[cast_channel] Implement CastSocketService::OpenSocket()

components/cast_channel/cast_socket_service.cc

 // Copyright 2017 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 "components/cast_channel/cast_socket_service.h"
 
 #include "base/memory/ptr_util.h"
+#include "components/cast_channel/cast_socket.h"
+#include "components/cast_channel/cast_transport.h"
+#include "components/cast_channel/keep_alive_delegate.h"
+#include "components/cast_channel/logger.h"
 #include "content/public/browser/browser_thread.h"
 
 using content::BrowserThread;
 
+namespace {
+// Connect timeout for connect calls.
+const int kConnectTimeoutSecs = 10;
+
+// Ping interval
+const int kPingIntervalInSecs = 5;
+
+// Liveness timeout for connect calls, in milliseconds. If no message is
+// received from the receiver during LIVENESS_INTERVAL, it is considered gone.
+const int kConnectLivenessTimeoutSecs = kPingIntervalInSecs * 2;
+}  // namespace
+
 namespace cast_channel {
 
+PassThroughMessageHandler::PassThroughMessageHandler() {}
+
+PassThroughMessageHandler::~PassThroughMessageHandler() {}
+
+void PassThroughMessageHandler::RegisterDelegate(
+    std::unique_ptr<CastTransport::Delegate> delegate) {
+  inner_delegate_ = std::move(delegate);
+}
+
+void PassThroughMessageHandler::OnError(ChannelError error_state) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  if (inner_delegate_)
+    inner_delegate_->OnError(error_state);
+}
+
+void PassThroughMessageHandler::OnMessage(const CastMessage& message) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  if (inner_delegate_)
+    inner_delegate_->OnMessage(message);
+}
+
+void PassThroughMessageHandler::Start() {}
+
 int CastSocketService::last_channel_id_ = 0;
 
 CastSocketService::CastSocketService()
     : RefcountedKeyedService(
-          BrowserThread::GetTaskRunnerForThread(BrowserThread::IO)) {
+          BrowserThread::GetTaskRunnerForThread(BrowserThread::IO)),
+      logger_(new Logger()) {
   DETACH_FROM_THREAD(thread_checker_);
 }
 
 CastSocketService::~CastSocketService() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
 }
 
-int CastSocketService::AddSocket(std::unique_ptr<CastSocket> socket) {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  DCHECK(socket);
-  int id = ++last_channel_id_;
-  socket->set_id(id);
-  sockets_.insert(std::make_pair(id, std::move(socket)));
-  return id;
-}
-
 std::unique_ptr<CastSocket> CastSocketService::RemoveSocket(int channel_id) {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   DCHECK(channel_id > 0);
-  auto socket_it = sockets_.find(channel_id);
+  auto socket_record_it = socket_records_.find(channel_id);
 
   std::unique_ptr<CastSocket> socket;
-  if (socket_it != sockets_.end()) {
-    socket = std::move(socket_it->second);
-    sockets_.erase(socket_it);
+  if (socket_record_it != socket_records_.end()) {
+    auto* socket_record = socket_record_it->second.get();
+    socket = std::move(socket_record->cast_socket);
+    // Invoke all pending OnOpen callbacks.
+    for (const auto& on_open_callback :
+         socket_record->pending_on_open_callbacks) {
+      on_open_callback.Run(socket->id(), ChannelError::CONNECT_ERROR);
+    }
+
+    socket_records_.erase(socket_record_it);
   }
   return socket;
 }
 
