Mercurial > hg > truffle
view graal/com.oracle.max.base/src/com/sun/max/collect/SortedLongArrayMapping.java @ 4213:e4cfa571d8c4
Do not emit stack-to-stack moves.
author | Christian Wimmer <Christian.Wimmer@Oracle.com> |
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date | Tue, 03 Jan 2012 18:47:27 -0800 |
parents | e233f5660da4 |
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/* * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.max.collect; import com.sun.max.*; /** * Two arrays: one holding sorted long keys, * the parallel other one holding lookup values corresponding to those keys. * Insertion/deletion moderately costly, lookup by binary search pretty fast. */ public class SortedLongArrayMapping<V> { public SortedLongArrayMapping() { } private long[] keys = {}; private Object[] values = {}; private int findIndex(long key) { int left = 0; int right = keys.length; while (right > left) { final int middle = left + ((right - left) >> 1); final long middleKey = keys[middle]; if (middleKey == key) { return middle; } else if (middleKey > key) { right = middle; } else { left = middle + 1; } } return left; } /** * Binary search in the key array. * @return the value corresponding to the key or null if the key is not found */ public V get(long key) { final int index = findIndex(key); if (index < keys.length && keys[index] == key) { final Class<V> type = null; return Utils.cast(type, values[index]); } return null; } public void put(long key, V value) { final int index = findIndex(key); if (index < keys.length && keys[index] == key) { values[index] = value; } else { long[] newKeys = new long[keys.length + 1]; System.arraycopy(keys, 0, newKeys, 0, index); System.arraycopy(keys, index, newKeys, index + 1, keys.length - index); newKeys[index] = key; keys = newKeys; Object[] newValues = new Object[values.length + 1]; System.arraycopy(values, 0, newValues, 0, index); System.arraycopy(values, index, newValues, index + 1, values.length - index); newValues[index] = value; values = newValues; } } public void remove(long key) { final int index = findIndex(key); if (keys[index] == key) { int newLength = keys.length - 1; long[] newKeys = new long[newLength]; System.arraycopy(keys, 0, newKeys, 0, index); System.arraycopy(keys, index + 1, newKeys, index, newLength - index); keys = newKeys; Object[] newValues = new Object[newLength]; System.arraycopy(values, 0, newValues, 0, index); System.arraycopy(values, index + 1, newValues, index, newLength - index); values = newValues; } } }