2 * Copyright © 2010 Anthony Towns <aj@erisian.com.au>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
18 package org.altusmetrum.altoslib_10;
23 public class AltosMapCache implements AltosMapCacheListener {
25 /* An entry in the MapCache */
26 class MapCacheElement implements AltosMapTileListener {
28 AltosMapTile tile; /* Notify when image has been loaded */
32 class loader implements Runnable {
36 image = map_interface.load_image(tile.store.file);
37 } catch (Exception ex) {
40 tile.notify_image(image);
45 loader l = new loader();
46 Thread lt = new Thread(l);
57 public boolean has_map() {
58 return tile.status == AltosMapTile.loaded;
61 public synchronized void notify_tile(AltosMapTile tile, int status) {
62 if (status == AltosMapTile.fetched) {
67 public MapCacheElement(AltosMapTile tile) {
71 tile.add_listener(this);
75 int min_cache_size; /* configured minimum cache size */
76 int cache_size; /* current cache size */
77 int requested_cache_size; /* cache size computed by application */
79 private Object fetch_lock = new Object();
80 private Object cache_lock = new Object();
82 AltosMapInterface map_interface;
84 MapCacheElement[] elements = new MapCacheElement[cache_size];
88 public void set_cache_size(int new_size) {
90 requested_cache_size = new_size;
92 if (new_size < min_cache_size)
93 new_size = min_cache_size;
95 if (new_size == cache_size)
98 synchronized(cache_lock) {
99 MapCacheElement[] new_elements = new MapCacheElement[new_size];
101 for (int i = 0; i < cache_size; i++) {
103 new_elements[i] = elements[i];
104 else if (elements[i] != null)
107 elements = new_elements;
108 cache_size = new_size;
112 public AltosImage get(AltosMapTile tile) {
116 synchronized(cache_lock) {
117 MapCacheElement element = null;
118 for (int i = 0; i < cache_size; i++) {
119 element = elements[i];
121 if (element == null) {
125 if (tile.store.equals(element.tile.store)) {
126 element.used = used++;
127 return element.image;
129 if (element.used < age) {
135 element = new MapCacheElement(tile);
136 element.used = used++;
137 if (elements[oldest] != null)
138 elements[oldest].flush();
140 elements[oldest] = element;
141 return element.image;
145 public void map_cache_changed(int map_cache) {
146 min_cache_size = map_cache;
148 set_cache_size(requested_cache_size);
151 public void dispose() {
152 AltosPreferences.unregister_map_cache_listener(this);
154 for (int i = 0; i < cache_size; i++) {
155 MapCacheElement element = elements[i];
162 public AltosMapCache(AltosMapInterface map_interface) {
163 this.map_interface = map_interface;
164 min_cache_size = AltosPreferences.map_cache();
168 AltosPreferences.register_map_cache_listener(this);