001/*
002 *  Copyright 2001-2005 Stephen Colebourne
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.joda.time.tz;
017
018import java.io.DataInput;
019import java.io.DataInputStream;
020import java.io.DataOutput;
021import java.io.DataOutputStream;
022import java.io.IOException;
023import java.io.InputStream;
024import java.io.OutputStream;
025import java.text.DateFormatSymbols;
026import java.util.ArrayList;
027import java.util.Arrays;
028import java.util.HashSet;
029import java.util.Iterator;
030import java.util.Locale;
031import java.util.Set;
032
033import org.joda.time.Chronology;
034import org.joda.time.DateTime;
035import org.joda.time.DateTimeUtils;
036import org.joda.time.DateTimeZone;
037import org.joda.time.Period;
038import org.joda.time.PeriodType;
039import org.joda.time.chrono.ISOChronology;
040
041/**
042 * DateTimeZoneBuilder allows complex DateTimeZones to be constructed. Since
043 * creating a new DateTimeZone this way is a relatively expensive operation,
044 * built zones can be written to a file. Reading back the encoded data is a
045 * quick operation.
046 * <p>
047 * DateTimeZoneBuilder itself is mutable and not thread-safe, but the
048 * DateTimeZone objects that it builds are thread-safe and immutable.
049 * <p>
050 * It is intended that {@link ZoneInfoCompiler} be used to read time zone data
051 * files, indirectly calling DateTimeZoneBuilder. The following complex
052 * example defines the America/Los_Angeles time zone, with all historical
053 * transitions:
054 * 
055 * <pre>
056 * DateTimeZone America_Los_Angeles = new DateTimeZoneBuilder()
057 *     .addCutover(-2147483648, 'w', 1, 1, 0, false, 0)
058 *     .setStandardOffset(-28378000)
059 *     .setFixedSavings("LMT", 0)
060 *     .addCutover(1883, 'w', 11, 18, 0, false, 43200000)
061 *     .setStandardOffset(-28800000)
062 *     .addRecurringSavings("PDT", 3600000, 1918, 1919, 'w',  3, -1, 7, false, 7200000)
063 *     .addRecurringSavings("PST",       0, 1918, 1919, 'w', 10, -1, 7, false, 7200000)
064 *     .addRecurringSavings("PWT", 3600000, 1942, 1942, 'w',  2,  9, 0, false, 7200000)
065 *     .addRecurringSavings("PPT", 3600000, 1945, 1945, 'u',  8, 14, 0, false, 82800000)
066 *     .addRecurringSavings("PST",       0, 1945, 1945, 'w',  9, 30, 0, false, 7200000)
067 *     .addRecurringSavings("PDT", 3600000, 1948, 1948, 'w',  3, 14, 0, false, 7200000)
068 *     .addRecurringSavings("PST",       0, 1949, 1949, 'w',  1,  1, 0, false, 7200000)
069 *     .addRecurringSavings("PDT", 3600000, 1950, 1966, 'w',  4, -1, 7, false, 7200000)
070 *     .addRecurringSavings("PST",       0, 1950, 1961, 'w',  9, -1, 7, false, 7200000)
071 *     .addRecurringSavings("PST",       0, 1962, 1966, 'w', 10, -1, 7, false, 7200000)
072 *     .addRecurringSavings("PST",       0, 1967, 2147483647, 'w', 10, -1, 7, false, 7200000)
073 *     .addRecurringSavings("PDT", 3600000, 1967, 1973, 'w', 4, -1,  7, false, 7200000)
074 *     .addRecurringSavings("PDT", 3600000, 1974, 1974, 'w', 1,  6,  0, false, 7200000)
075 *     .addRecurringSavings("PDT", 3600000, 1975, 1975, 'w', 2, 23,  0, false, 7200000)
076 *     .addRecurringSavings("PDT", 3600000, 1976, 1986, 'w', 4, -1,  7, false, 7200000)
077 *     .addRecurringSavings("PDT", 3600000, 1987, 2147483647, 'w', 4, 1, 7, true, 7200000)
078 *     .toDateTimeZone("America/Los_Angeles", true);
079 * </pre>
080 *
081 * @author Brian S O'Neill
082 * @see ZoneInfoCompiler
083 * @see ZoneInfoProvider
084 * @since 1.0
085 */
086public class DateTimeZoneBuilder {
087    /**
088     * Decodes a built DateTimeZone from the given stream, as encoded by
089     * writeTo.
090     *
091     * @param in input stream to read encoded DateTimeZone from.
092     * @param id time zone id to assign
093     */
094    public static DateTimeZone readFrom(InputStream in, String id) throws IOException {
095        if (in instanceof DataInput) {
096            return readFrom((DataInput)in, id);
097        } else {
098            return readFrom((DataInput)new DataInputStream(in), id);
099        }
100    }
101
102    /**
103     * Decodes a built DateTimeZone from the given stream, as encoded by
104     * writeTo.
105     *
106     * @param in input stream to read encoded DateTimeZone from.
107     * @param id time zone id to assign
108     */
109    public static DateTimeZone readFrom(DataInput in, String id) throws IOException {
110        switch (in.readUnsignedByte()) {
111        case 'F':
112            DateTimeZone fixed = new FixedDateTimeZone
113                (id, in.readUTF(), (int)readMillis(in), (int)readMillis(in));
114            if (fixed.equals(DateTimeZone.UTC)) {
115                fixed = DateTimeZone.UTC;
116            }
117            return fixed;
118        case 'C':
119            return CachedDateTimeZone.forZone(PrecalculatedZone.readFrom(in, id));
120        case 'P':
121            return PrecalculatedZone.readFrom(in, id);
122        default:
123            throw new IOException("Invalid encoding");
124        }
125    }
126
127    /**
128     * Millisecond encoding formats:
129     *
130     * upper two bits  units       field length  approximate range
131     * ---------------------------------------------------------------
132     * 00              30 minutes  1 byte        +/- 16 hours
133     * 01              minutes     4 bytes       +/- 1020 years
134     * 10              seconds     5 bytes       +/- 4355 years
135     * 11              millis      9 bytes       +/- 292,000,000 years
136     *
137     * Remaining bits in field form signed offset from 1970-01-01T00:00:00Z.
138     */
139    static void writeMillis(DataOutput out, long millis) throws IOException {
140        if (millis % (30 * 60000L) == 0) {
141            // Try to write in 30 minute units.
142            long units = millis / (30 * 60000L);
143            if (((units << (64 - 6)) >> (64 - 6)) == units) {
144                // Form 00 (6 bits effective precision)
145                out.writeByte((int)(units & 0x3f));
146                return;
147            }
148        }
149
150        if (millis % 60000L == 0) {
151            // Try to write minutes.
152            long minutes = millis / 60000L;
153            if (((minutes << (64 - 30)) >> (64 - 30)) == minutes) {
154                // Form 01 (30 bits effective precision)
155                out.writeInt(0x40000000 | (int)(minutes & 0x3fffffff));
156                return;
157            }
158        }
159        
160        if (millis % 1000L == 0) {
161            // Try to write seconds.
162            long seconds = millis / 1000L;
163            if (((seconds << (64 - 38)) >> (64 - 38)) == seconds) {
164                // Form 10 (38 bits effective precision)
165                out.writeByte(0x80 | (int)((seconds >> 32) & 0x3f));
166                out.writeInt((int)(seconds & 0xffffffff));
167                return;
168            }
169        }
170
171        // Write milliseconds either because the additional precision is
172        // required or the minutes didn't fit in the field.
