NativeUint8Array.java revision 1062:f9ed1ca59030 
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
26package jdk.nashorn.internal.objects;
27
28import static jdk.nashorn.internal.codegen.CompilerConstants.specialCall;
29
30import java.lang.invoke.MethodHandle;
31import java.lang.invoke.MethodHandles;
32import java.nio.ByteBuffer;
33import jdk.nashorn.internal.objects.annotations.Attribute;
34import jdk.nashorn.internal.objects.annotations.Constructor;
35import jdk.nashorn.internal.objects.annotations.Function;
36import jdk.nashorn.internal.objects.annotations.Property;
37import jdk.nashorn.internal.objects.annotations.ScriptClass;
38import jdk.nashorn.internal.objects.annotations.Where;
39import jdk.nashorn.internal.runtime.JSType;
40import jdk.nashorn.internal.runtime.PropertyMap;
41import jdk.nashorn.internal.runtime.ScriptObject;
42import jdk.nashorn.internal.runtime.arrays.ArrayData;
43import jdk.nashorn.internal.runtime.arrays.TypedArrayData;
44
45/**
46 * Uint8 array for TypedArray extension
47 */
48@ScriptClass("Uint8Array")
49public final class NativeUint8Array extends ArrayBufferView {
50
51    /**
52     * The size in bytes of each element in the array.
53     */
54    @Property(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_WRITABLE | Attribute.NOT_CONFIGURABLE, where = Where.CONSTRUCTOR)
55    public static final int BYTES_PER_ELEMENT = 1;
56
57    // initialized by nasgen
58    @SuppressWarnings("unused")
59    private static PropertyMap $nasgenmap$;
60
61    private static final Factory FACTORY = new Factory(BYTES_PER_ELEMENT) {
62        @Override
63        public ArrayBufferView construct(final NativeArrayBuffer buffer, final int byteOffset, final int length) {
64            return new NativeUint8Array(buffer, byteOffset, length);
65        }
66
67        @Override
68        public Uint8ArrayData createArrayData(final ByteBuffer nb, final int start, final int end) {
69            return new Uint8ArrayData(nb, start, end);
70        }
71
72        @Override
73        public String getClassName() {
74            return "Uint8Array";
75        }
76    };
77
78    private static final class Uint8ArrayData extends TypedArrayData<ByteBuffer> {
79
80        private static final MethodHandle GET_ELEM = specialCall(MethodHandles.lookup(), Uint8ArrayData.class, "getElem", int.class, int.class).methodHandle();
81        private static final MethodHandle SET_ELEM = specialCall(MethodHandles.lookup(), Uint8ArrayData.class, "setElem", void.class, int.class, int.class).methodHandle();
82
83        private Uint8ArrayData(final ByteBuffer nb, final int start, final int end) {
84            super(((ByteBuffer)nb.position(start).limit(end)).slice(), end - start);
85        }
86
87        @Override
88        protected MethodHandle getGetElem() {
89            return GET_ELEM;
90        }
91
92        @Override
93        protected MethodHandle getSetElem() {
94            return SET_ELEM;
95        }
96
97        private int getElem(final int index) {
98            try {
99                return nb.get(index) & 0xff;
100            } catch (final IndexOutOfBoundsException e) {
101                throw new ClassCastException(); //force relink - this works for unoptimistic too
102            }
103        }
104
105        private void setElem(final int index, final int elem) {
106            try {
107                nb.put(index, (byte)elem);
108            } catch (final IndexOutOfBoundsException e) {
109                //swallow valid array indexes. it's ok.
110                if (index < 0) {
111                    throw new ClassCastException();
112                }
113            }
114        }
115
116        @Override
117        public boolean isUnsigned() {
118            return true;
119        }
120
121        @Override
122        public Class<?> getElementType() {
123            return int.class;
124        }
125
126        @Override
127        public int getInt(final int index) {
128            return getElem(index);
129        }
130
131        @Override
132        public int getIntOptimistic(final int index, final int programPoint) {
133            return getElem(index);
134        }
135
136        @Override
137        public long getLong(final int index) {
138            return getInt(index);
139        }
140
141        @Override
142        public long getLongOptimistic(final int index, final int programPoint) {
143            return getElem(index);
144        }
145
146        @Override
147        public double getDouble(final int index) {
148            return getInt(index);
149        }
150
151        @Override
152        public double getDoubleOptimistic(final int index, final int programPoint) {
153            return getElem(index);
154        }
155
156        @Override
157        public Object getObject(final int index) {
158            return getInt(index);
159        }
160
161        @Override
162        public ArrayData set(final int index, final Object value, final boolean strict) {
163            return set(index, JSType.toInt32(value), strict);
164        }
165
166        @Override
167        public ArrayData set(final int index, final int value, final boolean strict) {
168            setElem(index, value);
169            return this;
170        }
171
172        @Override
173        public ArrayData set(final int index, final long value, final boolean strict) {
174            return set(index, (int)value, strict);
175        }
176
177        @Override
178        public ArrayData set(final int index, final double value, final boolean strict) {
179            return set(index, (int)value, strict);
180        }
181
182    }
183
184    /**
185     * Constructor
186     *
187     * @param newObj is this typed array instantiated with the new operator
188     * @param self   self reference
189     * @param args   args
190     *
191     * @return new typed array
192     */
193    @Constructor(arity = 1)
194    public static NativeUint8Array constructor(final boolean newObj, final Object self, final Object... args) {
195        return (NativeUint8Array)constructorImpl(newObj, args, FACTORY);
196    }
197
198    NativeUint8Array(final NativeArrayBuffer buffer, final int byteOffset, final int length) {
199        super(buffer, byteOffset, length);
200    }
201
202    @Override
203    protected Factory factory() {
204        return FACTORY;
205    }
206
207    /**
208     * Set values
209     * @param self   self reference
210     * @param array  multiple values of array's type to set
211     * @param offset optional start index, interpreted  0 if undefined
212     * @return undefined
213     */
214    @Function(attributes = Attribute.NOT_ENUMERABLE)
215    protected static Object set(final Object self, final Object array, final Object offset) {
216        return ArrayBufferView.setImpl(self, array, offset);
217    }
218
219    /**
220     * Returns a new TypedArray view of the ArrayBuffer store for this TypedArray,
221     * referencing the elements at begin, inclusive, up to end, exclusive. If either
222     * begin or end is negative, it refers to an index from the end of the array,
223     * as opposed to from the beginning.
224     * <p>
225     * If end is unspecified, the subarray contains all elements from begin to the end
226     * of the TypedArray. The range specified by the begin and end values is clamped to
227     * the valid index range for the current array. If the computed length of the new
228     * TypedArray would be negative, it is clamped to zero.
229     * <p>
230     * The returned TypedArray will be of the same type as the array on which this
231     * method is invoked.
232     *
233     * @param self self reference
234     * @param begin begin position
235     * @param end end position
236     *
237     * @return sub array
238     */
239    @Function(attributes = Attribute.NOT_ENUMERABLE)
240    protected static NativeUint8Array subarray(final Object self, final Object begin, final Object end) {
241        return (NativeUint8Array)ArrayBufferView.subarrayImpl(self, begin, end);
242    }
243
244    @Override
245    protected ScriptObject getPrototype(final Global global) {
246        return global.getUint8ArrayPrototype();
247    }
248}
249