| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.providers.settings; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Message; |
| import android.os.SystemClock; |
| import android.provider.Settings; |
| import android.text.TextUtils; |
| import android.util.ArrayMap; |
| import android.util.AtomicFile; |
| import android.util.Base64; |
| import android.util.Slog; |
| import android.util.Xml; |
| import com.android.internal.annotations.GuardedBy; |
| import libcore.io.IoUtils; |
| import libcore.util.Objects; |
| import org.xmlpull.v1.XmlPullParser; |
| import org.xmlpull.v1.XmlPullParserException; |
| import org.xmlpull.v1.XmlSerializer; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.nio.charset.StandardCharsets; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * This class contains the state for one type of settings. It is responsible |
| * for saving the state asynchronously to an XML file after a mutation and |
| * loading the from an XML file on construction. |
| * <p> |
| * This class uses the same lock as the settings provider to ensure that |
| * multiple changes made by the settings provider, e,g, upgrade, bulk insert, |
| * etc, are atomically persisted since the asynchronous persistence is using |
| * the same lock to grab the current state to write to disk. |
| * </p> |
| */ |
| final class SettingsState { |
| private static final boolean DEBUG = false; |
| private static final boolean DEBUG_PERSISTENCE = false; |
| |
| private static final String LOG_TAG = "SettingsState"; |
| |
| static final int SETTINGS_VERSOIN_NEW_ENCODING = 121; |
| |
| private static final long WRITE_SETTINGS_DELAY_MILLIS = 200; |
| private static final long MAX_WRITE_SETTINGS_DELAY_MILLIS = 2000; |
| |
| public static final int MAX_BYTES_PER_APP_PACKAGE_UNLIMITED = -1; |
| public static final int MAX_BYTES_PER_APP_PACKAGE_LIMITED = 20000; |
| |
| public static final String SYSTEM_PACKAGE_NAME = "android"; |
| |
| public static final int VERSION_UNDEFINED = -1; |
| |
| private static final String TAG_SETTINGS = "settings"; |
| private static final String TAG_SETTING = "setting"; |
| private static final String ATTR_PACKAGE = "package"; |
| |
| private static final String ATTR_VERSION = "version"; |
| private static final String ATTR_ID = "id"; |
| private static final String ATTR_NAME = "name"; |
| |
| /** Non-binary value will be written in this attribute. */ |
| private static final String ATTR_VALUE = "value"; |
| |
| /** |
| * KXmlSerializer won't like some characters. We encode such characters in base64 and |
| * store in this attribute. |
| * NOTE: A null value will have NEITHER ATTR_VALUE nor ATTR_VALUE_BASE64. |
| */ |
| private static final String ATTR_VALUE_BASE64 = "valueBase64"; |
| |
| // This was used in version 120 and before. |
| private static final String NULL_VALUE_OLD_STYLE = "null"; |
| |
| private final Object mLock; |
| |
| private final Handler mHandler; |
| |
| @GuardedBy("mLock") |
| private final ArrayMap<String, Setting> mSettings = new ArrayMap<>(); |
| |
| @GuardedBy("mLock") |
| private final ArrayMap<String, Integer> mPackageToMemoryUsage; |
| |
| @GuardedBy("mLock") |
| private final int mMaxBytesPerAppPackage; |
| |
| @GuardedBy("mLock") |
| private final File mStatePersistFile; |
| |
| private final Setting mNullSetting = new Setting(null, null, null) { |
| @Override |
| public boolean isNull() { |
| return true; |
| } |
| }; |
| |
| @GuardedBy("mLock") |
| public final int mKey; |
| |
| @GuardedBy("mLock") |
| private int mVersion = VERSION_UNDEFINED; |
| |
| @GuardedBy("mLock") |
| private long mLastNotWrittenMutationTimeMillis; |
| |
| @GuardedBy("mLock") |
| private boolean mDirty; |
| |
| @GuardedBy("mLock") |
| private boolean mWriteScheduled; |
| |
| @GuardedBy("mLock") |
| private long mNextId; |
| |
| public SettingsState(Object lock, File file, int key, int maxBytesPerAppPackage, |
| Looper looper) { |
| // It is important that we use the same lock as the settings provider |
