ObjectArrayData.java revision 1056:e0b9b2ef8442 
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 len = length;
75        assert len <= Integer.MAX_VALUE;
76        final Object[] copy = new Object[(int)len];
77        System.arraycopy(array, 0, copy, 0, (int)len);
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        // hi parameter is inclusive, but Arrays.fill toIndex parameter is exclusive
159        Arrays.fill(array, (int)Math.max(lo, 0L), (int)Math.min(hi + 1, Integer.MAX_VALUE), ScriptRuntime.EMPTY);
160        return this;
161    }
162
163    @Override
164    public Type getOptimisticType() {
165        return Type.OBJECT;
166    }
167
168    private static final MethodHandle HAS_GET_ELEM = specialCall(MethodHandles.lookup(), ObjectArrayData.class, "getElem", Object.class, int.class).methodHandle();
169    private static final MethodHandle SET_ELEM     = specialCall(MethodHandles.lookup(), ObjectArrayData.class, "setElem", void.class, int.class, Object.class).methodHandle();
170
171    @SuppressWarnings("unused")
172    private Object getElem(final int index) {
173        if (has(index)) {
174            return array[index];
175        }
176        throw new ClassCastException();
177    }
178
179    @SuppressWarnings("unused")
180    private void setElem(final int index, final Object elem) {
181        if (hasRoomFor(index)) {
182            array[index] = elem;
183            return;
184        }
185        throw new ClassCastException();
186    }
187
188    @Override
189    public MethodHandle getElementGetter(final Class<?> returnType, final int programPoint) {
190        if (returnType.isPrimitive()) {
191            return null;
192        }
193        return getContinuousElementGetter(HAS_GET_ELEM, returnType, programPoint);
194    }
195
196    @Override
197    public MethodHandle getElementSetter(final Class<?> elementType) {
198        return getContinuousElementSetter(SET_ELEM, Object.class);
199    }
200
201
202    @Override
203    public int getInt(final int index) {
204        return JSType.toInt32(array[index]);
205    }
206
207    @Override
208    public long getLong(final int index) {
209        return JSType.toLong(array[index]);
210    }
211
212    @Override
213    public double getDouble(final int index) {
214        return JSType.toNumber(array[index]);
215    }
216
217    @Override
218    public Object getObject(final int index) {
219        return array[index];
220    }
221
222    @Override
223    public boolean has(final int index) {
224        return 0 <= index && index < length;
225    }
226
227    @Override
228    public ArrayData delete(final int index) {
229        setEmpty(index);
230        return new DeletedRangeArrayFilter(this, index, index);
231    }
232
233    @Override
234    public ArrayData delete(final long fromIndex, final long toIndex) {
235        setEmpty(fromIndex, toIndex);
236        return new DeletedRangeArrayFilter(this, fromIndex, toIndex);
237    }
238
239    @Override
240    public long fastPush(final int arg) {
241        return fastPush((Object)arg);
242    }
243
244    @Override
245    public long fastPush(final long arg) {
246        return fastPush((Object)arg);
247    }
248
249    @Override
250    public long fastPush(final double arg) {
251        return fastPush((Object)arg);
252    }
253
254    @Override
255    public long fastPush(final Object arg) {
256        final int len = (int)length;
257        if (len == array.length) {
258            array = Arrays.copyOf(array, nextSize(len));
259        }
260        array[len] = arg;
261        return ++length;
262    }
263
264    @Override
265    public Object fastPopObject() {
266        if (length == 0) {
267            return ScriptRuntime.UNDEFINED;
268        }
269        final int newLength = (int)--length;
270        final Object elem = array[newLength];
271        array[newLength] = ScriptRuntime.EMPTY;
272        return elem;
273    }
274
275    @Override
276    public Object pop() {
277        if (length == 0) {
278            return ScriptRuntime.UNDEFINED;
279        }
280
281        final int newLength = (int)length - 1;
282        final Object elem = array[newLength];
283        setEmpty(newLength);
284        setLength(newLength);
285        return elem;
286    }
287
288    @Override
289    public ArrayData slice(final long from, final long to) {
290        final long start     = from < 0 ? from + length : from;
291        final long newLength = to - start;
292        return new ObjectArrayData(Arrays.copyOfRange(array, (int)from, (int)to), (int)newLength);
293    }
294
295    @Override
296    public ArrayData push(final boolean strict, final Object item) {
297        final long      len     = length;
298        final ArrayData newData = ensure(len);
299        if (newData == this) {
300            array[(int)len] = item;
301            return this;
302        }
303        return newData.set((int)len, item, strict);
304    }
305
306    @Override
307    public ArrayData fastSplice(final int start, final int removed, final int added) throws UnsupportedOperationException {
308        final long oldLength = length;
309        final long newLength = oldLength - removed + added;
310        if (newLength > SparseArrayData.MAX_DENSE_LENGTH && newLength > array.length) {
311            throw new UnsupportedOperationException();
312        }
313        final ArrayData returnValue = removed == 0 ?
314                EMPTY_ARRAY : new ObjectArrayData(Arrays.copyOfRange(array, start, start + removed), removed);
315
316        if (newLength != oldLength) {
317            final Object[] newArray;
318
319            if (newLength > array.length) {
320                newArray = new Object[ArrayData.nextSize((int)newLength)];
321                System.arraycopy(array, 0, newArray, 0, start);
322            } else {
323                newArray = array;
324            }
325
326            System.arraycopy(array, start + removed, newArray, start + added, (int)(oldLength - start - removed));
327            array = newArray;
328            setLength(newLength);
329        }
330
331        return returnValue;
332    }
333}
334