The Tor Browser: comparison mobile/android/base/health/BrowserHealthRecorder.java

--1:000000000000
+:84e582a48bc6
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+* 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/. */
+package org.mozilla.gecko.health;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Scanner;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.mozilla.gecko.AppConstants;
+import org.mozilla.gecko.Distribution;
+import org.mozilla.gecko.Distribution.DistributionDescriptor;
+import org.mozilla.gecko.EventDispatcher;
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.GeckoEvent;
+import org.mozilla.gecko.background.healthreport.EnvironmentBuilder;
+import org.mozilla.gecko.background.healthreport.HealthReportDatabaseStorage;
+import org.mozilla.gecko.background.healthreport.HealthReportStorage.Field;
+import org.mozilla.gecko.background.healthreport.HealthReportStorage.MeasurementFields;
+import org.mozilla.gecko.background.healthreport.ProfileInformationCache;
+import org.mozilla.gecko.util.GeckoEventListener;
+import org.mozilla.gecko.util.ThreadUtils;
+import android.content.ContentProviderClient;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.util.Log;
+/**
+* BrowserHealthRecorder is the browser's interface to the Firefox Health
+* Report storage system. It manages environments (a collection of attributes
+* that are tracked longitudinally) on the browser's behalf, exposing a simpler
+* interface for recording changes.
+*
+* Keep an instance of this class around.
+*
+* Tell it when an environment attribute has changed: call {@link
+* #onAppLocaleChanged(String)} followed by {@link
+* #onEnvironmentChanged()}.
+*
+* Use it to record events: {@link #recordSearch(String, String)}.
+*
+* Shut it down when you're done being a browser: {@link #close()}.
+*/
+public class BrowserHealthRecorder implements HealthRecorder, GeckoEventListener {
+private static final String LOG_TAG = "GeckoHealthRec";
+private static final String PREF_ACCEPT_LANG = "intl.accept_languages";
+private static final String PREF_BLOCKLIST_ENABLED = "extensions.blocklist.enabled";
+private static final String EVENT_SNAPSHOT = "HealthReport:Snapshot";
+private static final String EVENT_ADDONS_CHANGE = "Addons:Change";
+private static final String EVENT_ADDONS_UNINSTALLING = "Addons:Uninstalling";
+private static final String EVENT_PREF_CHANGE = "Pref:Change";
+// This is raised from Gecko and signifies a search via the URL bar (not a bookmarks keyword
+// search). Using this event (rather than passing the invocation location as an arg) avoids
+// browser.js having to know about the invocation location.
+public static final String EVENT_KEYWORD_SEARCH = "Search:Keyword";
+// This is raised from Java. We include the location in the message.
+public static final String EVENT_SEARCH = "Search:Event";
+public enum State {
+NOT_INITIALIZED,
+INITIALIZING,
+INITIALIZED,
+INITIALIZATION_FAILED,
+CLOSED
+}
+protected volatile State state = State.NOT_INITIALIZED;
+private final AtomicBoolean orphanChecked = new AtomicBoolean(false);
+private volatile int env = -1;
+private ContentProviderClient client;
+private volatile HealthReportDatabaseStorage storage;
+private final ProfileInformationCache profileCache;
+private final EventDispatcher dispatcher;
+private final SharedPreferences prefs;
+// We track previousSession to avoid order-of-initialization confusion. We
+// accept it in the constructor, and process it after init.
+private final SessionInformation previousSession;
+private volatile SessionInformation session = null;
+public void setCurrentSession(SessionInformation session) {
+this.session = session;
+}
+public void recordGeckoStartupTime(long duration) {
+if (this.session == null) {
+return;
+}
+this.session.setTimedGeckoStartup(duration);
+}
+public void recordJavaStartupTime(long duration) {
+if (this.session == null) {
+return;
+}
+this.session.setTimedJavaStartup(duration);
+}
+/**
+* This constructor does IO. Run it on a background thread.
+*
+* appLocale can be null, which indicates that it will be provided later.
