1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/*
* Copyright (c) 2010, 2013, 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.nashorn.internal.runtime;
import static jdk.nashorn.internal.codegen.Compiler.SCRIPTS_PACKAGE;
import static jdk.nashorn.internal.codegen.Compiler.binaryName;
import static jdk.nashorn.internal.codegen.CompilerConstants.JS_OBJECT_DUAL_FIELD_PREFIX;
import static jdk.nashorn.internal.codegen.CompilerConstants.JS_OBJECT_SINGLE_FIELD_PREFIX;
import java.security.ProtectionDomain;
import jdk.nashorn.internal.codegen.ObjectClassGenerator;
/**
* Responsible for on the fly construction of structure classes.
*/
final class StructureLoader extends NashornLoader {
private static final String SINGLE_FIELD_PREFIX = binaryName(SCRIPTS_PACKAGE) + '.' + JS_OBJECT_SINGLE_FIELD_PREFIX.symbolName();
private static final String DUAL_FIELD_PREFIX = binaryName(SCRIPTS_PACKAGE) + '.' + JS_OBJECT_DUAL_FIELD_PREFIX.symbolName();
/**
* Constructor.
*/
StructureLoader(final ClassLoader parent) {
super(parent);
}
/**
* Returns true if the class name represents a structure object with dual primitive/object fields.
* @param name a class name
* @return true if a dual field structure class
*/
private static boolean isDualFieldStructure(final String name) {
return name.startsWith(DUAL_FIELD_PREFIX);
}
/**
* Returns true if the class name represents a structure object with single object-only fields.
* @param name a class name
* @return true if a single field structure class
*/
static boolean isSingleFieldStructure(final String name) {
return name.startsWith(SINGLE_FIELD_PREFIX);
}
/**
* Returns true if the class name represents a Nashorn structure object.
* @param name a class name
* @return true if a structure class
*/
static boolean isStructureClass(final String name) {
return isDualFieldStructure(name) || isSingleFieldStructure(name);
}
@Override
protected Class<?> findClass(final String name) throws ClassNotFoundException {
if (isDualFieldStructure(name)) {
return generateClass(name, name.substring(DUAL_FIELD_PREFIX.length()), true);
} else if (isSingleFieldStructure(name)) {
return generateClass(name, name.substring(SINGLE_FIELD_PREFIX.length()), false);
}
return super.findClass(name);
}
/**
* Generate a layout class.
* @param name Name of class.
* @param descriptor Layout descriptor.
* @return Generated class.
*/
private Class<?> generateClass(final String name, final String descriptor, final boolean dualFields) {
final Context context = Context.getContextTrusted();
final byte[] code = new ObjectClassGenerator(context, dualFields).generate(descriptor);
return defineClass(name, code, 0, code.length, new ProtectionDomain(null, getPermissions(null)));
}
}
|