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 return new NativeArrayBuffer(0);
107 }
108
109 final Object arg0 = args[0];
110 if (arg0 instanceof ByteBuffer) {
111 return new NativeArrayBuffer((ByteBuffer)arg0);
112 } else {
113 return new NativeArrayBuffer(JSType.toInt32(arg0));
114 }
115 }
116
117 private static ByteBuffer cloneBuffer(final ByteBuffer original, final int begin, final int end) {
118 final ByteBuffer clone = ByteBuffer.allocateDirect(original.capacity());
119 original.rewind();//copy from the beginning
120 clone.put(original);
121 original.rewind();
122 clone.flip();
123 clone.position(begin);
124 clone.limit(end);
125 return clone.slice();
126 }
127
128 ByteBuffer getNioBuffer() {
129 return nb;
130 }
131
132 @Override
133 public String getClassName() {
134 return "ArrayBuffer";
135 }
136
137 /**
138 * Byte length for native array buffer
139 * @param self native array buffer
140 * @return byte length
141 */
142 @Getter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_WRITABLE | Attribute.NOT_CONFIGURABLE)
143 public static int byteLength(final Object self) {
144 return ((NativeArrayBuffer)self).getByteLength();
145 }
146
147 /**
148 * Returns true if an object is an ArrayBufferView
149 *
150 * @param self self
151 * @param obj object to check
152 *
153 * @return true if obj is an ArrayBufferView
154 */
155 @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
156 public static boolean isView(final Object self, final Object obj) {
157 return obj instanceof ArrayBufferView;
158 }
159
160 /**
161 * Slice function
162 * @param self native array buffer
163 * @param begin0 start byte index
164 * @param end0 end byte index
165 * @return new array buffer, sliced
166 */
167 @Function(attributes = Attribute.NOT_ENUMERABLE)
168 public static NativeArrayBuffer slice(final Object self, final Object begin0, final Object end0) {
169 final NativeArrayBuffer arrayBuffer = (NativeArrayBuffer)self;
170 final int byteLength = arrayBuffer.getByteLength();
171 final int begin = adjustIndex(JSType.toInt32(begin0), byteLength);
172 final int end = adjustIndex(end0 != ScriptRuntime.UNDEFINED ? JSType.toInt32(end0) : byteLength, byteLength);
173 return new NativeArrayBuffer(arrayBuffer, begin, Math.max(end, begin));
174 }
175
176 /**
177 * Specialized slice function
178 * @param self native array buffer
179 * @param begin start byte index
180 * @param end end byte index
181 * @return new array buffer, sliced
182 */
183 @SpecializedFunction
184 public static Object slice(final Object self, final int begin, final int end) {
185 final NativeArrayBuffer arrayBuffer = (NativeArrayBuffer)self;
186 final int byteLength = arrayBuffer.getByteLength();
187 return new NativeArrayBuffer(arrayBuffer, adjustIndex(begin, byteLength), Math.max(adjustIndex(end, byteLength), begin));
188 }
189
190 /**
191 * Specialized slice function
192 * @param self native array buffer
193 * @param begin start byte index
194 * @return new array buffer, sliced
195 */
196 @SpecializedFunction
197 public static Object slice(final Object self, final int begin) {
198 return slice(self, begin, ((NativeArrayBuffer)self).getByteLength());
199 }
200
201 /**
202 * If index is negative, it refers to an index from the end of the array, as
203 * opposed to from the beginning. The index is clamped to the valid index
204 * range for the array.
205 *
206 * @param index The index.
207 * @param length The length of the array.
208 * @return valid index index in the range [0, length).
209 */
210 static int adjustIndex(final int index, final int length) {
211 return index < 0 ? clamp(index + length, length) : clamp(index, length);
212 }
213
214 /**
215 * Clamp index into the range [0, length).
216 */
217 private static int clamp(final int index, final int length) {
218 if (index < 0) {
219 return 0;
220 } else if (index > length) {
221 return length;
222 }
223 return index;
224 }
225
226 int getByteLength() {
227 return nb.limit();
228 }
229
230 ByteBuffer getBuffer() {
231 return nb;
232 }
233
234 ByteBuffer getBuffer(final int offset) {
235 return nb.duplicate().position(offset);
236 }
237
238 ByteBuffer getBuffer(final int offset, final int length) {
239 return getBuffer(offset).limit(length);
240 }
241 }