conf_plugin_interface.h File Reference

Plugin ABI for dynamically loaded transport Conf factories. More...

#include <memory>
#include "../base/plugin.h"
#include "./conf.h"

Include dependency graph for conf_plugin_interface.h:

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Classes
struct	vlink::ConfPluginInterface
	Pure-virtual plugin interface for external transport Conf factories. More...

Namespaces
namespace	vlink

Detailed Description

Plugin ABI for dynamically loaded transport Conf factories.

ConfPluginInterface is the abstract C++ interface that every externally loaded VLink transport plugin must implement. Plugins are shared libraries discovered at runtime via the VLINK_URL_PLUGINS environment variable (or the Url::init_plugins() call).

Plugin Discovery and Loading

When a Url is constructed and the built-in transport table does not recognise the transport field in the URL, Url::load_for_plugin() iterates over all loaded plugins and calls get_transport_type() on each to find a matching transport. If found, create() is called to obtain a fresh Conf instance for that transport.

Implementing a Plugin

// In your plugin shared library:
struct MyTransportPlugin final : public vlink::ConfPluginInterface {
  vlink::TransportType get_transport_type() const override {
    return vlink::TransportType::kMyCustomTransport;
  }
  std::unique_ptr<vlink::Conf> create() const override {
    return std::make_unique<MyTransportConf>();
  }
};
VLINK_PLUGIN_EXPORT(MyTransportPlugin)

Note

The VLINK_PLUGIN_EXPORT macro (from base/plugin.h) injects the symbol needed for the plugin loader to locate and instantiate this type.

Implementations must be stateless; create() may be called multiple times to produce independent Conf objects for different Url instances.