diff -r 836adbf7a2cd -r 3317bb8137f4 jdk/src/java.desktop/share/classes/javax/swing/text/SegmentCache.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/classes/javax/swing/text/SegmentCache.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package javax.swing.text;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * SegmentCache caches Segment
s to avoid continually creating
+ * and destroying of Segment
s. A common use of this class would
+ * be:
+ *
+ * Segment segment = segmentCache.getSegment(); + * // do something with segment + * ... + * segmentCache.releaseSegment(segment); + *+ * + */ +class SegmentCache { + /** + * A global cache. + */ + private static SegmentCache sharedCache = new SegmentCache(); + + /** + * A list of the currently unused Segments. + */ + private List
SegmentCache
.
+ */
+ public static Segment getSharedSegment() {
+ return getSharedInstance().getSegment();
+ }
+
+ /**
+ * A convenience method to release a Segment to the shared
+ * SegmentCache
.
+ */
+ public static void releaseSharedSegment(Segment segment) {
+ getSharedInstance().releaseSegment(segment);
+ }
+
+
+
+ /**
+ * Creates and returns a SegmentCache.
+ */
+ public SegmentCache() {
+ segments = new ArrayListSegment
. When done, the Segment
+ * should be recycled by invoking releaseSegment
.
+ */
+ public Segment getSegment() {
+ synchronized(this) {
+ int size = segments.size();
+
+ if (size > 0) {
+ return segments.remove(size - 1);
+ }
+ }
+ return new CachedSegment();
+ }
+
+ /**
+ * Releases a Segment. You should not use a Segment after you release it,
+ * and you should NEVER release the same Segment more than once, eg:
+ * + * segmentCache.releaseSegment(segment); + * segmentCache.releaseSegment(segment); + *+ * Will likely result in very bad things happening! + */ + public void releaseSegment(Segment segment) { + if (segment instanceof CachedSegment) { + synchronized(this) { + segment.array = null; + segment.count = 0; + segments.add(segment); + } + } + } + + + /** + * CachedSegment is used as a tagging interface to determine if + * a Segment can successfully be shared. + */ + private static class CachedSegment extends Segment { + } +}