 CastSocket* CastSocketService::GetSocket(int channel_id) const {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  auto* socket_record = GetSocketRecord(channel_id);
+  return socket_record ? socket_record->cast_socket.get() : nullptr;
+}
+
+int CastSocketService::OpenSocket(const net::IPEndPoint& ip_endpoint,
+                                  ChannelAuthType channel_auth,
+                                  net::NetLog* net_log,
+                                  const base::TimeDelta& connect_timeout,
+                                  const base::TimeDelta& ping_interval,
+                                  const base::TimeDelta& liveness_timeout,
+                                  const scoped_refptr<Logger>& logger,
+                                  uint64_t device_capabilities,
+                                  const OnOpenCallback& open_cb) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+
+  auto* socket_record = GetSocketRecord(ip_endpoint);
+  auto* socket = socket_record ? socket_record->cast_socket.get() : nullptr;
+  // If cast socket exists.
+  if (socket) {
+    switch (socket->ready_state()) {
+      case ReadyState::NONE:
+        NOTREACHED();
+        break;
+      case ReadyState::CONNECTING:
+        DCHECK(socket_record->pending_on_open_callbacks.size() > 0);
+        socket_record->pending_on_open_callbacks.push_back(open_cb);
+        break;
+      case ReadyState::OPEN:
+        open_cb.Run(socket->id(), ChannelError::NONE);
+        break;
+      case ReadyState::CLOSING:
+        NOTREACHED();

[mark a. foltz, 2017/06/12 21:14:08]

Why is it not possible for the socket to be CLOSING here?

[zhaobin, 2017/06/20 01:37:42]

ReadyState::CLOSING is not used anywhere.

+        break;
+      case ReadyState::CLOSED:
+        RemoveSocket(socket->id());
+        socket = nullptr;
+        break;
+      default:
+        NOTREACHED();
+    }
+    if (socket)
+      return socket->id();
+  }
+
+  // If cast socket does not exist.
+  if (socket_for_test_) {
+    socket = socket_for_test_.release();
+  } else {
+    socket = new CastSocketImpl(
+        ip_endpoint, channel_auth, net_log, connect_timeout,
+        liveness_timeout > base::TimeDelta(), logger, device_capabilities);
+  }
+
+  PassThroughMessageHandler* pass_through_delegate =
+      new PassThroughMessageHandler();
+  std::unique_ptr<CastTransport::Delegate> delegate(pass_through_delegate);

[mark a. foltz, 2017/06/12 21:14:08]

base::MakeUnique?

[zhaobin, 2017/06/20 01:37:42]

Code removed.

+  AddSocketRecord(base::WrapUnique(socket), open_cb, pass_through_delegate);
+
+  if (socket->keep_alive()) {
+    // Wrap read delegate in a KeepAliveDelegate for timeout handling.
+    KeepAliveDelegate* keep_alive = new KeepAliveDelegate(
+        socket, logger_, std::move(delegate), ping_interval, liveness_timeout);
+    if (injected_timeout_timer_) {
+      keep_alive->SetTimersForTest(base::MakeUnique<base::Timer>(false, false),
+                                   std::move(injected_timeout_timer_));
+    }
+    delegate.reset(keep_alive);
+  }
+
+  socket->Connect(std::move(delegate),
+                  base::Bind(&CastSocketService::OnOpen, this, socket->id()));
+  return socket->id();
+}
+
+int CastSocketService::OpenSocket(const net::IPEndPoint& ip_endpoint,
+                                  net::NetLog* net_log,
+                                  const OnOpenCallback& open_cb) {
+  auto connect_timeout = base::TimeDelta::FromSeconds(kConnectTimeoutSecs);
+  auto ping_interval = base::TimeDelta::FromSeconds(kPingIntervalInSecs);
+  auto liveness_timeout =
+      base::TimeDelta::FromSeconds(kConnectLivenessTimeoutSecs);
+  return OpenSocket(ip_endpoint, ChannelAuthType::SSL_VERIFIED, net_log,
+                    connect_timeout, ping_interval, liveness_timeout, logger_,
+                    CastDeviceCapability::NONE, open_cb);
+}
+
+bool CastSocketService::RegisterDelegate(
+    int channel_id,
+    std::unique_ptr<CastTransport::Delegate> delegate) {
   DCHECK(channel_id > 0);
-  const auto& socket_it = sockets_.find(channel_id);
-  return socket_it == sockets_.end() ? nullptr : socket_it->second.get();
+  auto* socket_record = GetSocketRecord(channel_id);
+  if (!socket_record)
+    return false;
+
+  socket_record->pass_through_message_handler->RegisterDelegate(

[mark a. foltz, 2017/06/12 21:14:08]

Why does the CastSocketRecord have a "pass-through" delegate that just invokes
an inner delegate when assigned later?

