/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ /* $Id$ */ package org.apache.fop.hyphenation; import java.util.Hashtable; import java.util.Map; import java.util.Set; /** * <p>This is a cache for HyphenationTree instances.</p> */ public class HyphenationTreeCache { /** Contains the cached hyphenation trees */ private Hashtable hyphenTrees = new Hashtable(); /** Used to avoid multiple error messages for the same language if a pattern file is missing. */ private Set missingHyphenationTrees; /** * Looks in the cache if a hyphenation tree is available and returns it if it is found. * @param lang the language * @param country the country (may be null or "none") * @return the HyhenationTree instance or null if it's not in the cache */ public HyphenationTree getHyphenationTree(String lang, String country) { String key = constructLlccKey(lang, country); // first try to find it in the cache if (hyphenTrees.containsKey(key)) { return (HyphenationTree)hyphenTrees.get(key); } else if (hyphenTrees.containsKey(lang)) { return (HyphenationTree)hyphenTrees.get(lang); } else { return null; } } /** * Constructs the key for the hyphenation pattern file. * @param lang the language * @param country the country (may be null or "none") * @return the resulting key */ public static String constructLlccKey(String lang, String country) { String key = lang; // check whether the country code has been used if (country != null && !country.equals("none")) { key += "_" + country; } return key; } /** * If the user configured a hyphenation pattern file name * for this (lang,country) value, return it. If not, return null. * @param lang the language * @param country the country (may be null or "none") * @param hyphPatNames the map of user-configured hyphenation pattern file names * @return the hyphenation pattern file name or null */ public static String constructUserKey(String lang, String country, Map hyphPatNames) { String userKey = null; if (hyphPatNames != null) { String key = constructLlccKey(lang, country); key = key.replace('_', '-'); userKey = (String) hyphPatNames.get(key); } return userKey; } /** * Cache a hyphenation tree under its key. * @param key the key (ex. "de_CH" or "en") * @param hTree the hyphenation tree */ public void cache(String key, HyphenationTree hTree) { hyphenTrees.put(key, hTree); } /** * Notes a key to a hyphenation tree as missing. * This is to avoid searching a second time for a hyphenation pattern file which is not * available. * @param key the key (ex. "de_CH" or "en") */ public void noteMissing(String key) { if (missingHyphenationTrees == null) { missingHyphenationTrees = new java.util.HashSet(); } missingHyphenationTrees.add(key); } /** * Indicates whether a hyphenation file has been requested before but it wasn't available. * This is to avoid searching a second time for a hyphenation pattern file which is not * available. * @param key the key (ex. "de_CH" or "en") * @return true if the hyphenation tree is unavailable */ public boolean isMissing(String key) { return (missingHyphenationTrees != null && missingHyphenationTrees.contains(key)); } }