Support custom message filtering on Mojo binding objects

mojo/public/cpp/bindings/associated_binding.h

 // Copyright 2015 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_BINDING_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_BINDING_H_
 
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "mojo/public/cpp/bindings/associated_group.h"
 #include "mojo/public/cpp/bindings/associated_group_controller.h"
 #include "mojo/public/cpp/bindings/associated_interface_request.h"
 #include "mojo/public/cpp/bindings/interface_endpoint_client.h"
 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
 
 namespace mojo {
 
+class MessageReceiver;
+
 // Represents the implementation side of an associated interface. It is similar
 // to Binding, except that it doesn't own a message pipe handle.
 //
 // When you bind this class to a request, optionally you can specify a
 // base::SingleThreadTaskRunner. This task runner must belong to the same
 // thread. It will be used to dispatch incoming method calls and connection
 // error notification. It is useful when you attach multiple task runners to a
 // single thread for the purposes of task scheduling. Please note that incoming
 // synchrounous method calls may not be run from this task runner, when they
 // reenter outgoing synchrounous calls on the same thread.
@@ skipping 67 matching lines @@
         base::WrapUnique(new typename Interface::RequestValidator_()),
         Interface::HasSyncMethods_, std::move(runner)));
     endpoint_client_->set_connection_error_handler(
         base::Bind(&AssociatedBinding::RunConnectionErrorHandler,
                    base::Unretained(this)));
 
     stub_.serialization_context()->group_controller =
         endpoint_client_->group_controller();
   }
 
+  // Adds a message filter to be notified of each incoming message before
+  // dispatch. If a filter returns |false| from Accept(), the message is not
+  // dispatched and the pipe is closed. Filters cannot be removed.
+  void AddFilter(std::unique_ptr<MessageReceiver> filter) {
+    DCHECK(endpoint_client_);
+    endpoint_client_->AddFilter(std::move(filter));
+  }
+
   // Closes the associated interface. Puts this object into a state where it can
   // be rebound.
   void Close() {
     DCHECK(endpoint_client_);
     endpoint_client_.reset();
     connection_error_handler_.Reset();
   }
 
   // Unbinds and returns the associated interface request so it can be
   // used in another context, such as on another thread or with a different
@@ skipping 43 matching lines @@
   typename Interface::Stub_ stub_;
   Interface* impl_;
   base::Closure connection_error_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(AssociatedBinding);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_BINDING_H_