1 /* 2 * Copyright (c) 2010, 2014, 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.nashorn.internal.runtime; 26 27 import java.io.ByteArrayOutputStream; 28 import java.io.IOException; 29 import java.io.ObjectOutputStream; 30 import java.util.zip.Deflater; 31 import java.util.zip.DeflaterOutputStream; 32 import jdk.nashorn.internal.ir.FunctionNode; 33 import jdk.nashorn.internal.runtime.options.Options; 34 35 /** 36 * This static utility class performs serialization of FunctionNode ASTs to a byte array. 37 * The format is a standard Java serialization stream, deflated. 38 */ 39 final class AstSerializer { 40 // Experimentally, we concluded that compression level 4 gives a good tradeoff between serialization speed 41 // and size. 42 private static final int COMPRESSION_LEVEL = Options.getIntProperty("nashorn.serialize.compression", 4); 43 static byte[] serialize(final FunctionNode fn) { 44 final ByteArrayOutputStream out = new ByteArrayOutputStream(); 45 final Deflater deflater = new Deflater(COMPRESSION_LEVEL); 46 try (final ObjectOutputStream oout = new ObjectOutputStream(new DeflaterOutputStream(out, deflater))) { 47 oout.writeObject(fn); 48 } catch (final IOException e) { 49 throw new AssertionError("Unexpected exception serializing function", e); 50 } finally { 51 deflater.end(); 52 } 53 return out.toByteArray(); 54 } 55 }