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/*
 ****************************************************************************************
 * Copyright (C) 2009-2016, Google, Inc.; International Business Machines Corporation   *
 * and others. All Rights Reserved.                                                     *
 ****************************************************************************************
 */
package com.ibm.icu.util;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.ibm.icu.impl.ICUResourceBundle;
import com.ibm.icu.impl.Relation;
import com.ibm.icu.impl.Row;
import com.ibm.icu.impl.Row.R3;
import com.ibm.icu.impl.Utility;

/**
 * Provides a way to match the languages (locales) supported by a product to the
 * languages (locales) acceptable to a user, and get the best match. For
 * example:
 * 
 * 
 * LocaleMatcher matcher = new LocaleMatcher("fr, en-GB, en");
 * 
 * // afterwards:
 * matcher.getBestMatch("en-US").toLanguageTag() => "en"
 * 
* * It takes into account when languages are close to one another, such as fil * and tl, and when language regional variants are close, like en-GB and en-AU. * It also handles scripts, like zh-Hant vs zh-TW. For examples, see the test * file. *

All classes implementing this interface should be immutable. Often a * product will just need one static instance, built with the languages * that it supports. However, it may want multiple instances with different * default languages based on additional information, such as the domain. * * @author [email protected] * @stable ICU 4.4 */ public class LocaleMatcher { /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public static final boolean DEBUG = false; private static final ULocale UNKNOWN_LOCALE = new ULocale("und"); /** * Threshold for falling back to the default (first) language. May make this * a parameter in the future. */ private static final double DEFAULT_THRESHOLD = 0.5; /** * The default language, in case the threshold is not met. */ private final ULocale defaultLanguage; /** * The default language, in case the threshold is not met. */ private final double threshold; /** * Create a new language matcher. The highest-weighted language is the * default. That means that if no other language is matches closer than a given * threshold, that default language is chosen. Typically the default is English, * but it could be different based on additional information, such as the domain * of the page. * * @param languagePriorityList weighted list * @stable ICU 4.4 */ public LocaleMatcher(LocalePriorityList languagePriorityList) { this(languagePriorityList, defaultWritten); } /** * Create a new language matcher from a String form. The highest-weighted * language is the default. * * @param languagePriorityListString String form of LanguagePriorityList * @stable ICU 4.4 */ public LocaleMatcher(String languagePriorityListString) { this(LocalePriorityList.add(languagePriorityListString).build()); } /** * Internal testing function; may expose API later. * @param languagePriorityList LocalePriorityList to match * @param matcherData Internal matching data * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LocaleMatcher(LocalePriorityList languagePriorityList, LanguageMatcherData matcherData) { this(languagePriorityList, matcherData, DEFAULT_THRESHOLD); } /** * Internal testing function; may expose API later. * @param languagePriorityList LocalePriorityList to match * @param matcherData Internal matching data * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LocaleMatcher(LocalePriorityList languagePriorityList, LanguageMatcherData matcherData, double threshold) { this.matcherData = matcherData == null ? defaultWritten : matcherData.freeze(); for (final ULocale language : languagePriorityList) { add(language, languagePriorityList.getWeight(language)); } processMapping(); Iterator it = languagePriorityList.iterator(); defaultLanguage = it.hasNext() ? it.next() : null; this.threshold = threshold; } /** * Returns a fraction between 0 and 1, where 1 means that the languages are a * perfect match, and 0 means that they are completely different. Note that * the precise values may change over time; no code should be made dependent * on the values remaining constant. * @param desired Desired locale * @param desiredMax Maximized locale (using likely subtags) * @param supported Supported locale * @param supportedMax Maximized locale (using likely subtags) * @return value between 0 and 1, inclusive. * @stable ICU 4.4 */ public double match(ULocale desired, ULocale desiredMax, ULocale supported, ULocale supportedMax) { return matcherData.match(desired, desiredMax, supported, supportedMax); } /** * Canonicalize a locale (language). Note that for now, it is canonicalizing * according