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.ByteArrayInputStream;
  28 import java.io.IOException;
  29 import java.io.ObjectInputStream;
  30 import java.security.AccessController;
  31 import java.security.PrivilegedAction;
  32 import java.util.zip.InflaterInputStream;
  33 import jdk.nashorn.internal.ir.FunctionNode;
  34 
  35 /**
  36  * This static utility class performs deserialization of FunctionNode ASTs from a byte array.
  37  * The format is a standard Java serialization stream, deflated.
  38  */
  39 final class AstDeserializer {
  40     static FunctionNode deserialize(final byte[] serializedAst) {
  41         return AccessController.doPrivileged(new PrivilegedAction<FunctionNode>() {
  42             @Override
  43             public FunctionNode run() {
  44                 try {
  45                     return (FunctionNode)new ObjectInputStream(new InflaterInputStream(
  46                         new ByteArrayInputStream(serializedAst))).readObject();
  47                 } catch (final ClassNotFoundException | IOException e) {
  48                     // This is internal, can't happen
  49                     throw new AssertionError("Unexpected exception deserializing function", e);
  50                 }
  51             }
  52         });
  53     }
  54 }