1 files changed, 102 insertions, 0 deletions
diff --git a/subsonic-android/src/net/sourceforge/subsonic/androidapp/util/LRUCache.java b/subsonic-android/src/net/sourceforge/subsonic/androidapp/util/LRUCache.java
new file mode 100644
index 00000000..f6145fb7
--- /dev/null
+++ b/subsonic-android/src/net/sourceforge/subsonic/androidapp/util/LRUCache.java
@@ -0,0 +1,102 @@
+/*
+ This file is part of Subsonic.
+
+ Subsonic is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Subsonic is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Subsonic.  If not, see <http://www.gnu.org/licenses/>.
+
+ Copyright 2009 (C) Sindre Mehus
+ */
+package net.sourceforge.subsonic.androidapp.util;
+
+import java.lang.ref.SoftReference;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author Sindre Mehus
+ */
+public class LRUCache<K,V>{
+
+    private final int capacity;
+    private final Map<K, TimestampedValue> map;
+
+    public LRUCache(int capacity) {
+        map = new HashMap<K, TimestampedValue>(capacity);
+        this.capacity = capacity;
+    }
+
+    public synchronized V get(K key) {
+        TimestampedValue value = map.get(key);
+
+        V result = null;
+        if (value != null) {
+            value.updateTimestamp();
+            result = value.getValue();
+        }
+
+        return result;
+    }
+
+    public synchronized void put(K key, V value) {
+        if (map.size() >= capacity) {
+            removeOldest();
+        }
+        map.put(key, new TimestampedValue(value));
+    }
+
+    public void clear() {
+        map.clear();
+    }
+
+    private void removeOldest() {
+        K oldestKey = null;
+        long oldestTimestamp = Long.MAX_VALUE;
+
+        for (Map.Entry<K, TimestampedValue> entry : map.entrySet()) {
+            K key = entry.getKey();
+            TimestampedValue value = entry.getValue();
+            if (value.getTimestamp() < oldestTimestamp) {
+                oldestTimestamp = value.getTimestamp();
+                oldestKey = key;
+            }
+        }
+
+        if (oldestKey != null) {
+            map.remove(oldestKey);
+        }
+    }
+
+    private final class TimestampedValue {
+
+        private final SoftReference<V> value;
+        private long timestamp;
+
+        public TimestampedValue(V value) {
+            this.value = new SoftReference<V>(value);
+            updateTimestamp();
+        }
+
+        public V getValue() {
+            return value.get();
+        }
+
+        public long getTimestamp() {
+            return timestamp;
+        }
+
+        public void updateTimestamp() {
+            timestamp = System.currentTimeMillis();
+        }
+    }
+
+}
+\ No newline at end of file