DataManager.java revision f9a0a4306d589b4a4e20554fed512a603426bfa1 
1/*
2 * Copyright (C) 2010 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.gallery3d.data;
18
19import com.android.gallery3d.app.GalleryApp;
20import com.android.gallery3d.common.Utils;
21import com.android.gallery3d.data.MediaSet.ItemConsumer;
22import com.android.gallery3d.data.MediaSource.PathId;
23import com.android.gallery3d.picasasource.PicasaSource;
24
25import android.database.ContentObserver;
26import android.net.Uri;
27import android.os.Handler;
28
29import java.util.ArrayList;
30import java.util.Comparator;
31import java.util.HashMap;
32import java.util.LinkedHashMap;
33import java.util.Map.Entry;
34import java.util.WeakHashMap;
35
36// DataManager manages all media sets and media items in the system.
37//
38// Each MediaSet and MediaItem has a unique 64 bits id. The most significant
39// 32 bits represents its parent, and the least significant 32 bits represents
40// the self id. For MediaSet the self id is is globally unique, but for
41// MediaItem it's unique only relative to its parent.
42//
43// To make sure the id is the same when the MediaSet is re-created, a child key
44// is provided to obtainSetId() to make sure the same self id will be used as
45// when the parent and key are the same. A sequence of child keys is called a
46// path. And it's used to identify a specific media set even if the process is
47// killed and re-created, so child keys should be stable identifiers.
48
49public class DataManager {
50    public static final int INCLUDE_IMAGE = 1;
51    public static final int INCLUDE_VIDEO = 2;
52    public static final int INCLUDE_ALL = INCLUDE_IMAGE | INCLUDE_VIDEO;
53    public static final int INCLUDE_LOCAL_ONLY = 4;
54    public static final int INCLUDE_LOCAL_IMAGE_ONLY =
55            INCLUDE_LOCAL_ONLY | INCLUDE_IMAGE;
56    public static final int INCLUDE_LOCAL_VIDEO_ONLY =
57            INCLUDE_LOCAL_ONLY | INCLUDE_VIDEO;
58    public static final int INCLUDE_LOCAL_ALL_ONLY =
59            INCLUDE_LOCAL_ONLY | INCLUDE_IMAGE | INCLUDE_VIDEO;
60
61    // Any one who would like to access data should require this lock
62    // to prevent concurrency issue.
63    public static final Object LOCK = new Object();
64
65    private static final String TAG = "DataManager";
66
67    // This is the path for the media set seen by the user at top level.
68    private static final String TOP_SET_PATH =
69            "/combo/{/mtp,/local/all,/picasa/all}";
70    private static final String TOP_IMAGE_SET_PATH =
71            "/combo/{/mtp,/local/image,/picasa/image}";
72    private static final String TOP_VIDEO_SET_PATH =
73            "/combo/{/local/video,/picasa/video}";
74    private static final String TOP_LOCAL_SET_PATH =
75            "/local/all";
76    private static final String TOP_LOCAL_IMAGE_SET_PATH =
77            "/local/image";
78    private static final String TOP_LOCAL_VIDEO_SET_PATH =
79            "/local/video";
80
81    public static final Comparator<MediaItem> sDateTakenComparator =
82            new DateTakenComparator();
83
84    private static class DateTakenComparator implements Comparator<MediaItem> {
85        public int compare(MediaItem item1, MediaItem item2) {
86            return -Utils.compare(item1.getDateInMs(), item2.getDateInMs());
87        }
88    }
89
90    private final Handler mDefaultMainHandler;
91
92    private GalleryApp mApplication;
93    private int mActiveCount = 0;
94
95    private HashMap<Uri, NotifyBroker> mNotifierMap =
96            new HashMap<Uri, NotifyBroker>();
97
98
99    private HashMap<String, MediaSource> mSourceMap =
100            new LinkedHashMap<String, MediaSource>();
