ObjectArrayData.java revision 1036:f0b5e3900a10 
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.runtime.arrays;
27
28import static jdk.nashorn.internal.codegen.CompilerConstants.specialCall;
29import java.lang.invoke.MethodHandle;
30import java.lang.invoke.MethodHandles;
31import java.util.Arrays;
32import jdk.nashorn.internal.codegen.types.Type;
33import jdk.nashorn.internal.runtime.JSType;
34import jdk.nashorn.internal.runtime.ScriptRuntime;
35
36/**
37 * Implementation of {@link ArrayData} as soon as an Object has been
38 * written to the array
39 */
40final class ObjectArrayData extends ContinuousArrayData {
41
42    /**
43     * The wrapped array
44     */
45    private Object[] array;
46
47    /**
48     * Constructor
49     * @param array an int array
50     * @param length a length, not necessarily array.length
51     */
52    ObjectArrayData(final Object array[], final int length) {
53        super(length);
54        assert array.length >= length;
55        this.array  = array;
56    }
57
58    @Override
59    public Class<?> getElementType() {
60        return Object.class;
61    }
62
63    @Override
64    public ArrayData copy() {
65        return new ObjectArrayData(array.clone(), (int)length);
66    }
67
68    @Override
69    public Object[] asObjectArray() {
70        return array.length == length() ? array.clone() : asObjectArrayCopy();
71    }
72
73    private Object[] asObjectArrayCopy() {
74        final long l = length();
75        assert l <= Integer.MAX_VALUE;
76        final Object[] copy = new Object[(int)l];
77        System.arraycopy(array, 0, copy, 0, (int)l);
78        return copy;
79    }
80
81    @Override
82    public ArrayData convert(final Class<?> type) {
83        return this;
84    }
85
86    @Override
87    public void shiftLeft(final int by) {
88        System.arraycopy(array, by, array, 0, array.length - by);
89    }
90
91    @Override
92    public ArrayData shiftRight(final int by) {
93        final ArrayData newData = ensure(by + length() - 1);
94        if (newData != this) {
95            newData.shiftRight(by);
96            return newData;
97        }
98        System.arraycopy(array, 0, array, by, array.length - by);
99        return this;
100    }
101
102    @Override
103    public ArrayData ensure(final long safeIndex) {
104        if (safeIndex >= SparseArrayData.MAX_DENSE_LENGTH) {
105            return new SparseArrayData(this, safeIndex + 1);
106        }
107        final int alen = array.length;
108        if (safeIndex >= alen) {
109            final int newLength = ArrayData.nextSize((int)safeIndex);
110            array = Arrays.copyOf(array, newLength); //fill with undefined or OK? TODO
111        }
112        setLength(safeIndex + 1);
113        return this;
114    }
115
116    @Override
117    public ArrayData shrink(final long newLength) {
118        Arrays.fill(array, (int) newLength, array.length, ScriptRuntime.UNDEFINED);
119        return this;
120    }
121
122    @Override
123    public ArrayData set(final int index, final Object value, final boolean strict) {
124        array[index] = value;
125        setLength(Math.max(index + 1, length()));
126        return this;
127    }
128
129    @Override
130    public ArrayData set(final int index, final int value, final boolean strict) {
131        array[index] = value;
132        setLength(Math.max(index + 1, length()));
133        return this;
134    }
135
136    @Override
137    public ArrayData set(final int index, final long value, final boolean strict) {
138        array[index] = value;
139        setLength(Math.max(index + 1, length()));
140        return this;
141    }
142
143    @Override
144    public ArrayData set(final int index, final double value, final boolean strict) {
145        array[index] = value;
146        setLength(Math.max(index + 1, length()));
147        return this;
148    }
149
150    @Override
151    public ArrayData setEmpty(final int index) {
152        array[index] = ScriptRuntime.EMPTY;
153        return this;
154    }
155
156    @Override
157    public ArrayData setEmpty(final long lo, final long hi) {
158        Arrays.fill(array, (int)Math.max(lo, 0L), (int)Math.min(hi, Integer.MAX_VALUE), ScriptRuntime.EMPTY);
159        return this;
160    }
161
162    @Override
163    public Type getOptimisticType() {
164        return Type.OBJECT;
165    }
166
167    private static final MethodHandle HAS_GET_ELEM = specialCall(MethodHandles.lookup(), ObjectArrayData.class, "getElem", Object.class, int.class).methodHandle();
168    private static final MethodHandle SET_ELEM     = specialCall(MethodHandles.lookup(), ObjectArrayData.class, "setElem", void.class, int.class, Object.class).methodHandle();
169
170    @SuppressWarnings("unused")
171    private Object getElem(final int index) {
172        if (has(index)) {
173            return array[index];
174        }
175        throw new ClassCastException();
176    }
177
