Wireframe scheduler implementation

chrome/browser/android/offline_pages/background_scheduler_bridge.cc

 // Copyright 2016 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 "base/android/scoped_java_ref.h"
 #include "chrome/browser/android/offline_pages/background_scheduler_bridge.h"
+#include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
+#include "chrome/browser/android/offline_pages/request_coordinator_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_android.h"
+#include "components/offline_pages/background/request_coordinator.h"
 #include "jni/BackgroundSchedulerBridge_jni.h"
 
 using base::android::ScopedJavaGlobalRef;
 
 namespace offline_pages {
 namespace android {
 
 namespace {
 
 // C++ callback that delegates to Java callback.
 void ProcessingDoneCallback(
     const ScopedJavaGlobalRef<jobject>& j_callback_obj, jboolean result) {
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_ProcessingDoneCallback_onProcessingDone(
       env, j_callback_obj.obj(), result);
 }
 
 }  // namespace
 
+// This static function acts as a factory to create the scheduler bridge if it
+// does not already exist, and re-use it if it does.  It also attaches the
+// Java side of the bridge to the java_ref_ variable, and returns the c++ side
+// pointer for the java side to attach to.  It is called from Java.
+// TODO(petewil): Is it better to use ScopedJavaLocalRef or ScopedJavaGlobalRef?
+static ScopedJavaLocalRef<jobject> GetBackgroundSchedulerBridgeForProfile(
+    JNIEnv* env,
+    const JavaParamRef<jclass>& jcaller,
+    const JavaParamRef<jobject>& j_profile) {
+  Profile* profile = ProfileAndroid::FromProfileAndroid(j_profile);
+
+  // The bridge pointer is owned by the request coordinator.
+  RequestCoordinator* request_coordinator =
+      RequestCoordinatorFactory::GetForBrowserContext(profile);

[dewittj, 2016/05/20 21:52:30]

please add a nullptr check since we don't support all profiles.

[Pete Williamson, 2016/05/23 19:36:30]

Done.

+
+  // We use a reinterpret cast here so that the type returned by the
+  // GetScheduler call can remain an interface, which we can mock differently
+  // for testing.
+  BackgroundSchedulerBridge* bridge =
+      reinterpret_cast<BackgroundSchedulerBridge*>(
+          request_coordinator->GetScheduler());
+  if (!bridge) {
+    bridge = new BackgroundSchedulerBridge();
+  }
+  bridge->AttachBridgeToJavaSide(env);
+  return ScopedJavaLocalRef<jobject>(bridge->java_ref());
+}
+
 // JNI call to start request processing.
 static jboolean StartProcessing(
     JNIEnv* env,
     const JavaParamRef<jclass>& jcaller,
-    const JavaParamRef<jobject>& j_profile,
+    const JavaParamRef<jobject>& j_context,
     const JavaParamRef<jobject>& j_callback_obj) {
   ScopedJavaGlobalRef<jobject> j_callback_ref;
   j_callback_ref.Reset(env, j_callback_obj);
   base::Bind(&ProcessingDoneCallback, j_callback_ref);
   // TODO(dougarnett): lookup/create RequestCoordinator KeyedService
   // and call StartProcessing on it with bound j_callback_obj.
   return false;
 }
 
-BackgroundSchedulerBridge::BackgroundSchedulerBridge() {
+// We split the construction into two steps, build and init.  The Ctor will be
+// called from the RequestCoordinatorFactory, and the init function will be
+// called from the Java side when a BackgroundTask arrives.
+// TODO(petewil): We eventually need some piece of Java code to call
+// BackgroundSchedulerBridge.getForProfile(); so "schedule()" will work
+// if BackgroundTask.incomingTask has not been called this session.
+BackgroundSchedulerBridge::BackgroundSchedulerBridge() {}
+
+BackgroundSchedulerBridge::~BackgroundSchedulerBridge() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+
+  // Native shutdown causes the destruction of |this|.
+  if (java_ref_.obj() != nullptr) {
+    Java_BackgroundSchedulerBridge_backgroundSchedulerBridgeDestroyed(
+        env, java_ref_.obj());
+  }
 }
 
-BackgroundSchedulerBridge::~BackgroundSchedulerBridge() {
+// Attach to the Java side of the bridge if it is not already attached.
+void BackgroundSchedulerBridge::AttachBridgeToJavaSide(JNIEnv* env) {
+if (java_ref().is_null()) {
+    ScopedJavaLocalRef<jobject> j_offline_page_bridge =
+        Java_BackgroundSchedulerBridge_create(
+            env, reinterpret_cast<jlong>(this));
+    java_ref_.Reset(j_offline_page_bridge);
+  }
 }
 
 void BackgroundSchedulerBridge::Schedule(
     const TriggerCondition& trigger_condition) {
   JNIEnv* env = base::android::AttachCurrentThread();
   // TODO(dougarnett): pass trigger_condition.
   Java_BackgroundSchedulerBridge_schedule(env);
 }
 
 void BackgroundSchedulerBridge::Unschedule() {
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_BackgroundSchedulerBridge_unschedule(env);
 }
 
 bool RegisterBackgroundSchedulerBridge(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace offline_pages