ApplicationConnection devolution, part 2.1.

examples/echo/echo_server.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <memory>
 
 #include "examples/echo/echo.mojom.h"
 #include "mojo/common/binding_set.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_runner.h"
-#include "mojo/public/cpp/application/interface_factory.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 
 namespace mojo {
 namespace examples {
 
 // This file demonstrates three ways to implement a simple Mojo server. Because
 // there's no state that's saved per-pipe, all three servers appear to the
 // client to do exactly the same thing.
 //
 // To choose one of the them, update MojoMain() at the end of this file.
 // 1. MultiServer - creates a new object for each connection. Cleans up by using
 //    StrongBinding.
 // 2. SingletonServer -- all requests are handled by one object. Connections are
 //    tracked using BindingSet.
-// 3. OneAtATimeServer -- each Create call from InterfaceFactory<> closes the
-//    old interface pipe and binds the new interface pipe.
+// 3. OneAtATimeServer -- each request "replaces" any previous request. Any old
+//    interface pipe is closed and the new interface pipe is bound.
 
 // EchoImpl defines our implementation of the Echo interface.
 // It is used by all three server variants.
 class EchoImpl : public Echo {
  public:
   void EchoString(const mojo::String& value,
                   const Callback<void(mojo::String)>& callback) override {
     callback.Run(value);
   }
 };
 
 // StrongBindingEchoImpl inherits from EchoImpl and adds the StrongBinding<>
 // class so instances will delete themselves when the message pipe is closed.
 // This simplifies lifetime management. This class is only used by MultiServer.
 class StrongBindingEchoImpl : public EchoImpl {
  public:
   explicit StrongBindingEchoImpl(InterfaceRequest<Echo> handle)
       : strong_binding_(this, handle.Pass()) {}
 
  private:
   mojo::StrongBinding<Echo> strong_binding_;
 };
 
 // MultiServer creates a new object to handle each message pipe.
-class MultiServer : public mojo::ApplicationDelegate,
-                    public mojo::InterfaceFactory<Echo> {
+class MultiServer : public mojo::ApplicationDelegate {
  public:
   MultiServer() {}
 
   // From ApplicationDelegate
   bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override {
-    connection->AddService<Echo>(this);
+    connection->GetServiceProviderImpl().AddService<Echo>(
+        [](const mojo::ConnectionContext& connection_context,
+           mojo::InterfaceRequest<Echo> echo_request) {
+          // This object will be deleted automatically because of the use of
+          // StrongBinding<> for the declaration of |strong_binding_|.
+          new StrongBindingEchoImpl(echo_request.Pass());
+        });
     return true;
   }
-
-  // From InterfaceFactory<Echo>
-  void Create(const mojo::ConnectionContext& connection_context,
-              mojo::InterfaceRequest<Echo> request) override {
-    // This object will be deleted automatically because of the use of
-    // StrongBinding<> for the declaration of |strong_binding_|.
-    new StrongBindingEchoImpl(request.Pass());
-  }
 };
 
 // SingletonServer uses the same object to handle all message pipes. Useful
 // for stateless operation.
-class SingletonServer : public mojo::ApplicationDelegate,
-                        public mojo::InterfaceFactory<Echo> {
+class SingletonServer : public mojo::ApplicationDelegate {
  public:
   SingletonServer() {}
 
   // From ApplicationDelegate
   bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override {
-    connection->AddService<Echo>(this);
+    connection->GetServiceProviderImpl().AddService<Echo>(
+        [this](const mojo::ConnectionContext& connection_context,
+               mojo::InterfaceRequest<Echo> echo_request) {
+          // All channels will connect to this singleton object, so just
+          // add the binding to our collection.
+          bindings_.AddBinding(&echo_impl_, echo_request.Pass());
+        });
     return true;
   }
 
-  // From InterfaceFactory<Echo>
-  void Create(const mojo::ConnectionContext& connection_context,
-              mojo::InterfaceRequest<Echo> request) override {
-    // All channels will connect to this singleton object, so just
-    // add the binding to our collection.
-    bindings_.AddBinding(&echo_impl_, request.Pass());
-  }
-
  private:
   EchoImpl echo_impl_;
 
   mojo::BindingSet<Echo> bindings_;
 };
 
 // OneAtATimeServer works with only one pipe at a time. When a new pipe tries
 // to bind, the previous pipe is closed. This would seem to be useful when
 // clients are expected to make a single call and then go away, but in fact it's
 // not reliable. There's a race condition because a second client could bind
 // to the server before the first client called EchoString(). Therefore, this
 // is an example of how not to write your code.
-class OneAtATimeServer : public mojo::ApplicationDelegate,
-                         public mojo::InterfaceFactory<Echo> {
+class OneAtATimeServer : public mojo::ApplicationDelegate {
  public:
   OneAtATimeServer() : binding_(&echo_impl_) {}
 
   // From ApplicationDelegate
   bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override {
-    connection->AddService<Echo>(this);
+    connection->GetServiceProviderImpl().AddService<Echo>(
+        [this](const mojo::ConnectionContext& connection_context,
+               mojo::InterfaceRequest<Echo> echo_request) {
+          binding_.Bind(echo_request.Pass());
+        });
     return true;
   }
 
-  // From InterfaceFactory<Echo>
-  void Create(const mojo::ConnectionContext& connection_context,
-              mojo::InterfaceRequest<Echo> request) override {
-    binding_.Bind(request.Pass());
-  }
-
  private:
   EchoImpl echo_impl_;
 
   mojo::Binding<Echo> binding_;
 };
 
 }  // namespace examples
 }  // namespace mojo
 
 MojoResult MojoMain(MojoHandle application_request) {
   // Uncomment one of the three servers at a time to see it work:
   mojo::ApplicationRunner runner(std::unique_ptr<mojo::examples::MultiServer>(
       new mojo::examples::MultiServer()));
   // mojo::ApplicationRunner runner(new mojo::examples::SingletonServer());
   // mojo::ApplicationRunner runner(new mojo::examples::OneAtATimeServer());
 
   return runner.Run(application_request);
 }