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.objects;
27
28 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
29
30 import java.nio.ByteBuffer;
31
32 import jdk.nashorn.internal.objects.annotations.Attribute;
33 import jdk.nashorn.internal.objects.annotations.Constructor;
34 import jdk.nashorn.internal.objects.annotations.Function;
35 import jdk.nashorn.internal.objects.annotations.Getter;
36 import jdk.nashorn.internal.objects.annotations.ScriptClass;
37 import jdk.nashorn.internal.objects.annotations.SpecializedFunction;
38 import jdk.nashorn.internal.objects.annotations.Where;
39 import jdk.nashorn.internal.runtime.JSType;
40 import jdk.nashorn.internal.runtime.PropertyMap;
41 import jdk.nashorn.internal.runtime.ScriptObject;
42 import jdk.nashorn.internal.runtime.ScriptRuntime;
43
44 /**
45 * NativeArrayBuffer - ArrayBuffer as described in the JS typed
46 * array spec
47 */
48 @ScriptClass("ArrayBuffer")
49 public final class NativeArrayBuffer extends ScriptObject {
50 private final ByteBuffer nb;
51
52 // initialized by nasgen
53 private static PropertyMap $nasgenmap$;
54
55 /**
56 * Constructor
57 * @param nb native byte buffer to wrap
58 * @param global global instance
59 */
60 protected NativeArrayBuffer(final ByteBuffer nb, final Global global) {
61 super(global.getArrayBufferPrototype(), $nasgenmap$);
62 this.nb = nb;
63 }
64
65 /**
66 * Constructor
67 * @param nb native byte buffer to wrap
68 */
69 protected NativeArrayBuffer(final ByteBuffer nb) {
70 this(nb, Global.instance());
71 }
72
73 /**
74 * Constructor
75 * @param byteLength byteLength for buffer
76 */
77 protected NativeArrayBuffer(final int byteLength) {
78 this(ByteBuffer.allocateDirect(byteLength));
79 }
80
81 /**
82 * Clone constructor
83 * Used only for slice
84 * @param other original buffer
85 * @param begin begin byte index
86 * @param end end byte index
87 */
88 protected NativeArrayBuffer(final NativeArrayBuffer other, final int begin, final int end) {
89 this(cloneBuffer(other.getNioBuffer(), begin, end));
90 }
91
92 /**
93 * Constructor
94 * @param newObj is this invoked with new
95 * @param self self reference
96 * @param args arguments to constructor
97 * @return new NativeArrayBuffer
98 */
99 @Constructor(arity = 1)
100 public static NativeArrayBuffer constructor(final boolean newObj, final Object self, final Object... args) {
101 if (!newObj) {
102 throw typeError("constructor.requires.new", "ArrayBuffer");
103 }
104
105 if (args.length == 0) {
106 //For ES6 rev28+ we should throw a TypeError here. None of the other runtimes
107 //currently do it, though, so I have chosen to not implement that for now.
108 return new NativeArrayBuffer(0);
109 }
110
111 return new NativeArrayBuffer(JSType.toInt32(args[0]));
112 }
113
114 private static ByteBuffer cloneBuffer(final ByteBuffer original, final int begin, final int end) {
115 final ByteBuffer clone = ByteBuffer.allocateDirect(original.capacity());
116 original.rewind();//copy from the beginning
117 clone.put(original);
118 original.rewind();
119 clone.flip();
120 clone.position(begin);
121 clone.limit(end);
122 return clone.slice();
123 }
124
125 ByteBuffer getNioBuffer() {
126 return nb;
127 }
128
129 @Override
130 public String getClassName() {
131 return "ArrayBuffer";
132 }
133
134 /**
135 * Byte length for native array buffer
136 * @param self native array buffer
137 * @return byte length
138 */
139 @Getter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_WRITABLE | Attribute.NOT_CONFIGURABLE)
140 public static int byteLength(final Object self) {
141 return ((NativeArrayBuffer)self).getByteLength();
142 }
143
144 /**
145 * Returns true if an object is an ArrayBufferView
146 *
147 * @param self self
148 * @param obj object to check
149 *
150 * @return true if obj is an ArrayBufferView
151 */
152 @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
153 public static boolean isView(final Object self, final Object obj) {
154 return obj instanceof ArrayBufferView;
155 }
156
157 /**
158 * Slice function
159 * @param self native array buffer
160 * @param begin0 start byte index
161 * @param end0 end byte index
162 * @return new array buffer, sliced
163 */
164 @Function(attributes = Attribute.NOT_ENUMERABLE)
165 public static NativeArrayBuffer slice(final Object self, final Object begin0, final Object end0) {
166 final NativeArrayBuffer arrayBuffer = (NativeArrayBuffer)self;
167 final int byteLength = arrayBuffer.getByteLength();
168 final int begin = adjustIndex(JSType.toInt32(begin0), byteLength);
169 final int end = adjustIndex(end0 != ScriptRuntime.UNDEFINED ? JSType.toInt32(end0) : byteLength, byteLength);
170 return new NativeArrayBuffer(arrayBuffer, begin, Math.max(end, begin));
171 }
172
173 /**
174 * Specialized slice function
175 * @param self native array buffer
176 * @param begin start byte index
177 * @param end end byte index
178 * @return new array buffer, sliced
179 */
180 @SpecializedFunction
181 public static Object slice(final Object self, final int begin, final int end) {
182 final NativeArrayBuffer arrayBuffer = (NativeArrayBuffer)self;
183 final int byteLength = arrayBuffer.getByteLength();
184 return new NativeArrayBuffer(arrayBuffer, adjustIndex(begin, byteLength), Math.max(adjustIndex(end, byteLength), begin));
185 }
186
187 /**
188 * Specialized slice function
189 * @param self native array buffer
190 * @param begin start byte index
191 * @return new array buffer, sliced
192 */
193 @SpecializedFunction
194 public static Object slice(final Object self, final int begin) {
195 return slice(self, begin, ((NativeArrayBuffer)self).getByteLength());
196 }
197
198 /**
199 * If index is negative, it refers to an index from the end of the array, as
200 * opposed to from the beginning. The index is clamped to the valid index
201 * range for the array.
202 *
203 * @param index The index.
204 * @param length The length of the array.
205 * @return valid index index in the range [0, length).
206 */
207 static int adjustIndex(final int index, final int length) {
208 return index < 0 ? clamp(index + length, length) : clamp(index, length);
209 }
210
211 /**
212 * Clamp index into the range [0, length).
213 */
214 private static int clamp(final int index, final int length) {
215 if (index < 0) {
216 return 0;
217 } else if (index > length) {
218 return length;
219 }
220 return index;
221 }
222
223 int getByteLength() {
224 return nb.limit();
225 }
226
227 ByteBuffer getBuffer() {
228 return nb;
229 }
230
231 ByteBuffer getBuffer(final int offset) {
232 return (ByteBuffer)nb.duplicate().position(offset);
233 }
234
235 ByteBuffer getBuffer(final int offset, final int length) {
236 return (ByteBuffer)getBuffer(offset).limit(length);
237 }
238 }