src/java.net.http/share/classes/java/net/http/internal/common/ByteBufferPool.java
branchhttp-client-branch
changeset 56089 42208b2f224e
parent 56088 38fac6d0521d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.net.http/share/classes/java/net/http/internal/common/ByteBufferPool.java	Wed Feb 07 14:17:24 2018 +0000
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2015, 2018, 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 java.net.http.internal.common;
+
+import java.nio.ByteBuffer;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+/**
+ * The class provides reuse of ByteBuffers.
+ * It is supposed that all requested buffers have the same size for a long period of time.
+ * That is why there is no any logic splitting buffers into different buckets (by size). It's unnecessary.
+ *
+ * At the same moment it is allowed to change requested buffers size (all smaller buffers will be discarded).
+ * It may be needed for example, if after rehandshaking netPacketBufferSize was changed.
+ */
+public class ByteBufferPool {
+
+    private final java.util.Queue<ByteBuffer> pool = new ConcurrentLinkedQueue<>();
+
+    public ByteBufferPool() {
+    }
+
+    public ByteBufferReference get(int size) {
+        ByteBuffer buffer;
+        while ((buffer = pool.poll()) != null) {
+            if (buffer.capacity() >= size) {
+                return ByteBufferReference.of(buffer, this);
+            }
+        }
+        return ByteBufferReference.of(ByteBuffer.allocate(size), this);
+    }
+
+    public void release(ByteBuffer buffer) {
+        buffer.clear();
+        pool.offer(buffer);
+    }
+
+}