It seems like there need to be two delegates:
1. One to tell the client (i.e. CastChannelAPI) when messages/errors happen
2. One for the keep alive timer to function.

The latter it might make more sense for the CastSocket to create and own vs.
being injected here.  I don't remember why it was originally created by the Cast
Channel API - maybe Kevin does.

As it is I'm having a hard time following the code that sets up the delegates.

[zhaobin, 2017/06/20 01:37:42]

Code removed. Use observers instead of delegates
(https://codereview.chromium.org/2942993003/).

+      std::move(delegate));
+  return true;
+}
+
+void CastSocketService::SetSocketForTest(
+    std::unique_ptr<cast_channel::CastSocket> socket_for_test) {
+  socket_for_test_ = std::move(socket_for_test);
+}
+
+void CastSocketService::SetPingTimeoutTimerForTest(
+    std::unique_ptr<base::Timer> timer) {
+  injected_timeout_timer_ = std::move(timer);
 }
 
 void CastSocketService::ShutdownOnUIThread() {}
 
+int CastSocketService::AddSocketRecord(
+    std::unique_ptr<CastSocket> socket,
+    const OnOpenCallback& on_open_callback,
+    PassThroughMessageHandler* message_handler) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  DCHECK(socket);
+  int id = ++last_channel_id_;
+  socket->set_id(id);
+  socket_records_.insert(std::make_pair(
+      id, base::MakeUnique<CastSocketRecord>(
+              std::move(socket), on_open_callback, message_handler)));
+  return id;
+}
+
+CastSocketService::CastSocketRecord* CastSocketService::GetSocketRecord(
+    int channel_id) const {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  DCHECK(channel_id > 0);
+  const auto& socket_record_it = socket_records_.find(channel_id);
+  return socket_record_it == socket_records_.end()
+             ? nullptr
+             : socket_record_it->second.get();
+}
+
+CastSocketService::CastSocketRecord* CastSocketService::GetSocketRecord(
+    const net::IPEndPoint& ip_endpoint) const {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  for (const auto& socket_record_it : socket_records_) {

[mark a. foltz, 2017/06/12 21:14:08]

Consider using std::find_if

[zhaobin, 2017/06/20 01:37:42]

Done.

+    auto* socket_record = socket_record_it.second.get();
+    if (socket_record->cast_socket->ip_endpoint() == ip_endpoint)
+      return socket_record;
+  }
+  return nullptr;
+}
+
+void CastSocketService::OnOpen(int channel_id, ChannelError error_state) {

[mark a. foltz, 2017/06/12 21:14:08]

It might make more sense for OnOpen to be declared on CastSocketRecord, since it
owns all of the client callbacks.

[zhaobin, 2017/06/20 01:37:42]

Code removed. Let CastSocket track OnOpen callbacks.

+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  auto* socket_record = GetSocketRecord(channel_id);
+  if (!socket_record)
+    return;
+
+  // Invoke all pending OnOpen callbacks.
+  for (const auto& on_open_callback :
+       socket_record->pending_on_open_callbacks) {
+    on_open_callback.Run(channel_id, error_state);
+  }
+  socket_record->pending_on_open_callbacks.clear();
+}
+
+CastSocketService::CastSocketRecord::CastSocketRecord(
+    std::unique_ptr<CastSocket> socket,
+    const OnOpenCallback& on_open_callback,
+    PassThroughMessageHandler* message_handler)
+    : cast_socket(std::move(socket)),
+      pass_through_message_handler(message_handler) {
+  DCHECK(cast_socket);
+  DCHECK(pass_through_message_handler);
+  pending_on_open_callbacks.push_back(on_open_callback);
+}
+
+CastSocketService::CastSocketRecord::~CastSocketRecord() {}
+
 }  // namespace cast_channel