Use notification-based API for getting system proxy settings on Mac rather than polling.

BUG=50587
Review URL: http://codereview.chromium.org/3078009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@54288 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 142 insertions, 9 deletions

diff --git a/net/proxy/proxy_config_service_mac.cc b/net/proxy/proxy_config_service_mac.cc
index 27a0426..38237a56 100644
--- a/net/proxy/proxy_config_service_mac.cc
+++ b/net/proxy/proxy_config_service_mac.cc
@@ -161,9 +161,104 @@ void GetCurrentProxyConfig(ProxyConfig* config) {
 
 }  // namespace
 
-ProxyConfigServiceMac::ProxyConfigServiceMac()
-    : PollingProxyConfigService(base::TimeDelta::FromSeconds(kPollIntervalSec),
-                                &GetCurrentProxyConfig) {
+// Reference-counted helper for posting a task to
+// ProxyConfigServiceMac::OnProxyConfigChanged between the notifier and IO
+// thread. This helper object may outlive the ProxyConfigServiceMac.
+class ProxyConfigServiceMac::Helper
+    : public base::RefCountedThreadSafe<ProxyConfigServiceMac::Helper> {
+ public:
+  explicit Helper(ProxyConfigServiceMac* parent) : parent_(parent) {
+    DCHECK(parent);
+  }
+
+  // Called when the parent is destroyed.
+  void Orphan() {
+    parent_ = NULL;
+  }
+
+  void OnProxyConfigChanged(const ProxyConfig& new_config) {
+    if (parent_)
+      parent_->OnProxyConfigChanged(new_config);
+  }
+
+ private:
+  ProxyConfigServiceMac* parent_;
+};
+
+ProxyConfigServiceMac::ProxyConfigServiceMac(MessageLoop* io_loop)
+    : has_fetched_config_(false),
+      helper_(new Helper(this)),
+      io_loop_(io_loop) {
+  DCHECK(io_loop);
+}
+
+ProxyConfigServiceMac::~ProxyConfigServiceMac() {
+  DCHECK_EQ(io_loop_, MessageLoop::current());
+  helper_->Orphan();
+  io_loop_ = NULL;
+}
+
+void ProxyConfigServiceMac::AddObserver(Observer* observer) {
+  DCHECK_EQ(io_loop_, MessageLoop::current());
+  observers_.AddObserver(observer);
+}
+
+void ProxyConfigServiceMac::RemoveObserver(Observer* observer) {
+  DCHECK_EQ(io_loop_, MessageLoop::current());
+  observers_.RemoveObserver(observer);
+}
+
+bool ProxyConfigServiceMac::GetLatestProxyConfig(ProxyConfig* config) {
+  DCHECK_EQ(io_loop_, MessageLoop::current());
+
+  // Lazy-initialize by fetching the proxy setting from this thread.
+  if (!has_fetched_config_) {
+    GetCurrentProxyConfig(&last_config_fetched_);
+    has_fetched_config_ = true;
+  }
+
+  *config = last_config_fetched_;
+  return has_fetched_config_;
+}
+
+void ProxyConfigServiceMac::SetDynamicStoreNotificationKeys(
+    SCDynamicStoreRef store) {
+  CFStringRef proxies_key = SCDynamicStoreKeyCreateProxies(NULL);
+  CFArrayRef key_array = CFArrayCreate(
+      NULL, (const void **)(&proxies_key), 1, &kCFTypeArrayCallBacks);
+
+  bool ret = SCDynamicStoreSetNotificationKeys(store, key_array, NULL);
+  // TODO(willchan): Figure out a proper way to handle this rather than crash.
+  CHECK(ret);
+
+  CFRelease(key_array);
+  CFRelease(proxies_key);
+}
+
+void ProxyConfigServiceMac::OnNetworkConfigChange(CFArrayRef changed_keys) {
+  // Called on notifier thread.
+
+  // Fetch the new system proxy configuration.
+  ProxyConfig new_config;
+  GetCurrentProxyConfig(&new_config);
+
+  // Call OnProxyConfigChanged() on the IO thread to notify our observers.
+  io_loop_->PostTask(
+      FROM_HERE,
+      NewRunnableMethod(
+          helper_.get(), &Helper::OnProxyConfigChanged, new_config));
+}
+
+void ProxyConfigServiceMac::OnProxyConfigChanged(
+    const ProxyConfig& new_config) {
+  DCHECK_EQ(io_loop_, MessageLoop::current());
+
+  // Keep track of the last value we have seen.
+  has_fetched_config_ = true;
+  last_config_fetched_ = new_config;
+
+  // Notify all the observers.
+  FOR_EACH_OBSERVER(Observer, observers_, OnProxyConfigChanged(new_config));
 }
 