101
102    public DataManager(GalleryApp application) {
103        mApplication = application;
104        mDefaultMainHandler = new Handler(application.getMainLooper());
105    }
106
107    public synchronized void initializeSourceMap() {
108        if (!mSourceMap.isEmpty()) return;
109
110        // the order matters, the UriSource must come last
111        addSource(new LocalSource(mApplication));
112        addSource(new PicasaSource(mApplication));
113        addSource(new MtpSource(mApplication));
114        addSource(new ComboSource(mApplication));
115        addSource(new ClusterSource(mApplication));
116        addSource(new FilterSource(mApplication));
117        addSource(new UriSource(mApplication));
118
119        if (mActiveCount > 0) {
120            for (MediaSource source : mSourceMap.values()) {
121                source.resume();
122            }
123        }
124    }
125
126    public String getTopSetPath(int typeBits) {
127
128        switch (typeBits) {
129            case INCLUDE_IMAGE: return TOP_IMAGE_SET_PATH;
130            case INCLUDE_VIDEO: return TOP_VIDEO_SET_PATH;
131            case INCLUDE_ALL: return TOP_SET_PATH;
132            case INCLUDE_LOCAL_IMAGE_ONLY: return TOP_LOCAL_IMAGE_SET_PATH;
133            case INCLUDE_LOCAL_VIDEO_ONLY: return TOP_LOCAL_VIDEO_SET_PATH;
134            case INCLUDE_LOCAL_ALL_ONLY: return TOP_LOCAL_SET_PATH;
135            default: throw new IllegalArgumentException();
136        }
137    }
138
139    // open for debug
140    void addSource(MediaSource source) {
141        mSourceMap.put(source.getPrefix(), source);
142    }
143
144    public MediaObject peekMediaObject(Path path) {
145        return path.getObject();
146    }
147
148    public MediaSet peekMediaSet(Path path) {
149        return (MediaSet) path.getObject();
150    }
151
152    public MediaObject getMediaObject(Path path) {
153        MediaObject obj = path.getObject();
154        if (obj != null) return obj;
155
156        MediaSource source = mSourceMap.get(path.getPrefix());
157        if (source == null) {
158            Log.w(TAG, "cannot find media source for path: " + path);
159            return null;
160        }
161
162        MediaObject object = source.createMediaObject(path);
163        if (object == null) {
164            Log.w(TAG, "cannot create media object: " + path);
165        }
166        return object;
167    }
168
169    public MediaObject getMediaObject(String s) {
170        return getMediaObject(Path.fromString(s));
171    }
172
173    public MediaSet getMediaSet(Path path) {
174        return (MediaSet) getMediaObject(path);
175    }
176
177    public MediaSet getMediaSet(String s) {
178        return (MediaSet) getMediaObject(s);
179    }
180
181    public MediaSet[] getMediaSetsFromString(String segment) {
182        String[] seq = Path.splitSequence(segment);
183        int n = seq.length;
184        MediaSet[] sets = new MediaSet[n];
185        for (int i = 0; i < n; i++) {
186            sets[i] = getMediaSet(seq[i]);
187        }
188        return sets;
189    }
190
191    // Maps a list of Paths to MediaItems, and invoke consumer.consume()
192    // for each MediaItem (may not be in the same order as the input list).
193    // An index number is also passed to consumer.consume() to identify
194    // the original position in the input list of the corresponding Path (plus
195    // startIndex).
196    public void mapMediaItems(ArrayList<Path> list, ItemConsumer consumer,
197            int startIndex) {
198        HashMap<String, ArrayList<PathId>> map =
199                new HashMap<String, ArrayList<PathId>>();
200
201        // Group the path by the prefix.
