DeletedArrayFilter.java revision 1040:cc3000241e57
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.runtime.ScriptRuntime.UNDEFINED; 29import java.lang.reflect.Array; 30import jdk.nashorn.internal.runtime.BitVector; 31 32/** 33 * This filter handles the deletion of array elements. 34 */ 35final class DeletedArrayFilter extends ArrayFilter { 36 /** Bit vector tracking deletions. */ 37 private final BitVector deleted; 38 39 DeletedArrayFilter(final ArrayData underlying) { 40 super(underlying); 41 42 this.deleted = new BitVector(underlying.length); 43 } 44 45 @Override 46 public ArrayData copy() { 47 final DeletedArrayFilter copy = new DeletedArrayFilter(underlying.copy()); 48 copy.getDeleted().copy(deleted); 49 return copy; 50 } 51 52 @Override 53 public Object[] asObjectArray() { 54 final Object[] value = super.asObjectArray(); 55 56 for (int i = 0; i < value.length; i++) { 57 if (deleted.isSet(i)) { 58 value[i] = UNDEFINED; 59 } 60 } 61 62 return value; 63 } 64 65 @Override 66 public Object asArrayOfType(final Class<?> componentType) { 67 final Object value = super.asArrayOfType(componentType); 68 final Object undefValue = convertUndefinedValue(componentType); 69 final int l = Array.getLength(value); 70 for (int i = 0; i < l; i++) { 71 if (deleted.isSet(i)) { 72 Array.set(value, i, undefValue); 73 } 74 } 75 76 return value; 77 } 78 79 @Override 80 public void shiftLeft(final int by) { 81 super.shiftLeft(by); 82 deleted.shiftLeft(by, length); 83 } 84 85 @Override 86 public ArrayData shiftRight(final int by) { 87 super.shiftRight(by); 88 deleted.shiftRight(by, length); 89 90 return this; 91 } 92 93 @Override 94 public ArrayData ensure(final long safeIndex) { 95 if (safeIndex >= SparseArrayData.MAX_DENSE_LENGTH && safeIndex >= length) { 96 return new SparseArrayData(this, safeIndex + 1); 97 } 98 99 super.ensure(safeIndex); 100 deleted.resize(length); 101 102 return this; 103 } 104 105 @Override 106 public ArrayData shrink(final long newLength) { 107 super.shrink(newLength); 108 deleted.resize(length); 109 110 return this; 111 } 112 113 @Override 114 public ArrayData set(final int index, final Object value, final boolean strict) { 115 deleted.clear(ArrayIndex.toLongIndex(index)); 116 117 return super.set(index, value, strict); 118 } 119 120 @Override 121 public ArrayData set(final int index, final int value, final boolean strict) { 122 deleted.clear(ArrayIndex.toLongIndex(index)); 123 124 return super.set(index, value, strict); 125 } 126 127 @Override 128 public ArrayData set(final int index, final long value, final boolean strict) { 129 deleted.clear(ArrayIndex.toLongIndex(index)); 130 131 return super.set(index, value, strict); 132 } 133 134 @Override 135 public ArrayData set(final int index, final double value, final boolean strict) { 136 deleted.clear(ArrayIndex.toLongIndex(index)); 137 138 return super.set(index, value, strict); 139 } 140 141 @Override 142 public boolean has(final int index) { 143 return super.has(index) && deleted.isClear(ArrayIndex.toLongIndex(index)); 144 } 145 146 @Override 147 public ArrayData delete(final int index) { 148 final long longIndex = ArrayIndex.toLongIndex(index); 149 assert longIndex >= 0 && longIndex < length; 150 deleted.set(longIndex); 151 underlying.setEmpty(index); 152 return this; 153 } 154 155 @Override 156 public ArrayData delete(final long fromIndex, final long toIndex) { 157 assert fromIndex >= 0 && fromIndex <= toIndex && toIndex < length; 158 deleted.setRange(fromIndex, toIndex + 1); 159 underlying.setEmpty(fromIndex, toIndex); 160 return this; 161 } 162 163 @Override 164 public Object pop() { 165 final long index = length - 1; 166 167 if (super.has((int)index)) { 168 final boolean isDeleted = deleted.isSet(index); 169 final Object value = super.pop(); 170 171 return isDeleted ? UNDEFINED : value; 172 } 173 174 return super.pop(); 175 } 176 177 @Override 178 public ArrayData slice(final long from, final long to) { 179 final ArrayData newArray = underlying.slice(from, to); 180 final DeletedArrayFilter newFilter = new DeletedArrayFilter(newArray); 181 newFilter.getDeleted().copy(deleted); 182 newFilter.getDeleted().shiftLeft(from, newFilter.length); 183 184 return newFilter; 185 } 186 187 private BitVector getDeleted() { 188 return deleted; 189 } 190} 191