1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.util; 18 19 import android.annotation.TestApi; 20 import android.content.Context; 21 import android.os.SystemProperties; 22 import android.provider.Settings; 23 import android.text.TextUtils; 24 25 import java.util.HashMap; 26 import java.util.HashSet; 27 import java.util.Map; 28 import java.util.Set; 29 30 /** 31 * Util class to get feature flag information. 32 * 33 * @hide 34 */ 35 @TestApi 36 public class FeatureFlagUtils { 37 38 public static final String FFLAG_PREFIX = "sys.fflag."; 39 public static final String FFLAG_OVERRIDE_PREFIX = FFLAG_PREFIX + "override."; 40 public static final String PERSIST_PREFIX = "persist." + FFLAG_OVERRIDE_PREFIX; 41 public static final String HEARING_AID_SETTINGS = "settings_bluetooth_hearing_aid"; 42 public static final String SETTINGS_WIFITRACKER2 = "settings_wifitracker2"; 43 /** @hide */ 44 public static final String SETTINGS_DO_NOT_RESTORE_PRESERVED = 45 "settings_do_not_restore_preserved"; 46 /** @hide */ 47 public static final String SETTINGS_PROVIDER_MODEL = "settings_provider_model"; 48 /** @hide */ 49 public static final String SETTINGS_USE_NEW_BACKUP_ELIGIBILITY_RULES 50 = "settings_use_new_backup_eligibility_rules"; 51 /** @hide */ 52 public static final String SETTINGS_ENABLE_SECURITY_HUB = "settings_enable_security_hub"; 53 54 /** @hide */ 55 public static final String SETTINGS_SUPPORT_LARGE_SCREEN = "settings_support_large_screen"; 56 57 /** @hide */ 58 public static final String SETTINGS_ENABLE_MONITOR_PHANTOM_PROCS = 59 "settings_enable_monitor_phantom_procs"; 60 61 private static final Map<String, String> DEFAULT_FLAGS; 62 63 static { 64 DEFAULT_FLAGS = new HashMap<>(); 65 DEFAULT_FLAGS.put("settings_audio_switcher", "true"); 66 DEFAULT_FLAGS.put("settings_systemui_theme", "true"); DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, R)67 DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, "false"); 68 DEFAULT_FLAGS.put("settings_wifi_details_datausage_header", "false"); 69 DEFAULT_FLAGS.put("settings_skip_direction_mutable", "true"); DEFAULT_FLAGS.put(SETTINGS_WIFITRACKER2, R)70 DEFAULT_FLAGS.put(SETTINGS_WIFITRACKER2, "true"); 71 DEFAULT_FLAGS.put("settings_controller_loading_enhancement", "true"); 72 DEFAULT_FLAGS.put("settings_conditionals", "false"); 73 // This flags guards a feature introduced in R and will be removed in the next release 74 // (b/148367230). DEFAULT_FLAGS.put(SETTINGS_DO_NOT_RESTORE_PRESERVED, R)75 DEFAULT_FLAGS.put(SETTINGS_DO_NOT_RESTORE_PRESERVED, "true"); 76 77 DEFAULT_FLAGS.put("settings_tether_all_in_one", "false"); 78 DEFAULT_FLAGS.put("settings_contextual_home", "false"); DEFAULT_FLAGS.put(SETTINGS_PROVIDER_MODEL, R)79 DEFAULT_FLAGS.put(SETTINGS_PROVIDER_MODEL, "true"); DEFAULT_FLAGS.put(SETTINGS_USE_NEW_BACKUP_ELIGIBILITY_RULES, R)80 DEFAULT_FLAGS.put(SETTINGS_USE_NEW_BACKUP_ELIGIBILITY_RULES, "true"); DEFAULT_FLAGS.put(SETTINGS_ENABLE_SECURITY_HUB, R)81 DEFAULT_FLAGS.put(SETTINGS_ENABLE_SECURITY_HUB, "true"); DEFAULT_FLAGS.put(SETTINGS_SUPPORT_LARGE_SCREEN, R)82 DEFAULT_FLAGS.put(SETTINGS_SUPPORT_LARGE_SCREEN, "true"); DEFAULT_FLAGS.put(SETTINGS_ENABLE_MONITOR_PHANTOM_PROCS, R)83 DEFAULT_FLAGS.put(SETTINGS_ENABLE_MONITOR_PHANTOM_PROCS, "true"); 84 } 85 86 private static final Set<String> PERSISTENT_FLAGS; 87 static { 88 PERSISTENT_FLAGS = new HashSet<>(); 89 PERSISTENT_FLAGS.add(SETTINGS_PROVIDER_MODEL); 90 PERSISTENT_FLAGS.add(SETTINGS_SUPPORT_LARGE_SCREEN); 91 PERSISTENT_FLAGS.add(SETTINGS_ENABLE_MONITOR_PHANTOM_PROCS); 92 } 93 94 /** 95 * Whether or not a flag is enabled. 96 * 97 * @param feature the flag name 98 * @return true if the flag is enabled (either by default in system, or override by user) 99 */ isEnabled(Context context, String feature)100 public static boolean isEnabled(Context context, String feature) { 101 // Override precedence: 102 // Settings.Global -> sys.fflag.override.* -> static list 103 104 // Step 1: check if feature flag is set in Settings.Global. 105 String value; 106 if (context != null) { 107 value = Settings.Global.getString(context.getContentResolver(), feature); 108 if (!TextUtils.isEmpty(value)) { 109 return Boolean.parseBoolean(value); 110 } 111 } 112 113 // Step 2: check if feature flag has any override. 114 // Flag name: [persist.]sys.fflag.override.<feature> 115 value = SystemProperties.get(getSystemPropertyPrefix(feature) + feature); 116 if (!TextUtils.isEmpty(value)) { 117 return Boolean.parseBoolean(value); 118 } 119 // Step 3: check if feature flag has any default value. 120 value = getAllFeatureFlags().get(feature); 121 return Boolean.parseBoolean(value); 122 } 123 124 /** 125 * Override feature flag to new state. 126 */ setEnabled(Context context, String feature, boolean enabled)127 public static void setEnabled(Context context, String feature, boolean enabled) { 128 SystemProperties.set(getSystemPropertyPrefix(feature) + feature, 129 enabled ? "true" : "false"); 130 } 131 132 /** 133 * Returns all feature flags in their raw form. 134 */ getAllFeatureFlags()135 public static Map<String, String> getAllFeatureFlags() { 136 return DEFAULT_FLAGS; 137 } 138 getSystemPropertyPrefix(String feature)139 private static String getSystemPropertyPrefix(String feature) { 140 return PERSISTENT_FLAGS.contains(feature) ? PERSIST_PREFIX : FFLAG_OVERRIDE_PREFIX; 141 } 142 } 143