202        int n = list.size();
203        for (int i = 0; i < n; i++) {
204            Path path = list.get(i);
205            String prefix = path.getPrefix();
206            ArrayList<PathId> group = map.get(prefix);
207            if (group == null) {
208                group = new ArrayList<PathId>();
209                map.put(prefix, group);
210            }
211            group.add(new PathId(path, i + startIndex));
212        }
213
214        // For each group, ask the corresponding media source to map it.
215        for (Entry<String, ArrayList<PathId>> entry : map.entrySet()) {
216            String prefix = entry.getKey();
217            MediaSource source = mSourceMap.get(prefix);
218            source.mapMediaItems(entry.getValue(), consumer);
219        }
220    }
221
222    // The following methods forward the request to the proper object.
223    public int getSupportedOperations(Path path) {
224        return getMediaObject(path).getSupportedOperations();
225    }
226
227    public void delete(Path path) {
228        getMediaObject(path).delete();
229    }
230
231    public void rotate(Path path, int degrees) {
232        getMediaObject(path).rotate(degrees);
233    }
234
235    public Uri getContentUri(Path path) {
236        return getMediaObject(path).getContentUri();
237    }
238
239    public int getMediaType(Path path) {
240        return getMediaObject(path).getMediaType();
241    }
242
243    public MediaDetails getDetails(Path path) {
244        return getMediaObject(path).getDetails();
245    }
246
247    public void cache(Path path, int flag) {
248        getMediaObject(path).cache(flag);
249    }
250
251    public Path findPathByUri(Uri uri) {
252        if (uri == null) return null;
253        for (MediaSource source : mSourceMap.values()) {
254            Path path = source.findPathByUri(uri);
255            if (path != null) return path;
256        }
257        return null;
258    }
259
260    public Path getDefaultSetOf(Path item) {
261        MediaSource source = mSourceMap.get(item.getPrefix());
262        return source == null ? null : source.getDefaultSetOf(item);
263    }
264
265    // Returns number of bytes used by cached pictures currently downloaded.
266    public long getTotalUsedCacheSize() {
267        long sum = 0;
268        for (MediaSource source : mSourceMap.values()) {
269            sum += source.getTotalUsedCacheSize();
270        }
271        return sum;
272    }
273
274    // Returns number of bytes used by cached pictures if all pending
275    // downloads and removals are completed.
276    public long getTotalTargetCacheSize() {
277        long sum = 0;
278        for (MediaSource source : mSourceMap.values()) {
279            sum += source.getTotalTargetCacheSize();
280        }
281        return sum;
282    }
283
284    public void registerChangeNotifier(Uri uri, ChangeNotifier notifier) {
285        NotifyBroker broker = null;
286        synchronized (mNotifierMap) {
287            broker = mNotifierMap.get(uri);
288            if (broker == null) {
289                broker = new NotifyBroker(mDefaultMainHandler);
290                mApplication.getContentResolver()
291                        .registerContentObserver(uri, true, broker);
292                mNotifierMap.put(uri, broker);
293            }
294        }
295        broker.registerNotifier(notifier);
296    }
297
298    public void resume() {
299        if (++mActiveCount == 1) {
300            for (MediaSource source : mSourceMap.values()) {
301                source.resume();
302            }
303        }
304    }
305
306    public void pause() {
307        if (--mActiveCount == 0) {
308            for (MediaSource source : mSourceMap.values()) {
309                source.pause();
310            }
311        }
312    }
313
314    private static class NotifyBroker extends ContentObserver {
315        private WeakHashMap<ChangeNotifier, Object> mNotifiers =
316                new WeakHashMap<ChangeNotifier, Object>();
317
318        public NotifyBroker(Handler handler) {
319            super(handler);
320        }
321
322        public synchronized void registerNotifier(ChangeNotifier notifier) {
323            mNotifiers.put(notifier, null);
324        }
325
326        @Override
327        public synchronized void onChange(boolean selfChange) {
328            for(ChangeNotifier notifier : mNotifiers.keySet()) {
329                notifier.onChange(selfChange);
330            }
331        }
332    }
333}
334