to CLDR conventions (he vs iw, etc), since that is what is needed * for likelySubtags. * @param ulocale language/locale code * @return ULocale with remapped subtags. * @stable ICU 4.4 */ public ULocale canonicalize(ULocale ulocale) { // TODO Get the data from CLDR, use Java conventions. String lang = ulocale.getLanguage(); String lang2 = canonicalMap.get(lang); String script = ulocale.getScript(); String script2 = canonicalMap.get(script); String region = ulocale.getCountry(); String region2 = canonicalMap.get(region); if (lang2 != null || script2 != null || region2 != null) { return new ULocale( lang2 == null ? lang : lang2, script2 == null ? script : script2, region2 == null ? region : region2 ); } return ulocale; } /** * Get the best match for a LanguagePriorityList * * @param languageList list to match * @return best matching language code * @stable ICU 4.4 */ public ULocale getBestMatch(LocalePriorityList languageList) { double bestWeight = 0; ULocale bestTableMatch = null; double penalty = 0; OutputDouble matchWeight = new OutputDouble(); for (final ULocale language : languageList) { final ULocale matchLocale = getBestMatchInternal(language, matchWeight); final double weight = matchWeight.value * languageList.getWeight(language) - penalty; if (weight > bestWeight) { bestWeight = weight; bestTableMatch = matchLocale; } penalty += 0.07000001; } if (bestWeight < threshold) { bestTableMatch = defaultLanguage; } return bestTableMatch; } /** * Convenience method: Get the best match for a LanguagePriorityList * * @param languageList String form of language priority list * @return best matching language code * @stable ICU 4.4 */ public ULocale getBestMatch(String languageList) { return getBestMatch(LocalePriorityList.add(languageList).build()); } /** * Get the best match for an individual language code. * * @param ulocale locale/language code to match * @return best matching language code * @stable ICU 4.4 */ public ULocale getBestMatch(ULocale ulocale) { return getBestMatchInternal(ulocale, null); } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public ULocale getBestMatch(ULocale... ulocales) { return getBestMatch(LocalePriorityList.add(ulocales).build()); } /** * {@inheritDoc} * @stable ICU 4.4 */ @Override public String toString() { return "{" + defaultLanguage + ", " + localeToMaxLocaleAndWeight + "}"; } // ================= Privates ===================== /** * Get the best match for an individual language code. * * @param languageCode * @return best matching language code and weight (as per * {@link #match(ULocale, ULocale)}) */ private ULocale getBestMatchInternal(ULocale languageCode, OutputDouble outputWeight) { languageCode = canonicalize(languageCode); final ULocale maximized = addLikelySubtags(languageCode); if (DEBUG) { System.out.println("\ngetBestMatchInternal: " + languageCode + ";\t" + maximized); } double bestWeight = 0; ULocale bestTableMatch = null; String baseLanguage = maximized.getLanguage(); Set> searchTable = desiredLanguageToPossibleLocalesToMaxLocaleToData.get(baseLanguage); if (searchTable != null) { // we preprocessed the table so as to filter by lanugage if (DEBUG) System.out.println("\tSearching: " + searchTable); for (final R3 tableKeyValue : searchTable) { ULocale tableKey = tableKeyValue.get0(); ULocale maxLocale = tableKeyValue.get1(); Double matchedWeight = tableKeyValue.get2(); final double match = match(languageCode, maximized, tableKey, maxLocale); if (DEBUG) { System.out.println("\t" + tableKeyValue + ";\t" + match + "\n"); } final double weight = match * matchedWeight; if (weight > bestWeight) { bestWeight = weight; bestTableMatch = tableKey; if (weight > 0.999d) { // bail on good enough match. break; } } } } if (bestWeight < threshold) { bestTableMatch = defaultLanguage; } if (outputWeight != null) { outputWeight.value = bestWeight; // only return the weight when needed } return bestTableMatch; } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated private static class OutputDouble { // TODO, move to where OutputInt is double value; } private void add(ULocale language, Double weight) { language = canonicalize(language); R3 row = Row.of(language, addLikelySubtags(language), weight); row.freeze(); localeToMaxLocaleAndWeight.add(row); } /** * We preprocess the data to get just the possible matches for each desired base language. */ private void processMapping() { for (Entry> desiredToMatchingLanguages : matcherData.matchingLanguages().keyValuesSet()) { String desired = desiredToMatchingLanguages.getKey(); Set supported = desiredToMatchingLanguages.getValue(); for (R3 localeToMaxAndWeight : localeToMaxLocaleAndWeight) { final ULocale key = localeToMaxAndWeight.get0(); String lang = key.getLanguage(); if (supported.contains(lang)) { addFiltered(desired, localeToMaxAndWeight); } } } // now put in the values directly, since languages always map to themselves for (R3 localeToMaxAndWeight : localeToMaxLocaleAndWeight) { final ULocale key = localeToMaxAndWeight.get0(); String lang = key.getLanguage(); addFiltered(lang, localeToMaxAndWeight); } } private void addFiltered(String desired, R3 localeToMaxAndWeight) { Set> map = desiredLanguageToPossibleLocalesToMaxLocaleToData.get(desired); if (map == null) { desiredLanguageToPossibleLocalesToMaxLocaleToData.put(desired, map = new LinkedHashSet>()); } map.add(localeToMaxAndWeight); if (DEBUG) { System.out.println(desired + ", " + localeToMaxAndWeight); } } Set> localeToMaxLocaleAndWeight = new LinkedHashSet>(); Map>> desiredLanguageToPossibleLocalesToMaxLocaleToData = new LinkedHashMap>>(); // =============== Special Mapping Information ============== /** * We need to add another method to addLikelySubtags that doesn't return * null, but instead substitutes Zzzz and ZZ if unknown. There are also * a few cases where addLikelySubtags needs to have expanded data, to handle * all deprecated codes. * @param languageCode * @return "fixed" addLikelySubtags */ private ULocale addLikelySubtags(ULocale languageCode) { // max("und") = "en_Latn_US", and since matching is based on maximized tags, the undefined // language would normally match English. But that would produce the counterintuitive results // that getBestMatch("und", LocaleMatcher("it,en")) would be "en", and // getBestMatch("en", LocaleMatcher("it,und")) would be "und". // // To avoid that, we change the matcher's definitions of max (AddLikelySubtagsWithDefaults) // so that max("und")="und". That produces the following, more desirable results: if (languageCode.equals(UNKNOWN_LOCALE)) { return UNKNOWN_LOCALE; } final ULocale result = ULocale.addLikelySubtags(languageCode); // should have method on getLikelySubtags for this if (result == null || result.equals(languageCode)) { final String language = languageCode.getLanguage(); final String script = languageCode.getScript(); final String region = languageCode.getCountry(); return new ULocale((language.length()==0 ? "und" : language) + "_" + (script.length()==0 ? "Zzzz" : script) + "_" + (region.length()==0 ? "ZZ" : region)); } return result; } private static class LocalePatternMatcher { // a value of null means a wildcard; matches any. private String lang; private String script; private String region; private Level level; static Pattern pattern = Pattern.compile( "([a-z]{1,8}|\\*)" + "(?:[_-]([A-Z][a-z]{3}|\\*))?" + "(?:[_-]([A-Z]{2}|[0-9]{3}|\\*))?"); public LocalePatternMatcher(String toMatch) { Matcher matcher = pattern.matcher(toMatch); if (!matcher.matches()) { throw new IllegalArgumentException("Bad pattern: " + toMatch); } lang = matcher.group(1); script = matcher.group(2); region = matcher.group(3); level = region != null ? Level.region : script != null ? Level.script : Level.language; if (lang.equals("*")) { lang = null; } if (script != null && script.equals("*")) { script = null; } if (region != null && region.equals("*")) { region = null; } } boolean matches(ULocale ulocale) { if (lang != null && !lang.equals(ulocale.getLanguage())) { return false; } if (script != null && !script.equals(ulocale.getScript())) { return false; } if (region != null && !region.equals(ulocale.getCountry())) { return false; } return true; } public Level getLevel() { return level; } public String getLanguage() { return (lang == null ? "*" : lang); } public String getScript() { return (script == null ? "*" : script); } public String getRegion() { return (region == null ? "*" : region); } public String toString() { String result = getLanguage(); if (level != Level.language) { result += "-" + getScript(); if (level != Level.script) { result += "-" + getRegion(); } } return result; } /* (non-Javadoc) * @see java.lang.Object#equals(java.lang.Object) */ @Override public boolean equals(Object obj) { LocalePatternMatcher other = (LocalePatternMatcher) obj; return Utility.objectEquals(level, other.level) && Utility.objectEquals(lang, other.lang) && Utility.objectEquals(script, other.script) && Utility.objectEquals(region, other.region); } /* (non-Javadoc) * @see java.lang.Object#hashCode() */ @Override public int hashCode() { return level.ordinal() ^ (lang == null ? 0 : lang.hashCode()) ^ (script == null ? 0 : script.hashCode()) ^ (region == null ? 