1 /*
2 * Copyright (c) 2010, 2013, 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
26 package jdk.nashorn.internal.runtime;
27
28 import static jdk.nashorn.internal.runtime.ECMAErrors.referenceError;
29 import static jdk.nashorn.internal.lookup.Lookup.MH;
30
31 import java.lang.invoke.MethodHandle;
32 import jdk.internal.dynalink.CallSiteDescriptor;
33 import jdk.internal.dynalink.linker.GuardedInvocation;
34 import jdk.nashorn.internal.lookup.Lookup;
35 import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
36 import jdk.nashorn.internal.runtime.linker.NashornGuards;
37
38
39 /**
40 * Instances of this class are quite ephemeral; they only exist for the duration of an invocation of
41 * {@link ScriptObject#findSetMethod(CallSiteDescriptor, jdk.internal.dynalink.linker.LinkRequest)} and
42 * serve as the actual encapsulation of the algorithm for creating an appropriate property setter method.
43 */
44 final class SetMethodCreator {
45 // See constructor parameters for description of fields
46 private final ScriptObject sobj;
47 private final PropertyMap map;
48 private final FindProperty find;
49 private final CallSiteDescriptor desc;
50
51 /**
52 * Creates a new property setter method creator.
53 * @param sobj the object for which we're creating the property setter
54 * @param find a result of a {@link ScriptObject#findProperty(String, boolean)} on the object for the property we
55 * want to create a setter for. Can be null if the property does not yet exist on the object.
56 * @param desc the descriptor of the call site that triggered the property setter lookup
57 */
58 SetMethodCreator(final ScriptObject sobj, final FindProperty find, final CallSiteDescriptor desc) {
59 this.sobj = sobj;
60 this.map = sobj.getMap();
61 this.find = find;
62 this.desc = desc;
63 }
64
65 private String getName() {
66 return desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
67 }
68
69 private PropertyMap getMap() {
70 return map;
71 }
72
73 /**
74 * Creates the actual guarded invocation that represents the dynamic setter method for the property.
75 * @return the actual guarded invocation that represents the dynamic setter method for the property.
76 */
77 GuardedInvocation createGuardedInvocation() {
78 return createSetMethod().createGuardedInvocation();
79 }
80
81 /**
82 * This class encapsulates the results of looking up a setter method; it's basically a triple of a method handle,
83 * a Property object, and flags for invocation.
84 *
85 */
86 private class SetMethod {
87 private final MethodHandle methodHandle;
88 private final Property property;
89
90 /**
91 * Creates a new lookup result.
92 * @param methodHandle the actual method handle
93 * @param property the property object. Can be null in case we're creating a new property in the global object.
94 */
95 SetMethod(final MethodHandle methodHandle, final Property property) {
96 assert methodHandle != null;
97 this.methodHandle = methodHandle;
98 this.property = property;
99 }
100
101 /**
102 * Composes from its components an actual guarded invocation that represents the dynamic setter method for the property.
103 * @return the composed guarded invocation that represents the dynamic setter method for the property.
104 */
105 GuardedInvocation createGuardedInvocation() {
106 return new GuardedInvocation(methodHandle, NashornGuards.getGuard(sobj, property, desc));
107 }
108
109 }
110
111 private SetMethod createSetMethod() {
112 if (find != null) {
113 return createExistingPropertySetter();
114 }
115
116 checkStrictCreateNewVariable();
117
118 if (sobj.isScope()) {
119 return createGlobalPropertySetter();
120 }
121
122 return createNewPropertySetter();
123 }
124
125 private void checkStrictCreateNewVariable() {
126 // In strict mode, assignment can not create a new variable.
127 // See also ECMA Annex C item 4. ReferenceError is thrown.
128 if (NashornCallSiteDescriptor.isScope(desc) && NashornCallSiteDescriptor.isStrict(desc)) {
129 throw referenceError("not.defined", getName());
130 }
131 }
132
133 private SetMethod createExistingPropertySetter() {
134 final Property property = find.getProperty();
135 final Class<?> type = desc.getMethodType().parameterType(1);
136 final MethodHandle methodHandle = find.getSetter(type, NashornCallSiteDescriptor.isStrict(desc));
137
138 assert methodHandle != null;
139 assert property != null;
140
141 final MethodHandle boundHandle;
142 if (!property.hasSetterFunction(find.getOwner()) && find.isInherited()) {
143 boundHandle = ScriptObject.addProtoFilter(methodHandle, find.getProtoChainLength());
144 } else {
145 boundHandle = methodHandle;
146 }
147 return new SetMethod(boundHandle, property);
148 }
149
150 private SetMethod createGlobalPropertySetter() {
151 final ScriptObject global = Context.getGlobalTrusted();
152 return new SetMethod(MH.filterArguments(global.addSpill(getName()), 0, ScriptObject.GLOBALFILTER), null);
153 }
154
155 private SetMethod createNewPropertySetter() {
156 final SetMethod sm = map.getFieldCount() < map.getFieldMaximum() ? createNewFieldSetter() : createNewSpillPropertySetter();
157 final PropertyListeners listeners = map.getListeners();
158 if (listeners != null) {
159 listeners.propertyAdded(sm.property);
160 }
161 return sm;
162 }
163
164 private SetMethod createNewFieldSetter() {
165 final PropertyMap oldMap = getMap();
166 final Property property = new AccessorProperty(getName(), 0, sobj.getClass(), oldMap.getFieldCount());
167 final PropertyMap newMap = oldMap.addProperty(property);
168 MethodHandle setter = MH.insertArguments(ScriptObject.SETFIELD, 0, desc, oldMap, newMap, property.getSetter(Object.class, newMap));
169
170 return new SetMethod(MH.asType(setter, Lookup.SET_OBJECT_TYPE), property);
171 }
172
173 private SetMethod createNewSpillPropertySetter() {
174 final int nextSpill = getMap().getSpillLength();
175
176 final Property property = new AccessorProperty(getName(), Property.IS_SPILL, nextSpill);
177 return new SetMethod(createSpillMethodHandle(nextSpill, property), property);
178 }
179
180 private MethodHandle createSpillMethodHandle(final int nextSpill, Property property) {
181 final PropertyMap oldMap = getMap();
182 final PropertyMap newMap = getNewMap(property);
183
184 final Object[] spill = sobj.spill;
185 if (spill == null) {
186 return MH.insertArguments(ScriptObject.SETSPILLWITHNEW, 0, desc, oldMap, newMap, nextSpill);
187 } else if (nextSpill < spill.length) {
188 return MH.insertArguments(ScriptObject.SETSPILL, 0, desc, oldMap, newMap, nextSpill);
189 } else {
190 final int newLength = (nextSpill + ScriptObject.SPILL_RATE) / ScriptObject.SPILL_RATE * ScriptObject.SPILL_RATE;
191 return MH.insertArguments(ScriptObject.SETSPILLWITHGROW, 0, desc, oldMap, newMap, nextSpill, newLength);
192 }
193 }
194
195 private PropertyMap getNewMap(Property property) {
196 return getMap().addProperty(property);
197 }
198 }
--- EOF ---