| // to ensure multiple mutations on this state are atomicaly persisted |
| // as the async persistence should be blocked while we make changes. |
| mLock = lock; |
| mStatePersistFile = file; |
| mKey = key; |
| mHandler = new MyHandler(looper); |
| if (maxBytesPerAppPackage == MAX_BYTES_PER_APP_PACKAGE_LIMITED) { |
| mMaxBytesPerAppPackage = maxBytesPerAppPackage; |
| mPackageToMemoryUsage = new ArrayMap<>(); |
| } else { |
| mMaxBytesPerAppPackage = maxBytesPerAppPackage; |
| mPackageToMemoryUsage = null; |
| } |
| synchronized (mLock) { |
| readStateSyncLocked(); |
| } |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public int getVersionLocked() { |
| return mVersion; |
| } |
| |
| public Setting getNullSetting() { |
| return mNullSetting; |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public void setVersionLocked(int version) { |
| if (version == mVersion) { |
| return; |
| } |
| mVersion = version; |
| |
| scheduleWriteIfNeededLocked(); |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public void onPackageRemovedLocked(String packageName) { |
| boolean removedSomething = false; |
| |
| final int settingCount = mSettings.size(); |
| for (int i = settingCount - 1; i >= 0; i--) { |
| String name = mSettings.keyAt(i); |
| // Settings defined by us are never dropped. |
| if (Settings.System.PUBLIC_SETTINGS.contains(name) |
| || Settings.System.PRIVATE_SETTINGS.contains(name)) { |
| continue; |
| } |
| Setting setting = mSettings.valueAt(i); |
| if (packageName.equals(setting.packageName)) { |
| mSettings.removeAt(i); |
| removedSomething = true; |
| } |
| } |
| |
| if (removedSomething) { |
| scheduleWriteIfNeededLocked(); |
| } |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public List<String> getSettingNamesLocked() { |
| ArrayList<String> names = new ArrayList<>(); |
| final int settingsCount = mSettings.size(); |
| for (int i = 0; i < settingsCount; i++) { |
| String name = mSettings.keyAt(i); |
| names.add(name); |
| } |
| return names; |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public Setting getSettingLocked(String name) { |
| if (TextUtils.isEmpty(name)) { |
| return mNullSetting; |
| } |
| Setting setting = mSettings.get(name); |
| if (setting != null) { |
| return new Setting(setting); |
| } |
| return mNullSetting; |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public boolean updateSettingLocked(String name, String value, String packageName) { |
| if (!hasSettingLocked(name)) { |
| return false; |
| } |
| |
| return insertSettingLocked(name, value, packageName); |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public boolean insertSettingLocked(String name, String value, String packageName) { |
| if (TextUtils.isEmpty(name)) { |
| return false; |
| } |
| |
| Setting oldState = mSettings.get(name); |
| String oldValue = (oldState != null) ? oldState.value : null; |
| |
| if (oldState != null) { |
| if (!oldState.update(value, packageName)) { |
| return false; |
| } |
| } else { |
| Setting state = new Setting(name, value, packageName); |
| mSettings.put(name, state); |
| } |
| |
| updateMemoryUsagePerPackageLocked(packageName, oldValue, value); |
| |
| scheduleWriteIfNeededLocked(); |
| |
| return true; |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public void persistSyncLocked() { |
| mHandler.removeMessages(MyHandler.MSG_PERSIST_SETTINGS); |
| doWriteState(); |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public boolean deleteSettingLocked(String name) { |
| if (TextUtils.isEmpty(name) || !hasSettingLocked(name)) { |
| return false; |
| } |
| |
| Setting oldState = mSettings.remove(name); |
| |
| updateMemoryUsagePerPackageLocked(oldState.packageName, oldState.value, null); |
| |
| scheduleWriteIfNeededLocked(); |
| |
| return true; |
| } |
| |
| // The settings provider must hold its lock when calling here. |
| public void destroyLocked(Runnable callback) { |
| mHandler.removeMessages(MyHandler.MSG_PERSIST_SETTINGS); |
