Bug 1134019 - Extract MLS fallback to its own class for reuse - r=jdm

dom/geolocation/MLSFallback.cpp

@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MLSFallback.h"
+#include "nsGeoPosition.h"
+#include "nsIGeolocationProvider.h"
+#include "nsServiceManagerUtils.h"
+
+NS_IMPL_ISUPPORTS(MLSFallback, nsITimerCallback)
+
+MLSFallback::MLSFallback(uint32_t delay)
+: mDelayMs(delay)
+{
+}
+
+MLSFallback::~MLSFallback()
+{
+}
+
+nsresult
+MLSFallback::Startup(nsIGeolocationUpdate* aWatcher)
+{
+  if (mHandoffTimer || mMLSFallbackProvider) {
+    return NS_OK;
+  }
+
+  mUpdateWatcher = aWatcher;
+  nsresult rv;
+  mHandoffTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mHandoffTimer->InitWithCallback(this, mDelayMs, nsITimer::TYPE_ONE_SHOT);
+  return rv;
+}
+
+nsresult
+MLSFallback::Shutdown()
+{
+  mUpdateWatcher = nullptr;
+
+  if (mHandoffTimer) {
+    mHandoffTimer->Cancel();
+    mHandoffTimer = nullptr;
+  }
+
+  nsresult rv = NS_OK;
+  if (mMLSFallbackProvider) {
+    rv = mMLSFallbackProvider->Shutdown();
+    mMLSFallbackProvider = nullptr;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+MLSFallback::Notify(nsITimer* aTimer)
+{
+  return CreateMLSFallbackProvider();
+}
+
+nsresult
+MLSFallback::CreateMLSFallbackProvider()
+{
+  if (mMLSFallbackProvider || !mUpdateWatcher) {
+    return NS_OK;
+  }
+
+  nsresult rv;
+  mMLSFallbackProvider = do_CreateInstance("@mozilla.org/geolocation/mls-provider;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mMLSFallbackProvider) {
+    rv = mMLSFallbackProvider->Startup();
+    if (NS_SUCCEEDED(rv)) {
+      mMLSFallbackProvider->Watch(mUpdateWatcher);
+    }
+  }
+  mUpdateWatcher = nullptr;
+  return rv;
+}
+

dom/geolocation/MLSFallback.h

@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsCOMPtr.h"
+#include "nsITimer.h"
+
+class nsIGeolocationUpdate;
+class nsIGeolocationProvider;
+
+/*
+ This class wraps the NetworkGeolocationProvider in a delayed startup.
+ It is for providing a fallback to MLS when:
+ 1) using another provider as the primary provider, and
+ 2) that primary provider may fail to return a result (i.e. the error returned
+ is indeterminate, or no error callback occurs)
+
+ The intent is that the primary provider is started, then MLSFallback
+ is started with sufficient delay that the primary provider will respond first
+ if successful (in the majority of cases).
+
+ MLS has an average response of 3s, so with the 2s default delay, a response can
+ be expected in 5s.
+
+ Telemetry is recommended to monitor that the primary provider is responding
+ first when expected to do so.
+*/
+class MLSFallback : public nsITimerCallback
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSITIMERCALLBACK
+
+  explicit MLSFallback(uint32_t delayMs = 2000);
+  nsresult Startup(nsIGeolocationUpdate* aWatcher);
+  nsresult Shutdown();
+
+private:
+  nsresult CreateMLSFallbackProvider();
+  virtual ~MLSFallback();
+  nsCOMPtr<nsITimer> mHandoffTimer;
+  nsCOMPtr<nsIGeolocationProvider> mMLSFallbackProvider;
+  nsCOMPtr<nsIGeolocationUpdate> mUpdateWatcher;
+  const uint32_t mDelayMs;
+};
+

dom/geolocation/moz.build

@@ -15,6 +15,7 @@ SOURCES += [
 ]
 
 UNIFIED_SOURCES += [
+    'MLSFallback.cpp',
     'nsGeoGridFuzzer.cpp',
     'nsGeolocationSettings.cpp',
     'nsGeoPosition.cpp',

dom/system/mac/CoreLocationLocationProvider.h

@@ -6,6 +6,7 @@
 #include "nsCOMPtr.h"
 #include "nsIGeolocationProvider.h"
 
+
 /*
  * The CoreLocationObjects class contains the CoreLocation objects
  * we'll need.
@@ -21,6 +22,7 @@
  * for nsGeolocation.cpp, which is C++-only, to include this header.
  */
 class CoreLocationObjects;
+class MLSFallback;
 
 class CoreLocationLocationProvider
   : public nsIGeolocationProvider
@@ -36,11 +38,11 @@ public:
   void CancelMLSFallbackProvider();
 
 private:
-  virtual ~CoreLocationLocationProvider() {};
+  virtual ~CoreLocationLocationProvider();
 
   CoreLocationObjects* mCLObjects;
   nsCOMPtr<nsIGeolocationUpdate> mCallback;
-  nsCOMPtr<nsIGeolocationProvider> mMLSFallbackProvider;
+  nsRefPtr<MLSFallback> mMLSFallbackProvider;
 
   class MLSUpdate : public nsIGeolocationUpdate
   {
@@ -52,6 +54,6 @@ private:
 
   private:
     CoreLocationLocationProvider& mParentLocationProvider;
-    virtual ~MLSUpdate() {}
+    virtual ~MLSUpdate();
   };
 };

dom/system/mac/CoreLocationLocationProvider.mm

@@ -13,6 +13,7 @@
 #include "nsCocoaFeatures.h"
 #include "prtime.h"
 #include "mozilla/Telemetry.h"
+#include "MLSFallback.h"
 
