FingerprintsUserState.java revision f501b58de8f467a80fef49c704555781bc61ea6f 
1/*
2 * Copyright (C) 2015 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
17package com.android.server.fingerprint;
18
19import android.content.Context;
20import android.hardware.fingerprint.Fingerprint;
21import android.os.AsyncTask;
22import android.os.Environment;
23import android.util.AtomicFile;
24import android.util.Slog;
25import android.util.Xml;
26
27import com.android.internal.annotations.GuardedBy;
28
29import libcore.io.IoUtils;
30import org.xmlpull.v1.XmlPullParser;
31import org.xmlpull.v1.XmlPullParserException;
32import org.xmlpull.v1.XmlSerializer;
33
34import java.io.File;
35import java.io.FileInputStream;
36import java.io.FileNotFoundException;
37import java.io.FileOutputStream;
38import java.io.IOException;
39import java.util.ArrayList;
40import java.util.List;
41
42/**
43 * Class managing the set of fingerprint per user across device reboots.
44 */
45class FingerprintsUserState {
46
47    private static final String TAG = "FingerprintState";
48    private static final String FINGERPRINT_FILE = "settings_fingerprint.xml";
49
50    private static final String TAG_FINGERPRINTS = "fingerprints";
51    private static final String TAG_FINGERPRINT = "fingerprint";
52    private static final String ATTR_NAME = "name";
53    private static final String ATTR_GROUP_ID = "groupId";
54    private static final String ATTR_FINGER_ID = "fingerId";
55    private static final String ATTR_DEVICE_ID = "deviceId";
56
57    private final File mFile;
58
59    @GuardedBy("this")
60    private final ArrayList<Fingerprint> mFingerprints = new ArrayList<Fingerprint>();
61    private final Context mCtx;
62
63    public FingerprintsUserState(Context ctx, int userId) {
64        mFile = getFileForUser(userId);
65        mCtx = ctx;
66        synchronized (this) {
67            readStateSyncLocked();
68        }
69    }
70
71    public void addFingerprint(int fingerId) {
72        synchronized (this) {
73            mFingerprints.add(new Fingerprint(getDefaultFingerprintName(fingerId), 0, fingerId, 0));
74            scheduleWriteStateLocked();
75        }
76    }
77
78    public void removeFingerprint(int fingerId) {
79        synchronized (this) {
80            for (int i = 0; i < mFingerprints.size(); i++) {
81                if (mFingerprints.get(i).getFingerId() == fingerId) {
82                    mFingerprints.remove(i);
83                    scheduleWriteStateLocked();
84                    break;
85                }
86            }
87        }
88    }
89
90    public void renameFingerprint(int fingerId, CharSequence name) {
91        synchronized (this) {
92            for (int i = 0; i < mFingerprints.size(); i++) {
93                if (mFingerprints.get(i).getFingerId() == fingerId) {
94                    Fingerprint old = mFingerprints.get(i);
95                    mFingerprints.set(i, new Fingerprint(name, old.getGroupId(), old.getFingerId(),
96                            old.getDeviceId()));
97                    scheduleWriteStateLocked();
98                    break;
99                }
100            }
101        }
102    }
103
104    public List<Fingerprint> getFingerprints() {
105        synchronized (this) {
106            return getCopy(mFingerprints);
107        }
108    }
109
110    private String getDefaultFingerprintName(int fingerId) {
111        return mCtx.getString(com.android.internal.R.string.fingerprint_name_template, fingerId);
112    }
113
114    private static File getFileForUser(int userId) {
115        return new File(Environment.getUserSystemDirectory(userId), FINGERPRINT_FILE);
116    }
117
118    private final Runnable mWriteStateRunnable = new Runnable() {
119        @Override
120        public void run() {
121            doWriteState();
122        }
123    };
124
125    private void scheduleWriteStateLocked() {
126        AsyncTask.execute(mWriteStateRunnable);
127    }
128
129    private ArrayList<Fingerprint> getCopy(ArrayList<Fingerprint> array) {
130        ArrayList<Fingerprint> result = new ArrayList<Fingerprint>(array.size());
131        for (int i = 0; i < array.size(); i++) {
132            Fingerprint fp = array.get(i);
133            result.add(new Fingerprint(fp.getName(), fp.getGroupId(), fp.getFingerId(),
134                    fp.getDeviceId()));
135        }
136        return result;
137    }
138
