Adding XMPP ping functionality to CLoudPrint. XMPP ping and timeout is controlled thorugh Service S…

chrome/service/cloud_print/cloud_print_proxy_backend.cc

 // Copyright (c) 2012 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/service/cloud_print/cloud_print_proxy_backend.h"
 
 #include <map>
 #include <vector>
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
 #include "base/rand_util.h"
 #include "base/values.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/service/cloud_print/cloud_print_auth.h"
 #include "chrome/service/cloud_print/cloud_print_connector.h"
 #include "chrome/service/cloud_print/cloud_print_consts.h"
 #include "chrome/service/cloud_print/cloud_print_helpers.h"
 #include "chrome/service/cloud_print/cloud_print_token_store.h"
 #include "chrome/service/cloud_print/connector_settings.h"
 #include "chrome/service/gaia/service_gaia_authenticator.h"
 #include "chrome/service/net/service_url_request_context.h"
 #include "chrome/service/service_process.h"
 #include "google_apis/gaia/gaia_oauth_client.h"
@@ skipping 87 matching lines @@
 
   // Init XMPP channel
   void InitNotifications(const std::string& robot_email,
                          const std::string& access_token);
 
   void HandlePrinterNotification(const std::string& printer_id);
   void PollForJobs();
   // Schedules a task to poll for jobs. Does nothing if a task is already
   // scheduled.
   void ScheduleJobPoll();
+  void PingXmppServer();
+  void ScheduleXmppPing();
+  void CheckXmppPingStatus();
+
   CloudPrintTokenStore* GetTokenStore();
 
   // Our parent CloudPrintProxyBackend
   CloudPrintProxyBackend* backend_;
 
   // Cloud Print authenticator.
   scoped_refptr<CloudPrintAuth> auth_;
 
   // Cloud Print connector.
   scoped_refptr<CloudPrintConnector> connector_;
 
   // OAuth client info.
   gaia::OAuthClientInfo oauth_client_info_;
   // Notification (xmpp) handler.
   scoped_ptr<notifier::PushClient> push_client_;
   // Indicates whether XMPP notifications are currently enabled.
   bool notifications_enabled_;
   // The time when notifications were enabled. Valid only when
   // notifications_enabled_ is true.
   base::TimeTicks notifications_enabled_since_;
   // Indicates whether a task to poll for jobs has been scheduled.
   bool job_poll_scheduled_;
   // Indicates whether we should poll for jobs when we lose XMPP connection.
   bool enable_job_poll_;
+  // Indicates whether a task to ping xmpp server has been scheduled.
+  bool xmpp_ping_scheduled_;
+  // Number of XMPP pings pending reply from the server.
+  int pending_xmpp_pings_;
   // Connector settings.
   ConnectorSettings settings_;
+  std::string robot_email_;
   scoped_ptr<CloudPrintTokenStore> token_store_;
 
   DISALLOW_COPY_AND_ASSIGN(Core);
 };
 
 CloudPrintProxyBackend::CloudPrintProxyBackend(
     CloudPrintProxyFrontend* frontend,
     const ConnectorSettings& settings,
     const gaia::OAuthClientInfo& oauth_client_info,
     bool enable_job_poll)
@@ skipping 75 matching lines @@
 
 CloudPrintProxyBackend::Core::Core(
     CloudPrintProxyBackend* backend,
     const ConnectorSettings& settings,
     const gaia::OAuthClientInfo& oauth_client_info,
     bool enable_job_poll)
       : backend_(backend),
         oauth_client_info_(oauth_client_info),
         notifications_enabled_(false),
         job_poll_scheduled_(false),
-        enable_job_poll_(enable_job_poll) {
+        enable_job_poll_(enable_job_poll),
+        xmpp_ping_scheduled_(false),
+        pending_xmpp_pings_(kDefaultXmppPingTimeoutSecs) {
   settings_.CopyFrom(settings);
 }
 
 void CloudPrintProxyBackend::Core::CreateAuthAndConnector() {
   if (!auth_.get()) {
     auth_ = new CloudPrintAuth(this, settings_.server_url(), oauth_client_info_,
                                settings_.proxy_id());
   }
 
   if (!connector_.get()) {
@@ skipping 44 matching lines @@
 }
 
 void CloudPrintProxyBackend::Core::OnAuthenticationComplete(
     const std::string& access_token,
     const std::string& robot_oauth_refresh_token,
     const std::string& robot_email,
     const std::string& user_email) {
   CloudPrintTokenStore* token_store  = GetTokenStore();
   bool first_time = token_store->token().empty();
   token_store->SetToken(access_token);
+  robot_email_ = robot_email;
   // Let the frontend know that we have authenticated.
   backend_->frontend_loop_->PostTask(
       FROM_HERE,
       base::Bind(&Core::NotifyAuthenticated, this, robot_oauth_refresh_token,
                  robot_email, user_email));
   if (first_time) {
     InitNotifications(robot_email, access_token);
   } else {
     // If we are refreshing a token, update the XMPP token too.
     DCHECK(push_client_.get());
@@ skipping 25 matching lines @@
 
   // Refresh Auth token.
   auth_->RefreshAccessToken();
 }
 
 void CloudPrintProxyBackend::Core::InitNotifications(
     const std::string& robot_email,
     const std::string& access_token) {
   DCHECK(MessageLoop::current() == backend_->core_thread_.message_loop());
 
