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.runtime.arrays; 27 28 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; 29 import java.lang.reflect.Array; 30 import jdk.nashorn.internal.runtime.BitVector; 31 32 /** 33 * This filter handles the deletion of array elements. 34 */ 35 final class DeletedArrayFilter extends ArrayFilter { 36 /** Bit vector tracking deletions. */ 37 private final BitVector deleted; 38 39 DeletedArrayFilter(final ArrayData underlying) { 40 super(underlying); 41 this.deleted = new BitVector(underlying.length()); 42 } 43 44 @Override 45 public ArrayData copy() { 46 final DeletedArrayFilter copy = new DeletedArrayFilter(underlying.copy()); 47 copy.getDeleted().copy(deleted); 48 return copy; 49 } 50 51 @Override 52 public Object[] asObjectArray() { 53 final Object[] value = super.asObjectArray(); 54 55 for (int i = 0; i < value.length; i++) { 56 if (deleted.isSet(i)) { 57 value[i] = UNDEFINED; 58 } 59 } 60 61 return value; 62 } 63 64 @Override 65 public Object asArrayOfType(final Class<?> componentType) { 66 final Object value = super.asArrayOfType(componentType); 67 final Object undefValue = convertUndefinedValue(componentType); 68 final int l = Array.getLength(value); 69 for (int i = 0; i < l; i++) { 70 if (deleted.isSet(i)) { 71 Array.set(value, i, undefValue); 72 } 73 } 74 75 return value; 76 } 77 78 @Override 79 public ArrayData shiftLeft(final int by) { 80 super.shiftLeft(by); 81 deleted.shiftLeft(by, length()); 82 return this; 83 } 84 85 @Override 86 public ArrayData shiftRight(final int by) { 87 super.shiftRight(by); 88 deleted.shiftRight(by, length()); 89 return this; 90 } 91 92 @Override 93 public ArrayData ensure(final long safeIndex) { 94 if (safeIndex >= SparseArrayData.MAX_DENSE_LENGTH && safeIndex >= length()) { 95 return new SparseArrayData(this, safeIndex + 1); 96 } 97 98 super.ensure(safeIndex); 99 deleted.resize(length()); 100 101 return this; 102 } 103 104 @Override 105 public ArrayData shrink(final long newLength) { 106 super.shrink(newLength); 107 deleted.resize(length()); 108 return this; 109 } 110 111 @Override 112 public ArrayData set(final int index, final Object value, final boolean strict) { 113 deleted.clear(ArrayIndex.toLongIndex(index)); 114 return super.set(index, value, strict); 115 } 116 117 @Override 118 public ArrayData set(final int index, final int value, final boolean strict) { 119 deleted.clear(ArrayIndex.toLongIndex(index)); 120 return super.set(index, value, strict); 121 } 122 123 @Override 124 public ArrayData set(final int index, final double value, final boolean strict) { 125 deleted.clear(ArrayIndex.toLongIndex(index)); 126 return super.set(index, value, strict); 127 } 128 129 @Override 130 public boolean has(final int index) { 131 return super.has(index) && deleted.isClear(ArrayIndex.toLongIndex(index)); 132 } 133 134 @Override 135 public ArrayData delete(final int index) { 136 final long longIndex = ArrayIndex.toLongIndex(index); 137 assert longIndex >= 0 && longIndex < length(); 138 deleted.set(longIndex); 139 underlying.setEmpty(index); 140 return this; 141 } 142 143 @Override 144 public ArrayData delete(final long fromIndex, final long toIndex) { 145 assert fromIndex >= 0 && fromIndex <= toIndex && toIndex < length(); 146 deleted.setRange(fromIndex, toIndex + 1); 147 underlying.setEmpty(fromIndex, toIndex); 148 return this; 149 } 150 151 @Override 152 public Object pop() { 153 final long index = length() - 1; 154 155 if (super.has((int)index)) { 156 final boolean isDeleted = deleted.isSet(index); 157 final Object value = super.pop(); 158 159 return isDeleted ? UNDEFINED : value; 160 } 161 162 return super.pop(); 163 } 164 165 @Override 166 public ArrayData slice(final long from, final long to) { 167 final ArrayData newArray = underlying.slice(from, to); 168 final DeletedArrayFilter newFilter = new DeletedArrayFilter(newArray); 169 newFilter.getDeleted().copy(deleted); 170 newFilter.getDeleted().shiftLeft(from, newFilter.length()); 171 172 return newFilter; 173 } 174 175 private BitVector getDeleted() { 176 return deleted; 177 } 178 }