0 : region.hashCode()); } } enum Level { language(0.99), script(0.2), region(0.04); final double worst; Level(double d) { worst = d; } } private static class ScoreData implements Freezable { @SuppressWarnings("unused") private static final double maxUnequal_changeD_sameS = 0.5; @SuppressWarnings("unused") private static final double maxUnequal_changeEqual = 0.75; LinkedHashSet> scores = new LinkedHashSet>(); final Level level; public ScoreData(Level level) { this.level = level; } void addDataToScores(String desired, String supported, R3 data) { // Map>> lang_result = scores.get(desired); // if (lang_result == null) { // scores.put(desired, lang_result = new HashMap()); // } // Set> result = lang_result.get(supported); // if (result == null) { // lang_result.put(supported, result = new LinkedHashSet()); // } // result.add(data); boolean added = scores.add(data); if (!added) { throw new ICUException("trying to add duplicate data: " + data); } } double getScore(ULocale dMax, String desiredRaw, String desiredMax, ULocale sMax, String supportedRaw, String supportedMax) { double distance = 0; if (!desiredMax.equals(supportedMax)) { distance = getRawScore(dMax, sMax); } else if (!desiredRaw.equals(supportedRaw)) { // maxes are equal, changes are equal distance += 0.001; } return distance; } private double getRawScore(ULocale desiredLocale, ULocale supportedLocale) { if (DEBUG) { System.out.println("\t\t\t" + level + " Raw Score:\t" + desiredLocale + ";\t" + supportedLocale); } for (R3 datum : scores) { // : result if (datum.get0().matches(desiredLocale) && datum.get1().matches(supportedLocale)) { if (DEBUG) { System.out.println("\t\t\t\tFOUND\t" + datum); } return datum.get2(); } } if (DEBUG) { System.out.println("\t\t\t\tNOTFOUND\t" + level.worst); } return level.worst; } public String toString() { StringBuilder result = new StringBuilder().append(level); for (R3 score : scores) { result.append("\n\t\t").append(score); } return result.toString(); } @SuppressWarnings("unchecked") public ScoreData cloneAsThawed() { try { ScoreData result = (ScoreData) clone(); result.scores = (LinkedHashSet>) result.scores.clone(); result.frozen = false; return result; } catch (CloneNotSupportedException e) { throw new ICUCloneNotSupportedException(e); // will never happen } } private volatile boolean frozen = false; public ScoreData freeze() { return this; } public boolean isFrozen() { return frozen; } public Relation getMatchingLanguages() { Relation desiredToSupported = Relation.of(new LinkedHashMap>(), HashSet.class); for (R3 item : scores) { LocalePatternMatcher desired = item.get0(); LocalePatternMatcher supported = item.get1(); if (desired.lang != null && supported.lang != null) { // explicitly mentioned languages must have reasonable distance desiredToSupported.put(desired.lang, supported.lang); } } desiredToSupported.freeze(); return desiredToSupported; } } /** * Only for testing and use by tools. Interface may change!! * @internal * @deprecated This API is ICU internal only. */ @Deprecated public static class LanguageMatcherData implements Freezable { private ScoreData languageScores = new ScoreData(Level.language); private ScoreData scriptScores = new ScoreData(Level.script); private ScoreData regionScores = new ScoreData(Level.region); private Relation matchingLanguages; private volatile boolean frozen = false; /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LanguageMatcherData() { } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public Relation matchingLanguages() { return matchingLanguages; } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public String toString() { return languageScores + "\n\t" + scriptScores + "\n\t" + regionScores; } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public double match(ULocale a, ULocale aMax, ULocale b, ULocale bMax) { double diff = 0; diff += languageScores.getScore(aMax, a.getLanguage(), aMax.getLanguage(), bMax, b.getLanguage(), bMax.getLanguage()); if (diff > 0.999d) { // with no language match, we bail return 0.0d; } diff += scriptScores.getScore(aMax, a.getScript(), aMax.getScript(), bMax, b.getScript(), bMax.getScript()); diff += regionScores.getScore(aMax, a.getCountry(), aMax.getCountry(), bMax, b.getCountry(), bMax.getCountry()); if (!a.getVariant().equals(b.getVariant())) { diff += 0.01; } if (diff < 0.0d) { diff = 0.0d; } else if (diff > 1.0d) { diff = 1.0d; } if (DEBUG) { System.out.println("\t\t\tTotal Distance\t" + diff); } return 1.0 - diff; } /** * Add an exceptional distance between languages, typically because regional * dialects were given their own language codes. At this point the code is * symmetric. We don't bother producing an equivalence class because there are * so few cases; this function depends on the other permutations being * added specifically. * @internal * @deprecated This API is ICU internal only. */ @SuppressWarnings("unused") @Deprecated private LanguageMatcherData addDistance(String desired, String supported, int percent) { return addDistance(desired, supported, percent, false, null); } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LanguageMatcherData