[Omaha] Move most functionality to OmahaBase, add JobService

chrome/android/java/src/org/chromium/chrome/browser/omaha/OmahaService.java

+// Copyright 2017 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.
+
+package org.chromium.chrome.browser.omaha;
+
+import android.annotation.TargetApi;
+import android.app.IntentService;
+import android.app.job.JobService;
+import android.content.Context;
+import android.os.AsyncTask;
+import android.os.Build;
+import android.support.annotation.Nullable;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
+import org.chromium.components.background_task_scheduler.BackgroundTask;
+import org.chromium.components.background_task_scheduler.BackgroundTaskSchedulerFactory;
+import org.chromium.components.background_task_scheduler.TaskIds;
+import org.chromium.components.background_task_scheduler.TaskInfo;
+import org.chromium.components.background_task_scheduler.TaskParameters;
+
+/**
+ * Manages scheduling and running of the Omaha client code.
+ * Delegates out to either an {@link IntentService} or {@link JobService}, as necessary.
+ */
+public class OmahaService extends OmahaBase implements BackgroundTask {
+    private static final String TAG = "omaha";
+
+    private static class OmahaClientDelegate extends OmahaDelegateBase {
+        public OmahaClientDelegate(Context context) {
+            super(context);
+        }
+
+        @Override
+        public void scheduleService(long currentTimestampMs, long nextTimestampMs) {
+            if (Build.VERSION.SDK_INT < OmahaBase.MIN_API_JOB_SCHEDULER) {
+                getScheduler().createAlarm(OmahaClient.createIntent(getContext()), nextTimestampMs);
+                Log.i(TAG, "Scheduled using AlarmManager and IntentService");
+            } else {
+                final long delay = nextTimestampMs - currentTimestampMs;
+                ThreadUtils.runOnUiThread(new Runnable() {
+                    @Override
+                    public void run() {
+                        if (scheduleJobService(getContext(), delay)) {
+                            Log.i(TAG, "Scheduled using JobService");
+                        } else {
+                            Log.e(TAG, "Failed to schedule job");
+                        }
+                    }
+                });
+            }
+        }
+    }
+
+    private static final Object DELEGATE_LOCK = new Object();
+    private static OmahaService sInstance;
+
+    @Nullable
+    public static OmahaService getInstance(Context context) {
+        synchronized (DELEGATE_LOCK) {
+            if (sInstance == null) sInstance = new OmahaService(context);
+            return sInstance;
+        }
+    }
+
+    private AsyncTask<Void, Void, Void> mJobServiceTask;
+
+    /** Used only by {@link BackgroundTaskScheduler}. */
+    public OmahaService() {
+        this(ContextUtils.getApplicationContext());
+    }
+
+    private OmahaService(Context context) {
+        super(new OmahaClientDelegate(context));
+    }
+
+    /**
+     * Trigger the {@link BackgroundTaskScheduler} immediately.
+     * Must only be called by {@link OmahaBase#onForegroundSessionStart}.
+     */
+    static void startServiceImmediately(Context context) {
+        if (Build.VERSION.SDK_INT < OmahaBase.MIN_API_JOB_SCHEDULER) {
+            context.startService(OmahaClient.createIntent(context));
+        } else {
+            scheduleJobService(context, 0);
+        }
+    }
+
+    @Override
+    @TargetApi(Build.VERSION_CODES.M)
+    public boolean onStartTask(
+            Context context, TaskParameters parameters, final TaskFinishedCallback callback) {
+        mJobServiceTask = new AsyncTask<Void, Void, Void>() {
+            @Override
+            public Void doInBackground(Void... params) {
+                run();
+                return null;
+            }
+
+            @Override
+            public void onPostExecute(Void result) {
+                callback.taskFinished(false);
+            }
+        }.executeOnExecutor(AsyncTask.SERIAL_EXECUTOR);
+        return false;
+    }
+
+    @Override
+    @TargetApi(Build.VERSION_CODES.M)
+    public boolean onStopTask(Context context, TaskParameters taskParameters) {
+        if (mJobServiceTask != null) {
+            mJobServiceTask.cancel(false);
+            mJobServiceTask = null;
+        }
+        return false;
+    }
+
+    /**
+     * Schedules the Omaha code to run at the given time.
+     * @param context Context to use.
+     * @param delayMs How long to wait until the job should be triggered.
+     */
+    @TargetApi(Build.VERSION_CODES.M)
+    static boolean scheduleJobService(Context context, long delayMs) {
+        long latency = Math.max(0, delayMs);
+
+        TaskInfo taskInfo = TaskInfo.createOneOffTask(TaskIds.OMAHA_JOB_ID, OmahaService.class,
+                                            latency, latency)
+                                    .build();
+        return BackgroundTaskSchedulerFactory.getScheduler().schedule(context, taskInfo);
+    }
+}