+*/
+public BrowserHealthRecorder(final Context context,
+final SharedPreferences appPrefs,
+final String profilePath,
+final EventDispatcher dispatcher,
+final String osLocale,
+final String appLocale,
+SessionInformation previousSession) {
+Log.d(LOG_TAG, "Initializing. Dispatcher is " + dispatcher);
+this.dispatcher = dispatcher;
+this.previousSession = previousSession;
+this.client = EnvironmentBuilder.getContentProviderClient(context);
+if (this.client == null) {
+throw new IllegalStateException("Could not fetch Health Report content provider.");
+}
+this.storage = EnvironmentBuilder.getStorage(this.client, profilePath);
+if (this.storage == null) {
+// Stick around even if we don't have storage: eventually we'll
+// want to report total failures of FHR storage itself, and this
+// way callers don't need to worry about whether their health
+// recorder didn't initialize.
+this.client.release();
+this.client = null;
+}
+// Note that the PIC is not necessarily fully initialized at this point:
+// we haven't set the app locale. This must be done before an environment
+// is recorded.
+this.profileCache = new ProfileInformationCache(profilePath);
+try {
+this.initialize(context, profilePath, osLocale, appLocale);
+} catch (Exception e) {
+Log.e(LOG_TAG, "Exception initializing.", e);
+}
+this.prefs = appPrefs;
+}
+public boolean isEnabled() {
+return true;
+}
+/**
+* Shut down database connections, unregister event listeners, and perform
+* provider-specific uninitialization.
+*/
+public synchronized void close() {
+switch (this.state) {
+case CLOSED:
+Log.w(LOG_TAG, "Ignoring attempt to double-close closed BrowserHealthRecorder.");
+return;
+case INITIALIZED:
+Log.i(LOG_TAG, "Closing Health Report client.");
+break;
+default:
+Log.i(LOG_TAG, "Closing incompletely initialized BrowserHealthRecorder.");
+}
+this.state = State.CLOSED;
+this.unregisterEventListeners();
+// Add any necessary provider uninitialization here.
+this.storage = null;
+if (this.client != null) {
+this.client.release();
+this.client = null;
+}
+}
+private void unregisterEventListeners() {
+if (state != State.INITIALIZED) {
+return;
+}
+this.dispatcher.unregisterEventListener(EVENT_SNAPSHOT, this);
+this.dispatcher.unregisterEventListener(EVENT_ADDONS_CHANGE, this);
+this.dispatcher.unregisterEventListener(EVENT_ADDONS_UNINSTALLING, this);
+this.dispatcher.unregisterEventListener(EVENT_PREF_CHANGE, this);
+this.dispatcher.unregisterEventListener(EVENT_KEYWORD_SEARCH, this);
+this.dispatcher.unregisterEventListener(EVENT_SEARCH, this);
+}
+public void onAppLocaleChanged(String to) {
+Log.d(LOG_TAG, "Setting health recorder app locale to " + to);
+this.profileCache.beginInitialization();
+this.profileCache.setAppLocale(to);
+}
+public void onAddonChanged(String id, JSONObject json) {
+this.profileCache.beginInitialization();
+try {
+this.profileCache.updateJSONForAddon(id, json);
+} catch (IllegalStateException e) {
+Log.w(LOG_TAG, "Attempted to update add-on cache prior to full init.", e);
+}
+}
+public void onAddonUninstalling(String id) {
+this.profileCache.beginInitialization();
+try {
+this.profileCache.removeAddon(id);
+} catch (IllegalStateException e) {
+Log.w(LOG_TAG, "Attempted to update add-on cache prior to full init.", e);
+}
+}
+/**
+* Call this when a material change might have occurred in the running
+* environment, such that a new environment should be computed and prepared
+* for use in future events.
+*
+* Invoke this method after calls that mutate the environment.
+*
+* If this change resulted in a transition between two environments, {@link
+* #onEnvironmentTransition(int, int, boolean, String)} will be invoked on the background
+* thread.
+*/
+public synchronized void onEnvironmentChanged() {
+onEnvironmentChanged(true, "E");
+}
+/**
+* If `startNewSession` is false, it means no new session should begin
+* (e.g., because we're about to restart, and we don't want to create
+* an orphan).
