1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/GeckoSharedPrefs.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,275 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +package org.mozilla.gecko;
1.9 +
1.10 +import org.mozilla.gecko.mozglue.RobocopTarget;
1.11 +import org.mozilla.gecko.util.ThreadUtils;
1.12 +
1.13 +import android.content.Context;
1.14 +import android.content.SharedPreferences;
1.15 +import android.content.SharedPreferences.Editor;
1.16 +import android.os.Build;
1.17 +import android.os.StrictMode;
1.18 +import android.preference.PreferenceManager;
1.19 +import android.util.Log;
1.20 +
1.21 +import java.util.Arrays;
1.22 +import java.util.EnumSet;
1.23 +import java.util.List;
1.24 +import java.util.Map;
1.25 +import java.util.Set;
1.26 +
1.27 +/**
1.28 + * {@code GeckoSharedPrefs} provides scoped SharedPreferences instances.
1.29 + * You should use this API instead of using Context.getSharedPreferences()
1.30 + * directly. There are three methods to get scoped SharedPreferences instances:
1.31 + *
1.32 + * forApp()
1.33 + * Use it for app-wide, cross-profile pref keys.
1.34 + * forProfile()
1.35 + * Use it to fetch and store keys for the current profile.
1.36 + * forProfileName()
1.37 + * Use it to fetch and store keys from/for a specific profile.
1.38 + *
1.39 + * {@code GeckoSharedPrefs} has a notion of migrations. Migrations can used to
1.40 + * migrate keys from one scope to another. You can trigger a new migration by
1.41 + * incrementing PREFS_VERSION and updating migrateIfNecessary() accordingly.
1.42 + *
1.43 + * Migration history:
1.44 + * 1: Move all PreferenceManager keys to app/profile scopes
1.45 + */
1.46 +@RobocopTarget
1.47 +public final class GeckoSharedPrefs {
1.48 + private static final String LOGTAG = "GeckoSharedPrefs";
1.49 +
1.50 + // Increment it to trigger a new migration
1.51 + public static final int PREFS_VERSION = 1;
1.52 +
1.53 + // Name for app-scoped prefs
1.54 + public static final String APP_PREFS_NAME = "GeckoApp";
1.55 +
1.56 + // The prefs key that holds the current migration
1.57 + private static final String PREFS_VERSION_KEY = "gecko_shared_prefs_migration";
1.58 +
1.59 + // For disabling migration when getting a SharedPreferences instance
1.60 + private static final EnumSet<Flags> disableMigrations = EnumSet.of(Flags.DISABLE_MIGRATIONS);
1.61 +
1.62 + // Timeout for migration commits to be done (10 seconds)
1.63 + private static final int MIGRATION_COMMIT_TIMEOUT_MSEC = 10000;
1.64 +
1.65 + // The keys that have to be moved from ProfileManager's default
1.66 + // shared prefs to the profile from version 0 to 1.
1.67 + private static final String[] PROFILE_MIGRATIONS_0_TO_1 = {
1.68 + "home_panels",
1.69 + "home_locale"
1.70 + };
1.71 +
1.72 + // For optimizing the migration check in subsequent get() calls
1.73 + private static volatile boolean migrationDone = false;
1.74 +
1.75 + public enum Flags {
1.76 + DISABLE_MIGRATIONS
1.77 + }
1.78 +
1.79 + // Used when fetching profile-scoped prefs.
1.80 + private static final String PROFILE_PREFS_NAME_PREFIX = "GeckoProfile-";
1.81 +
1.82 + public static SharedPreferences forApp(Context context) {
1.83 + return forApp(context, EnumSet.noneOf(Flags.class));
1.84 + }
1.85 +
1.86 + /**
1.87 + * Returns an app-scoped SharedPreferences instance. You can disable
1.88 + * migrations by using the DISABLE_MIGRATIONS flag.
