
2: 没有用上
3:ｕｉｄ
４：fw 分配的流

 stream_service->api->create_sensor_stream(stream_service, this, sns_get_suid_lookup(),
                                               &shared_state->suid_stream);

好，继续回到　send_suid_req　函数

继续的话，会进入到　这个里面．　在上面　这个　流创建了，不为空
填充　　suid_req

对数据　进行编码.

    encoded_len = pb_encode_request(buffer, sizeof(buffer), &suid_req, sns_suid_req_fields, NULL);

编码　成功，开始　发送…
buffer 存放了　　pb 编码后的内容…
发生　分为２步：
１：讲数据封包成　sns_request　类型
２：send_request　发送　.

if(0 < encoded_len)
    {
      sns_request request = (sns_request){
        .request_len = encoded_len, .request = buffer, .message_id = SNS_SUID_MSGID_SNS_SUID_REQ };
      rc = shared_state->suid_stream->api->
             send_request(shared_state->suid_stream, &request);
    }

我们在来看下　这个　send_request　怎么发送的
关键的　就这个

if(sns_data_stream_validate(stream))
  {
  //  加入　队列　等等执行.
    sns_stream_service_add_request(stream, request);
    rv = SNS_RC_SUCCESS;
  }

也许　这个关键字　对调试　有用，先记录下.
send_request: Invalid stream
发送完毕

后面接收的话

通过SNS_SUID_MSGID_SNS_SUID_EVENT接收的event，获取suid

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