173        
174        // Form 11 (64 bits effective precision, but write as if 70 bits)
175        out.writeByte(millis < 0 ? 0xff : 0xc0);
176        out.writeLong(millis);
177    }
178
179    /**
180     * Reads encoding generated by writeMillis.
181     */
182    static long readMillis(DataInput in) throws IOException {
183        int v = in.readUnsignedByte();
184        switch (v >> 6) {
185        case 0: default:
186            // Form 00 (6 bits effective precision)
187            v = (v << (32 - 6)) >> (32 - 6);
188            return v * (30 * 60000L);
189
190        case 1:
191            // Form 01 (30 bits effective precision)
192            v = (v << (32 - 6)) >> (32 - 30);
193            v |= (in.readUnsignedByte()) << 16;
194            v |= (in.readUnsignedByte()) << 8;
195            v |= (in.readUnsignedByte());
196            return v * 60000L;
197
198        case 2:
199            // Form 10 (38 bits effective precision)
200            long w = (((long)v) << (64 - 6)) >> (64 - 38);
201            w |= (in.readUnsignedByte()) << 24;
202            w |= (in.readUnsignedByte()) << 16;
203            w |= (in.readUnsignedByte()) << 8;
204            w |= (in.readUnsignedByte());
205            return w * 1000L;
206
207        case 3:
208            // Form 11 (64 bits effective precision)
209            return in.readLong();
210        }
211    }
212
213    private static DateTimeZone buildFixedZone(String id, String nameKey,
214                                               int wallOffset, int standardOffset) {
215        if ("UTC".equals(id) && id.equals(nameKey) &&
216            wallOffset == 0 && standardOffset == 0) {
217            return DateTimeZone.UTC;
218        }
219        return new FixedDateTimeZone(id, nameKey, wallOffset, standardOffset);
220    }
221
222    // List of RuleSets.
223    private final ArrayList iRuleSets;
224
225    public DateTimeZoneBuilder() {
226        iRuleSets = new ArrayList(10);
227    }
228
229    /**
230     * Adds a cutover for added rules. The standard offset at the cutover
231     * defaults to 0. Call setStandardOffset afterwards to change it.
232     *
233     * @param year  the year of cutover
234     * @param mode 'u' - cutover is measured against UTC, 'w' - against wall
235     *  offset, 's' - against standard offset
236     * @param monthOfYear  the month from 1 (January) to 12 (December)
237     * @param dayOfMonth  if negative, set to ((last day of month) - ~dayOfMonth).
238     *  For example, if -1, set to last day of month
239     * @param dayOfWeek  from 1 (Monday) to 7 (Sunday), if 0 then ignore
240     * @param advanceDayOfWeek  if dayOfMonth does not fall on dayOfWeek, advance to
241     *  dayOfWeek when true, retreat when false.
242     * @param millisOfDay  additional precision for specifying time of day of cutover
243     */
244    public DateTimeZoneBuilder addCutover(int year,
245                                          char mode,
246                                          int monthOfYear,
247                                          int dayOfMonth,
248                                          int dayOfWeek,
249                                          boolean advanceDayOfWeek,
250                                          int millisOfDay)
251    {
252        OfYear ofYear = new OfYear
253            (mode, monthOfYear, dayOfMonth, dayOfWeek, advanceDayOfWeek, millisOfDay);
254        if (iRuleSets.size() > 0) {
255            RuleSet lastRuleSet = (RuleSet)iRuleSets.get(iRuleSets.size() - 1);
256            lastRuleSet.setUpperLimit(year, ofYear);
257        }
258        iRuleSets.add(new RuleSet());
259        return this;
260    }
261
262    /**
263     * Sets the standard offset to use for newly added rules until the next
264     * cutover is added.
265     * @param standardOffset  the standard offset in millis
266     */
267    public DateTimeZoneBuilder setStandardOffset(int standardOffset) {
268        getLastRuleSet().setStandardOffset(standardOffset);
269        return this;
270    }
271
272    /**
273     * Set a fixed savings rule at the cutover.
274     */
275    public DateTimeZoneBuilder setFixedSavings(String nameKey, int saveMillis) {
276        getLastRuleSet().setFixedSavings(nameKey, saveMillis);
277        return this;
278    }
279
280    /**
281     * Add a recurring daylight saving time rule.
282     *
283     * @param nameKey  the name key of new rule
284     * @param saveMillis  the milliseconds to add to standard offset
285     * @param fromYear  the first year that rule is in effect, MIN_VALUE indicates
286     * beginning of time
287     * @param toYear  the last year (inclusive) that rule is in effect, MAX_VALUE
288     *  indicates end of time
289     * @param mode  'u' - transitions are calculated against UTC, 'w' -
290     *  transitions are calculated against wall offset, 's' - transitions are
291     *  calculated against standard offset
292     * @param monthOfYear  the month from 1 (January) to 12 (December)
293     * @param dayOfMonth  if negative, set to ((last day of month) - ~dayOfMonth).
294     *  For example, if -1, set to last day of month
295     * @param dayOfWeek  from 1 (Monday) to 7 (Sunday), if 0 then ignore
296     * @param advanceDayOfWeek  if dayOfMonth does not fall on dayOfWeek, advance to
297     *  dayOfWeek when true, retreat when false.
298     * @param millisOfDay  additional precision for specifying time of day of transitions
299     */
300    public DateTimeZoneBuilder addRecurringSavings(String nameKey, int saveMillis,
301                                                   int fromYear, int toYear,
302                                                   char mode,
303                                                   int monthOfYear,
304                                                   int dayOfMonth,
305                                                   int dayOfWeek,
306                                                   boolean advanceDayOfWeek,
307                                                   int millisOfDay)
308    {
309        if (fromYear <= toYear) {
310            OfYear ofYear = new OfYear
311                (mode, monthOfYear, dayOfMonth, dayOfWeek, advanceDayOfWeek, millisOfDay);
312            Recurrence recurrence = new Recurrence(ofYear, nameKey, saveMillis);
313            Rule rule = new Rule(recurrence, fromYear, toYear);
314            getLastRuleSet().addRule(rule);
315        }
316        return this;
317    }
318
319    private RuleSet getLastRuleSet() {
320        if (iRuleSets.size() == 0) {
321            addCutover(Integer.MIN_VALUE, 'w', 1, 1, 0, false, 0);
322        }
323        return (RuleSet)iRuleSets.get(iRuleSets.size() - 1);
324    }
325    
326    /**
327     * Processes all the rules and builds a DateTimeZone.
328     *
329     * @param id  time zone id to assign
330     * @param outputID  true if the zone id should be output
331     */
332    public DateTimeZone toDateTimeZone(String id, boolean outputID) {
333        if (id == null) {
334            throw new IllegalArgumentException();
335        }
336
337        // Discover where all the transitions occur and store the results in
338        // these lists.
339        ArrayList transitions = new ArrayList();
340
341        // Tail zone picks up remaining transitions in the form of an endless
342        // DST cycle.
343        DSTZone tailZone = null;
344
345        long millis = Long.MIN_VALUE;
346        int saveMillis = 0;
347            
348        int ruleSetCount = iRuleSets.size();
349        for (int i=0; i<ruleSetCount; i++) {
350            RuleSet rs = (RuleSet)iRuleSets.get(i);
351            Transition next = rs.firstTransition(millis);
352            if (next == null) {
353                continue;
354            }
355            addTransition(transitions, next);
356            millis = next.getMillis();
357            saveMillis = next.getSaveMillis();
358
359            // Copy it since we're going to destroy it.