1.89 + */
1.90 + public static SharedPreferences forApp(Context context, EnumSet<Flags> flags) {
1.91 + if (flags != null && !flags.contains(Flags.DISABLE_MIGRATIONS)) {
1.92 + migrateIfNecessary(context);
1.93 + }
1.94 +
1.95 + return context.getSharedPreferences(APP_PREFS_NAME, 0);
1.96 + }
1.97 +
1.98 + public static SharedPreferences forProfile(Context context) {
1.99 + return forProfile(context, EnumSet.noneOf(Flags.class));
1.100 + }
1.101 +
1.102 + /**
1.103 + * Returns a SharedPreferences instance scoped to the current profile
1.104 + * in the app. You can disable migrations by using the DISABLE_MIGRATIONS
1.105 + * flag.
1.106 + */
1.107 + public static SharedPreferences forProfile(Context context, EnumSet<Flags> flags) {
1.108 + String profileName = GeckoProfile.get(context).getName();
1.109 + if (profileName == null) {
1.110 + throw new IllegalStateException("Could not get current profile name");
1.111 + }
1.112 +
1.113 + return forProfileName(context, profileName, flags);
1.114 + }
1.115 +
1.116 + public static SharedPreferences forProfileName(Context context, String profileName) {
1.117 + return forProfileName(context, profileName, EnumSet.noneOf(Flags.class));
1.118 + }
1.119 +
1.120 + /**
1.121 + * Returns an SharedPreferences instance scoped to the given profile name.
1.122 + * You can disable migrations by using the DISABLE_MIGRATION flag.
1.123 + */
1.124 + public static SharedPreferences forProfileName(Context context, String profileName,
1.125 + EnumSet<Flags> flags) {
1.126 + if (flags != null && !flags.contains(Flags.DISABLE_MIGRATIONS)) {
1.127 + migrateIfNecessary(context);
1.128 + }
1.129 +
1.130 + final String prefsName = PROFILE_PREFS_NAME_PREFIX + profileName;
1.131 + return context.getSharedPreferences(prefsName, 0);
1.132 + }
1.133 +
1.134 + /**
1.135 + * Returns the current version of the prefs.
1.136 + */
1.137 + public static int getVersion(Context context) {
1.138 + return forApp(context, disableMigrations).getInt(PREFS_VERSION_KEY, 0);
1.139 + }
1.140 +
1.141 + /**
1.142 + * Resets migration flag. Should only be used in tests.
1.143 + */
1.144 + public static synchronized void reset() {
1.145 + migrationDone = false;
1.146 + }
1.147 +
1.148 + /**
1.149 + * Performs all prefs migrations in the background thread to avoid StrictMode
1.150 + * exceptions from reading/writing in the UI thread. This method will block
1.151 + * the current thread until the migration is finished.
1.152 + */
1.153 + private static synchronized void migrateIfNecessary(final Context context) {
1.154 + if (migrationDone) {
1.155 + return;
1.156 + }
1.157 +
1.158 + // We deliberatly perform the migration in the current thread (which
1.159 + // is likely the UI thread) as this is actually cheaper than enforcing a
1.160 + // context switch to another thread (see bug 940575).
1.161 + if (Build.VERSION.SDK_INT < 9) {
1.162 + performMigration(context);
1.163 + } else {
1.164 + // Avoid strict mode warnings.
1.165 + final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
1.166 + StrictMode.allowThreadDiskWrites();
1.167 +
1.168 + try {
1.169 + performMigration(context);
1.170 + } finally {
1.171 + StrictMode.setThreadPolicy(savedPolicy);
1.172 + }
1.173 + }
1.174 +
1.175 + migrationDone = true;
1.176 + }
1.177 +
1.178 + private static void performMigration(Context context) {
1.179 + final SharedPreferences appPrefs = forApp(context, disableMigrations);
1.180 +
1.181 + final int currentVersion = appPrefs.getInt(PREFS_VERSION_KEY, 0);
1.182 + Log.d(LOGTAG, "Current version = " + currentVersion + ", prefs version = " + PREFS_VERSION);
1.183 +
1.184 + if (currentVersion == PREFS_VERSION) {
1.185 + return;
1.186 + }
1.187 +
1.188 + Log.d(LOGTAG, "Performing migration");
1.189 +
1.190 + final Editor appEditor = appPrefs.edit();
1.191 +
1.192 + // The migration always moves prefs to the default profile, not
1.193 + // the current one. We might have to revisit this if we ever support
1.194 + // multiple profiles.