 #include <CoreLocation/CLError.h>
 #include <CoreLocation/CLLocation.h>
@@ -32,7 +33,6 @@ static const CLLocationAccuracy kDEFAULT_ACCURACY = kCLLocationAccuracyNearestTe
 @interface LocationDelegate : NSObject <CLLocationManagerDelegate>
 {
   CoreLocationLocationProvider* mProvider;
-  NSTimer* mHandoffTimer;
 }
 
 - (id)init:(CoreLocationLocationProvider*)aProvider;
@@ -52,23 +52,6 @@ static const CLLocationAccuracy kDEFAULT_ACCURACY = kCLLocationAccuracyNearestTe
   return self;
 }
 
-- (void)shutdownHandoffTimer
-{
-  if (!mHandoffTimer) {
-    return;
-  }
-
-  [mHandoffTimer invalidate];
-  [mHandoffTimer release];
-  mHandoffTimer = nil;
-}
-
-- (void)handoffToGeoIPProvider
-{
-  [self shutdownHandoffTimer];
-  mProvider->CreateMLSFallbackProvider();
-}
-
 - (void)locationManager:(CLLocationManager*)aManager
   didFailWithError:(NSError *)aError
 {
@@ -87,21 +70,15 @@ static const CLLocationAccuracy kDEFAULT_ACCURACY = kCLLocationAccuracyNearestTe
     return;
   }
 
-  if (!mHandoffTimer) {
-    // The CL provider does not fallback to GeoIP, so use NetworkGeolocationProvider for this.
-    // The concept here is: on error, hand off geolocation to MLS, which will then report
-    // back a location or error. We can't call this with no delay however, as this method
-    // is called with an error code of 0 in both failed geolocation cases, and also when
-    // geolocation is not immediately available.
-    // The 2 sec delay is arbitrarily large enough that CL has a reasonable head start and
-    // if it is likely to succeed, it should complete before the MLS provider.
-    // Take note that in locationManager:didUpdateLocations: the handoff to MLS is stopped.
-    mHandoffTimer = [[NSTimer scheduledTimerWithTimeInterval:2.0
-                                                     target:self
-                                                   selector:@selector(handoffToGeoIPProvider)
-                                                   userInfo:nil
-                                                    repeats:NO] retain];
-  }
+  // The CL provider does not fallback to GeoIP, so use NetworkGeolocationProvider for this.
+  // The concept here is: on error, hand off geolocation to MLS, which will then report
+  // back a location or error. We can't call this with no delay however, as this method
+  // is called with an error code of 0 in both failed geolocation cases, and also when
+  // geolocation is not immediately available.
+  // The 2 sec delay is arbitrarily large enough that CL has a reasonable head start and
+  // if it is likely to succeed, it should complete before the MLS provider.
+  // Take note that in locationManager:didUpdateLocations: the handoff to MLS is stopped.
+  mProvider->CreateMLSFallbackProvider();
 }
 
 - (void)locationManager:(CLLocationManager*)aManager didUpdateLocations:(NSArray*)aLocations
@@ -110,7 +87,6 @@ static const CLLocationAccuracy kDEFAULT_ACCURACY = kCLLocationAccuracyNearestTe
     return;
   }
 
-  [self shutdownHandoffTimer];
   mProvider->CancelMLSFallbackProvider();
 
   CLLocation* location = [aLocations objectAtIndex:0];
@@ -137,6 +113,10 @@ CoreLocationLocationProvider::MLSUpdate::MLSUpdate(CoreLocationLocationProvider&
 {
 }
 
+CoreLocationLocationProvider::MLSUpdate::~MLSUpdate()
+{
+}
+
 NS_IMETHODIMP
 CoreLocationLocationProvider::MLSUpdate::Update(nsIDOMGeoPosition *position)
 {
@@ -200,6 +180,10 @@ CoreLocationLocationProvider::CoreLocationLocationProvider()
 {
 }
 
+CoreLocationLocationProvider::~CoreLocationLocationProvider()
+{
+}
+
 NS_IMETHODIMP
 CoreLocationLocationProvider::Startup()
 {
@@ -234,7 +218,6 @@ CoreLocationLocationProvider::Shutdown()
 {
   NS_ENSURE_STATE(mCLObjects);
 
-  [mCLObjects->mLocationDelegate shutdownHandoffTimer];
   [mCLObjects->mLocationManager stopUpdatingLocation];
 
   delete mCLObjects;
@@ -280,13 +263,8 @@ CoreLocationLocationProvider::CreateMLSFallbackProvider()
     return;
   }
 
-  mMLSFallbackProvider = do_CreateInstance("@mozilla.org/geolocation/mls-provider;1");
-  if (mMLSFallbackProvider) {
-    nsresult rv = mMLSFallbackProvider->Startup();
-    if (NS_SUCCEEDED(rv)) {
-      mMLSFallbackProvider->Watch(new CoreLocationLocationProvider::MLSUpdate(*this));
-    }
-  }
+  mMLSFallbackProvider = new MLSFallback();
+  mMLSFallbackProvider->Startup(new MLSUpdate(*this));
 }
 
 void