| if (callback != null) { |
| if (mDirty) { |
| // Do it without a delay. |
| mHandler.obtainMessage(MyHandler.MSG_PERSIST_SETTINGS, |
| callback).sendToTarget(); |
| return; |
| } |
| callback.run(); |
| } |
| } |
| |
| private void updateMemoryUsagePerPackageLocked(String packageName, String oldValue, |
| String newValue) { |
| if (mMaxBytesPerAppPackage == MAX_BYTES_PER_APP_PACKAGE_UNLIMITED) { |
| return; |
| } |
| |
| if (SYSTEM_PACKAGE_NAME.equals(packageName)) { |
| return; |
| } |
| |
| final int oldValueSize = (oldValue != null) ? oldValue.length() : 0; |
| final int newValueSize = (newValue != null) ? newValue.length() : 0; |
| final int deltaSize = newValueSize - oldValueSize; |
| |
| Integer currentSize = mPackageToMemoryUsage.get(packageName); |
| final int newSize = Math.max((currentSize != null) |
| ? currentSize + deltaSize : deltaSize, 0); |
| |
| if (newSize > mMaxBytesPerAppPackage) { |
| throw new IllegalStateException("You are adding too many system settings. " |
| + "You should stop using system settings for app specific data" |
| + " package: " + packageName); |
| } |
| |
| if (DEBUG) { |
| Slog.i(LOG_TAG, "Settings for package: " + packageName |
| + " size: " + newSize + " bytes."); |
| } |
| |
| mPackageToMemoryUsage.put(packageName, newSize); |
| } |
| |
| private boolean hasSettingLocked(String name) { |
| return mSettings.indexOfKey(name) >= 0; |
| } |
| |
| private void scheduleWriteIfNeededLocked() { |
| // If dirty then we have a write already scheduled. |
| if (!mDirty) { |
| mDirty = true; |
| writeStateAsyncLocked(); |
| } |
| } |
| |
| private void writeStateAsyncLocked() { |
| final long currentTimeMillis = SystemClock.uptimeMillis(); |
| |
| if (mWriteScheduled) { |
| mHandler.removeMessages(MyHandler.MSG_PERSIST_SETTINGS); |
| |
| // If enough time passed, write without holding off anymore. |
| final long timeSinceLastNotWrittenMutationMillis = currentTimeMillis |
| - mLastNotWrittenMutationTimeMillis; |
| if (timeSinceLastNotWrittenMutationMillis >= MAX_WRITE_SETTINGS_DELAY_MILLIS) { |
| mHandler.obtainMessage(MyHandler.MSG_PERSIST_SETTINGS).sendToTarget(); |
| return; |
| } |
| |
| // Hold off a bit more as settings are frequently changing. |
| final long maxDelayMillis = Math.max(mLastNotWrittenMutationTimeMillis |
| + MAX_WRITE_SETTINGS_DELAY_MILLIS - currentTimeMillis, 0); |
| final long writeDelayMillis = Math.min(WRITE_SETTINGS_DELAY_MILLIS, maxDelayMillis); |
| |
| Message message = mHandler.obtainMessage(MyHandler.MSG_PERSIST_SETTINGS); |
| mHandler.sendMessageDelayed(message, writeDelayMillis); |
| } else { |
| mLastNotWrittenMutationTimeMillis = currentTimeMillis; |
| Message message = mHandler.obtainMessage(MyHandler.MSG_PERSIST_SETTINGS); |
| mHandler.sendMessageDelayed(message, WRITE_SETTINGS_DELAY_MILLIS); |
| mWriteScheduled = true; |
| } |
| } |
| |
| private void doWriteState() { |
| if (DEBUG_PERSISTENCE) { |
| Slog.i(LOG_TAG, "[PERSIST START]"); |
| } |
| |
| AtomicFile destination = new AtomicFile(mStatePersistFile); |
| |
| final int version; |
| final ArrayMap<String, Setting> settings; |
| |
| synchronized (mLock) { |
| version = mVersion; |
| settings = new ArrayMap<>(mSettings); |
| mDirty = false; |
| mWriteScheduled = false; |
| } |
| |
| FileOutputStream out = null; |
| try { |
| out = destination.startWrite(); |
| |
| XmlSerializer serializer = Xml.newSerializer(); |
| serializer.setOutput(out, StandardCharsets.UTF_8.name()); |
| serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true); |
| serializer.startDocument(null, true); |
| serializer.startTag(null, TAG_SETTINGS); |
| serializer.attribute(null, ATTR_VERSION, String.valueOf(version)); |
| |
| final int settingCount = settings.size(); |
| for (int i = 0; i < settingCount; i++) { |
| Setting setting = settings.valueAt(i); |
| |
| writeSingleSetting(mVersion, serializer, setting.getId(), setting.getName(), |
| setting.getValue(), setting.getPackageName()); |
