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 java.lang.reflect.Array; 29 import jdk.nashorn.internal.runtime.ScriptRuntime; 30 31 /** 32 * This filter handles the deletion of array elements. 33 */ 34 final class DeletedRangeArrayFilter extends ArrayFilter { 35 /** Range (inclusive) tracking deletions */ 36 private long lo, hi; 37 38 DeletedRangeArrayFilter(final ArrayData underlying, final long lo, final long hi) { 39 super(maybeSparse(underlying, hi)); 40 this.lo = lo; 41 this.hi = hi; 42 } 43 44 private static ArrayData maybeSparse(final ArrayData underlying, final long hi) { 45 if (hi < SparseArrayData.MAX_DENSE_LENGTH || underlying instanceof SparseArrayData) { 46 return underlying; 47 } 48 return new SparseArrayData(underlying, underlying.length()); 49 } 50 51 private boolean isEmpty() { 52 return lo > hi; 53 } 54 55 private boolean isDeleted(final int index) { 56 final long longIndex = ArrayIndex.toLongIndex(index); 57 return lo <= longIndex && longIndex <= hi; 58 } 59 60 @Override 61 public ArrayData copy() { 62 return new DeletedRangeArrayFilter(underlying.copy(), lo, hi); 63 } 64 65 @Override 66 public Object[] asObjectArray() { 67 final Object[] value = super.asObjectArray(); 68 69 if (lo < Integer.MAX_VALUE) { 70 final int end = (int)Math.min(hi + 1, Integer.MAX_VALUE); 71 for (int i = (int)lo; i < end; i++) { 72 value[i] = ScriptRuntime.UNDEFINED; 73 } 74 } 75 76 return value; 77 } 78 79 @Override 80 public Object asArrayOfType(final Class<?> componentType) { 81 final Object value = super.asArrayOfType(componentType); 82 final Object undefValue = convertUndefinedValue(componentType); 83 84 if (lo < Integer.MAX_VALUE) { 85 final int end = (int)Math.min(hi + 1, Integer.MAX_VALUE); 86 for (int i = (int)lo; i < end; i++) { 87 Array.set(value, i, undefValue); 88 } 89 } 90 91 return value; 92 } 93 94 @Override 95 public ArrayData ensure(final long safeIndex) { 96 if (safeIndex >= SparseArrayData.MAX_DENSE_LENGTH && safeIndex >= length()) { 97 return new SparseArrayData(this, safeIndex + 1); 98 } 99 100 return super.ensure(safeIndex); 101 } 102 103 @Override 104 public void shiftLeft(final int by) { 105 super.shiftLeft(by); 106 lo = Math.max(0, lo - by); 107 hi = Math.max(-1, hi - by); 108 } 109 110 @Override 111 public ArrayData shiftRight(final int by) { 112 super.shiftRight(by); 113 final long len = length(); 114 lo = Math.min(len, lo + by); 115 hi = Math.min(len - 1, hi + by); 116 117 return isEmpty() ? getUnderlying() : this; 118 } 119 120 @Override 121 public ArrayData shrink(final long newLength) { 122 super.shrink(newLength); 123 lo = Math.min(newLength, lo); 124 hi = Math.min(newLength - 1, hi); 125 126 return isEmpty() ? getUnderlying() : this; 127 } 128 129 @Override 130 public ArrayData set(final int index, final Object value, final boolean strict) { 131 final long longIndex = ArrayIndex.toLongIndex(index); 132 if (longIndex < lo || longIndex > hi) { 133 return super.set(index, value, strict); 134 } else if (longIndex > lo && longIndex < hi) { 135 return getDeletedArrayFilter().set(index, value, strict); 136 } 137 if (longIndex == lo) { 138 lo++; 139 } else { 140 assert longIndex == hi; 141 hi--; 142 } 143 144 return isEmpty() ? getUnderlying().set(index, value, strict) : super.set(index, value, strict); 145 } 146 147 @Override 148 public ArrayData set(final int index, final int value, final boolean strict) { 149 final long longIndex = ArrayIndex.toLongIndex(index); 150 if (longIndex < lo || longIndex > hi) { 151 return super.set(index, value, strict); 152 } else if (longIndex > lo && longIndex < hi) { 153 return getDeletedArrayFilter().set(index, value, strict); 154 } 155 if (longIndex == lo) { 156 lo++; 157 } else { 158 assert longIndex == hi; 159 hi--; 160 } 161 162 return isEmpty() ? getUnderlying().set(index, value, strict) : super.set(index, value, strict); 163 } 164 165 @Override 166 public ArrayData set(final int index, final long value, final boolean strict) { 167 final long longIndex = ArrayIndex.toLongIndex(index); 168 if (longIndex < lo || longIndex > hi) { 169 return super.set(index, value, strict); 170 } else if (longIndex > lo && longIndex < hi) { 171 return getDeletedArrayFilter().set(index, value, strict); 172 } 173 if (longIndex == lo) { 174 lo++; 175 } else { 176 assert longIndex == hi; 177 hi--; 178 } 179 180 return isEmpty() ? getUnderlying().set(index, value, strict) : super.set(index, value, strict); 181 } 182 183 @Override 184 public ArrayData set(final int index, final double value, final boolean strict) { 185 final long longIndex = ArrayIndex.toLongIndex(index); 186 if (longIndex < lo || longIndex > hi) { 187 return super.set(index, value, strict); 188 } else if (longIndex > lo && longIndex < hi) { 189 return getDeletedArrayFilter().set(index, value, strict); 190 } 191 if (longIndex == lo) { 192 lo++; 193 } else { 194 assert longIndex == hi; 195 hi--; 196 } 197 198 return isEmpty() ? getUnderlying().set(index, value, strict) : super.set(index, value, strict); 199 } 200 201 @Override 202 public boolean has(final int index) { 203 return super.has(index) && !isDeleted(index); 204 } 205 206 private ArrayData getDeletedArrayFilter() { 207 final ArrayData deleteFilter = new DeletedArrayFilter(getUnderlying()); 208 deleteFilter.delete(lo, hi); 209 return deleteFilter; 210 } 211 212 @Override 213 public ArrayData delete(final int index) { 214 final long longIndex = ArrayIndex.toLongIndex(index); 215 underlying.setEmpty(index); 216 217 if (longIndex + 1 == lo) { 218 lo = longIndex; 219 } else if (longIndex - 1 == hi) { 220 hi = longIndex; 221 } else if (longIndex < lo || hi < longIndex) { 222 return getDeletedArrayFilter().delete(index); 223 } 224 225 return this; 226 } 227 228 @Override 229 public ArrayData delete(final long fromIndex, final long toIndex) { 230 if (fromIndex > hi + 1 || toIndex < lo - 1) { 231 return getDeletedArrayFilter().delete(fromIndex, toIndex); 232 } 233 lo = Math.min(fromIndex, lo); 234 hi = Math.max(toIndex, hi); 235 underlying.setEmpty(lo, hi); 236 return this; 237 } 238 239 @Override 240 public Object pop() { 241 final int index = (int)length() - 1; 242 if (super.has(index)) { 243 final boolean isDeleted = isDeleted(index); 244 final Object value = super.pop(); 245 246 lo = Math.min(index + 1, lo); 247 hi = Math.min(index, hi); 248 return isDeleted ? ScriptRuntime.UNDEFINED : value; 249 } 250 251 return super.pop(); 252 } 253 254 @Override 255 public ArrayData slice(final long from, final long to) { 256 return new DeletedRangeArrayFilter(underlying.slice(from, to), Math.max(0, lo - from), Math.max(0, hi - from)); 257 } 258 }