1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package libcore.icu; 18 19 import java.util.ArrayList; 20 import java.util.Arrays; 21 import java.util.Comparator; 22 import java.util.HashMap; 23 import java.util.Locale; 24 import java.util.TimeZone; 25 import libcore.util.BasicLruCache; 26 import libcore.util.ZoneInfoDB; 27 28 /** 29 * Provides access to ICU's time zone name data. 30 */ 31 public final class TimeZoneNames { 32 private static final String[] availableTimeZoneIds = TimeZone.getAvailableIDs(); 33 34 /* 35 * Offsets into the arrays returned by DateFormatSymbols.getZoneStrings. 36 */ 37 public static final int OLSON_NAME = 0; 38 public static final int LONG_NAME = 1; 39 public static final int SHORT_NAME = 2; 40 public static final int LONG_NAME_DST = 3; 41 public static final int SHORT_NAME_DST = 4; 42 public static final int NAME_COUNT = 5; 43 44 private static final ZoneStringsCache cachedZoneStrings = new ZoneStringsCache(); 45 static { 46 // Ensure that we pull in the zone strings for the root locale, en_US, and the 47 // user's default locale. (All devices must support the root locale and en_US, 48 // and they're used for various system things like HTTP headers.) Pre-populating 49 // the cache is especially useful on Android because we'll share this via the Zygote. 50 cachedZoneStrings.get(Locale.ROOT); 51 cachedZoneStrings.get(Locale.US); 52 cachedZoneStrings.get(Locale.getDefault()); 53 } 54 55 public static class ZoneStringsCache extends BasicLruCache<Locale, String[][]> { 56 // De-duplicate the strings (http://b/2672057). 57 private final HashMap<String, String> internTable = new HashMap<String, String>(); 58 59 public ZoneStringsCache() { 60 // We make room for all the time zones known to the system, since each set of strings 61 // isn't particularly large (and we remove duplicates), but is currently (Honeycomb) 62 // really expensive to compute. 63 // If you change this, you might want to change the scope of the intern table too. 64 super(availableTimeZoneIds.length); 65 } 66 67 @Override protected String[][] create(Locale locale) { 68 long start = System.currentTimeMillis(); 69 70 // Set up the 2D array used to hold the names. The first column contains the Olson ids. 71 String[][] result = new String[availableTimeZoneIds.length][5]; 72 for (int i = 0; i < availableTimeZoneIds.length; ++i) { 73 result[i][0] = availableTimeZoneIds[i]; 74 } 75 76 long nativeStart = System.currentTimeMillis(); 77 fillZoneStrings(locale.toString(), result); 78 long nativeEnd = System.currentTimeMillis(); 79 80 internStrings(result); 81 // Ending up in this method too often is an easy way to make your app slow, so we ensure 82 // it's easy to tell from the log (a) what we were doing, (b) how long it took, and 83 // (c) that it's all ICU's fault. 84 long end = System.currentTimeMillis(); 85 long nativeDuration = nativeEnd - nativeStart; 86 long duration = end - start; 87 System.logI("Loaded time zone names for \"" + locale + "\" in " + duration + "ms" + 88 " (" + nativeDuration + "ms in ICU)"); 89 return result; 90 } 91 92 private synchronized void internStrings(String[][] result) { 93 for (int i = 0; i < result.length; ++i) { 94 for (int j = 1; j < NAME_COUNT; ++j) { 95 String original = result[i][j]; 96 String nonDuplicate = internTable.get(original); 97 if (nonDuplicate == null) { 98 internTable.put(original, original); 99 } else { 100 result[i][j] = nonDuplicate; 101 } 102 } 103 } 104 } 105 } 106 107 private static final Comparator<String[]> ZONE_STRINGS_COMPARATOR = new Comparator<String[]>() { 108 public int compare(String[] lhs, String[] rhs) { 109 return lhs[OLSON_NAME].compareTo(rhs[OLSON_NAME]); 110 } 111 }; 112 113 private TimeZoneNames() {} 114 115 /** 116 * Returns the appropriate string from 'zoneStrings'. Used with getZoneStrings. 117 */ 118 public static String getDisplayName(String[][] zoneStrings, String id, boolean daylight, int style) { 119 String[] needle = new String[] { id }; 120 int index = Arrays.binarySearch(zoneStrings, needle, ZONE_STRINGS_COMPARATOR); 121 if (index >= 0) { 122 String[] row = zoneStrings[index]; 123 if (daylight) { 124 return (style == TimeZone.LONG) ? row[LONG_NAME_DST] : row[SHORT_NAME_DST]; 125 } else { 126 return (style == TimeZone.LONG) ? row[LONG_NAME] : row[SHORT_NAME]; 127 } 128 } 129 return null; 130 } 131 132 /** 133 * Returns an array of time zone strings, as used by DateFormatSymbols.getZoneStrings. 134 */ 135 public static String[][] getZoneStrings(Locale locale) { 136 if (locale == null) { 137 locale = Locale.getDefault(); 138 } 139 return cachedZoneStrings.get(locale); 140 } 141 142 /** 143 * Returns an array containing the time zone ids in use in the country corresponding to 144 * the given locale. This is not necessary for Java API, but is used by telephony as a 145 * fallback. We retrieve these strings from zone.tab rather than icu4c because the latter 146 * supplies them in alphabetical order where zone.tab has them in a kind of "importance" 147 * order (as defined in the zone.tab header). 148 */ 149 public static String[] forLocale(Locale locale) { 150 String countryCode = locale.getCountry(); 151 ArrayList<String> ids = new ArrayList<String>(); 152 for (String line : ZoneInfoDB.getInstance().getZoneTab().split("\n")) { 153 if (line.startsWith(countryCode)) { 154 int olsonIdStart = line.indexOf('\t', 4) + 1; 155 int olsonIdEnd = line.indexOf('\t', olsonIdStart); 156 if (olsonIdEnd == -1) { 157 olsonIdEnd = line.length(); // Not all zone.tab lines have a comment. 158 } 159 ids.add(line.substring(olsonIdStart, olsonIdEnd)); 160 } 161 } 162 return ids.toArray(new String[ids.size()]); 163 } 164 165 private static native void fillZoneStrings(String locale, String[][] result); 166 } 167