360            rs = new RuleSet(rs);
361
362            while ((next = rs.nextTransition(millis, saveMillis)) != null) {
363                if (addTransition(transitions, next)) {
364                    if (tailZone != null) {
365                        // Got the extra transition before DSTZone.
366                        break;
367                    }
368                }
369                millis = next.getMillis();
370                saveMillis = next.getSaveMillis();
371                if (tailZone == null && i == ruleSetCount - 1) {
372                    tailZone = rs.buildTailZone(id);
373                    // If tailZone is not null, don't break out of main loop until
374                    // at least one more transition is calculated. This ensures a
375                    // correct 'seam' to the DSTZone.
376                }
377            }
378
379            millis = rs.getUpperLimit(saveMillis);
380        }
381
382        // Check if a simpler zone implementation can be returned.
383        if (transitions.size() == 0) {
384            if (tailZone != null) {
385                // This shouldn't happen, but handle just in case.
386                return tailZone;
387            }
388            return buildFixedZone(id, "UTC", 0, 0);
389        }
390        if (transitions.size() == 1 && tailZone == null) {
391            Transition tr = (Transition)transitions.get(0);
392            return buildFixedZone(id, tr.getNameKey(),
393                                  tr.getWallOffset(), tr.getStandardOffset());
394        }
395
396        PrecalculatedZone zone = PrecalculatedZone.create(id, outputID, transitions, tailZone);
397        if (zone.isCachable()) {
398            return CachedDateTimeZone.forZone(zone);
399        }
400        return zone;
401    }
402
403    private boolean addTransition(ArrayList transitions, Transition tr) {
404        int size = transitions.size();
405        if (size == 0) {
406            transitions.add(tr);
407            return true;
408        }
409
410        Transition last = (Transition)transitions.get(size - 1);
411        if (!tr.isTransitionFrom(last)) {
412            return false;
413        }
414
415        // If local time of new transition is same as last local time, just
416        // replace last transition with new one.
417        int offsetForLast = 0;
418        if (size >= 2) {
419            offsetForLast = ((Transition)transitions.get(size - 2)).getWallOffset();
420        }
421        int offsetForNew = last.getWallOffset();
422
423        long lastLocal = last.getMillis() + offsetForLast;
424        long newLocal = tr.getMillis() + offsetForNew;
425
426        if (newLocal != lastLocal) {
427            transitions.add(tr);
428            return true;
429        }
430
431        transitions.remove(size - 1);
432        return addTransition(transitions, tr);
433    }
434
435    /**
436     * Encodes a built DateTimeZone to the given stream. Call readFrom to
437     * decode the data into a DateTimeZone object.
438     *
439     * @param out  the output stream to receive the encoded DateTimeZone
440     * @since 1.5 (parameter added)
441     */
442    public void writeTo(String zoneID, OutputStream out) throws IOException {
443        if (out instanceof DataOutput) {
444            writeTo(zoneID, (DataOutput)out);
445        } else {
446            writeTo(zoneID, (DataOutput)new DataOutputStream(out));
447        }
448    }
449
450    /**
451     * Encodes a built DateTimeZone to the given stream. Call readFrom to
452     * decode the data into a DateTimeZone object.
453     *
454     * @param out  the output stream to receive the encoded DateTimeZone
455     * @since 1.5 (parameter added)
456     */
457    public void writeTo(String zoneID, DataOutput out) throws IOException {
458        // pass false so zone id is not written out
459        DateTimeZone zone = toDateTimeZone(zoneID, false);
460
461        if (zone instanceof FixedDateTimeZone) {
462            out.writeByte('F'); // 'F' for fixed
463            out.writeUTF(zone.getNameKey(0));
464            writeMillis(out, zone.getOffset(0));
465            writeMillis(out, zone.getStandardOffset(0));
466        } else {
467            if (zone instanceof CachedDateTimeZone) {
468                out.writeByte('C'); // 'C' for cached, precalculated
469                zone = ((CachedDateTimeZone)zone).getUncachedZone();
470            } else {
471                out.writeByte('P'); // 'P' for precalculated, uncached
472            }
473            ((PrecalculatedZone)zone).writeTo(out);
474        }
475    }
476
477    /**
478     * Supports setting fields of year and moving between transitions.
479     */
480    private static final class OfYear {
481        static OfYear readFrom(DataInput in) throws IOException {
482            return new OfYear((char)in.readUnsignedByte(),
483                              (int)in.readUnsignedByte(),
484                              (int)in.readByte(),
485                              (int)in.readUnsignedByte(),
486                              in.readBoolean(),
487                              (int)readMillis(in));
488        }
489
490        // Is 'u', 'w', or 's'.
491        final char iMode;
492
493        final int iMonthOfYear;
494        final int iDayOfMonth;
495        final int iDayOfWeek;
496        final boolean iAdvance;
497        final int iMillisOfDay;
498
499        OfYear(char mode,
500               int monthOfYear,
501               int dayOfMonth,
502               int dayOfWeek, boolean advanceDayOfWeek,
503               int millisOfDay)
504        {
505            if (mode != 'u' && mode != 'w' && mode != 's') {
506                throw new IllegalArgumentException("Unknown mode: " + mode);
507            }
508
509            iMode = mode;
510            iMonthOfYear = monthOfYear;
511            iDayOfMonth = dayOfMonth;
512            iDayOfWeek = dayOfWeek;
513            iAdvance = advanceDayOfWeek;
514            iMillisOfDay = millisOfDay;
515        }
516
517        /**
518         * @param standardOffset standard offset just before instant
519         */
520        public long setInstant(int year, int standardOffset, int saveMillis) {
521            int offset;
522            if (iMode == 'w') {
523                offset = standardOffset + saveMillis;
524            } else if (iMode == 's') {
525                offset = standardOffset;
526            } else {
527                offset = 0;
528            }
529
530            Chronology chrono = ISOChronology.getInstanceUTC();
531            long millis = chrono.year().set(0, year);
532            millis = chrono.monthOfYear().set(millis, iMonthOfYear);
533            millis = chrono.millisOfDay().set(millis, iMillisOfDay);
534            millis = setDayOfMonth(chrono, millis);
535
536            if (iDayOfWeek != 0) {
537                millis = setDayOfWeek(chrono, millis);
538            }
539
540            // Convert from local time to UTC.
541            return millis - offset;
542        }
543
544        /**
545         * @param standardOffset standard offset just before next recurrence
546         */
547        public long next(long instant, int standardOffset, int saveMillis) {
548            int offset;
549            if (iMode == 'w') {
550                offset = standardOffset + saveMillis;
551            } else if (iMode == 's') {
552                offset = standardOffset;
553            } else {
554                offset = 0;
555            }
556
557            // Convert from UTC to local time.
558            instant += offset;
559
560            Chronology chrono = ISOChronology.getInstanceUTC();
561            long next = chrono.monthOfYear().set(instant, iMonthOfYear);
562            // Be lenient with millisOfDay.
563            next = chrono.millisOfDay().set(next, 0);
564            next = chrono.millisOfDay().add(next, iMillisOfDay);
565            next = setDayOfMonthNext(chrono, next);
566
567            if (iDayOfWeek == 0) {
568                if (next <= instant) {
569                    next = chrono.year().add(next, 1);
570                    next = setDayOfMonthNext(chrono, next);
571                }
572            } else {
573                next = setDayOfWeek(chrono, next);
574                if (next <= instant) {
575                    next = chrono.year().add(next, 1);
576                    next = chrono.monthOfYear().set(next, iMonthOfYear);
577                    next = setDayOfMonthNext(chrono, next);
578                    next = setDayOfWeek(chrono, next);
579                }
580            }
581
582            // Convert from local time to UTC.
