1 /* 2 * Copyright (c) 1999, 2004, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.java2d.loops; 27 28 public final class RenderCache { 29 final class Entry { 30 private SurfaceType src; 31 private CompositeType comp; 32 private SurfaceType dst; 33 private Object value; 34 35 public Entry(SurfaceType src, 36 CompositeType comp, 37 SurfaceType dst, 38 Object value) 39 { 40 this.src = src; 41 this.comp = comp; 42 this.dst = dst; 43 this.value = value; 44 } 45 46 public boolean matches(SurfaceType src, 47 CompositeType comp, 48 SurfaceType dst) 49 { 50 // bug 4725045: using equals() causes different SurfaceType 51 // objects with the same strings to match in the cache, which is 52 // not the behavior we want. Constrain the match to succeed only 53 // on object matches instead. 54 return ((this.src == src) && 55 (this.comp == comp) && 56 (this.dst == dst)); 57 } 58 59 public Object getValue() { 60 return value; 61 } 62 } 63 64 private Entry entries[]; 65 66 public RenderCache(int size) { 67 entries = new Entry[size]; 68 } 69 70 public synchronized Object get(SurfaceType src, 71 CompositeType comp, 72 SurfaceType dst) 73 { 74 int max = entries.length - 1; 75 for (int i = max; i >= 0; i--) { 76 Entry e = entries[i]; 77 if (e == null) { 78 break; 79 } 80 if (e.matches(src, comp, dst)) { 81 if (i < max - 4) { 82 System.arraycopy(entries, i+1, entries, i, max - i); 83 entries[max] = e; 84 } 85 return e.getValue(); 86 } 87 } 88 89 return null; 90 } 91 92 public synchronized void put(SurfaceType src, 93 CompositeType comp, 94 SurfaceType dst, 95 Object value) 96 { 97 Entry e = new Entry(src, comp, dst, value); 98 99 int num = entries.length; 100 System.arraycopy(entries, 1, entries, 0, num - 1); 101 entries[num - 1] = e; 102 } 103 }