| |
| if (DEBUG_PERSISTENCE) { |
| Slog.i(LOG_TAG, "[PERSISTED]" + setting.getName() + "=" + setting.getValue()); |
| } |
| } |
| |
| serializer.endTag(null, TAG_SETTINGS); |
| serializer.endDocument(); |
| destination.finishWrite(out); |
| |
| if (DEBUG_PERSISTENCE) { |
| Slog.i(LOG_TAG, "[PERSIST END]"); |
| } |
| } catch (Throwable t) { |
| Slog.wtf(LOG_TAG, "Failed to write settings, restoring backup", t); |
| destination.failWrite(out); |
| } finally { |
| IoUtils.closeQuietly(out); |
| } |
| } |
| |
| static void writeSingleSetting(int version, XmlSerializer serializer, String id, |
| String name, String value, String packageName) throws IOException { |
| if (id == null || isBinary(id) || name == null || isBinary(name) |
| || packageName == null || isBinary(packageName)) { |
| // This shouldn't happen. |
| return; |
| } |
| serializer.startTag(null, TAG_SETTING); |
| serializer.attribute(null, ATTR_ID, id); |
| serializer.attribute(null, ATTR_NAME, name); |
| setValueAttribute(version, serializer, value); |
| serializer.attribute(null, ATTR_PACKAGE, packageName); |
| serializer.endTag(null, TAG_SETTING); |
| } |
| |
| static void setValueAttribute(int version, XmlSerializer serializer, String value) |
| throws IOException { |
| if (version >= SETTINGS_VERSOIN_NEW_ENCODING) { |
| if (value == null) { |
| // Null value -> No ATTR_VALUE nor ATTR_VALUE_BASE64. |
| } else if (isBinary(value)) { |
| serializer.attribute(null, ATTR_VALUE_BASE64, base64Encode(value)); |
| } else { |
| serializer.attribute(null, ATTR_VALUE, value); |
| } |
| } else { |
| // Old encoding. |
| if (value == null) { |
| serializer.attribute(null, ATTR_VALUE, NULL_VALUE_OLD_STYLE); |
| } else { |
| serializer.attribute(null, ATTR_VALUE, value); |
| } |
| } |
| } |
| |
| private String getValueAttribute(XmlPullParser parser) { |
| if (mVersion >= SETTINGS_VERSOIN_NEW_ENCODING) { |
| final String value = parser.getAttributeValue(null, ATTR_VALUE); |
| if (value != null) { |
| return value; |
| } |
| final String base64 = parser.getAttributeValue(null, ATTR_VALUE_BASE64); |
| if (base64 != null) { |
| return base64Decode(base64); |
| } |
| // null has neither ATTR_VALUE nor ATTR_VALUE_BASE64. |
| return null; |
| } else { |
| // Old encoding. |
| final String stored = parser.getAttributeValue(null, ATTR_VALUE); |
| if (NULL_VALUE_OLD_STYLE.equals(stored)) { |
| return null; |
| } else { |
| return stored; |
| } |
| } |
| } |
| |
| private void readStateSyncLocked() { |
| FileInputStream in; |
| if (!mStatePersistFile.exists()) { |
| return; |
| } |
| try { |
| in = new AtomicFile(mStatePersistFile).openRead(); |
| } catch (FileNotFoundException fnfe) { |
| Slog.i(LOG_TAG, "No settings state"); |
| return; |
| } |
| try { |
| XmlPullParser parser = Xml.newPullParser(); |
| parser.setInput(in, StandardCharsets.UTF_8.name()); |
| parseStateLocked(parser); |
| |
| } catch (XmlPullParserException | IOException e) { |
| throw new IllegalStateException("Failed parsing settings file: " |
| + mStatePersistFile , e); |
| } finally { |
| IoUtils.closeQuietly(in); |
| } |
| } |
| |
| private void parseStateLocked(XmlPullParser parser) |
| throws IOException, XmlPullParserException { |
| final int outerDepth = parser.getDepth(); |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { |
| if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) { |
| continue; |
| } |
| |
| String tagName = parser.getName(); |
| if (tagName.equals(TAG_SETTINGS)) { |
| parseSettingsLocked(parser); |
| } |
| } |
| } |
| |
| private void parseSettingsLocked(XmlPullParser parser) |
| throws IOException, XmlPullParserException { |
| |
| mVersion = Integer.parseInt(parser.getAttributeValue(null, ATTR_VERSION)); |
| |
| final int outerDepth = parser.getDepth(); |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { |
| if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) { |
| continue; |
| } |
| |
| String tagName = parser.getName(); |