583            return next - offset;
584        }
585
586        /**
587         * @param standardOffset standard offset just before previous recurrence
588         */
589        public long previous(long instant, int standardOffset, int saveMillis) {
590            int offset;
591            if (iMode == 'w') {
592                offset = standardOffset + saveMillis;
593            } else if (iMode == 's') {
594                offset = standardOffset;
595            } else {
596                offset = 0;
597            }
598
599            // Convert from UTC to local time.
600            instant += offset;
601
602            Chronology chrono = ISOChronology.getInstanceUTC();
603            long prev = chrono.monthOfYear().set(instant, iMonthOfYear);
604            // Be lenient with millisOfDay.
605            prev = chrono.millisOfDay().set(prev, 0);
606            prev = chrono.millisOfDay().add(prev, iMillisOfDay);
607            prev = setDayOfMonthPrevious(chrono, prev);
608
609            if (iDayOfWeek == 0) {
610                if (prev >= instant) {
611                    prev = chrono.year().add(prev, -1);
612                    prev = setDayOfMonthPrevious(chrono, prev);
613                }
614            } else {
615                prev = setDayOfWeek(chrono, prev);
616                if (prev >= instant) {
617                    prev = chrono.year().add(prev, -1);
618                    prev = chrono.monthOfYear().set(prev, iMonthOfYear);
619                    prev = setDayOfMonthPrevious(chrono, prev);
620                    prev = setDayOfWeek(chrono, prev);
621                }
622            }
623
624            // Convert from local time to UTC.
625            return prev - offset;
626        }
627
628        public boolean equals(Object obj) {
629            if (this == obj) {
630                return true;
631            }
632            if (obj instanceof OfYear) {
633                OfYear other = (OfYear)obj;
634                return
635                    iMode == other.iMode &&
636                    iMonthOfYear == other.iMonthOfYear &&
637                    iDayOfMonth == other.iDayOfMonth &&
638                    iDayOfWeek == other.iDayOfWeek &&
639                    iAdvance == other.iAdvance &&
640                    iMillisOfDay == other.iMillisOfDay;
641            }
642            return false;
643        }
644
645        /*
646        public String toString() {
647            return
648                "[OfYear]\n" + 
649                "Mode: " + iMode + '\n' +
650                "MonthOfYear: " + iMonthOfYear + '\n' +
651                "DayOfMonth: " + iDayOfMonth + '\n' +
652                "DayOfWeek: " + iDayOfWeek + '\n' +
653                "AdvanceDayOfWeek: " + iAdvance + '\n' +
654                "MillisOfDay: " + iMillisOfDay + '\n';
655        }
656        */
657
658        public void writeTo(DataOutput out) throws IOException {
659            out.writeByte(iMode);
660            out.writeByte(iMonthOfYear);
661            out.writeByte(iDayOfMonth);
662            out.writeByte(iDayOfWeek);
663            out.writeBoolean(iAdvance);
664            writeMillis(out, iMillisOfDay);
665        }
666
667        /**
668         * If month-day is 02-29 and year isn't leap, advances to next leap year.
669         */
670        private long setDayOfMonthNext(Chronology chrono, long next) {
671            try {
672                next = setDayOfMonth(chrono, next);
673            } catch (IllegalArgumentException e) {
674                if (iMonthOfYear == 2 && iDayOfMonth == 29) {
675                    while (chrono.year().isLeap(next) == false) {
676                        next = chrono.year().add(next, 1);
677                    }
678                    next = setDayOfMonth(chrono, next);
679                } else {
680                    throw e;
681                }
682            }
683            return next;
684        }
685
686        /**
687         * If month-day is 02-29 and year isn't leap, retreats to previous leap year.
688         */
689        private long setDayOfMonthPrevious(Chronology chrono, long prev) {
690            try {
691                prev = setDayOfMonth(chrono, prev);
692            } catch (IllegalArgumentException e) {
693                if (iMonthOfYear == 2 && iDayOfMonth == 29) {
694                    while (chrono.year().isLeap(prev) == false) {
695                        prev = chrono.year().add(prev, -1);
696                    }
697                    prev = setDayOfMonth(chrono, prev);
698                } else {
699                    throw e;
700                }
701            }
702            return prev;
703        }
704
705        private long setDayOfMonth(Chronology chrono, long instant) {
706            if (iDayOfMonth >= 0) {
707                instant = chrono.dayOfMonth().set(instant, iDayOfMonth);
708            } else {
709                instant = chrono.dayOfMonth().set(instant, 1);
710                instant = chrono.monthOfYear().add(instant, 1);
711                instant = chrono.dayOfMonth().add(instant, iDayOfMonth);
712            }
713            return instant;
714        }
715
716        private long setDayOfWeek(Chronology chrono, long instant) {
717            int dayOfWeek = chrono.dayOfWeek().get(instant);
718            int daysToAdd = iDayOfWeek - dayOfWeek;
719            if (daysToAdd != 0) {
720                if (iAdvance) {
721                    if (daysToAdd < 0) {
722                        daysToAdd += 7;
723                    }
724                } else {
725                    if (daysToAdd > 0) {
726                        daysToAdd -= 7;
727                    }
728                }
729                instant = chrono.dayOfWeek().add(instant, daysToAdd);
730            }
731            return instant;
732        }
733    }
734
735    /**
736     * Extends OfYear with a nameKey and savings.
737     */
738    private static final class Recurrence {
739        static Recurrence readFrom(DataInput in) throws IOException {
740            return new Recurrence(OfYear.readFrom(in), in.readUTF(), (int)readMillis(in));
741        }
742
743        final OfYear iOfYear;
744        final String iNameKey;
745        final int iSaveMillis;
746
747        Recurrence(OfYear ofYear, String nameKey, int saveMillis) {
748            iOfYear = ofYear;
749            iNameKey = nameKey;
750            iSaveMillis = saveMillis;
751        }
752
753        public OfYear getOfYear() {
754            return iOfYear;
755        }
756
757        /**
758         * @param standardOffset standard offset just before next recurrence
759         */
760        public long next(long instant, int standardOffset, int saveMillis) {
761            return iOfYear.next(instant, standardOffset, saveMillis);
762        }
763
764        /**
765         * @param standardOffset standard offset just before previous recurrence
766         */
767        public long previous(long instant, int standardOffset, int saveMillis) {
768            return iOfYear.previous(instant, standardOffset, saveMillis);
769        }
770
771        public String getNameKey() {
772            return iNameKey;
773        }
774
775        public int getSaveMillis() {
776            return iSaveMillis;
777        }
778
779        public boolean equals(Object obj) {
780            if (this == obj) {
781                return true;
782            }
783            if (obj instanceof Recurrence) {
784                Recurrence other = (Recurrence)obj;
785                return
786                    iSaveMillis == other.iSaveMillis &&
787                    iNameKey.equals(other.iNameKey) &&
788                    iOfYear.equals(other.iOfYear);
789            }
790            return false;
791        }
792
793        public void writeTo(DataOutput out) throws IOException {
794            iOfYear.writeTo(out);
795            out.writeUTF(iNameKey);
796            writeMillis(out, iSaveMillis);
797        }
798
799        Recurrence rename(String nameKey) {
800            return new Recurrence(iOfYear, nameKey, iSaveMillis);
801        }
802
803        Recurrence renameAppend(String appendNameKey) {
804            return rename((iNameKey + appendNameKey).intern());
805        }
806    }
807
808    /**
809     * Extends Recurrence with inclusive year limits.
