Apollo 应用与源码分析：CyberRT-话题通信

话题通信

目录

话题通信

创建node

API

参数

创建写端

API

参数:

创建读端

API

参数

代码样例

Talker

Listener

BUILD

---

创建node

API

std::unique_ptr apollo::cyber::CreateNode(const std::string& node_name, const std::string& name_space = "");

参数

Node_name: 节点名，全局唯一标识符
Name_space:节点所在的空间名称
Name_space 默认为空。是与node_name连在一起的空间名。格式为/namespace/node_name
返回值-指向Node的独占智能指针
错误条件—当cyber::Init()未被调用时，系统处于未初始化状态，无法创建节点，返回nullptr

创建写端

API

template <typename MessageT>
   auto CreateWriter(const std::string& channel_name)
       -> std::shared_ptr>;
template <typename MessageT>
   auto CreateWriter(const proto::RoleAttributes& role_attr)
       -> std::shared_ptr>;

参数:

Channel_name:要写入的通道名
MessageT:要写入的消息类型
返回值- Writer对象的共享指针

创建读端

API

template <typename MessageT>
auto CreateReader(const std::string& channel_name, const std::function<void(const std::shared_ptr&)>& reader_func)
    -> std::shared_ptr>;
 
template <typename MessageT>
auto CreateReader(const ReaderConfig& config,
                  const CallbackFunc& reader_func = nullptr)
    -> std::shared_ptr>;
 
template <typename MessageT>
auto CreateReader(const proto::RoleAttributes& role_attr,
                  const CallbackFunc& reader_func = nullptr)
-> std::shared_ptr>;

参数

MessageT:要读取的消息类型
Channel_name:要接收的通道的名称
Reader_func:处理消息的回调函数
返回值—Reader对象的共享指针

代码样例

Talker

#include "cyber/cyber.h"
 
#include "cyber/proto/chatter.pb.h"
 
#include "cyber/time/rate.h"
 
#include "cyber/time/time.h"
 
using apollo::cyber::Rate;
 
using apollo::cyber::Time;
 
using apollo::cyber::proto::Chatter;
 
int main(int argc, char *argv[]) {
 
// init cyber framework
 
apollo::cyber::Init(argv[0]);
 
// create talker node
 
std::shared_ptr talker_node(
apollo::cyber::CreateNode("talker"));
 
// create talker
 
auto talker = talker_node->CreateWriter("channel/chatter");
 
Rate rate(1.0);
 
while (apollo::cyber::OK()) {
 
static uint64_t seq = 0;
 
auto msg = std::make_shared();
 
msg->set_timestamp(Time::Now().ToNanosecond());
 
msg->set_lidar_timestamp(Time::Now().ToNanosecond());
 
msg->set_seq(seq++);
 
msg->set_content("Hello, apollo!");
 
talker->Write(msg);
 
AINFO << "talker sent a message!";
 
rate.Sleep();
 
}
 
return 0;
 
}

Listener

#include "cyber/cyber.h"
 
#include "cyber/proto/chatter.pb.h"
 
void MessageCallback(
 
const std::shared_ptr& msg) {
 
AINFO << "Received message seq-> " << msg->seq();
 
AINFO << "msgcontent->" << msg->content();
 
}
 
int main(int argc, char *argv[]) {
 
// init cyber framework
 
apollo::cyber::Init(argv[0]);
 
// create listener node
 
auto listener_node = apollo::cyber::CreateNode("listener");
 
// create listener
 
auto listener =
 
listener_node->CreateReader(
 
"channel/chatter", MessageCallback);
 
apollo::cyber::WaitForShutdown();
 
return 0;
 
}

BUILD

cc_binary(
 
name = "talker",
 
srcs = [ "talker.cc", ],
 
deps = [
 
"//cyber",
 
"//cyber/examples/proto:examples_cc_proto",
 
],
 
)
 
 
 
cc_binary(
 
name = "listener",
 
srcs = [ "listener.cc", ],
 
deps = [
 
"//cyber",
 
"//cyber/examples/proto:examples_cc_proto",
 
],
 
)