| if (tagName.equals(TAG_SETTING)) { |
| String id = parser.getAttributeValue(null, ATTR_ID); |
| String name = parser.getAttributeValue(null, ATTR_NAME); |
| String value = getValueAttribute(parser); |
| String packageName = parser.getAttributeValue(null, ATTR_PACKAGE); |
| mSettings.put(name, new Setting(name, value, packageName, id)); |
| |
| if (DEBUG_PERSISTENCE) { |
| Slog.i(LOG_TAG, "[RESTORED] " + name + "=" + value); |
| } |
| } |
| } |
| } |
| |
| private final class MyHandler extends Handler { |
| public static final int MSG_PERSIST_SETTINGS = 1; |
| |
| public MyHandler(Looper looper) { |
| super(looper); |
| } |
| |
| @Override |
| public void handleMessage(Message message) { |
| switch (message.what) { |
| case MSG_PERSIST_SETTINGS: { |
| Runnable callback = (Runnable) message.obj; |
| doWriteState(); |
| if (callback != null) { |
| callback.run(); |
| } |
| } |
| break; |
| } |
| } |
| } |
| |
| class Setting { |
| private String name; |
| private String value; |
| private String packageName; |
| private String id; |
| |
| public Setting(Setting other) { |
| name = other.name; |
| value = other.value; |
| packageName = other.packageName; |
| id = other.id; |
| } |
| |
| public Setting(String name, String value, String packageName) { |
| init(name, value, packageName, String.valueOf(mNextId++)); |
| } |
| |
| public Setting(String name, String value, String packageName, String id) { |
| mNextId = Math.max(mNextId, Long.valueOf(id) + 1); |
| init(name, value, packageName, id); |
| } |
| |
| private void init(String name, String value, String packageName, String id) { |
| this.name = name; |
| this.value = value; |
| this.packageName = packageName; |
| this.id = id; |
| } |
| |
| public String getName() { |
| return name; |
| } |
| |
| public int getkey() { |
| return mKey; |
| } |
| |
| public String getValue() { |
| return value; |
| } |
| |
| public String getPackageName() { |
| return packageName; |
| } |
| |
| public String getId() { |
| return id; |
| } |
| |
| public boolean isNull() { |
| return false; |
| } |
| |
| public boolean update(String value, String packageName) { |
| if (Objects.equal(value, this.value)) { |
| return false; |
| } |
| this.value = value; |
| this.packageName = packageName; |
| this.id = String.valueOf(mNextId++); |
| return true; |
| } |
| } |
| |
| /** |
| * @return TRUE if a string is considered "binary" from KXML's point of view. NOTE DO NOT |
| * pass null. |
| */ |
| public static boolean isBinary(String s) { |
| if (s == null) { |
| throw new NullPointerException(); |
| } |
| // See KXmlSerializer.writeEscaped |
| for (int i = 0; i < s.length(); i++) { |
| char c = s.charAt(i); |
| boolean allowedInXml = (c >= 0x20 && c <= 0xd7ff) || (c >= 0xe000 && c <= 0xfffd); |
| if (!allowedInXml) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private static String base64Encode(String s) { |
| return Base64.encodeToString(toBytes(s), Base64.NO_WRAP); |
| } |
| |
| private static String base64Decode(String s) { |
| return fromBytes(Base64.decode(s, Base64.DEFAULT)); |
| } |
| |
| // Note the followings are basically just UTF-16 encode/decode. But we want to preserve |
| // contents as-is, even if it contains broken surrogate pairs, we do it by ourselves, |
| // since I don't know how Charset would treat them. |
| |
| private static byte[] toBytes(String s) { |
| final byte[] result = new byte[s.length() * 2]; |
| int resultIndex = 0; |
| for (int i = 0; i < s.length(); ++i) { |
| char ch = s.charAt(i); |
| result[resultIndex++] = (byte) (ch >> 8); |
| result[resultIndex++] = (byte) ch; |
| } |
| return result; |
| } |
| |
| private static String fromBytes(byte[] bytes) { |
| final StringBuffer sb = new StringBuffer(bytes.length / 2); |
| |
| final int last = bytes.length - 1; |
| |
| for (int i = 0; i < last; i += 2) { |
| final char ch = (char) ((bytes[i] & 0xff) << 8 | (bytes[i + 1] & 0xff)); |
| sb.append(ch); |
| } |
| return sb.toString(); |
| } |
| } |