810     */
811    private static final class Rule {
812        final Recurrence iRecurrence;
813        final int iFromYear; // inclusive
814        final int iToYear;   // inclusive
815
816        Rule(Recurrence recurrence, int fromYear, int toYear) {
817            iRecurrence = recurrence;
818            iFromYear = fromYear;
819            iToYear = toYear;
820        }
821
822        public int getFromYear() {
823            return iFromYear;
824        }
825
826        public int getToYear() {
827            return iToYear;
828        }
829
830        public OfYear getOfYear() {
831            return iRecurrence.getOfYear();
832        }
833
834        public String getNameKey() {
835            return iRecurrence.getNameKey();
836        }
837
838        public int getSaveMillis() {
839            return iRecurrence.getSaveMillis();
840        }
841
842        public long next(final long instant, int standardOffset, int saveMillis) {
843            Chronology chrono = ISOChronology.getInstanceUTC();
844
845            final int wallOffset = standardOffset + saveMillis;
846            long testInstant = instant;
847
848            int year;
849            if (instant == Long.MIN_VALUE) {
850                year = Integer.MIN_VALUE;
851            } else {
852                year = chrono.year().get(instant + wallOffset);
853            }
854
855            if (year < iFromYear) {
856                // First advance instant to start of from year.
857                testInstant = chrono.year().set(0, iFromYear) - wallOffset;
858                // Back off one millisecond to account for next recurrence
859                // being exactly at the beginning of the year.
860                testInstant -= 1;
861            }
862
863            long next = iRecurrence.next(testInstant, standardOffset, saveMillis);
864
865            if (next > instant) {
866                year = chrono.year().get(next + wallOffset);
867                if (year > iToYear) {
868                    // Out of range, return original value.
869                    next = instant;
870                }
871            }
872
873            return next;
874        }
875    }
876
877    private static final class Transition {
878        private final long iMillis;
879        private final String iNameKey;
880        private final int iWallOffset;
881        private final int iStandardOffset;
882
883        Transition(long millis, Transition tr) {
884            iMillis = millis;
885            iNameKey = tr.iNameKey;
886            iWallOffset = tr.iWallOffset;
887            iStandardOffset = tr.iStandardOffset;
888        }
889
890        Transition(long millis, Rule rule, int standardOffset) {
891            iMillis = millis;
892            iNameKey = rule.getNameKey();
893            iWallOffset = standardOffset + rule.getSaveMillis();
894            iStandardOffset = standardOffset;
895        }
896
897        Transition(long millis, String nameKey,
898                   int wallOffset, int standardOffset) {
899            iMillis = millis;
900            iNameKey = nameKey;
901            iWallOffset = wallOffset;
902            iStandardOffset = standardOffset;
903        }
904
905        public long getMillis() {
906            return iMillis;
907        }
908
909        public String getNameKey() {
910            return iNameKey;
911        }
912
913        public int getWallOffset() {
914            return iWallOffset;
915        }
916
917        public int getStandardOffset() {
918            return iStandardOffset;
919        }
920
921        public int getSaveMillis() {
922            return iWallOffset - iStandardOffset;
923        }
924
925        /**
926         * There must be a change in the millis, wall offsets or name keys.
927         */
928        public boolean isTransitionFrom(Transition other) {
929            if (other == null) {
930                return true;
931            }
932            return iMillis > other.iMillis &&
933                (iWallOffset != other.iWallOffset ||
934                 //iStandardOffset != other.iStandardOffset ||
935                 !(iNameKey.equals(other.iNameKey)));
936        }
937    }
938
939    private static final class RuleSet {
940        private static final int YEAR_LIMIT;
941
942        static {
943            // Don't pre-calculate more than 100 years into the future. Almost
944            // all zones will stop pre-calculating far sooner anyhow. Either a
945            // simple DST cycle is detected or the last rule is a fixed
946            // offset. If a zone has a fixed offset set more than 100 years
947            // into the future, then it won't be observed.
948            long now = DateTimeUtils.currentTimeMillis();
949            YEAR_LIMIT = ISOChronology.getInstanceUTC().year().get(now) + 100;
950        }
951
952        private int iStandardOffset;
953        private ArrayList iRules;
954
955        // Optional.
956        private String iInitialNameKey;
957        private int iInitialSaveMillis;
958
959        // Upper limit is exclusive.
960        private int iUpperYear;
961        private OfYear iUpperOfYear;
962
963        RuleSet() {
964            iRules = new ArrayList(10);
965            iUpperYear = Integer.MAX_VALUE;
966        }
967
968        /**
969         * Copy constructor.
970         */
971        RuleSet(RuleSet rs) {
972            iStandardOffset = rs.iStandardOffset;
973            iRules = new ArrayList(rs.iRules);
974            iInitialNameKey = rs.iInitialNameKey;
975            iInitialSaveMillis = rs.iInitialSaveMillis;
976            iUpperYear = rs.iUpperYear;
977            iUpperOfYear = rs.iUpperOfYear;
978        }
979
980        public int getStandardOffset() {
981            return iStandardOffset;
982        }
983
984        public void setStandardOffset(int standardOffset) {
985            iStandardOffset = standardOffset;
986        }
987
988        public void setFixedSavings(String nameKey, int saveMillis) {
989            iInitialNameKey = nameKey;
990            iInitialSaveMillis = saveMillis;
991        }
992
993        public void addRule(Rule rule) {
994            if (!iRules.contains(rule)) {
995                iRules.add(rule);
996            }
997        }
998
999        public void setUpperLimit(int year, OfYear ofYear) {
1000            iUpperYear = year;
1001            iUpperOfYear = ofYear;
1002        }
1003
1004        /**
1005         * Returns a transition at firstMillis with the first name key and
1006         * offsets for this rule set. This method may return null.
1007         *
1008         * @param firstMillis millis of first transition
1009         */
1010        public Transition firstTransition(final long firstMillis) {
1011            if (iInitialNameKey != null) {
1012                // Initial zone info explicitly set, so don't search the rules.
1013                return new Transition(firstMillis, iInitialNameKey,
1014                                      iStandardOffset + iInitialSaveMillis, iStandardOffset);
1015            }
1016
1017            // Make a copy before we destroy the rules.
1018            ArrayList copy = new ArrayList(iRules);
1019
1020            // Iterate through all the transitions until firstMillis is
1021            // reached. Use the name key and savings for whatever rule reaches
1022            // the limit.
1023
1024            long millis = Long.MIN_VALUE;
1025            int saveMillis = 0;
1026            Transition first = null;
1027
1028            Transition next;
1029            while ((next = nextTransition(millis, saveMillis)) != null) {
1030                millis = next.getMillis();
1031
1032                if (millis == firstMillis) {
1033                    first = new Transition(firstMillis, next);
1034                    break;
1035                }
1036
1037                if (millis > firstMillis) {
1038                    if (first == null) {
1039                        // Find first rule without savings. This way a more
1040                        // accurate nameKey is found even though no rule
1041                        // extends to the RuleSet's lower limit.
