diff options
Diffstat (limited to 'services/core/java/com/android/server/display/PersistentDataStore.java')
| -rw-r--r-- | services/core/java/com/android/server/display/PersistentDataStore.java | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/services/core/java/com/android/server/display/PersistentDataStore.java b/services/core/java/com/android/server/display/PersistentDataStore.java new file mode 100644 index 0000000..67b3695 --- /dev/null +++ b/services/core/java/com/android/server/display/PersistentDataStore.java @@ -0,0 +1,287 @@ +/* + * Copyright (C) 2012 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.server.display; + +import com.android.internal.util.FastXmlSerializer; +import com.android.internal.util.XmlUtils; + +import org.xmlpull.v1.XmlPullParser; +import org.xmlpull.v1.XmlPullParserException; +import org.xmlpull.v1.XmlSerializer; + +import android.hardware.display.WifiDisplay; +import android.util.AtomicFile; +import android.util.Slog; +import android.util.Xml; + +import java.io.BufferedInputStream; +import java.io.BufferedOutputStream; +import java.io.File; +import java.io.FileNotFoundException; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.util.ArrayList; + +import libcore.io.IoUtils; +import libcore.util.Objects; + +/** + * Manages persistent state recorded by the display manager service as an XML file. + * Caller must acquire lock on the data store before accessing it. + * + * File format: + * <code> + * <display-manager-state> + * <remembered-wifi-displays> + * <wifi-display deviceAddress="00:00:00:00:00:00" deviceName="XXXX" deviceAlias="YYYY" /> + * >remembered-wifi-displays> + * >/display-manager-state> + * </code> + * + * TODO: refactor this to extract common code shared with the input manager's data store + */ +final class PersistentDataStore { + static final String TAG = "DisplayManager"; + + // Remembered Wifi display devices. + private ArrayList<WifiDisplay> mRememberedWifiDisplays = new ArrayList<WifiDisplay>(); + + // The atomic file used to safely read or write the file. + private final AtomicFile mAtomicFile; + + // True if the data has been loaded. + private boolean mLoaded; + + // True if there are changes to be saved. + private boolean mDirty; + + public PersistentDataStore() { + mAtomicFile = new AtomicFile(new File("/data/system/display-manager-state.xml")); + } + + public void saveIfNeeded() { + if (mDirty) { + save(); + mDirty = false; + } + } + + public WifiDisplay getRememberedWifiDisplay(String deviceAddress) { + loadIfNeeded(); + int index = findRememberedWifiDisplay(deviceAddress); + if (index >= 0) { + return mRememberedWifiDisplays.get(index); + } + return null; + } + + public WifiDisplay[] getRememberedWifiDisplays() { + loadIfNeeded(); + return mRememberedWifiDisplays.toArray(new WifiDisplay[mRememberedWifiDisplays.size()]); + } + + public WifiDisplay applyWifiDisplayAlias(WifiDisplay display) { + if (display != null) { + loadIfNeeded(); + + String alias = null; + int index = findRememberedWifiDisplay(display.getDeviceAddress()); + if (index >= 0) { + alias = mRememberedWifiDisplays.get(index).getDeviceAlias(); + } + if (!Objects.equal(display.getDeviceAlias(), alias)) { + return new WifiDisplay(display.getDeviceAddress(), display.getDeviceName(), + alias, display.isAvailable(), display.canConnect(), display.isRemembered()); + } + } + return display; + } + + public WifiDisplay[] applyWifiDisplayAliases(WifiDisplay[] displays) { + WifiDisplay[] results = displays; + if (results != null) { + int count = displays.length; + for (int i = 0; i < count; i++) { + WifiDisplay result = applyWifiDisplayAlias(displays[i]); + if (result != displays[i]) { + if (results == displays) { + results = new WifiDisplay[count]; + System.arraycopy(displays, 0, results, 0, count); + } + results[i] = result; + } + } + } + return results; + } + + public boolean rememberWifiDisplay(WifiDisplay display) { + loadIfNeeded(); + + int index = findRememberedWifiDisplay(display.getDeviceAddress()); + if (index >= 0) { + WifiDisplay other = mRememberedWifiDisplays.get(index); + if (other.equals(display)) { + return false; // already remembered without change + } + mRememberedWifiDisplays.set(index, display); + } else { + mRememberedWifiDisplays.add(display); + } + setDirty(); + return true; + } + + public boolean forgetWifiDisplay(String deviceAddress) { + int index = findRememberedWifiDisplay(deviceAddress); + if (index >= 0) { + mRememberedWifiDisplays.remove(index); + setDirty(); + return true; + } + return false; + } + + private int findRememberedWifiDisplay(String deviceAddress) { + int count = mRememberedWifiDisplays.size(); + for (int i = 0; i < count; i++) { + if (mRememberedWifiDisplays.get(i).getDeviceAddress().equals(deviceAddress)) { + return i; + } + } + return -1; + } + + private void loadIfNeeded() { + if (!mLoaded) { + load(); + mLoaded = true; + } + } + + private void setDirty() { + mDirty = true; + } + + private void clearState() { + mRememberedWifiDisplays.clear(); + } + + private void load() { + clearState(); + + final InputStream is; + try { + is = mAtomicFile.openRead(); + } catch (FileNotFoundException ex) { + return; + } + + XmlPullParser parser; + try { + parser = Xml.newPullParser(); + parser.setInput(new BufferedInputStream(is), null); + loadFromXml(parser); + } catch (IOException ex) { + Slog.w(TAG, "Failed to load display manager persistent store data.", ex); + clearState(); + } catch (XmlPullParserException ex) { + Slog.w(TAG, "Failed to load display manager persistent store data.", ex); + clearState(); + } finally { + IoUtils.closeQuietly(is); + } + } + + private void save() { + final FileOutputStream os; + try { + os = mAtomicFile.startWrite(); + boolean success = false; + try { + XmlSerializer serializer = new FastXmlSerializer(); + serializer.setOutput(new BufferedOutputStream(os), "utf-8"); + saveToXml(serializer); + serializer.flush(); + success = true; + } finally { + if (success) { + mAtomicFile.finishWrite(os); + } else { + mAtomicFile.failWrite(os); + } + } + } catch (IOException ex) { + Slog.w(TAG, "Failed to save display manager persistent store data.", ex); + } + } + + private void loadFromXml(XmlPullParser parser) + throws IOException, XmlPullParserException { + XmlUtils.beginDocument(parser, "display-manager-state"); + final int outerDepth = parser.getDepth(); + while (XmlUtils.nextElementWithin(parser, outerDepth)) { + if (parser.getName().equals("remembered-wifi-displays")) { + loadRememberedWifiDisplaysFromXml(parser); + } + } + } + + private void loadRememberedWifiDisplaysFromXml(XmlPullParser parser) + throws IOException, XmlPullParserException { + final int outerDepth = parser.getDepth(); + while (XmlUtils.nextElementWithin(parser, outerDepth)) { + if (parser.getName().equals("wifi-display")) { + String deviceAddress = parser.getAttributeValue(null, "deviceAddress"); + String deviceName = parser.getAttributeValue(null, "deviceName"); + String deviceAlias = parser.getAttributeValue(null, "deviceAlias"); + if (deviceAddress == null || deviceName == null) { + throw new XmlPullParserException( + "Missing deviceAddress or deviceName attribute on wifi-display."); + } + if (findRememberedWifiDisplay(deviceAddress) >= 0) { + throw new XmlPullParserException( + "Found duplicate wifi display device address."); + } + + mRememberedWifiDisplays.add( + new WifiDisplay(deviceAddress, deviceName, deviceAlias, + false, false, false)); + } + } + } + + private void saveToXml(XmlSerializer serializer) throws IOException { + serializer.startDocument(null, true); + serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true); + serializer.startTag(null, "display-manager-state"); + serializer.startTag(null, "remembered-wifi-displays"); + for (WifiDisplay display : mRememberedWifiDisplays) { + serializer.startTag(null, "wifi-display"); + serializer.attribute(null, "deviceAddress", display.getDeviceAddress()); + serializer.attribute(null, "deviceName", display.getDeviceName()); + if (display.getDeviceAlias() != null) { + serializer.attribute(null, "deviceAlias", display.getDeviceAlias()); + } + serializer.endTag(null, "wifi-display"); + } + serializer.endTag(null, "remembered-wifi-displays"); + serializer.endTag(null, "display-manager-state"); + serializer.endDocument(); + } +}
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