178    @SuppressWarnings("unused")
179    private void setElem(final int index, final Object elem) {
180        if (hasRoomFor(index)) {
181            array[index] = elem;
182            return;
183        }
184        throw new ClassCastException();
185    }
186
187    @Override
188    public MethodHandle getElementGetter(final Class<?> returnType, final int programPoint) {
189        if (returnType.isPrimitive()) {
190            return null;
191        }
192        return getContinuousElementGetter(HAS_GET_ELEM, returnType, programPoint);
193    }
194
195    @Override
196    public MethodHandle getElementSetter(final Class<?> elementType) {
197        return getContinuousElementSetter(SET_ELEM, Object.class);
198    }
199
200
201    @Override
202    public int getInt(final int index) {
203        return JSType.toInt32(array[index]);
204    }
205
206    @Override
207    public long getLong(final int index) {
208        return JSType.toLong(array[index]);
209    }
210
211    @Override
212    public double getDouble(final int index) {
213        return JSType.toNumber(array[index]);
214    }
215
216    @Override
217    public Object getObject(final int index) {
218        return array[index];
219    }
220
221    @Override
222    public boolean has(final int index) {
223        return 0 <= index && index < length();
224    }
225
226    @Override
227    public ArrayData delete(final int index) {
228        setEmpty(index);
229        return new DeletedRangeArrayFilter(this, index, index);
230    }
231
232    @Override
233    public ArrayData delete(final long fromIndex, final long toIndex) {
234        setEmpty(fromIndex, toIndex);
235        return new DeletedRangeArrayFilter(this, fromIndex, toIndex);
236    }
237
238    @Override
239    public long fastPush(final int arg) {
240        return fastPush((Object)arg);
241    }
242
243    @Override
244    public long fastPush(final long arg) {
245        return fastPush((Object)arg);
246    }
247
248    @Override
249    public long fastPush(final double arg) {
250        return fastPush((Object)arg);
251    }
252
253    @Override
254    public long fastPush(final Object arg) {
255        final int len = (int)length;
256        if (len == array.length) {
257            array = Arrays.copyOf(array, nextSize(len));
258        }
259        array[len] = arg;
260        return ++length;
261    }
262
263    @Override
264    public Object fastPopObject() {
265        if (length == 0) {
266            return ScriptRuntime.UNDEFINED;
267        }
268        final int newLength = (int)--length;
269        final Object elem = array[newLength];
270        array[newLength] = ScriptRuntime.EMPTY;
271        return elem;
272    }
273
274    @Override
275    public Object pop() {
276        if (length() == 0) {
277            return ScriptRuntime.UNDEFINED;
278        }
279
280        final int newLength = (int) (length() - 1);
281        final Object elem = array[newLength];
282        setEmpty(newLength);
283        setLength(newLength);
284        return elem;
285    }
286
287    @Override
288    public ArrayData slice(final long from, final long to) {
289        final long start     = from < 0 ? from + length() : from;
290        final long newLength = to - start;
291        return new ObjectArrayData(Arrays.copyOfRange(array, (int)from, (int)to), (int)newLength);
292    }
293
294    @Override
295    public ArrayData push(final boolean strict, final Object item) {
296        final long      length = length();
297        final ArrayData newData = ensure(length);
298        if (newData == this) {
299            array[(int)length] = item;
300            return this;
301        }
302        return newData.set((int)length, item, strict);
303    }
304
305    @Override
306    public ArrayData fastSplice(final int start, final int removed, final int added) throws UnsupportedOperationException {
307        final long oldLength = length();
308        final long newLength = oldLength - removed + added;
309        if (newLength > SparseArrayData.MAX_DENSE_LENGTH && newLength > array.length) {
310            throw new UnsupportedOperationException();
311        }
312        final ArrayData returnValue = removed == 0 ?
313                EMPTY_ARRAY : new ObjectArrayData(Arrays.copyOfRange(array, start, start + removed), removed);
314
315        if (newLength != oldLength) {
316            final Object[] newArray;
317
318            if (newLength > array.length) {
319                newArray = new Object[ArrayData.nextSize((int)newLength)];
320                System.arraycopy(array, 0, newArray, 0, start);
321            } else {
322                newArray = array;
323            }
324
325            System.arraycopy(array, start + removed, newArray, start + added, (int)(oldLength - start - removed));
326            array = newArray;
327            setLength(newLength);
328        }
329
330        return returnValue;
331    }
332}
333