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package sun.misc;

Utility class for small LRU caches.
Author:Mark Reinhold
/** * Utility class for small LRU caches. * * @author Mark Reinhold */
public abstract class LRUCache<N,V> { private V[] oa = null; private final int size; public LRUCache(int size) { this.size = size; } abstract protected V create(N name); abstract protected boolean hasName(V ob, N name); public static void moveToFront(Object[] oa, int i) { Object ob = oa[i]; for (int j = i; j > 0; j--) oa[j] = oa[j - 1]; oa[0] = ob; } public V forName(N name) { if (oa == null) { oa = (V[])new Object[size]; } else { for (int i = 0; i < oa.length; i++) { V ob = oa[i]; if (ob == null) continue; if (hasName(ob, name)) { if (i > 0) moveToFront(oa, i); return ob; } } } // Create a new object V ob = create(name); oa[oa.length - 1] = ob; moveToFront(oa, oa.length - 1); return ob; } }