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; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 package org.altusmetrum.altoslib_11;
24 public class AltosMapCache implements AltosMapCacheListener {
26 /* An entry in the MapCache */
27 class MapCacheElement implements AltosMapTileListener {
29 AltosMapTile tile; /* Notify when image has been loaded */
33 class loader implements Runnable {
37 image = map_interface.load_image(tile.store.file);
38 } catch (Exception ex) {
41 tile.notify_image(image);
46 loader l = new loader();
47 Thread lt = new Thread(l);
58 public boolean has_map() {
59 return tile.status == AltosMapTile.loaded;
62 public synchronized void notify_tile(AltosMapTile tile, int status) {
63 if (status == AltosMapTile.fetched) {
68 public MapCacheElement(AltosMapTile tile) {
72 tile.add_listener(this);
76 int min_cache_size; /* configured minimum cache size */
77 int cache_size; /* current cache size */
78 int requested_cache_size; /* cache size computed by application */
80 private Object fetch_lock = new Object();
81 private Object cache_lock = new Object();
83 AltosMapInterface map_interface;
85 MapCacheElement[] elements = new MapCacheElement[cache_size];
89 public void set_cache_size(int new_size) {
91 requested_cache_size = new_size;
93 if (new_size < min_cache_size)
94 new_size = min_cache_size;
96 if (new_size == cache_size)
99 synchronized(cache_lock) {
100 MapCacheElement[] new_elements = new MapCacheElement[new_size];
102 for (int i = 0; i < cache_size; i++) {
104 new_elements[i] = elements[i];
105 else if (elements[i] != null)
108 elements = new_elements;
109 cache_size = new_size;
113 public AltosImage get(AltosMapTile tile) {
117 synchronized(cache_lock) {
118 MapCacheElement element = null;
119 for (int i = 0; i < cache_size; i++) {
120 element = elements[i];
122 if (element == null) {
126 if (tile.store.equals(element.tile.store)) {
127 element.used = used++;
128 return element.image;
130 if (element.used < age) {
136 element = new MapCacheElement(tile);
137 element.used = used++;
138 if (elements[oldest] != null)
139 elements[oldest].flush();
141 elements[oldest] = element;
142 return element.image;
146 public void map_cache_changed(int map_cache) {
147 min_cache_size = map_cache;
149 set_cache_size(requested_cache_size);
152 public void dispose() {
153 AltosPreferences.unregister_map_cache_listener(this);
155 for (int i = 0; i < cache_size; i++) {
156 MapCacheElement element = elements[i];
163 public AltosMapCache(AltosMapInterface map_interface) {
164 this.map_interface = map_interface;
165 min_cache_size = AltosPreferences.map_cache();
169 AltosPreferences.register_map_cache_listener(this);