| /* |
| * Copyright 2005-2010 Roger Kapsi |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /** |
| * This class is taken from https://github.com/rkapsi/patricia-trie (v0.6), and slightly modified |
| * to correspond to Cassandra code style, as the only Patricia Trie implementation, |
| * which supports pluggable key comparators (e.g. commons-collections PatriciaTrie (which is based |
| * on rkapsi/patricia-trie project) only supports String keys) |
| * but unfortunately is not deployed to the maven central as a downloadable artifact. |
| */ |
| |
| package org.apache.cassandra.index.sasi.utils.trie; |
| |
| /** |
| * A collection of {@link Trie} utilities |
| */ |
| public class Tries |
| { |
| /** |
| * Returns true if bitIndex is a {@link KeyAnalyzer#OUT_OF_BOUNDS_BIT_KEY} |
| */ |
| static boolean isOutOfBoundsIndex(int bitIndex) |
| { |
| return bitIndex == KeyAnalyzer.OUT_OF_BOUNDS_BIT_KEY; |
| } |
| |
| /** |
| * Returns true if bitIndex is a {@link KeyAnalyzer#EQUAL_BIT_KEY} |
| */ |
| static boolean isEqualBitKey(int bitIndex) |
| { |
| return bitIndex == KeyAnalyzer.EQUAL_BIT_KEY; |
| } |
| |
| /** |
| * Returns true if bitIndex is a {@link KeyAnalyzer#NULL_BIT_KEY} |
| */ |
| static boolean isNullBitKey(int bitIndex) |
| { |
| return bitIndex == KeyAnalyzer.NULL_BIT_KEY; |
| } |
| |
| /** |
| * Returns true if the given bitIndex is valid. Indices |
| * are considered valid if they're between 0 and |
| * {@link Integer#MAX_VALUE} |
| */ |
| static boolean isValidBitIndex(int bitIndex) |
| { |
| return 0 <= bitIndex; |
| } |
| |
| /** |
| * Returns true if both values are either null or equal |
| */ |
| static boolean areEqual(Object a, Object b) |
| { |
| return (a == null ? b == null : a.equals(b)); |
| } |
| |
| /** |
| * Throws a {@link NullPointerException} with the given message if |
| * the argument is null. |
| */ |
| static <T> T notNull(T o, String message) |
| { |
| if (o == null) |
| throw new NullPointerException(message); |
| |
| return o; |
| } |
| |
| /** |
| * A utility method to cast keys. It actually doesn't |
| * cast anything. It's just fooling the compiler! |
| */ |
| @SuppressWarnings("unchecked") |
| static <K> K cast(Object key) |
| { |
| return (K)key; |
| } |
| } |