[Chromoting] Add DataChannelManager to manage optional incoming data channels

remoting/protocol/data_channel_manager.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 "remoting/protocol/data_channel_manager.h"
+
+#include <utility>
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "remoting/protocol/data_channel_handler.h"
+#include "third_party/re2/src/re2/re2.h"
+
+namespace remoting {
+namespace protocol {
+
+DataChannelManager::DataChannelManager() = default;
+DataChannelManager::~DataChannelManager() = default;
+
+bool DataChannelManager::RegisterHandlerFactory(
+    const std::string& regex,
+    HandlerFactory constructor) {
+  if (regex.empty() || !constructor) {
+    return false;
+  }
+
+  constructors_.push_back(std::make_pair(regex, constructor));
+  return true;
+}
+
+bool DataChannelManager::OnIncomingDataChannel(
+    const std::string& name,
+    std::unique_ptr<MessagePipe> pipe) {
+#if DCHECK_IS_ON()
+  // Ensures the name matches only one regex.
+  bool matched = false;
+  for (auto& constructor : constructors_) {
+    if (re2::RE2::FullMatch(name, constructor.first)) {
+      DCHECK(!matched);
+      matched = true;
+    }
+  }
+  if (!matched) {
+    return false;
+  }
+#endif
+  for (auto& constructor : constructors_) {
+    if (re2::RE2::FullMatch(name, constructor.first)) {
+      constructor.second.Run(name, std::move(pipe));
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace protocol
+}  // namespace remoting