--- /dev/null 2016-07-12 14:35:29.888302783 -0700 +++ new/src/jdk.jshell/share/classes/jdk/jshell/execution/MultiplexingOutputStream.java 2016-07-12 22:46:57.522006378 -0700 @@ -0,0 +1,91 @@ +/* + * Copyright (c) 2016, 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 jdk.jshell.execution; + +import java.io.IOException; +import java.io.OutputStream; +import java.io.UnsupportedEncodingException; + +/** + * Packetize an OutputStream, dividing it into named channels. + * + * @author Jan Lahoda + */ +class MultiplexingOutputStream extends OutputStream { + + private static final int PACKET_SIZE = 127; + private final byte[] name; + private final OutputStream delegate; + + MultiplexingOutputStream(String name, OutputStream delegate) { + try { + this.name = name.getBytes("UTF-8"); + this.delegate = delegate; + } catch (UnsupportedEncodingException ex) { + throw new IllegalStateException(ex); //should not happen + } + } + + @Override + public void write(int b) throws IOException { + synchronized (delegate) { + delegate.write(name.length); //assuming the len is small enough to fit into byte + delegate.write(name); + delegate.write(1); + delegate.write(b); + delegate.flush(); + } + } + + @Override + public void write(byte[] b, int off, int len) throws IOException { + synchronized (delegate) { + int i = 0; + while (len > 0) { + int size = Math.min(PACKET_SIZE, len); + delegate.write(name.length); //assuming the len is small enough to fit into byte + delegate.write(name); + delegate.write(size); + delegate.write(b, off + i, size); + i += size; + len -= size; + } + delegate.flush(); + } + } + + @Override + public void flush() throws IOException { + super.flush(); + delegate.flush(); + } + + @Override + public void close() throws IOException { + super.close(); + delegate.close(); + } + +}