GCP2.0 Device: XMPP pings.

BUG=

Review URL: https://chromiumcodereview.appspot.com/21916003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@216107 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 125 insertions, 14 deletions

diff --git a/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.cc b/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.cc
index bcf7dcc..6ad90230 100644
--- a/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.cc
+++ b/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.cc
@@ -4,7 +4,10 @@
 
 #include "cloud_print/gcp20/prototype/cloud_print_xmpp_listener.h"
 
+#include "base/bind.h"
 #include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "base/rand_util.h"
 #include "base/single_thread_task_runner.h"
 #include "cloud_print/gcp20/prototype/cloud_print_url_request_context_getter.h"
 #include "jingle/notifier/base/notifier_options.h"
@@ -12,6 +15,10 @@
 
 namespace {
 
+const int kUrgentPingInterval = 60;  // in seconds
+const int kPingTimeout = 30;  // in seconds
+const double kRandomDelayPercentage = 0.2;
+
 const char kCloudPrintPushNotificationsSource[] = "cloudprint.google.com";
 
 // Splits message into two parts (e.g. '<device_id>/delete' will be splitted
@@ -32,21 +39,29 @@ void TokenizeXmppMessage(const std::string& message, std::string* device_id,
 
 CloudPrintXmppListener::CloudPrintXmppListener(
     const std::string& robot_email,
+    int standard_ping_interval,
     scoped_refptr<base::SingleThreadTaskRunner> task_runner,
     Delegate* delegate)
     : robot_email_(robot_email),
+      standard_ping_interval_(standard_ping_interval),
+      ping_timeouts_posted_(0),
+      ping_responses_pending_(0),
+      ping_scheduled_(false),
       context_getter_(new CloudPrintURLRequestContextGetter(task_runner)),
       delegate_(delegate) {
 }
 
 CloudPrintXmppListener::~CloudPrintXmppListener() {
-  push_client_->RemoveObserver(this);
-  push_client_.reset();
+  if (push_client_) {
+    push_client_->RemoveObserver(this);
+    push_client_.reset();
+  }
 }
 
 void CloudPrintXmppListener::Connect(const std::string& access_token) {
-  push_client_.reset();
   access_token_ = access_token;
+  ping_responses_pending_ = 0;
+  ping_scheduled_ = 0;
 
   notifier::NotifierOptions options;
   options.request_context_getter = context_getter_;
@@ -66,8 +81,13 @@ void CloudPrintXmppListener::Connect(const std::string& access_token) {
   push_client_->UpdateCredentials(robot_email_, access_token_);
 }
 
+void CloudPrintXmppListener::set_standard_ping_interval(int interval) {
+  standard_ping_interval_ = interval;
+}
+
 void CloudPrintXmppListener::OnNotificationsEnabled() {
   delegate_->OnXmppConnected();
+  SchedulePing();
 }
 
 void CloudPrintXmppListener::OnNotificationsDisabled(
@@ -77,7 +97,7 @@ void CloudPrintXmppListener::OnNotificationsDisabled(
       delegate_->OnXmppAuthError();
       break;
     case notifier::TRANSIENT_NOTIFICATION_ERROR:
-      delegate_->OnXmppNetworkError();
+      Disconnect();
       break;
     default:
       NOTREACHED() << "XMPP failed with unexpected reason code: " << reason;
@@ -102,7 +122,65 @@ void CloudPrintXmppListener::OnIncomingNotification(
 }
 
 void CloudPrintXmppListener::OnPingResponse() {
-  // TODO(maksymb): Implement pings
-  NOTIMPLEMENTED();
+  ping_responses_pending_ = 0;
+  SchedulePing();
+}
+
+void CloudPrintXmppListener::Disconnect() {
+  push_client_.reset();
+  delegate_->OnXmppNetworkError();
+}
+
+void CloudPrintXmppListener::SchedulePing() {
+  if (ping_scheduled_)
+    return;
+
+  DCHECK_LE(kPingTimeout, kUrgentPingInterval);
+  int delay = (ping_responses_pending_ > 0)
+      ? kUrgentPingInterval - kPingTimeout
+      : standard_ping_interval_;
+
+  delay += base::RandInt(0, delay*kRandomDelayPercentage);
+
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&CloudPrintXmppListener::SendPing, AsWeakPtr()),
+      base::TimeDelta::FromSeconds(delay));
+
+  ping_scheduled_ = true;
+}
+
+void CloudPrintXmppListener::SendPing() {
+  ping_scheduled_ = false;
+
+  DCHECK(push_client_);
+  push_client_->SendPing();
+  ++ping_responses_pending_;
+
+  base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&CloudPrintXmppListener::OnPingTimeoutReached, AsWeakPtr()),
+        base::TimeDelta::FromSeconds(kPingTimeout));
+  ++ping_timeouts_posted_;
+}
+
+void CloudPrintXmppListener::OnPingTimeoutReached() {
+  DCHECK_GT(ping_timeouts_posted_, 0);
+  --ping_timeouts_posted_;
+  if (ping_timeouts_posted_ > 0)
+    return;  // Fake (old) timeout.
+
+  switch (ping_responses_pending_) {
+    case 0:
+      break;
+    case 1:
+      SchedulePing();
+      break;
+    case 2:
+      Disconnect();
+      break;
+    default:
+      NOTREACHED();
+  }
 }
 
diff --git a/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.h b/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.h
index 843ba89..7c612fe 100644
--- a/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.h
+++ b/cloud_print/gcp20/prototype/cloud_print_xmpp_listener.h
@@ -11,6 +11,7 @@
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "jingle/notifier/listener/push_client_observer.h"
 
 namespace base {
@@ -31,7 +32,9 @@ class PushClient;
 
