1 /* 2 * Copyright (c) 2016, 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 package jdk.jshell.execution; 26 27 import java.io.IOException; 28 import java.io.OutputStream; 29 import java.io.UnsupportedEncodingException; 30 31 /** 32 * Packetize an OutputStream, dividing it into named channels. 33 * 34 * @author Jan Lahoda 35 */ 36 class MultiplexingOutputStream extends OutputStream { 37 38 private static final int PACKET_SIZE = 127; 39 private final byte[] name; 40 private final OutputStream delegate; 41 42 MultiplexingOutputStream(String name, OutputStream delegate) { 43 try { 44 this.name = name.getBytes("UTF-8"); 45 this.delegate = delegate; 46 } catch (UnsupportedEncodingException ex) { 47 throw new IllegalStateException(ex); //should not happen 48 } 49 } 50 51 @Override 52 public void write(int b) throws IOException { 53 synchronized (delegate) { 54 delegate.write(name.length); //assuming the len is small enough to fit into byte 55 delegate.write(name); 56 delegate.write(1); 57 delegate.write(b); 58 delegate.flush(); 59 } 60 } 61 62 @Override 63 public void write(byte[] b, int off, int len) throws IOException { 64 synchronized (delegate) { 65 int i = 0; 66 while (len > 0) { 67 int size = Math.min(PACKET_SIZE, len); 68 delegate.write(name.length); //assuming the len is small enough to fit into byte 69 delegate.write(name); 70 delegate.write(size); 71 delegate.write(b, off + i, size); 72 i += size; 73 len -= size; 74 } 75 delegate.flush(); 76 } 77 } 78 79 @Override 80 public void flush() throws IOException { 81 super.flush(); 82 delegate.flush(); 83 } 84 85 @Override 86 public void close() throws IOException { 87 super.close(); 88 delegate.close(); 89 } 90 91 }