 }  // namespace net
diff --git a/net/proxy/proxy_config_service_mac.h b/net/proxy/proxy_config_service_mac.h
index 3602313..fd2d524 100644
--- a/net/proxy/proxy_config_service_mac.h
+++ b/net/proxy/proxy_config_service_mac.h
@@ -6,15 +6,53 @@
 #define NET_PROXY_PROXY_CONFIG_SERVICE_MAC_H_
 #pragma once
 
-#include "net/proxy/polling_proxy_config_service.h"
+#include "base/basictypes.h"
+#include "base/observer_list.h"
+#include "base/ref_counted.h"
+#include "net/base/network_config_watcher_mac.h"
+#include "net/proxy/proxy_config.h"
+#include "net/proxy/proxy_config_service.h"
 
 namespace net {
 
-// TODO(eroman): Use notification-based system APIs instead of polling for
-//               changes.
-class ProxyConfigServiceMac : public PollingProxyConfigService {
+class ProxyConfigServiceMac : public ProxyConfigService,
+                              public NetworkConfigWatcherMac {
  public:
-  ProxyConfigServiceMac();
+  // Constructs a ProxyConfigService that watches the Mac OS system settings.
+  // This instance is expected to be operated and deleted on |io_loop|
+  // (however it may be constructed from a different thread).
+  explicit ProxyConfigServiceMac(MessageLoop* io_loop);
+  virtual ~ProxyConfigServiceMac();
+
+ public:
+  // ProxyConfigService implementation:
+  virtual void AddObserver(Observer* observer);
+  virtual void RemoveObserver(Observer* observer);
+  virtual bool GetLatestProxyConfig(ProxyConfig* config);
+
+ protected:
+  // NetworkConfigWatcherMac implementation:
+  virtual void SetDynamicStoreNotificationKeys(SCDynamicStoreRef store);
+  virtual void OnNetworkConfigChange(CFArrayRef changed_keys);
+
+ private:
+  class Helper;
+
+  // Called when the proxy configuration has changed, to notify the observers.
+  void OnProxyConfigChanged(const ProxyConfig& new_config);
+
+  ObserverList<Observer> observers_;
+
+  // Holds the last system proxy settings that we fetched.
+  bool has_fetched_config_;
+  ProxyConfig last_config_fetched_;
+
+  scoped_refptr<Helper> helper_;
+
+  // The thread that we expect to be operated on.
+  MessageLoop* io_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProxyConfigServiceMac);
 };
 
 }  // namespace net
diff --git a/net/proxy/proxy_service.cc b/net/proxy/proxy_service.cc
index d13b1f1..7358f1c 100644
--- a/net/proxy/proxy_service.cc
+++ b/net/proxy/proxy_service.cc
@@ -614,7 +614,7 @@ ProxyConfigService* ProxyService::CreateSystemProxyConfigService(
 #if defined(OS_WIN)
   return new ProxyConfigServiceWin();
 #elif defined(OS_MACOSX)
-  return new ProxyConfigServiceMac();
+  return new ProxyConfigServiceMac(io_loop);
 #elif defined(OS_LINUX)
   ProxyConfigServiceLinux* linux_config_service
       = new ProxyConfigServiceLinux();