139    private void doWriteState() {
140        AtomicFile destination = new AtomicFile(mFile);
141
142        ArrayList<Fingerprint> fingerprints;
143
144        synchronized (this) {
145            fingerprints = getCopy(mFingerprints);
146        }
147
148        FileOutputStream out = null;
149        try {
150            out = destination.startWrite();
151
152            XmlSerializer serializer = Xml.newSerializer();
153            serializer.setOutput(out, "utf-8");
154            serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);
155            serializer.startDocument(null, true);
156            serializer.startTag(null, TAG_FINGERPRINTS);
157
158            final int count = fingerprints.size();
159            for (int i = 0; i < count; i++) {
160                Fingerprint fp = fingerprints.get(i);
161                serializer.startTag(null, TAG_FINGERPRINT);
162                serializer.attribute(null, ATTR_FINGER_ID, Integer.toString(fp.getFingerId()));
163                serializer.attribute(null, ATTR_NAME, fp.getName().toString());
164                serializer.attribute(null, ATTR_GROUP_ID, Integer.toString(fp.getGroupId()));
165                serializer.attribute(null, ATTR_DEVICE_ID, Long.toString(fp.getDeviceId()));
166                serializer.endTag(null, TAG_FINGERPRINT);
167            }
168
169            serializer.endTag(null, TAG_FINGERPRINTS);
170            serializer.endDocument();
171            destination.finishWrite(out);
172
173            // Any error while writing is fatal.
174        } catch (Throwable t) {
175            Slog.wtf(TAG, "Failed to write settings, restoring backup", t);
176            destination.failWrite(out);
177            throw new IllegalStateException("Failed to write fingerprints", t);
178        } finally {
179            IoUtils.closeQuietly(out);
180        }
181    }
182
183    private void readStateSyncLocked() {
184        FileInputStream in;
185        if (!mFile.exists()) {
186            return;
187        }
188        try {
189            in = new FileInputStream(mFile);
190        } catch (FileNotFoundException fnfe) {
191            Slog.i(TAG, "No fingerprint state");
192            return;
193        }
194        try {
195            XmlPullParser parser = Xml.newPullParser();
196            parser.setInput(in, null);
197            parseStateLocked(parser);
198
199        } catch (XmlPullParserException | IOException e) {
200            throw new IllegalStateException("Failed parsing settings file: "
201                    + mFile , e);
202        } finally {
203            IoUtils.closeQuietly(in);
204        }
205    }
206
207    private void parseStateLocked(XmlPullParser parser)
208            throws IOException, XmlPullParserException {
209        final int outerDepth = parser.getDepth();
210        int type;
211        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
212                && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
213            if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
214                continue;
215            }
216
217            String tagName = parser.getName();
218            if (tagName.equals(TAG_FINGERPRINTS)) {
219                parseFingerprintsLocked(parser);
220            }
221        }
222    }
223
224    private void parseFingerprintsLocked(XmlPullParser parser)
225            throws IOException, XmlPullParserException {
226
227        final int outerDepth = parser.getDepth();
228        int type;
229        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
230                && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
231            if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
232                continue;
233            }
234
235            String tagName = parser.getName();
236            if (tagName.equals(TAG_FINGERPRINT)) {
237                String name = parser.getAttributeValue(null, ATTR_NAME);
238                String groupId = parser.getAttributeValue(null, ATTR_GROUP_ID);
239                String fingerId = parser.getAttributeValue(null, ATTR_FINGER_ID);
240                String deviceId = parser.getAttributeValue(null, ATTR_DEVICE_ID);
241                mFingerprints.add(new Fingerprint(name, Integer.parseInt(groupId),
242                        Integer.parseInt(fingerId), Integer.parseInt(deviceId)));
243            }
244        }
245    }
246
247}
248