addDistance(String desired, String supported, int percent, String comment) { return addDistance(desired, supported, percent, false, comment); } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LanguageMatcherData addDistance(String desired, String supported, int percent, boolean oneway) { return addDistance(desired, supported, percent, oneway, null); } private LanguageMatcherData addDistance(String desired, String supported, int percent, boolean oneway, String comment) { if (DEBUG) { System.out.println("\t" + (comment == null ? "" : "\t")); // // .addDistance("nn", "nb", 4, true) // System.out.println(".addDistance(\"" + desired + "\"" + // ", \"" + supported + "\"" + // ", " + percent + "" // + (oneway ? "" : ", true") // + (comment == null ? "" : ", \"" + comment + "\"") // + ")" // ); } double score = 1-percent/100.0; // convert from percentage LocalePatternMatcher desiredMatcher = new LocalePatternMatcher(desired); Level desiredLen = desiredMatcher.getLevel(); LocalePatternMatcher supportedMatcher = new LocalePatternMatcher(supported); Level supportedLen = supportedMatcher.getLevel(); if (desiredLen != supportedLen) { throw new IllegalArgumentException("Lengths unequal: " + desired + ", " + supported); } R3 data = Row.of(desiredMatcher, supportedMatcher, score); R3 data2 = oneway ? null : Row.of(supportedMatcher, desiredMatcher, score); boolean desiredEqualsSupported = desiredMatcher.equals(supportedMatcher); switch (desiredLen) { case language: String dlanguage = desiredMatcher.getLanguage(); String slanguage = supportedMatcher.getLanguage(); languageScores.addDataToScores(dlanguage, slanguage, data); if (!oneway && !desiredEqualsSupported) { languageScores.addDataToScores(slanguage, dlanguage, data2); } break; case script: String dscript = desiredMatcher.getScript(); String sscript = supportedMatcher.getScript(); scriptScores.addDataToScores(dscript, sscript, data); if (!oneway && !desiredEqualsSupported) { scriptScores.addDataToScores(sscript, dscript, data2); } break; case region: String dregion = desiredMatcher.getRegion(); String sregion = supportedMatcher.getRegion(); regionScores.addDataToScores(dregion, sregion, data); if (!oneway && !desiredEqualsSupported) { regionScores.addDataToScores(sregion, dregion, data2); } break; } return this; } /** * {@inheritDoc} * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LanguageMatcherData cloneAsThawed() { LanguageMatcherData result; try { result = (LanguageMatcherData) clone(); result.languageScores = languageScores.cloneAsThawed(); result.scriptScores = scriptScores.cloneAsThawed(); result.regionScores = regionScores.cloneAsThawed(); result.frozen = false; return result; } catch (CloneNotSupportedException e) { throw new ICUCloneNotSupportedException(e); // will never happen } } /** * {@inheritDoc} * @internal * @deprecated This API is ICU internal only. */ @Deprecated public LanguageMatcherData freeze() { languageScores.freeze(); regionScores.freeze(); scriptScores.freeze(); matchingLanguages = languageScores.getMatchingLanguages(); frozen = true; return this; } /** * {@inheritDoc} * @internal * @deprecated This API is ICU internal only. */ @Deprecated public boolean isFrozen() { return frozen; } } LanguageMatcherData matcherData; private static final LanguageMatcherData defaultWritten; private static HashMap canonicalMap = new HashMap(); static { canonicalMap.put("iw", "he"); canonicalMap.put("mo", "ro"); canonicalMap.put("tl", "fil"); ICUResourceBundle suppData = getICUSupplementalData(); ICUResourceBundle languageMatching = suppData.findTopLevel("languageMatching"); ICUResourceBundle written = (ICUResourceBundle) languageMatching.get("written"); defaultWritten = new LanguageMatcherData(); for(UResourceBundleIterator iter = written.getIterator(); iter.hasNext();) { ICUResourceBundle item = (ICUResourceBundle) iter.next(); /* "*_*_*", "*_*_*", "96", */ // boolean oneway = item.getSize() > 3 && "1".equals(item.getString(3)); defaultWritten.addDistance(item.getString(0), item.getString(1), Integer.parseInt(item.getString(2)), oneway); } defaultWritten.freeze(); } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public static ICUResourceBundle getICUSupplementalData() { ICUResourceBundle suppData = (ICUResourceBundle) UResourceBundle.getBundleInstance( ICUResourceBundle.ICU_BASE_NAME, "supplementalData", ICUResourceBundle.ICU_DATA_CLASS_LOADER); return suppData; } /** * @internal * @deprecated This API is ICU internal only. */ @Deprecated public static double match(ULocale a, ULocale b) { final LocaleMatcher matcher = new LocaleMatcher(""); return matcher.match(a, matcher.addLikelySubtags(a), b, matcher.addLikelySubtags(b)); } }





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