Initial chrome.mdns API.

chrome/browser/extensions/api/mdns/mdns_api.cc

+// Copyright (c) 2013 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 "chrome/browser/extensions/api/mdns/mdns_api.h"
+
+#include <vector>
+
+#include "base/lazy_instance.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/common/extensions/api/mdns.h"
+
+namespace extensions {
+
+namespace mdns = api::mdns;
+
+namespace {
+
+// Whitelisted mDNS service types.
+const char kCastServiceType[] = "_googlecast._tcp.local";
+
+bool IsServiceTypeWhitelisted(std::string service_type) {
+  return service_type == kCastServiceType;
+}
+
+}  // namespace
+
+MDnsAPI::MDnsAPI(Profile* profile) : profile_(profile) {
+  DCHECK(profile_);
+  ExtensionSystem::Get(profile)->event_router()->RegisterObserver(
+      this, mdns::OnServiceList::kEventName);
+}
+
+MDnsAPI::~MDnsAPI() {
+  if (nsd_registry_.get()) {
+    nsd_registry_->RemoveObserver(this);
+  }
+}
+
+// static
+MDnsAPI* MDnsAPI::Get(Profile* profile) {
+  return ProfileKeyedAPIFactory<MDnsAPI>::GetForProfile(profile);
+}
+
+static base::LazyInstance<ProfileKeyedAPIFactory<MDnsAPI> > g_factory =
+    LAZY_INSTANCE_INITIALIZER;
+
+// static
+ProfileKeyedAPIFactory<MDnsAPI>* MDnsAPI::GetFactoryInstance() {
+  return &g_factory.Get();
+}
+
+void MDnsAPI::SetNsdRegistryForTesting(scoped_ptr<NsdRegistry> nsd_registry) {
+  nsd_registry_ = nsd_registry.Pass();
+}
+
+NsdRegistry* MDnsAPI::nsd_registry() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (!nsd_registry_.get()) {
+    nsd_registry_.reset(new extensions::NsdRegistry());
+    nsd_registry_->AddObserver(this);
+  }
+  return nsd_registry_.get();
+}
+
+bool GetURLFromValue(const base::Value* in_value, std::string* out_value) {
+  return in_value && out_value && in_value->GetAsString(out_value);
+}
+
+void MDnsAPI::OnListenerAdded(const EventListenerInfo& details) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(mdns::OnServiceList::kEventName, details.event_name);
+  UpdateMDnsListeners(details);
+}
+
+void MDnsAPI::OnListenerRemoved(const EventListenerInfo& details) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(mdns::OnServiceList::kEventName, details.event_name);
+  UpdateMDnsListeners(details);
+}
+
+void MDnsAPI::UpdateMDnsListeners(const EventListenerInfo& details) {
+  std::set<std::string> new_service_types;
+
+  // Check all listeners for service type filers.
+  const EventListenerMap::ListenerList& listeners =
+      extensions::ExtensionSystem::Get(profile_)->event_router()->
+          listeners().GetEventListenersByName(details.event_name);
+  for (EventListenerMap::ListenerList::const_iterator it = listeners.begin();
+       it != listeners.end(); ++it) {
+    base::DictionaryValue* filter = ((*it)->filter.get());
+    for (base::DictionaryValue::Iterator iter(*filter);
+       !iter.IsAtEnd(); iter.Advance()) {
+    }
+
+    std::string filter_value;
+    filter->GetStringASCII(kEventFilterServiceTypeKey, &filter_value);
+    if (filter_value.empty())
+      continue;
+
+    new_service_types.insert(filter_value);
+  }
+
+  // Find all the added and removed service types since last update.
+  std::set<std::string> added_service_types =
+      base::STLSetDifference<std::set<std::string> >(
+          service_types_, new_service_types);
+  std::set<std::string> removed_service_types =
+      base::STLSetDifference<std::set<std::string> >(
+          new_service_types, service_types_);
+
+  // Update the registry.
+  NsdRegistry* registry = nsd_registry();
+  for (std::set<std::string>::iterator it = added_service_types.begin();
+       it != added_service_types.end(); ++it) {
+    if (IsServiceTypeWhitelisted(*it))
+      registry->RegisterMDnsListener(*it);
+  }
+  for (std::set<std::string>::iterator it = removed_service_types.begin();
+       it != removed_service_types.end(); ++it) {
+    if (IsServiceTypeWhitelisted(*it))
+      registry->UnregisterMDnsListener(*it);
+  }
+
+  service_types_ = new_service_types;
+}
+
+void MDnsAPI::OnMDnsEvent(const std::string& service_type,
+                          const NsdRegistry::NsdServiceList& services) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (services.size() == 0)
+    return;
+
+  std::vector<linked_ptr<mdns::MDnsService> > args;
+  for (NsdRegistry::NsdServiceList::const_iterator it = services.begin();
+       it != services.end(); ++it) {
+    linked_ptr<mdns::MDnsService> mdns_service =
+        make_linked_ptr(new mdns::MDnsService);
+    // TODO(justinlin, mfoltz): Copy data from service list.
+    mdns_service->service_name = service_type;
+    args.push_back(mdns_service);
+  }
+
+  EventFilteringInfo filter_info;
+  filter_info.SetServiceType(service_type);

[Matt Perry, 2013/09/05 20:14:18]

nit: why not set this directly on event, e.g.
event->filter_info.SetServiceType(etc)

[justinlin, 2013/09/05 21:44:04]

Done.

+
+  scoped_ptr<base::ListValue> results = mdns::OnServiceList::Create(args);
+  scoped_ptr<Event> event(
+      new Event(mdns::OnServiceList::kEventName, results.Pass()));
+  event->restrict_to_profile = profile_;
+  event->filter_info = filter_info;
+
+  extensions::ExtensionSystem::Get(profile_)->event_router()->
+      BroadcastEvent(event.Pass());
+}
+
+}  // namespace extensions