+*/
+public synchronized void onEnvironmentChanged(final boolean startNewSession, final String sessionEndReason) {
+final int previousEnv = this.env;
+this.env = -1;
+try {
+profileCache.completeInitialization();
+} catch (java.io.IOException e) {
+Log.e(LOG_TAG, "Error completing profile cache initialization.", e);
+this.state = State.INITIALIZATION_FAILED;
+return;
+}
+final int updatedEnv = ensureEnvironment();
+if (updatedEnv == -1 ||
+updatedEnv == previousEnv) {
+Log.v(LOG_TAG, "Environment didn't change.");
+return;
+}
+ThreadUtils.postToBackgroundThread(new Runnable() {
+@Override
+public void run() {
+try {
+onEnvironmentTransition(previousEnv, updatedEnv, startNewSession, sessionEndReason);
+} catch (Exception e) {
+Log.w(LOG_TAG, "Could not record environment transition.", e);
+}
+}
+});
+}
+protected synchronized int ensureEnvironment() {
+if (!(state == State.INITIALIZING ||
+state == State.INITIALIZED)) {
+throw new IllegalStateException("Not initialized.");
+}
+if (this.env != -1) {
+return this.env;
+}
+if (this.storage == null) {
+// Oh well.
+return -1;
+}
+return this.env = EnvironmentBuilder.registerCurrentEnvironment(this.storage,
+this.profileCache);
+}
+private static final String getTimesPath(final String profilePath) {
+return profilePath + File.separator + "times.json";
+}
+/**
+* Retrieve the stored profile creation time from the profile directory.
+*
+* @return the <code>created</code> value from the times.json file, or -1 on failure.
+*/
+protected static long getProfileInitTimeFromFile(final String profilePath) {
+final File times = new File(getTimesPath(profilePath));
+Log.d(LOG_TAG, "Looking for " + times.getAbsolutePath());
+if (!times.exists()) {
+return -1;
+}
+Log.d(LOG_TAG, "Using times.json for profile creation time.");
+Scanner scanner = null;
+try {
+scanner = new Scanner(times, "UTF-8");
+final String contents = scanner.useDelimiter("\\A").next();
+return new JSONObject(contents).getLong("created");
+} catch (Exception e) {
+// There are assorted reasons why this might occur, but we
+// don't care. Move on.
+Log.w(LOG_TAG, "Failed to read times.json.", e);
+} finally {
+if (scanner != null) {
+scanner.close();
+}
+}
+return -1;
+}
+/**
+* Only works on API 9 and up.
+*
+* @return the package install time, or -1 if an error occurred.
+*/
+protected static long getPackageInstallTime(final Context context) {
+if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.GINGERBREAD) {
+return -1;
+}
+try {
+return context.getPackageManager().getPackageInfo(AppConstants.ANDROID_PACKAGE_NAME, 0).firstInstallTime;
+} catch (android.content.pm.PackageManager.NameNotFoundException e) {
+Log.e(LOG_TAG, "Unable to fetch our own package info. This should never occur.", e);
+}
+return -1;
+}
+private static long getProfileInitTimeHeuristic(final Context context, final String profilePath) {
+// As a pretty good shortcut, settle for installation time.
+// In all recent Firefox profiles, times.json should exist.
+final long time = getPackageInstallTime(context);
+if (time != -1) {
+return time;
+}
+// Otherwise, fall back to the filesystem.
+// We'll settle for the modification time of the profile directory.
+Log.d(LOG_TAG, "Using profile directory modified time as proxy for profile creation time.");
+return new File(profilePath).lastModified();
+}
+private static long getAndPersistProfileInitTime(final Context context, final String profilePath) {
+// Let's look in the profile.
+long time = getProfileInitTimeFromFile(profilePath);
+if (time > 0) {
+Log.d(LOG_TAG, "Incorporating environment: times.json profile creation = " + time);
+return time;
+}
+// Otherwise, we need to compute a valid creation time and write it out.
+time = getProfileInitTimeHeuristic(context, profilePath);
+if (time > 0) {
+// Write out a stub times.json.
+try {
+FileOutputStream stream = new FileOutputStream(getTimesPath(profilePath));
+OutputStreamWriter writer = new OutputStreamWriter(stream, Charset.forName("UTF-8"));
+try {
+writer.append("{\"created\": " + time + "}\n");
+} finally {
+writer.close();
+}
+} catch (Exception e) {
+// Best-effort.
+Log.w(LOG_TAG, "Couldn't write times.json.", e);
+}
+}
+Log.d(LOG_TAG, "Incorporating environment: profile creation = " + time);
+return time;
+}
+private void onPrefMessage(final String pref, final JSONObject message) {
+Log.d(LOG_TAG, "Incorporating environment: " + pref);
+if (PREF_ACCEPT_LANG.equals(pref)) {
+// We only record whether this is user-set.