1042                        Iterator it = copy.iterator();
1043                        while (it.hasNext()) {
1044                            Rule rule = (Rule)it.next();
1045                            if (rule.getSaveMillis() == 0) {
1046                                first = new Transition(firstMillis, rule, iStandardOffset);
1047                                break;
1048                            }
1049                        }
1050                    }
1051                    if (first == null) {
1052                        // Found no rule without savings. Create a transition
1053                        // with no savings anyhow, and use the best available
1054                        // name key.
1055                        first = new Transition(firstMillis, next.getNameKey(),
1056                                               iStandardOffset, iStandardOffset);
1057                    }
1058                    break;
1059                }
1060                
1061                // Set first to the best transition found so far, but next
1062                // iteration may find something closer to lower limit.
1063                first = new Transition(firstMillis, next);
1064
1065                saveMillis = next.getSaveMillis();
1066            }
1067
1068            iRules = copy;
1069            return first;
1070        }
1071
1072        /**
1073         * Returns null if RuleSet is exhausted or upper limit reached. Calling
1074         * this method will throw away rules as they each become
1075         * exhausted. Copy the RuleSet before using it to compute transitions.
1076         *
1077         * Returned transition may be a duplicate from previous
1078         * transition. Caller must call isTransitionFrom to filter out
1079         * duplicates.
1080         *
1081         * @param saveMillis savings before next transition
1082         */
1083        public Transition nextTransition(final long instant, final int saveMillis) {
1084            Chronology chrono = ISOChronology.getInstanceUTC();
1085
1086            // Find next matching rule.
1087            Rule nextRule = null;
1088            long nextMillis = Long.MAX_VALUE;
1089            
1090            Iterator it = iRules.iterator();
1091            while (it.hasNext()) {
1092                Rule rule = (Rule)it.next();
1093                long next = rule.next(instant, iStandardOffset, saveMillis);
1094                if (next <= instant) {
1095                    it.remove();
1096                    continue;
1097                }
1098                // Even if next is same as previous next, choose the rule
1099                // in order for more recently added rules to override.
1100                if (next <= nextMillis) {
1101                    // Found a better match.
1102                    nextRule = rule;
1103                    nextMillis = next;
1104                }
1105            }
1106            
1107            if (nextRule == null) {
1108                return null;
1109            }
1110            
1111            // Stop precalculating if year reaches some arbitrary limit.
1112            if (chrono.year().get(nextMillis) >= YEAR_LIMIT) {
1113                return null;
1114            }
1115            
1116            // Check if upper limit reached or passed.
1117            if (iUpperYear < Integer.MAX_VALUE) {
1118                long upperMillis =
1119                    iUpperOfYear.setInstant(iUpperYear, iStandardOffset, saveMillis);
1120                if (nextMillis >= upperMillis) {
1121                    // At or after upper limit.
1122                    return null;
1123                }
1124            }
1125            
1126            return new Transition(nextMillis, nextRule, iStandardOffset);
1127        }
1128
1129        /**
1130         * @param saveMillis savings before upper limit
1131         */
1132        public long getUpperLimit(int saveMillis) {
1133            if (iUpperYear == Integer.MAX_VALUE) {
1134                return Long.MAX_VALUE;
1135            }
1136            return iUpperOfYear.setInstant(iUpperYear, iStandardOffset, saveMillis);
1137        }
1138
1139        /**
1140         * Returns null if none can be built.
1141         */
1142        public DSTZone buildTailZone(String id) {
1143            if (iRules.size() == 2) {
1144                Rule startRule = (Rule)iRules.get(0);
1145                Rule endRule = (Rule)iRules.get(1);
1146                if (startRule.getToYear() == Integer.MAX_VALUE &&
1147                    endRule.getToYear() == Integer.MAX_VALUE) {
1148
1149                    // With exactly two infinitely recurring rules left, a
1150                    // simple DSTZone can be formed.
1151
1152                    // The order of rules can come in any order, and it doesn't
1153                    // really matter which rule was chosen the 'start' and
1154                    // which is chosen the 'end'. DSTZone works properly either
1155                    // way.
1156                    return new DSTZone(id, iStandardOffset,
1157                                       startRule.iRecurrence, endRule.iRecurrence);
1158                }
1159            }
1160            return null;
1161        }
1162    }
1163
1164    private static final class DSTZone extends DateTimeZone {
1165        private static final long serialVersionUID = 6941492635554961361L;
1166
1167        static DSTZone readFrom(DataInput in, String id) throws IOException {
1168            return new DSTZone(id, (int)readMillis(in), 
1169                               Recurrence.readFrom(in), Recurrence.readFrom(in));
1170        }
1171
1172        final int iStandardOffset;
1173        final Recurrence iStartRecurrence;
1174        final Recurrence iEndRecurrence;
1175
1176        DSTZone(String id, int standardOffset,
1177                Recurrence startRecurrence, Recurrence endRecurrence) {
1178            super(id);
1179            iStandardOffset = standardOffset;
1180            iStartRecurrence = startRecurrence;
1181            iEndRecurrence = endRecurrence;
1182        }
1183
1184        public String getNameKey(long instant) {
1185            return findMatchingRecurrence(instant).getNameKey();
1186        }
1187
1188        public int getOffset(long instant) {
1189            return iStandardOffset + findMatchingRecurrence(instant).getSaveMillis();
1190        }
1191
1192        public int getStandardOffset(long instant) {
1193            return iStandardOffset;
1194        }
1195
1196        public boolean isFixed() {
1197            return false;
1198        }
1199
1200        public long nextTransition(long instant) {
1201            int standardOffset = iStandardOffset;
1202            Recurrence startRecurrence = iStartRecurrence;
1203            Recurrence endRecurrence = iEndRecurrence;
1204
1205            long start, end;
1206
1207            try {
1208                start = startRecurrence.next
1209                    (instant, standardOffset, endRecurrence.getSaveMillis());
1210                if (instant > 0 && start < 0) {
1211                    // Overflowed.
1212                    start = instant;
1213                }
1214            } catch (IllegalArgumentException e) {
1215                // Overflowed.
1216                start = instant;
1217            } catch (ArithmeticException e) {
1218                // Overflowed.
1219                start = instant;
1220            }
1221
1222            try {
1223                end = endRecurrence.next
1224                    (instant, standardOffset, startRecurrence.getSaveMillis());
1225                if (instant > 0 && end < 0) {
1226                    // Overflowed.
1227                    end = instant;
1228                }
1229            } catch (IllegalArgumentException e) {
1230                // Overflowed.
1231                end = instant;
1232            } catch (ArithmeticException e) {
1233                // Overflowed.
1234                end = instant;
1235            }
1236
1237            return (start > end) ? end : start;
1238        }
1239
1240        public long previousTransition(long instant) {
1241            // Increment in order to handle the case where instant is exactly at
1242            // a transition.
1243            instant++;
1244
1245            int standardOffset = iStandardOffset;
1246            Recurrence startRecurrence = iStartRecurrence;
1247            Recurrence endRecurrence = iEndRecurrence;
1248
1249            long start, end;
1250
1251            try {
1252                start = startRecurrence.previous
1253                    (instant, standardOffset, endRecurrence.getSaveMillis());
1254                if (instant < 0 && start > 0) {
1255                    // Overflowed.
1256                    start = instant;
1257                }
1258            } catch (IllegalArgumentException e) {
1259                // Overflowed.
1260                start = instant;
1261            } catch (ArithmeticException e) {
1262                // Overflowed.
1263                start = instant;
1264            }
1265
1266            try {
1267                end = endRecurrence.previous
1268                    (instant, standardOffset, startRecurrence.getSaveMillis());
1269                if (instant < 0 && end > 0) {
1270                    // Overflowed.