1.195 + final String defaultProfileName;
1.196 + try {
1.197 + defaultProfileName = GeckoProfile.getDefaultProfileName(context);
1.198 + } catch (Exception e) {
1.199 + throw new IllegalStateException("Failed to get default profile name for migration");
1.200 + }
1.201 +
1.202 + final Editor profileEditor = forProfileName(context, defaultProfileName, disableMigrations).edit();
1.203 +
1.204 + List<String> profileKeys;
1.205 + Editor pmEditor = null;
1.206 +
1.207 + for (int v = currentVersion + 1; v <= PREFS_VERSION; v++) {
1.208 + Log.d(LOGTAG, "Migrating to version = " + v);
1.209 +
1.210 + switch (v) {
1.211 + case 1:
1.212 + profileKeys = Arrays.asList(PROFILE_MIGRATIONS_0_TO_1);
1.213 + pmEditor = migrateFromPreferenceManager(context, appEditor, profileEditor, profileKeys);
1.214 + break;
1.215 + }
1.216 + }
1.217 +
1.218 + // Update prefs version accordingly.
1.219 + appEditor.putInt(PREFS_VERSION_KEY, PREFS_VERSION);
1.220 +
1.221 + appEditor.commit();
1.222 + profileEditor.commit();
1.223 + if (pmEditor != null) {
1.224 + pmEditor.commit();
1.225 + }
1.226 +
1.227 + Log.d(LOGTAG, "All keys have been migrated");
1.228 + }
1.229 +
1.230 + /**
1.231 + * Moves all preferences stored in PreferenceManager's default prefs
1.232 + * to either app or profile scopes. The profile-scoped keys are defined
1.233 + * in given profileKeys list, all other keys are moved to the app scope.
1.234 + */
1.235 + public static Editor migrateFromPreferenceManager(Context context, Editor appEditor,
1.236 + Editor profileEditor, List<String> profileKeys) {
1.237 + Log.d(LOGTAG, "Migrating from PreferenceManager");
1.238 +
1.239 + final SharedPreferences pmPrefs =
1.240 + PreferenceManager.getDefaultSharedPreferences(context);
1.241 +
1.242 + for (Map.Entry<String, ?> entry : pmPrefs.getAll().entrySet()) {
1.243 + final String key = entry.getKey();
1.244 +
1.245 + final Editor to;
1.246 + if (profileKeys.contains(key)) {
1.247 + to = profileEditor;
1.248 + } else {
1.249 + to = appEditor;
1.250 + }
1.251 +
1.252 + putEntry(to, key, entry.getValue());
1.253 + }
1.254 +
1.255 + // Clear PreferenceManager's prefs once we're done
1.256 + // and return the Editor to be committed.
1.257 + return pmPrefs.edit().clear();
1.258 + }
1.259 +
1.260 + @SuppressWarnings("unchecked")
1.261 + private static void putEntry(Editor to, String key, Object value) {
1.262 + Log.d(LOGTAG, "Migrating key = " + key + " with value = " + value);
1.263 +
1.264 + if (value instanceof String) {
1.265 + to.putString(key, (String) value);
1.266 + } else if (value instanceof Boolean) {
1.267 + to.putBoolean(key, (Boolean) value);
1.268 + } else if (value instanceof Long) {
1.269 + to.putLong(key, (Long) value);
1.270 + } else if (value instanceof Float) {
1.271 + to.putFloat(key, (Float) value);
1.272 + } else if (value instanceof Integer) {
1.273 + to.putInt(key, (Integer) value);
1.274 + } else {
1.275 + throw new IllegalStateException("Unrecognized value type for key: " + key);
1.276 + }
1.277 + }
1.278 +}
1.279 \ No newline at end of file
