| /* |
| * Copyright (c) 2010, 2013, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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 jdk.nashorn.internal.runtime.regexp; |
| |
| import java.util.Collections; |
| import java.util.Map; |
| import java.util.WeakHashMap; |
| import jdk.nashorn.internal.runtime.ParserException; |
| import jdk.nashorn.internal.runtime.options.Options; |
| |
| /** |
| * Factory class for regular expressions. This class creates instances of {@link JdkRegExp}. |
| * An alternative factory can be installed using the {@code nashorn.regexp.impl} system property. |
| */ |
| public class RegExpFactory { |
| |
| private final static RegExpFactory instance; |
| |
| private final static String JDK = "jdk"; |
| private final static String JONI = "joni"; |
| |
| /** Weak cache of already validated regexps - when reparsing, we don't, for example |
| * need to recompile (reverify) all regexps that have previously been parsed by this |
| * RegExpFactory in a previous compilation. This saves significant time in e.g. avatar |
| * startup |
| */ |
| private static final Map<String, RegExp> REGEXP_CACHE = |
| Collections.synchronizedMap(new WeakHashMap<String, RegExp>()); |
| |
| static { |
| final String impl = Options.getStringProperty("nashorn.regexp.impl", JONI); |
| switch (impl) { |
| case JONI: |
| instance = new JoniRegExp.Factory(); |
| break; |
| case JDK: |
| instance = new RegExpFactory(); |
| break; |
| default: |
| instance = null; |
| throw new InternalError("Unsupported RegExp factory: " + impl); |
| } |
| } |
| |
| /** |
| * Creates a Regular expression from the given {@code pattern} and {@code flags} strings. |
| * |
| * @param pattern RegExp pattern string |
| * @param flags RegExp flags string |
| * @return new RegExp |
| * @throws ParserException if flags is invalid or pattern string has syntax error. |
| */ |
| public RegExp compile(final String pattern, final String flags) throws ParserException { |
| return new JdkRegExp(pattern, flags); |
| } |
| |
| /** |
| * Compile a regexp with the given {@code source} and {@code flags}. |
| * |
| * @param pattern RegExp pattern string |
| * @param flags flag string |
| * @return new RegExp |
| * @throws ParserException if invalid source or flags |
| */ |
| public static RegExp create(final String pattern, final String flags) { |
| final String key = pattern + "/" + flags; |
| RegExp regexp = REGEXP_CACHE.get(key); |
| if (regexp == null) { |
| regexp = instance.compile(pattern, flags); |
| REGEXP_CACHE.put(key, regexp); |
| } |
| return regexp; |
| } |
| |
| /** |
| * Validate a regexp with the given {@code source} and {@code flags}. |
| * |
| * @param pattern RegExp pattern string |
| * @param flags flag string |
| * |
| * @throws ParserException if invalid source or flags |
| */ |
| public static void validate(final String pattern, final String flags) throws ParserException { |
| create(pattern, flags); |
| } |
| |
| /** |
| * Returns true if the instance uses the JDK's {@code java.util.regex} package. |
| * |
| * @return true if instance uses JDK regex package |
| */ |
| public static boolean usesJavaUtilRegex() { |
| return instance != null && instance.getClass() == RegExpFactory.class; |
| } |
| } |