 }  // namespace notifier
 
-class CloudPrintXmppListener: public notifier::PushClientObserver {
+class CloudPrintXmppListener
+    : public base::SupportsWeakPtr<CloudPrintXmppListener>,
+      public notifier::PushClientObserver {
  public:
   class Delegate {
    public:
@@ -52,12 +55,13 @@ class CloudPrintXmppListener: public notifier::PushClientObserver {
     // Invoked when local settings was updated.
     virtual void OnXmppNewLocalSettings(const std::string& device_id) = 0;
 
-    // Invoked when printer was deleted from server.
+    // Invoked when printer was deleted from the server.
     virtual void OnXmppDeleteNotification(const std::string& device_id) = 0;
   };
 
   CloudPrintXmppListener(
       const std::string& robot_email,
+      int standard_ping_interval,
       scoped_refptr<base::SingleThreadTaskRunner> task_runner,
       Delegate* delegate);
 
@@ -66,6 +70,9 @@ class CloudPrintXmppListener: public notifier::PushClientObserver {
   // Connects to the server.
   void Connect(const std::string& access_token);
 
+  // Update ping interval when new local_settings was received.
+  void set_standard_ping_interval(int interval);
+
  private:
   // notifier::PushClientObserver methods:
   virtual void OnNotificationsEnabled() OVERRIDE;
@@ -75,18 +82,41 @@ class CloudPrintXmppListener: public notifier::PushClientObserver {
       const notifier::Notification& notification) OVERRIDE;
   virtual void OnPingResponse() OVERRIDE;
 
-  // Is used for reconnection when number of retries is now exhausted.
-  void ReconnectInternal();
+  // Stops listening and sending pings.
+  void Disconnect();
+
+  // Schedules ping (unless it was already scheduled).
+  void SchedulePing();
+
+  // Sends ping.
+  void SendPing();
+
+  // Checks if ping was received.
+  void OnPingTimeoutReached();
 
   // Credentials:
   std::string robot_email_;
   std::string access_token_;
 
-  scoped_refptr<net::URLRequestContextGetter> context_getter_;
-
   // Internal listener.
   scoped_ptr<notifier::PushClient> push_client_;
 
+  // Interval between pings in regular workflow.
+  int standard_ping_interval_;
+
+  // Number of timeouts posted to MessageLoop. Is used for controlling "fake"
+  // timeout calls.
+  int ping_timeouts_posted_;
+
+  // Number of responses awaiting from XMPP server. Is used for controlling
+  // number of failed pings.
+  int ping_responses_pending_;
+
+  // Is used for preventing multiple pings at the moment.
+  bool ping_scheduled_;
+
+  scoped_refptr<net::URLRequestContextGetter> context_getter_;
+
   Delegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(CloudPrintXmppListener);
diff --git a/cloud_print/gcp20/prototype/printer.cc b/cloud_print/gcp20/prototype/printer.cc
index a161edd..4583aa7 100644
--- a/cloud_print/gcp20/prototype/printer.cc
+++ b/cloud_print/gcp20/prototype/printer.cc
@@ -27,7 +27,8 @@ const char kPrinterStatePathDefault[] = "printer_state.json";
 namespace {
 
 const uint16 kHttpPortDefault = 10101;
-const uint32 kTtlDefault = 60*60;
+const uint32 kTtlDefault = 60*60;  // in seconds
+const int kXmppPingIntervalDefault = 5*60;  // in seconds
 
 const char kServiceType[] = "_privet._tcp.local";
 const char kServiceNamePrefixDefault[] = "first_gcp20_device";
@@ -182,6 +183,7 @@ void Printer::Stop() {
 }
 
 void Printer::OnAuthError() {
+  LOG(ERROR) << "Auth error occurred";
   access_token_update_ = base::Time::Now();
   ChangeState(OFFLINE);
   // TODO(maksymb): Implement *instant* updating of access_token.
@@ -476,7 +478,8 @@ void Printer::TryConnect() {
 
 void Printer::ConnectXmpp() {
   xmpp_listener_.reset(
-      new CloudPrintXmppListener(reg_info_.xmpp_jid, GetTaskRunner(), this));
+      new CloudPrintXmppListener(reg_info_.xmpp_jid, kXmppPingIntervalDefault,
+                                 GetTaskRunner(), this));
   xmpp_listener_->Connect(access_token_);
 }