+try {
+this.profileCache.beginInitialization();
+this.profileCache.setAcceptLangUserSet(message.getBoolean("isUserSet"));
+} catch (JSONException ex) {
+Log.w(LOG_TAG, "Unexpected JSONException fetching isUserSet for " + pref);
+}
+return;
+}
+// (We only handle boolean prefs right now.)
+try {
+boolean value = message.getBoolean("value");
+if (AppConstants.TELEMETRY_PREF_NAME.equals(pref)) {
+this.profileCache.beginInitialization();
+this.profileCache.setTelemetryEnabled(value);
+return;
+}
+if (PREF_BLOCKLIST_ENABLED.equals(pref)) {
+this.profileCache.beginInitialization();
+this.profileCache.setBlocklistEnabled(value);
+return;
+}
+} catch (JSONException ex) {
+Log.w(LOG_TAG, "Unexpected JSONException fetching boolean value for " + pref);
+return;
+}
+Log.w(LOG_TAG, "Unexpected pref: " + pref);
+}
+/**
+* Background init helper.
+*/
+private void initializeStorage() {
+Log.d(LOG_TAG, "Done initializing profile cache. Beginning storage init.");
+final BrowserHealthRecorder self = this;
+ThreadUtils.postToBackgroundThread(new Runnable() {
+@Override
+public void run() {
+synchronized (self) {
+if (state != State.INITIALIZING) {
+Log.w(LOG_TAG, "Unexpected state during init: " + state);
+return;
+}
+// Belt and braces.
+if (storage == null) {
+Log.w(LOG_TAG, "Storage is null during init; shutting down?");
+if (state == State.INITIALIZING) {
+state = State.INITIALIZATION_FAILED;
+}
+return;
+}
+try {
+storage.beginInitialization();
+} catch (Exception e) {
+Log.e(LOG_TAG, "Failed to init storage.", e);
+state = State.INITIALIZATION_FAILED;
+return;
+}
+try {
+// Listen for add-ons and prefs changes.
+dispatcher.registerEventListener(EVENT_ADDONS_UNINSTALLING, self);
+dispatcher.registerEventListener(EVENT_ADDONS_CHANGE, self);
+dispatcher.registerEventListener(EVENT_PREF_CHANGE, self);
+// Initialize each provider here.
+initializeSessionsProvider();
+initializeSearchProvider();
+Log.d(LOG_TAG, "Ensuring environment.");
+ensureEnvironment();
+Log.d(LOG_TAG, "Finishing init.");
+storage.finishInitialization();
+state = State.INITIALIZED;
+} catch (Exception e) {
+state = State.INITIALIZATION_FAILED;
+storage.abortInitialization();
+Log.e(LOG_TAG, "Initialization failed.", e);
+return;
+}
+// Now do whatever we do after we start up.
+checkForOrphanSessions();
+}
+}
+});
+}
+/**
+* Add provider-specific initialization in this method.
+*/
+private synchronized void initialize(final Context context,
+final String profilePath,
+final String osLocale,
+final String appLocale)
+throws java.io.IOException {
+Log.d(LOG_TAG, "Initializing profile cache.");
+this.state = State.INITIALIZING;
+// If we can restore state from last time, great.
+if (this.profileCache.restoreUnlessInitialized()) {
+this.profileCache.updateLocales(osLocale, appLocale);
+this.profileCache.completeInitialization();
+Log.d(LOG_TAG, "Successfully restored state. Initializing storage.");
+initializeStorage();
+return;
+}
+// Otherwise, let's initialize it from scratch.
+this.profileCache.beginInitialization();
+this.profileCache.setProfileCreationTime(getAndPersistProfileInitTime(context, profilePath));
+this.profileCache.setOSLocale(osLocale);
+this.profileCache.setAppLocale(appLocale);
+// Because the distribution lookup can take some time, do it at the end of
+// our background startup work, along with the Gecko snapshot fetch.
+final GeckoEventListener self = this;
+ThreadUtils.postToBackgroundThread(new Runnable() {
+@Override
+public void run() {
+final DistributionDescriptor desc = new Distribution(context).getDescriptor();
+if (desc != null && desc.valid) {
+profileCache.setDistributionString(desc.id, desc.version);
+}
+Log.d(LOG_TAG, "Requesting all add-ons and FHR prefs from Gecko.");
+dispatcher.registerEventListener(EVENT_SNAPSHOT, self);
+GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("HealthReport:RequestSnapshot", null));
+}
+});
+}
+/**
+* Invoked in the background whenever the environment transitions between
+* two valid values.
