Make it possible to have multiple InspectorBackends

sky/services/inspector/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 "mojo/application/application_runner_chromium.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
-#include "sky/services/inspector/inspector_frontend_impl.h"
+#include "mojo/public/cpp/application/interface_factory_impl.h"
+#include "mojo/public/cpp/bindings/interface_impl.h"
+#include "net/server/http_server.h"
+#include "net/socket/tcp_server_socket.h"
+#include "sky/services/inspector/inspector.mojom.h"
+
 
 namespace sky {
 namespace inspector {
 
-class Server : public mojo::ApplicationDelegate {
+// TODO(eseidel): None of this Impl nonsense is necessary: crbug.com/431963
+class InspectorServerImpl : public mojo::InterfaceImpl<InspectorServer> {
+public:
+  class Delegate {
+  public:
+    virtual void Register(InspectorServerImpl* impl) = 0;
+    virtual void Unregister(InspectorServerImpl* impl) = 0;
+    virtual void Listen(int32_t port) = 0;
+  };
+  InspectorServerImpl(Delegate* delegate) : delegate_(delegate) {
+    delegate_->Register(this);
+  }
+  virtual ~InspectorServerImpl() {
+    delegate_->Unregister(this);
+  }
+
+  // InspectorServer:
+  void Listen(int32_t port, const mojo::Callback<void()>& callback) override {
+    delegate_->Listen(port);
+    callback.Run();
+  }
+
+  void OnShutdown() {
+    delete this;
+  }
+
+private:
+  // InterfaceImpl:
+  void OnConnectionError() override {
+    delete this; // crbug.com/431911
+  }
+
+  Delegate* delegate_;
+};
+
+class InspectorFrontendImpl : public mojo::InterfaceImpl<InspectorFrontend> {
  public:
-  Server() {}
-  virtual ~Server() {}
+  class Delegate {
+  public:
+    virtual void Register(InspectorFrontendImpl*) = 0;
+    virtual void Unregister(InspectorFrontendImpl*) = 0;
+    virtual void SendMessage(const mojo::String&) = 0;
+  };
+
+  InspectorFrontendImpl(Delegate* delegate);
+  virtual ~InspectorFrontendImpl();
+
+  void OnShutdown();
 
  private:
-  // Overridden from mojo::ApplicationDelegate:
-  virtual void Initialize(mojo::ApplicationImpl* app) override {
-  }
-
-  virtual bool ConfigureIncomingConnection(
+  // InspectorFrontend:
+  void SendMessage(const mojo::String& message) override;
+
+  // InterfaceImpl:
+  void OnConnectionError() override;
+
+  Delegate* delegate_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(InspectorFrontendImpl);
+};
+
+InspectorFrontendImpl::InspectorFrontendImpl(Delegate* delegate)
+    : delegate_(delegate) {
+  delegate_->Register(this);
+}
+
+InspectorFrontendImpl::~InspectorFrontendImpl() {
+  delegate_->Unregister(this);
+}
+
+void InspectorFrontendImpl::OnShutdown() {
+  client()->OnDisconnect();
+  delete this;
+}
+
+void InspectorFrontendImpl::OnConnectionError() {
+  delete this; // crbug.com/431911
+}
+
+void InspectorFrontendImpl::SendMessage(const mojo::String& message) {
+  delegate_->SendMessage(message);
+}
+
+
+namespace {
+const int kNotConnected = -1;
+}
+
+class Server : public mojo::ApplicationDelegate,
+    public InspectorFrontendImpl::Delegate,
+    public InspectorServerImpl::Delegate,
+    public mojo::InterfaceFactory<InspectorFrontend>,
+    public mojo::InterfaceFactory<InspectorServer>,
+    public net::HttpServer::Delegate {
+ public:
+  Server() : connection_id_(kNotConnected) {}
+  virtual ~Server();
+
+ private:
+  // mojo::ApplicationDelegate:
+  void Initialize(mojo::ApplicationImpl* app) override {
+  }
+  bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override {
-    connection->AddService(&frontend_factory_);
+    connection->AddService<InspectorFrontend>(this);
+    connection->AddService<InspectorServer>(this);
     return true;
   }
 
