abstract_factory.h 文件参考

Topic-scoped registration store that fans transport callbacks across NodeImpl peers. 更多...

#include <algorithm>
#include <atomic>
#include <map>
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include "../base/functional.h"
#include "../base/logger.h"
#include "./node_impl.h"

abstract_factory.h 的引用(Include)关系图:

浏览源代码.

类
class	vlink::AbstractObject< FilterT >
	Topic-scoped fan-out store of NodeImpl peers and their callbacks. 更多...
class	vlink::AbstractFactory< FilterT >
	Lazily allocates and caches AbstractObject instances keyed by FilterT. 更多...

命名空间
	vlink

详细描述

Topic-scoped registration store that fans transport callbacks across NodeImpl peers.

This is an internal implementation header used by the public VLink node templates (Publisher, Subscriber, Client, Server, Setter, Getter); it should not be included directly by application code. The header introduces two co-operating class templates that let several NodeImpl instances bound to the same logical topic share one registration record:

• AbstractObject – a per-topic record that owns the set of registered NodeImpl pointers together with six callback dictionaries (server connect, subscriber connect, request/response, serialised message, intra-process message and transport status).
• AbstractFactory – a thread-safe map keyed on FilterT (commonly the topic URL string) that lazily creates an AbstractObject for each key and reuses it via a cached std::weak_ptr until the last owner releases it.

Registration flow

              +----------------------+
              | AbstractFactory<K>   |
              |  map<K, weak_ptr<O>> |
              +----------+-----------+
                         | get_object<O>(key)
                         v
              +----------------------+
              |  AbstractObject<K>   |
              |  ImplList            |
              |  ConnectCallbackMap  |
              |  MsgCallbackMap ...  |
              +----------+-----------+
                 ^       |   ^
add_impl(impl)   |       |   | register_msg_callback(impl, cb)
remove_impl(impl)|       |   |
                 |       v
          +------+--+   +-+--------+   +----------+
          | NodeImpl|   | NodeImpl |   | NodeImpl |
          +---------+   +----------+   +----------+

Registry keys

Map field	Callback signature
server_connect_callback_map_	void(bool) – server side peer presence change
sub_connect_callback_map_	void(bool) – subscriber side presence change
req_resp_callback_map_	void(uint64_t, const Bytes&, Bytes*)
msg_callback_map_	void(const Bytes&)
intra_msg_callback_map_	void(const IntraData&)
status_callback_map_	void(const Status::BasePtr&)

Example

struct TopicObject final : vlink::AbstractObject<std::string> {
  using AbstractObject::AbstractObject;
};
 
vlink::AbstractFactory<std::string> factory;
 
auto object = factory.get_object<TopicObject>("dds://my_topic");
object->add_impl(impl);
object->register_msg_callback(impl, [](const vlink::Bytes& bytes) {
  // forward each delivery to the owning node
});
 
object->traverse_msg_callback([](vlink::NodeImpl*, const vlink::NodeImpl::MsgCallback& cb) {
  cb(payload);
});

注解

Every public AbstractObject method acquires the internal std::recursive_mutex; callbacks invoked through traverse_*() execute under that lock and may re-enter the same AbstractObject safely.

模板参数

FilterT

Key type used to identify topics inside the factory map.