+*/
+protected void onEnvironmentTransition(int prev, int env, boolean startNewSession, String sessionEndReason) {
+if (this.state != State.INITIALIZED) {
+Log.d(LOG_TAG, "Not initialized: not recording env transition (" + prev + " => " + env + ").");
+return;
+}
+final SharedPreferences.Editor editor = this.prefs.edit();
+recordSessionEnd(sessionEndReason, editor, prev);
+if (!startNewSession) {
+editor.commit();
+return;
+}
+final SessionInformation newSession = SessionInformation.forRuntimeTransition();
+setCurrentSession(newSession);
+newSession.recordBegin(editor);
+editor.commit();
+}
+@Override
+public void handleMessage(String event, JSONObject message) {
+try {
+if (EVENT_SNAPSHOT.equals(event)) {
+Log.d(LOG_TAG, "Got all add-ons and prefs.");
+try {
+JSONObject json = message.getJSONObject("json");
+JSONObject addons = json.getJSONObject("addons");
+Log.i(LOG_TAG, "Persisting " + addons.length() + " add-ons.");
+profileCache.setJSONForAddons(addons);
+JSONObject prefs = json.getJSONObject("prefs");
+Log.i(LOG_TAG, "Persisting prefs.");
+Iterator<?> keys = prefs.keys();
+while (keys.hasNext()) {
+String pref = (String) keys.next();
+this.onPrefMessage(pref, prefs.getJSONObject(pref));
+}
+profileCache.completeInitialization();
+} catch (java.io.IOException e) {
+Log.e(LOG_TAG, "Error completing profile cache initialization.", e);
+state = State.INITIALIZATION_FAILED;
+return;
+}
+if (state == State.INITIALIZING) {
+initializeStorage();
+} else {
+this.onEnvironmentChanged();
+}
+return;
+}
+if (EVENT_ADDONS_UNINSTALLING.equals(event)) {
+this.onAddonUninstalling(message.getString("id"));
+this.onEnvironmentChanged();
+return;
+}
+if (EVENT_ADDONS_CHANGE.equals(event)) {
+this.onAddonChanged(message.getString("id"), message.getJSONObject("json"));
+this.onEnvironmentChanged();
+return;
+}
+if (EVENT_PREF_CHANGE.equals(event)) {
+final String pref = message.getString("pref");
+Log.d(LOG_TAG, "Pref changed: " + pref);
+this.onPrefMessage(pref, message);
+this.onEnvironmentChanged();
+return;
+}
+// Searches.
+if (EVENT_KEYWORD_SEARCH.equals(event)) {
+// A search via the URL bar. Since we eliminate all other search possibilities
+// (e.g. bookmarks keyword, search suggestion) when we initially process the
+// search URL, this is considered a default search.
+recordSearch(message.getString("identifier"), "bartext");
+return;
+}
+if (EVENT_SEARCH.equals(event)) {
+if (!message.has("location")) {
+Log.d(LOG_TAG, "Ignoring search without location.");
+return;
+}
+recordSearch(message.optString("identifier", null), message.getString("location"));
+return;
+}
+} catch (Exception e) {
+Log.e(LOG_TAG, "Exception handling message \"" + event + "\":", e);
+}
+}
+/*
+* Searches.
+*/
+public static final String MEASUREMENT_NAME_SEARCH_COUNTS = "org.mozilla.searches.counts";
+public static final int MEASUREMENT_VERSION_SEARCH_COUNTS = 5;
+public static final Set<String> SEARCH_LOCATIONS = Collections.unmodifiableSet(new HashSet<String>(Arrays.asList(new String[] {
+"barkeyword",
+"barsuggest",
+"bartext",
+})));
+private void initializeSearchProvider() {
+this.storage.ensureMeasurementInitialized(
+MEASUREMENT_NAME_SEARCH_COUNTS,
+MEASUREMENT_VERSION_SEARCH_COUNTS,
+new MeasurementFields() {
+@Override
+public Iterable<FieldSpec> getFields() {
+ArrayList<FieldSpec> out = new ArrayList<FieldSpec>(SEARCH_LOCATIONS.size());
+for (String location : SEARCH_LOCATIONS) {
+// We're not using a counter, because the set of engine
+// identifiers is potentially unbounded, and thus our
+// measurement version would have to keep growing as
+// fields changed. Instead we store discrete values, and
+// accumulate them into a counting map during processing.
