DataManager.java revision 2b3ee0ea07246b859a5b75d8a6102a7cce7ec838 
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 android.database.ContentObserver;
20import android.net.Uri;
21import android.os.Handler;
22
23import com.android.gallery3d.app.GalleryApp;
24import com.android.gallery3d.common.Utils;
25import com.android.gallery3d.data.MediaSet.ItemConsumer;
26import com.android.gallery3d.data.MediaSource.PathId;
27import com.android.gallery3d.picasasource.PicasaSource;
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 MediaObject getMediaObject(Path path) {
149        MediaObject obj = path.getObject();
150        if (obj != null) return obj;
151
152        MediaSource source = mSourceMap.get(path.getPrefix());
153        if (source == null) {
154            Log.w(TAG, "cannot find media source for path: " + path);
155            return null;
156        }
157
158        try {
159            MediaObject object = source.createMediaObject(path);
160            if (object == null) {
161                Log.w(TAG, "cannot create media object: " + path);
162            }
163            return object;
164        } catch (Throwable t) {
165            Log.w(TAG, "exception in creating media object: " + path, t);
166            return null;
167        }
168    }
169
170    public MediaObject getMediaObject(String s) {
171        return getMediaObject(Path.fromString(s));
172    }
173
174    public MediaSet getMediaSet(Path path) {
175        return (MediaSet) getMediaObject(path);
176    }
177
178    public MediaSet getMediaSet(String s) {
179        return (MediaSet) getMediaObject(s);
180    }
181
182    public MediaSet[] getMediaSetsFromString(String segment) {
183        String[] seq = Path.splitSequence(segment);
184        int n = seq.length;
185        MediaSet[] sets = new MediaSet[n];
186        for (int i = 0; i < n; i++) {
187            sets[i] = getMediaSet(seq[i]);
188        }
189        return sets;
190    }
191
192    // Maps a list of Paths to MediaItems, and invoke consumer.consume()
193    // for each MediaItem (may not be in the same order as the input list).
194    // An index number is also passed to consumer.consume() to identify
195    // the original position in the input list of the corresponding Path (plus
196    // startIndex).
197    public void mapMediaItems(ArrayList<Path> list, ItemConsumer consumer,
198            int startIndex) {
199        HashMap<String, ArrayList<PathId>> map =
200                new HashMap<String, ArrayList<PathId>>();
201
202        // Group the path by the prefix.
203        int n = list.size();
204        for (int i = 0; i < n; i++) {
205            Path path = list.get(i);
206            String prefix = path.getPrefix();
207            ArrayList<PathId> group = map.get(prefix);
208            if (group == null) {
209                group = new ArrayList<PathId>();
210                map.put(prefix, group);
211            }
212            group.add(new PathId(path, i + startIndex));
213        }
214
215        // For each group, ask the corresponding media source to map it.
216        for (Entry<String, ArrayList<PathId>> entry : map.entrySet()) {
217            String prefix = entry.getKey();
218            MediaSource source = mSourceMap.get(prefix);
219            source.mapMediaItems(entry.getValue(), consumer);
220        }
221    }
222
223    // The following methods forward the request to the proper object.
224    public int getSupportedOperations(Path path) {
225        return getMediaObject(path).getSupportedOperations();
226    }
227
228    public void delete(Path path) {
229        getMediaObject(path).delete();
230    }
231
232    public void rotate(Path path, int degrees) {
233        getMediaObject(path).rotate(degrees);
234    }
235
236    public Uri getContentUri(Path path) {
237        return getMediaObject(path).getContentUri();
238    }
239
240    public int getMediaType(Path path) {
241        return getMediaObject(path).getMediaType();
242    }
243
244    public Path findPathByUri(Uri uri) {
245        if (uri == null) return null;
246        for (MediaSource source : mSourceMap.values()) {
247            Path path = source.findPathByUri(uri);
248            if (path != null) return path;
249        }
250        return null;
251    }
252
253    public Path getDefaultSetOf(Path item) {
254        MediaSource source = mSourceMap.get(item.getPrefix());
255        return source == null ? null : source.getDefaultSetOf(item);
256    }
257
258    // Returns number of bytes used by cached pictures currently downloaded.
259    public long getTotalUsedCacheSize() {
260        long sum = 0;
261        for (MediaSource source : mSourceMap.values()) {
262            sum += source.getTotalUsedCacheSize();
263        }
264        return sum;
265    }
266
267    // Returns number of bytes used by cached pictures if all pending
268    // downloads and removals are completed.
269    public long getTotalTargetCacheSize() {
270        long sum = 0;
271        for (MediaSource source : mSourceMap.values()) {
272            sum += source.getTotalTargetCacheSize();
273        }
274        return sum;
275    }
276
277    public void registerChangeNotifier(Uri uri, ChangeNotifier notifier) {
278        NotifyBroker broker = null;
279        synchronized (mNotifierMap) {
280            broker = mNotifierMap.get(uri);
281            if (broker == null) {
282                broker = new NotifyBroker(mDefaultMainHandler);
283                mApplication.getContentResolver()
284                        .registerContentObserver(uri, true, broker);
285                mNotifierMap.put(uri, broker);
286            }
287        }
288        broker.registerNotifier(notifier);
289    }
290
291    public void resume() {
292        if (++mActiveCount == 1) {
293            for (MediaSource source : mSourceMap.values()) {
294                source.resume();
295            }
296        }
297    }
298
299    public void pause() {
300        if (--mActiveCount == 0) {
301            for (MediaSource source : mSourceMap.values()) {
302                source.pause();
303            }
304        }
305    }
306
307    private static class NotifyBroker extends ContentObserver {
308        private WeakHashMap<ChangeNotifier, Object> mNotifiers =
309                new WeakHashMap<ChangeNotifier, Object>();
310
311        public NotifyBroker(Handler handler) {
312            super(handler);
313        }
314
315        public synchronized void registerNotifier(ChangeNotifier notifier) {
316            mNotifiers.put(notifier, null);
317        }
318
319        @Override
320        public synchronized void onChange(boolean selfChange) {
321            for(ChangeNotifier notifier : mNotifiers.keySet()) {
322                notifier.onChange(selfChange);
323            }
324        }
325    }
326}
327