AstDeserializer.java revision 1126:687430164864 
1/*
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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
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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
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24 */
25package jdk.nashorn.internal.runtime;
26
27import java.io.ByteArrayInputStream;
28import java.io.IOException;
29import java.io.ObjectInputStream;
30import java.security.AccessController;
31import java.security.PrivilegedAction;
32import java.util.zip.InflaterInputStream;
33import 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 */
39final class AstDeserializer {
40    static FunctionNode deserialize(final byte[] serializedAst) {
41        // FIXME: do we need this doPrivileged block at all?
42        return AccessController.doPrivileged(new PrivilegedAction<FunctionNode>() {
43            @Override
44            public FunctionNode run() {
45                try {
46                    return (FunctionNode)new ObjectInputStream(new InflaterInputStream(
47                        new ByteArrayInputStream(serializedAst))).readObject();
48                } catch (final ClassNotFoundException | IOException e) {
49                    // This is internal, can't happen
50                    throw new AssertionError("Unexpected exception deserializing function", e);
51                }
52            }
53        });
54    }
55}
56