1 files changed, 112 insertions, 0 deletions
diff --git a/src/com/android/messaging/mmslib/util/AbstractCache.java b/src/com/android/messaging/mmslib/util/AbstractCache.java
new file mode 100644
index 0000000..db98bb9
--- /dev/null
+++ b/src/com/android/messaging/mmslib/util/AbstractCache.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2008 Esmertec AG.
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.messaging.mmslib.util;
+
+import android.support.v4.util.SimpleArrayMap;
+import android.util.Log;
+
+public abstract class AbstractCache<K, V> {
+    private static final String TAG = "AbstractCache";
+    private static final boolean LOCAL_LOGV = false;
+
+    private static final int MAX_CACHED_ITEMS = 500;
+
+    private final SimpleArrayMap<K, CacheEntry<V>> mCacheMap;
+
+    protected AbstractCache() {
+        mCacheMap = new SimpleArrayMap<K, CacheEntry<V>>();
+    }
+
+    public boolean put(K key, V value) {
+        if (LOCAL_LOGV) {
+            Log.v(TAG, "Trying to put " + key + " into cache.");
+        }
+
+        if (mCacheMap.size() >= MAX_CACHED_ITEMS) {
+            // TODO: Should remove the oldest or least hit cached entry
+            // and then cache the new one.
+            if (LOCAL_LOGV) {
+                Log.v(TAG, "Failed! size limitation reached.");
+            }
+            return false;
+        }
+
+        if (key != null) {
+            CacheEntry<V> cacheEntry = new CacheEntry<V>();
+            cacheEntry.value = value;
+            mCacheMap.put(key, cacheEntry);
+
+            if (LOCAL_LOGV) {
+                Log.v(TAG, key + " cached, " + mCacheMap.size() + " items total.");
+            }
+            return true;
+        }
+        return false;
+    }
+
+    public V get(K key) {
+        if (LOCAL_LOGV) {
+            Log.v(TAG, "Trying to get " + key + " from cache.");
+        }
+
+        if (key != null) {
+            CacheEntry<V> cacheEntry = mCacheMap.get(key);
+            if (cacheEntry != null) {
+                cacheEntry.hit++;
+                if (LOCAL_LOGV) {
+                    Log.v(TAG, key + " hit " + cacheEntry.hit + " times.");
+                }
+                return cacheEntry.value;
+            }
+        }
+        return null;
+    }
+
+    public V purge(K key) {
+        if (LOCAL_LOGV) {
+            Log.v(TAG, "Trying to purge " + key);
+        }
+
+        CacheEntry<V> v = mCacheMap.remove(key);
+
+        if (LOCAL_LOGV) {
+            Log.v(TAG, mCacheMap.size() + " items cached.");
+        }
+
+        return v != null ? v.value : null;
+    }
+
+    public void purgeAll() {
+        if (LOCAL_LOGV) {
+            Log.v(TAG, "Purging cache, " + mCacheMap.size()
+                    + " items dropped.");
+        }
+        mCacheMap.clear();
+    }
+
+    public int size() {
+        return mCacheMap.size();
+    }
+
+    private static class CacheEntry<V> {
+
+        int hit;
+
+        V value;
+    }
+}