AU: Make proxy resolution asynchronous.

chrome_proxy_resolver.cc

 // Copyright (c) 2010 The Chromium OS 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 "update_engine/chrome_proxy_resolver.h"
 
 #include <base/json/json_reader.h>
 #include <base/scoped_ptr.h>
 #include <base/values.h>
 
 #include "update_engine/utils.h"
 
+using google::protobuf::Closure;
+using google::protobuf::NewCallback;
+using std::deque;
 using std::string;
 using std::vector;
 
 namespace chromeos_update_engine {
 
 const char kSessionManagerService[] = "org.chromium.SessionManager";
 const char kSessionManagerPath[] = "/org/chromium/SessionManager";
 const char kSessionManagerInterface[] = "org.chromium.SessionManagerInterface";
 const char kSessionManagerRetrievePropertyMethod[] =
     "RetrieveProperty";
 const char kSessionManagerProxySettingsKey[] = "cros.proxy.everywhere";
 
 bool ChromeProxyResolver::GetProxiesForUrl(
     const std::string& url,
-    std::deque<std::string>* out_proxies) {
-  // First, query dbus for the currently stored settings
-  DBusGProxy* proxy = DbusProxy();
-  TEST_AND_RETURN_FALSE(proxy);
-  string json_settings;
-  TEST_AND_RETURN_FALSE(GetJsonProxySettings(proxy, &json_settings));
-  LOG(INFO) << "got settings:" << json_settings;
-  TEST_AND_RETURN_FALSE(
-      GetProxiesForUrlWithSettings(url, json_settings, out_proxies));
+    ProxiesResolvedFn callback,
+    void* data) {
+  ChromeProxyResolverClosureArgs args;
+  args.url = url;
+  args.callback = callback;
+  args.data = data;
+  Closure* closure = NewCallback(this,
+                                 &ChromeProxyResolver::GetProxiesForUrlCallback,
+                                 args);
+  g_idle_add(utils::GlibRunClosure, closure);
   return true;
 }
 
+void ChromeProxyResolver::GetProxiesForUrlCallback(
+    ChromeProxyResolverClosureArgs args) {
+  deque<string> proxies;
+  // First, query dbus for the currently stored settings
+  DBusGProxy* proxy = DbusProxy();
+  if (proxy) {
+    string json_settings;
+    if (GetJsonProxySettings(proxy, &json_settings)) {
+      LOG(INFO) << "got settings:" << json_settings;
+      GetProxiesForUrlWithSettings(args.url, json_settings, &proxies);
+    }
+  }
+  (*args.callback)(proxies, args.data);
+}
+
 bool ChromeProxyResolver::GetJsonProxySettings(DBusGProxy* proxy,
                                                std::string* out_json) {
   gchar* value = NULL;
   GArray* sig = NULL;
   GError* error = NULL;
   TEST_AND_RETURN_FALSE(
       dbus_->ProxyCall(proxy,
                        kSessionManagerRetrievePropertyMethod,
                        &error,
                        G_TYPE_STRING, kSessionManagerProxySettingsKey,
@@ skipping 127 matching lines @@
   }
   if (utils::StringHasPrefix(proxy, kNoProxy)) {
     // known failure case. don't log.
     return false;
   }
   LOG(INFO) << "Unknown proxy type: " << proxy;
   return false;
 }
 
 }  // namespace chromeos_update_engine