+out.add(new FieldSpec(location, Field.TYPE_COUNTED_STRING_DISCRETE));
+}
+return out;
+}
+});
+// Do this here, rather than in a centralized registration spot, in
+// case the above throws and we wind up handling events that we can't
+// store.
+this.dispatcher.registerEventListener(EVENT_KEYWORD_SEARCH, this);
+this.dispatcher.registerEventListener(EVENT_SEARCH, this);
+}
+/**
+* Record a search.
+*
+* @param engineID the string identifier for the engine. Can be <code>null</code>.
+* @param location one of a fixed set of locations: see {@link #SEARCH_LOCATIONS}.
+*/
+public void recordSearch(final String engineID, final String location) {
+if (this.state != State.INITIALIZED) {
+Log.d(LOG_TAG, "Not initialized: not recording search. (" + this.state + ")");
+return;
+}
+final int env = this.env;
+if (env == -1) {
+Log.d(LOG_TAG, "No environment: not recording search.");
+return;
+}
+if (location == null) {
+throw new IllegalArgumentException("location must be provided for search.");
+}
+// Ensure that we don't throw when trying to look up the field for an
+// unknown location. If you add a search location, you must extend the
+// list of search locations *and update the measurement version*.
+if (!SEARCH_LOCATIONS.contains(location)) {
+throw new IllegalArgumentException("Unexpected location: " + location);
+}
+final int day = storage.getDay();
+final String key = (engineID == null) ? "other" : engineID;
+ThreadUtils.postToBackgroundThread(new Runnable() {
+@Override
+public void run() {
+final HealthReportDatabaseStorage storage = BrowserHealthRecorder.this.storage;
+if (storage == null) {
+Log.d(LOG_TAG, "No storage: not recording search. Shutting down?");
+return;
+}
+Log.d(LOG_TAG, "Recording search: " + key + ", " + location +
+" (" + day + ", " + env + ").");
+final int searchField = storage.getField(MEASUREMENT_NAME_SEARCH_COUNTS,
+MEASUREMENT_VERSION_SEARCH_COUNTS,
+location)
+.getID();
+storage.recordDailyDiscrete(env, day, searchField, key);
+}
+});
+}
+/*
+* Sessions.
+*
+* We record session beginnings in SharedPreferences, because it's cheaper
+* to do that than to either write to then update the DB (which requires
+* keeping a row identifier to update, as well as two writes) or to record
+* two events (which doubles storage space and requires rollup logic).
+*
+* The pattern is:
+*
+* 1. On startup, determine whether an orphan session exists by looking for
+*    a saved timestamp in prefs. If it does, then record the orphan in FHR
+*    storage.
+* 2. Record in prefs that a new session has begun. Track the timestamp (so
+*    we know to which day the session belongs).
+* 3. As startup timings become available, accumulate them in memory.
+* 4. On clean shutdown, read the values from here, write them to the DB, and
+*    delete the sentinel time from SharedPreferences.
+* 5. On a dirty shutdown, the in-memory session will not be written to the
+*    DB, and the current session will be orphaned.
+*
+* Sessions are begun in onResume (and thus implicitly onStart) and ended
+* in onPause.
+*
+* Session objects are stored as discrete JSON.
+*
+*   "org.mozilla.appSessions": {
+*     _v: 4,
+*     "normal": [
+*       {"r":"P", "d": 123},
+*     ],
+*     "abnormal": [
+*       {"r":"A", "oom": true, "stopped": false}
+*     ]
+*   }
+*
+* "r": reason. Values are "P" (activity paused), "A" (abnormal termination)
+* "d": duration. Value in seconds.
+* "sg": Gecko startup time. Present if this is a clean launch. This
+*       corresponds to the telemetry timer FENNEC_STARTUP_TIME_GECKOREADY.
+* "sj": Java activity init time. Present if this is a clean launch. This
+*       corresponds to the telemetry timer FENNEC_STARTUP_TIME_JAVAUI,
+*       and includes initialization tasks beyond initial
+*       onWindowFocusChanged.
+*
+* Abnormal terminations will be missing a duration and will feature these keys:
+*
+* "oom": was the session killed by an OOM exception?
