LruCache.java

/*
    Copyright (C) 2013 Prasanna Thirumalai
    
    This file is part of StackX.

    StackX 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.

    StackX 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 StackX.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.prasanna.android.cache;

import java.lang.ref.Reference;
import java.lang.ref.SoftReference;


public class LruCache<K, T> {
  private final int size;
  private final LRU<K, Reference<T>> lru;

  public LruCache(int size) {
    this.size = size;
    lru = new LRU<K, Reference<T>>(size);
  }

  public void add(K key, T value) {
    if (key != null && value != null)
      lru.put(key, new SoftReference<T>(value));
  }

  public T get(K key) {
    T value = null;

    if (key != null && lru.containsKey(key)) {
      value = lru.get(key).get();
      if (value == null)
        lru.remove(key);
    }

    return value;
  }

  public boolean containsKey(K key) {
    return lru.containsKey(key);
  }

  public T remove(K key) {
    if (key != null) {
      Reference<T> ref = lru.remove(key);
      if (ref != null)
        return ref.get();
    }

    return null;
  }

  public int getSize() {
    return size;
  }
}