1271                    end = instant;
1272                }
1273            } catch (IllegalArgumentException e) {
1274                // Overflowed.
1275                end = instant;
1276            } catch (ArithmeticException e) {
1277                // Overflowed.
1278                end = instant;
1279            }
1280
1281            return ((start > end) ? start : end) - 1;
1282        }
1283
1284        public boolean equals(Object obj) {
1285            if (this == obj) {
1286                return true;
1287            }
1288            if (obj instanceof DSTZone) {
1289                DSTZone other = (DSTZone)obj;
1290                return
1291                    getID().equals(other.getID()) &&
1292                    iStandardOffset == other.iStandardOffset &&
1293                    iStartRecurrence.equals(other.iStartRecurrence) &&
1294                    iEndRecurrence.equals(other.iEndRecurrence);
1295            }
1296            return false;
1297        }
1298
1299        public void writeTo(DataOutput out) throws IOException {
1300            writeMillis(out, iStandardOffset);
1301            iStartRecurrence.writeTo(out);
1302            iEndRecurrence.writeTo(out);
1303        }
1304
1305        private Recurrence findMatchingRecurrence(long instant) {
1306            int standardOffset = iStandardOffset;
1307            Recurrence startRecurrence = iStartRecurrence;
1308            Recurrence endRecurrence = iEndRecurrence;
1309
1310            long start, end;
1311
1312            try {
1313                start = startRecurrence.next
1314                    (instant, standardOffset, endRecurrence.getSaveMillis());
1315            } catch (IllegalArgumentException e) {
1316                // Overflowed.
1317                start = instant;
1318            } catch (ArithmeticException e) {
1319                // Overflowed.
1320                start = instant;
1321            }
1322
1323            try {
1324                end = endRecurrence.next
1325                    (instant, standardOffset, startRecurrence.getSaveMillis());
1326            } catch (IllegalArgumentException e) {
1327                // Overflowed.
1328                end = instant;
1329            } catch (ArithmeticException e) {
1330                // Overflowed.
1331                end = instant;
1332            }
1333
1334            return (start > end) ? startRecurrence : endRecurrence;
1335        }
1336    }
1337
1338    private static final class PrecalculatedZone extends DateTimeZone {
1339        private static final long serialVersionUID = 7811976468055766265L;
1340
1341        static PrecalculatedZone readFrom(DataInput in, String id) throws IOException {
1342            // Read string pool.
1343            int poolSize = in.readUnsignedShort();
1344            String[] pool = new String[poolSize];
1345            for (int i=0; i<poolSize; i++) {
1346                pool[i] = in.readUTF();
1347            }
1348
1349            int size = in.readInt();
1350            long[] transitions = new long[size];
1351            int[] wallOffsets = new int[size];
1352            int[] standardOffsets = new int[size];
1353            String[] nameKeys = new String[size];
1354            
1355            for (int i=0; i<size; i++) {
1356                transitions[i] = readMillis(in);
1357                wallOffsets[i] = (int)readMillis(in);
1358                standardOffsets[i] = (int)readMillis(in);
1359                try {
1360                    int index;
1361                    if (poolSize < 256) {
1362                        index = in.readUnsignedByte();
1363                    } else {
1364                        index = in.readUnsignedShort();
1365                    }
1366                    nameKeys[i] = pool[index];
1367                } catch (ArrayIndexOutOfBoundsException e) {
1368                    throw new IOException("Invalid encoding");
1369                }
1370            }
1371
1372            DSTZone tailZone = null;
1373            if (in.readBoolean()) {
1374                tailZone = DSTZone.readFrom(in, id);
1375            }
1376
1377            return new PrecalculatedZone
1378                (id, transitions, wallOffsets, standardOffsets, nameKeys, tailZone);
1379        }
1380
1381        /**
1382         * Factory to create instance from builder.
1383         * 
1384         * @param id  the zone id
1385         * @param outputID  true if the zone id should be output
1386         * @param transitions  the list of Transition objects
1387         * @param tailZone  optional zone for getting info beyond precalculated tables
1388         */
1389        static PrecalculatedZone create(String id, boolean outputID, ArrayList transitions,
1390                                        DSTZone tailZone) {
1391            int size = transitions.size();
1392            if (size == 0) {
1393                throw new IllegalArgumentException();
1394            }
1395
1396            long[] trans = new long[size];
1397            int[] wallOffsets = new int[size];
1398            int[] standardOffsets = new int[size];
1399            String[] nameKeys = new String[size];
1400
1401            Transition last = null;
1402            for (int i=0; i<size; i++) {
1403                Transition tr = (Transition)transitions.get(i);
1404
1405                if (!tr.isTransitionFrom(last)) {
1406                    throw new IllegalArgumentException(id);
1407                }
1408
1409                trans[i] = tr.getMillis();
1410                wallOffsets[i] = tr.getWallOffset();
1411                standardOffsets[i] = tr.getStandardOffset();
1412                nameKeys[i] = tr.getNameKey();
1413
1414                last = tr;
1415            }
1416
1417            // Some timezones (Australia) have the same name key for
1418            // summer and winter which messes everything up. Fix it here.
1419            String[] zoneNameData = new String[5];
1420            String[][] zoneStrings = new DateFormatSymbols(Locale.ENGLISH).getZoneStrings();
1421            for (int j = 0; j < zoneStrings.length; j++) {
1422                String[] set = zoneStrings[j];
1423                if (set != null && set.length == 5 && id.equals(set[0])) {
1424                    zoneNameData = set;
1425                }
1426            }
1427
1428            Chronology chrono = ISOChronology.getInstanceUTC();
1429
1430            for (int i = 0; i < nameKeys.length - 1; i++) {
1431                String curNameKey = nameKeys[i];
1432                String nextNameKey = nameKeys[i + 1];
1433                long curOffset = wallOffsets[i];
1434                long nextOffset = wallOffsets[i + 1];
1435                long curStdOffset = standardOffsets[i];
1436                long nextStdOffset = standardOffsets[i + 1];
1437                Period p = new Period(trans[i], trans[i + 1], PeriodType.yearMonthDay(), chrono);
1438                if (curOffset != nextOffset &&
1439                        curStdOffset == nextStdOffset &&
1440                        curNameKey.equals(nextNameKey) &&
1441                        p.getYears() == 0 && p.getMonths() > 4 && p.getMonths() < 8 &&
1442                        curNameKey.equals(zoneNameData[2]) &&
1443                        curNameKey.equals(zoneNameData[4])) {
1444                    
1445                    System.out.println("Fixing duplicate name key - " + nextNameKey);
1446                    System.out.println("     - " + new DateTime(trans[i], chrono) +
1447                                       " - " + new DateTime(trans[i + 1], chrono));
1448                    if (curOffset > nextOffset) {
1449                        nameKeys[i] = (curNameKey + "-Summer").intern();
1450                    } else if (curOffset < nextOffset) {
1451                        nameKeys[i + 1] = (nextNameKey + "-Summer").intern();
1452                        i++;
1453                    }
1454                }
1455            }
1456
1457            if (tailZone != null) {
1458                if (tailZone.iStartRecurrence.getNameKey()
1459                    .equals(tailZone.iEndRecurrence.getNameKey())) {
1460                    System.out.println("Fixing duplicate recurrent name key - " +
1461                                       tailZone.iStartRecurrence.getNameKey());
1462                    if (tailZone.iStartRecurrence.getSaveMillis() > 0) {
1463                        tailZone = new DSTZone(
1464                            tailZone.getID(),
1465                            tailZone.iStandardOffset,
1466                            tailZone.iStartRecurrence.renameAppend("-Summer"),
1467                            tailZone.iEndRecurrence);
1468                    } else {
1469                        tailZone = new DSTZone(
1470                            tailZone.getID(),
1471                            tailZone.iStandardOffset,
1472                            tailZone.iStartRecurrence,
1473                            tailZone.iEndRecurrence.renameAppend("-Summer"));
1474                    }
1475                }
1476            }
1477            
1478            return new PrecalculatedZone
1479                ((outputID ? id : ""), trans, wallOffsets, standardOffsets, nameKeys, tailZone);
1480        }
1481
1482        // All array fields have the same length.