-  InspectorFrontendFactory frontend_factory_;
+  // InterfaceFactory<InspectorFrontend>:
+  void Create(mojo::ApplicationConnection* connection,
+        mojo::InterfaceRequest<InspectorFrontend> request) override {
+    // Weak instead of strong, per crbug.com/431911
+    WeakBindToRequest(new InspectorFrontendImpl(this), &request);
+  }
+
+  // InterfaceFactory<InspectorServer>:
+  void Create(mojo::ApplicationConnection* connection,
+        mojo::InterfaceRequest<InspectorServer> request) override {
+    // Weak instead of strong, per crbug.com/431911
+    WeakBindToRequest(new InspectorServerImpl(this), &request);
+  }
+
+  // InspectorServerImpl::Delegate:
+  void Register(InspectorServerImpl*) override;
+  void Unregister(InspectorServerImpl*) override;
+  void Listen(int32_t port) override;
+
+  // InspectorFrontendImpl::Delegate:
+  void Register(InspectorFrontendImpl*) override;
+  void Unregister(InspectorFrontendImpl*) override;
+  void SendMessage(const mojo::String& message) override;
+
+  // net::HttpServer::Delegate:
+  void OnConnect(int connection_id) override;
+  void OnHttpRequest(
+      int connection_id, const net::HttpServerRequestInfo& info) override;
+  void OnWebSocketRequest(
+      int connection_id, const net::HttpServerRequestInfo& info) override;
+  void OnWebSocketMessage(
+      int connection_id, const std::string& data) override;
+  void OnClose(int connection_id) override;
+
+  void CloseAllAgentConnections();
+
+  int connection_id_;
+  scoped_ptr<net::HttpServer> web_server_;
+  ObserverList<InspectorFrontendImpl> agents_;
+  ObserverList<InspectorServerImpl> clients_;
 
   DISALLOW_COPY_AND_ASSIGN(Server);
 };
 
+Server::~Server()
+{
+  FOR_EACH_OBSERVER(InspectorServerImpl, clients_, OnShutdown());
+  CloseAllAgentConnections();
+}
+
+void Server::CloseAllAgentConnections() {
+  FOR_EACH_OBSERVER(InspectorFrontendImpl, agents_, OnShutdown());
+}
+
+void Server::OnConnect(int connection_id) {
+}
+
+void Server::OnHttpRequest(
+    int connection_id, const net::HttpServerRequestInfo& info) {
+  web_server_->Send500(connection_id, "websockets protocol only");
+}
+
+void Server::OnWebSocketRequest(
+    int connection_id, const net::HttpServerRequestInfo& info) {
+  if (connection_id_ != kNotConnected) {
+    web_server_->Close(connection_id);
+    return;
+  }
+  web_server_->AcceptWebSocket(connection_id, info);
+  connection_id_ = connection_id;
+  FOR_EACH_OBSERVER(InspectorFrontendImpl, agents_, client()->OnConnect());
+}
+
+void Server::OnWebSocketMessage(
+    int connection_id, const std::string& data) {
+  DCHECK_EQ(connection_id, connection_id_);
+  FOR_EACH_OBSERVER(InspectorFrontendImpl, agents_, client()->OnMessage(data));
+}
+
+void Server::OnClose(int connection_id) {
+  if (connection_id != connection_id_)
+    return;
+  connection_id_ = kNotConnected;
+  FOR_EACH_OBSERVER(InspectorFrontendImpl, agents_, client()->OnDisconnect());
+}
+
+void Server::Register(InspectorServerImpl* client) {
+  clients_.AddObserver(client);
+}
+
+void Server::Unregister(InspectorServerImpl* client) {
+  clients_.RemoveObserver(client);
+}
+
+void Server::Register(InspectorFrontendImpl* agent) {
+  agents_.AddObserver(agent);
+}
+
+void Server::Unregister(InspectorFrontendImpl* agent) {
+  agents_.RemoveObserver(agent);
+}
+
+void Server::Listen(int32_t port) {
+  CloseAllAgentConnections(); // Assume caller represents a new app.
+
+  // TODO(eseidel): Early-out here if we're already bound to the right port.
+  web_server_.reset();
+  scoped_ptr<net::ServerSocket> server_socket(
+      new net::TCPServerSocket(NULL, net::NetLog::Source()));
+  server_socket->ListenWithAddressAndPort("0.0.0.0", port, 1);
+  web_server_.reset(new net::HttpServer(server_socket.Pass(), this));
+}
+
+void Server::SendMessage(const mojo::String& message) {
+  if (connection_id_ == kNotConnected)
+    return;
+  web_server_->SendOverWebSocket(connection_id_, message);
+}
+
 }  // namespace inspector
 }  // namespace sky
 
 MojoResult MojoMain(MojoHandle shell_handle) {
   mojo::ApplicationRunnerChromium runner(new sky::inspector::Server);
   runner.set_message_loop_type(base::MessageLoop::TYPE_IO);
   return runner.Run(shell_handle);
 }