bpetrivs | 62f1598 | 2019-02-13 17:18:16 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2019 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 com.android.server.utils; |
| 18 | |
| 19 | import android.annotation.Nullable; |
| 20 | import android.provider.DeviceConfig; |
| 21 | |
| 22 | import com.android.server.RescueParty; |
| 23 | |
| 24 | import java.util.ArrayList; |
| 25 | import java.util.Arrays; |
| 26 | import java.util.List; |
| 27 | |
| 28 | /** |
| 29 | * Utilities for interacting with the {@link android.provider.DeviceConfig}. |
| 30 | * |
| 31 | * @hide |
| 32 | */ |
| 33 | public final class FlagNamespaceUtils { |
| 34 | /** |
| 35 | * Special String used for communicating through {@link #RESET_PLATFORM_PACKAGE_FLAG} that |
| 36 | * Settings were reset by the RescueParty, no actual namespace with this name exists in |
| 37 | * {@link DeviceConfig}. |
| 38 | */ |
| 39 | public static final String NAMESPACE_NO_PACKAGE = "no_package"; |
| 40 | |
| 41 | /** |
| 42 | * Name of the special namespace in DeviceConfig table used for communicating resets. |
| 43 | */ |
| 44 | private static final String NAMESPACE_RESCUE_PARTY = "rescue_party_namespace"; |
| 45 | /** |
| 46 | * Flag in the {@link DeviceConfig} in {@link #NAMESPACE_RESCUE_PARTY}, holding all known {@link |
| 47 | * DeviceConfig} namespaces, as a {@link #DELIMITER} separated String. It's updated after the |
| 48 | * first time flags are written to the new namespace in the {@link DeviceConfig}. |
| 49 | */ |
| 50 | private static final String ALL_KNOWN_NAMESPACES_FLAG = "all_known_namespaces"; |
| 51 | /** |
| 52 | * Flag in the {@link DeviceConfig} in {@link #NAMESPACE_RESCUE_PARTY} with integer counter |
| 53 | * suffix added to it, holding {@link DeviceConfig} namespace value whose flags were recently |
| 54 | * reset by the {@link RescueParty}. It's updated by {@link RescueParty} every time given |
| 55 | * namespace flags are reset. |
| 56 | */ |
| 57 | private static final String RESET_PLATFORM_PACKAGE_FLAG = "reset_platform_package"; |
| 58 | private static final String DELIMITER = ":"; |
| 59 | /** |
| 60 | * Maximum value of the counter used in combination with {@link #RESET_PLATFORM_PACKAGE_FLAG} |
| 61 | * when communicating recently reset by the RescueParty namespace values. |
| 62 | */ |
| 63 | private static final int MAX_COUNTER_VALUE = 50; |
| 64 | |
| 65 | private static int sKnownResetNamespacesFlagCounter = -1; |
| 66 | |
| 67 | /** |
| 68 | * Sets the union of {@link #RESET_PLATFORM_PACKAGE_FLAG} with |
| 69 | * {@link #sKnownResetNamespacesFlagCounter} in the DeviceConfig for each namespace |
| 70 | * in the consumed namespacesList. These flags are used for communicating the namespaces |
| 71 | * (aka platform packages) whose flags in {@link DeviceConfig} were just reset |
| 72 | * by the RescueParty. |
| 73 | */ |
| 74 | public static void addToKnownResetNamespaces(@Nullable List<String> namespacesList) { |
| 75 | if (namespacesList == null) { |
| 76 | return; |
| 77 | } |
| 78 | for (String namespace : namespacesList) { |
| 79 | addToKnownResetNamespaces(namespace); |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Sets the union of {@link #RESET_PLATFORM_PACKAGE_FLAG} with |
| 85 | * {@link #sKnownResetNamespacesFlagCounter} in the DeviceConfig for the consumed namespace. |
| 86 | * This flag is used for communicating the namespace (aka platform package) whose flags |
| 87 | * in {@link DeviceConfig} were just reset by the RescueParty. |
| 88 | */ |
| 89 | public static void addToKnownResetNamespaces(String namespace) { |
| 90 | int nextFlagCounter = incrementAndRetrieveResetNamespacesFlagCounter(); |
| 91 | DeviceConfig.setProperty(NAMESPACE_RESCUE_PARTY, |
| 92 | RESET_PLATFORM_PACKAGE_FLAG + nextFlagCounter, |
| 93 | namespace, /*makeDefault=*/ true); |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Reset all namespaces in DeviceConfig with consumed resetMode. |
| 98 | */ |
| 99 | public static void resetDeviceConfig(int resetMode) { |
| 100 | List<String> allKnownNamespaces = getAllKnownDeviceConfigNamespacesList(); |
| 101 | for (String namespace : allKnownNamespaces) { |
| 102 | DeviceConfig.resetToDefaults(resetMode, namespace); |
| 103 | } |
| 104 | addToKnownResetNamespaces(allKnownNamespaces); |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Returns a list of all known DeviceConfig namespaces, except for the special {@link |
| 109 | * #NAMESPACE_RESCUE_PARTY} |
| 110 | */ |
| 111 | private static List<String> getAllKnownDeviceConfigNamespacesList() { |
| 112 | String namespacesStr = DeviceConfig.getProperty(NAMESPACE_RESCUE_PARTY, |
| 113 | ALL_KNOWN_NAMESPACES_FLAG); |
| 114 | List<String> namespacesList = toStringList(namespacesStr); |
| 115 | namespacesList.remove(NAMESPACE_RESCUE_PARTY); |
| 116 | return namespacesList; |
| 117 | } |
| 118 | |
| 119 | private static List<String> toStringList(String serialized) { |
| 120 | if (serialized == null || serialized.length() == 0) { |
| 121 | return new ArrayList<>(); |
| 122 | } |
| 123 | return Arrays.asList(serialized.split(DELIMITER)); |
| 124 | } |
| 125 | |
| 126 | private static int incrementAndRetrieveResetNamespacesFlagCounter() { |
| 127 | sKnownResetNamespacesFlagCounter++; |
| 128 | if (sKnownResetNamespacesFlagCounter == MAX_COUNTER_VALUE) { |
| 129 | sKnownResetNamespacesFlagCounter = 0; |
| 130 | } |
| 131 | return sKnownResetNamespacesFlagCounter; |
| 132 | } |
| 133 | } |