+  pending_xmpp_pings_ = 0;
   notifier::NotifierOptions notifier_options;
   notifier_options.request_context_getter =
       g_service_process->GetServiceURLRequestContextGetter();
   notifier_options.auth_mechanism = "X-OAUTH2";
   notifier_options.try_ssltcp_first = true;
   push_client_ = notifier::PushClient::CreateDefault(notifier_options);
   push_client_->AddObserver(this);
   notifier::Subscription subscription;
   subscription.channel = kCloudPrintPushNotificationsSource;
   subscription.from = kCloudPrintPushNotificationsSource;
@@ skipping 60 matching lines @@
     base::TimeDelta interval = base::TimeDelta::FromSeconds(
         base::RandInt(kMinJobPollIntervalSecs, kMaxJobPollIntervalSecs));
     MessageLoop::current()->PostDelayedTask(
         FROM_HERE,
         base::Bind(&CloudPrintProxyBackend::Core::PollForJobs, this),
         interval);
     job_poll_scheduled_ = true;
   }
 }
 
+void CloudPrintProxyBackend::Core::PingXmppServer() {
+  xmpp_ping_scheduled_ = false;
+
+  if (!push_client_.get())
+    return;
+
+  notifier::Notification notification;
+  notification.ping = true;
+  push_client_->SendNotification(notification);
+
+  pending_xmpp_pings_++;
+  if (pending_xmpp_pings_ >= kMaxFailedXmppPings) {
+    // Check ping status is we a close to the limit.
+    MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&CloudPrintProxyBackend::Core::CheckXmppPingStatus, this),
+        base::TimeDelta::FromSeconds(kXmppPingCheckIntervalSecs));
+  }
+
+  // Schedule next ping if needed.
+  if (notifications_enabled_)
+    ScheduleXmppPing();
+}
+
+void CloudPrintProxyBackend::Core::ScheduleXmppPing() {
+  if (!settings_.xmpp_ping_enabled())
+    return;
+
+  if (!xmpp_ping_scheduled_) {
+    base::TimeDelta interval = base::TimeDelta::FromSeconds(
+      base::RandInt(settings_.xmpp_ping_timeout_sec() * 0.9,
+                    settings_.xmpp_ping_timeout_sec() * 1.1));
+    MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&CloudPrintProxyBackend::Core::PingXmppServer, this),
+        interval);
+    xmpp_ping_scheduled_ = true;
+  }
+}
+
+void CloudPrintProxyBackend::Core::CheckXmppPingStatus() {
+  if (pending_xmpp_pings_ >= kMaxFailedXmppPings) {
+    // Reconnect to XMPP.
+    pending_xmpp_pings_ = 0;
+    push_client_.reset();
+    InitNotifications(robot_email_, GetTokenStore()->token());
+  }
+}
+
 CloudPrintTokenStore* CloudPrintProxyBackend::Core::GetTokenStore() {
   DCHECK(MessageLoop::current() == backend_->core_thread_.message_loop());
   if (!token_store_.get())
     token_store_.reset(new CloudPrintTokenStore);
   return token_store_.get();
 }
 
 void CloudPrintProxyBackend::Core::NotifyAuthenticated(
     const std::string& robot_oauth_refresh_token,
     const std::string& robot_email,
@@ skipping 26 matching lines @@
   notifications_enabled_ = true;
   notifications_enabled_since_ = base::TimeTicks::Now();
   VLOG(1) << "Notifications for connector " << settings_.proxy_id()
           << " were enabled at "
           << notifications_enabled_since_.ToInternalValue();
   // Notifications just got re-enabled. In this case we want to schedule
   // a poll once for jobs we might have missed when we were dark.
   // Note that ScheduleJobPoll will not schedule again if a job poll task is
   // already scheduled.
   ScheduleJobPoll();
+
+  // Schedule periodic ping for XMPP notification channel.
+  ScheduleXmppPing();
 }
 
 void CloudPrintProxyBackend::Core::OnNotificationsDisabled(
     notifier::NotificationsDisabledReason reason) {
   DCHECK(MessageLoop::current() == backend_->core_thread_.message_loop());
   notifications_enabled_ = false;
   LOG(ERROR) << "Notifications for connector " << settings_.proxy_id()
              << " disabled.";
   notifications_enabled_since_ = base::TimeTicks();
   // We just lost notifications. This this case we want to schedule a
   // job poll if enable_job_poll_ is true.
   if (enable_job_poll_)
     ScheduleJobPoll();
 }
 
 
 void CloudPrintProxyBackend::Core::OnIncomingNotification(
     const notifier::Notification& notification) {
+  // Since we got some notification from the server (message or ping),
+  // reset pending ping counter to 0.
+  pending_xmpp_pings_ = 0;
+
+  if (notification.ping) {
+    VLOG(1) << "CP_CONNECTOR: Ping notification received.";
+    return;
+  }
+
   DCHECK(MessageLoop::current() == backend_->core_thread_.message_loop());
   VLOG(1) << "CP_CONNECTOR: Incoming notification.";
   if (0 == base::strcasecmp(kCloudPrintPushNotificationsSource,
                             notification.channel.c_str()))
     HandlePrinterNotification(notification.data);
 }