+* "stopped": was the session stopped gently?
+*/
+public static final String MEASUREMENT_NAME_SESSIONS = "org.mozilla.appSessions";
+public static final int MEASUREMENT_VERSION_SESSIONS = 4;
+private void initializeSessionsProvider() {
+this.storage.ensureMeasurementInitialized(
+MEASUREMENT_NAME_SESSIONS,
+MEASUREMENT_VERSION_SESSIONS,
+new MeasurementFields() {
+@Override
+public Iterable<FieldSpec> getFields() {
+List<FieldSpec> out = Arrays.asList(
+new FieldSpec("normal", Field.TYPE_JSON_DISCRETE),
+new FieldSpec("abnormal", Field.TYPE_JSON_DISCRETE));
+return out;
+}
+});
+}
+/**
+* Logic shared between crashed and normal sessions.
+*/
+private void recordSessionEntry(String field, SessionInformation session, final int environment, JSONObject value) {
+final HealthReportDatabaseStorage storage = this.storage;
+if (storage == null) {
+Log.d(LOG_TAG, "No storage: not recording session entry. Shutting down?");
+return;
+}
+try {
+final int sessionField = storage.getField(MEASUREMENT_NAME_SESSIONS,
+MEASUREMENT_VERSION_SESSIONS,
+field)
+.getID();
+final int day = storage.getDay(session.wallStartTime);
+storage.recordDailyDiscrete(environment, day, sessionField, value);
+Log.v(LOG_TAG, "Recorded session entry for env " + environment + ", current is " + env);
+} catch (Exception e) {
+Log.w(LOG_TAG, "Unable to record session completion.", e);
+}
+}
+public void checkForOrphanSessions() {
+if (!this.orphanChecked.compareAndSet(false, true)) {
+Log.w(LOG_TAG, "Attempting to check for orphan sessions more than once.");
+return;
+}
+Log.d(LOG_TAG, "Checking for orphan session.");
+if (this.previousSession == null) {
+return;
+}
+if (this.previousSession.wallStartTime == 0) {
+return;
+}
+if (state != State.INITIALIZED) {
+// Something has gone awry.
+Log.e(LOG_TAG, "Attempted to record bad session end without initialized recorder.");
+return;
+}
+try {
+recordSessionEntry("abnormal", this.previousSession, this.env,
+this.previousSession.getCrashedJSON());
+} catch (Exception e) {
+Log.w(LOG_TAG, "Unable to generate session JSON.", e);
+// Future: record this exception in FHR's own error submitter.
+}
+}
+public void recordSessionEnd(String reason, SharedPreferences.Editor editor) {
+recordSessionEnd(reason, editor, env);
+}
+/**
+* Record that the current session ended. Does not commit the provided editor.
+*
+* @param environment An environment ID. This allows callers to record the
+*                    end of a session due to an observed environment change.
+*/
+public void recordSessionEnd(String reason, SharedPreferences.Editor editor, final int environment) {
+Log.d(LOG_TAG, "Recording session end: " + reason);
+if (state != State.INITIALIZED) {
+// Something has gone awry.
+Log.e(LOG_TAG, "Attempted to record session end without initialized recorder.");
+return;
+}
+final SessionInformation session = this.session;
+this.session = null;        // So it can't be double-recorded.
+if (session == null) {
+Log.w(LOG_TAG, "Unable to record session end: no session. Already ended?");
+return;
+}
+if (session.wallStartTime <= 0) {
+Log.e(LOG_TAG, "Session start " + session.wallStartTime + " isn't valid! Can't record end.");
+return;
+}
+long realEndTime = android.os.SystemClock.elapsedRealtime();
+try {
+JSONObject json = session.getCompletionJSON(reason, realEndTime);
+recordSessionEntry("normal", session, environment, json);
+} catch (JSONException e) {
+Log.w(LOG_TAG, "Unable to generate session JSON.", e);
+// Continue so we don't hit it next time.
+// Future: record this exception in FHR's own error submitter.
+}
+// Track the end of this session in shared prefs, so it doesn't get
+// double-counted on next run.
+session.recordCompletion(editor);
+}
+}

The Tor Browser / file comparison

comparison: mobile/android/base/health/BrowserHealthRecorder.java

mobile/android/base/health/BrowserHealthRecorder.java