1483
1484        private final long[] iTransitions;
1485
1486        private final int[] iWallOffsets;
1487        private final int[] iStandardOffsets;
1488        private final String[] iNameKeys;
1489
1490        private final DSTZone iTailZone;
1491
1492        /**
1493         * Constructor used ONLY for valid input, loaded via static methods.
1494         */
1495        private PrecalculatedZone(String id, long[] transitions, int[] wallOffsets,
1496                          int[] standardOffsets, String[] nameKeys, DSTZone tailZone)
1497        {
1498            super(id);
1499            iTransitions = transitions;
1500            iWallOffsets = wallOffsets;
1501            iStandardOffsets = standardOffsets;
1502            iNameKeys = nameKeys;
1503            iTailZone = tailZone;
1504        }
1505
1506        public String getNameKey(long instant) {
1507            long[] transitions = iTransitions;
1508            int i = Arrays.binarySearch(transitions, instant);
1509            if (i >= 0) {
1510                return iNameKeys[i];
1511            }
1512            i = ~i;
1513            if (i < transitions.length) {
1514                if (i > 0) {
1515                    return iNameKeys[i - 1];
1516                }
1517                return "UTC";
1518            }
1519            if (iTailZone == null) {
1520                return iNameKeys[i - 1];
1521            }
1522            return iTailZone.getNameKey(instant);
1523        }
1524
1525        public int getOffset(long instant) {
1526            long[] transitions = iTransitions;
1527            int i = Arrays.binarySearch(transitions, instant);
1528            if (i >= 0) {
1529                return iWallOffsets[i];
1530            }
1531            i = ~i;
1532            if (i < transitions.length) {
1533                if (i > 0) {
1534                    return iWallOffsets[i - 1];
1535                }
1536                return 0;
1537            }
1538            if (iTailZone == null) {
1539                return iWallOffsets[i - 1];
1540            }
1541            return iTailZone.getOffset(instant);
1542        }
1543
1544        public int getStandardOffset(long instant) {
1545            long[] transitions = iTransitions;
1546            int i = Arrays.binarySearch(transitions, instant);
1547            if (i >= 0) {
1548                return iStandardOffsets[i];
1549            }
1550            i = ~i;
1551            if (i < transitions.length) {
1552                if (i > 0) {
1553                    return iStandardOffsets[i - 1];
1554                }
1555                return 0;
1556            }
1557            if (iTailZone == null) {
1558                return iStandardOffsets[i - 1];
1559            }
1560            return iTailZone.getStandardOffset(instant);
1561        }
1562
1563        public boolean isFixed() {
1564            return false;
1565        }
1566
1567        public long nextTransition(long instant) {
1568            long[] transitions = iTransitions;
1569            int i = Arrays.binarySearch(transitions, instant);
1570            i = (i >= 0) ? (i + 1) : ~i;
1571            if (i < transitions.length) {
1572                return transitions[i];
1573            }
1574            if (iTailZone == null) {
1575                return instant;
1576            }
1577            long end = transitions[transitions.length - 1];
1578            if (instant < end) {
1579                instant = end;
1580            }
1581            return iTailZone.nextTransition(instant);
1582        }
1583
1584        public long previousTransition(long instant) {
1585            long[] transitions = iTransitions;
1586            int i = Arrays.binarySearch(transitions, instant);
1587            if (i >= 0) {
1588                if (instant > Long.MIN_VALUE) {
1589                    return instant - 1;
1590                }
1591                return instant;
1592            }
1593            i = ~i;
1594            if (i < transitions.length) {
1595                if (i > 0) {
1596                    long prev = transitions[i - 1];
1597                    if (prev > Long.MIN_VALUE) {
1598                        return prev - 1;
1599                    }
1600                }
1601                return instant;
1602            }
1603            if (iTailZone != null) {
1604                long prev = iTailZone.previousTransition(instant);
1605                if (prev < instant) {
1606                    return prev;
1607                }
1608            }
1609            long prev = transitions[i - 1];
1610            if (prev > Long.MIN_VALUE) {
1611                return prev - 1;
1612            }
1613            return instant;
1614        }
1615
1616        public boolean equals(Object obj) {
1617            if (this == obj) {
1618                return true;
1619            }
1620            if (obj instanceof PrecalculatedZone) {
1621                PrecalculatedZone other = (PrecalculatedZone)obj;
1622                return
1623                    getID().equals(other.getID()) &&
1624                    Arrays.equals(iTransitions, other.iTransitions) &&
1625                    Arrays.equals(iNameKeys, other.iNameKeys) &&
1626                    Arrays.equals(iWallOffsets, other.iWallOffsets) &&
1627                    Arrays.equals(iStandardOffsets, other.iStandardOffsets) &&
1628                    ((iTailZone == null)
1629                     ? (null == other.iTailZone)
1630                     : (iTailZone.equals(other.iTailZone)));
1631            }
1632            return false;
1633        }
1634
1635        public void writeTo(DataOutput out) throws IOException {
1636            int size = iTransitions.length;
1637
1638            // Create unique string pool.
1639            Set poolSet = new HashSet();
1640            for (int i=0; i<size; i++) {
1641                poolSet.add(iNameKeys[i]);
1642            }
1643
1644            int poolSize = poolSet.size();
1645            if (poolSize > 65535) {
1646                throw new UnsupportedOperationException("String pool is too large");
1647            }
1648            String[] pool = new String[poolSize];
1649            Iterator it = poolSet.iterator();
1650            for (int i=0; it.hasNext(); i++) {
1651                pool[i] = (String)it.next();
1652            }
1653
1654            // Write out the pool.
1655            out.writeShort(poolSize);
1656            for (int i=0; i<poolSize; i++) {
1657                out.writeUTF(pool[i]);
1658            }
1659
1660            out.writeInt(size);
1661
1662            for (int i=0; i<size; i++) {
1663                writeMillis(out, iTransitions[i]);
1664                writeMillis(out, iWallOffsets[i]);
1665                writeMillis(out, iStandardOffsets[i]);
1666                
1667                // Find pool index and write it out.
1668                String nameKey = iNameKeys[i];
1669                for (int j=0; j<poolSize; j++) {
1670                    if (pool[j].equals(nameKey)) {
1671                        if (poolSize < 256) {
1672                            out.writeByte(j);
1673                        } else {
1674                            out.writeShort(j);
1675                        }
1676                        break;
1677                    }
1678                }
1679            }
1680
1681            out.writeBoolean(iTailZone != null);
1682            if (iTailZone != null) {
1683                iTailZone.writeTo(out);
1684            }
1685        }
1686
1687        public boolean isCachable() {
1688            if (iTailZone != null) {
1689                return true;
1690            }
1691            long[] transitions = iTransitions;
1692            if (transitions.length <= 1) {
1693                return false;
1694            }
1695
1696            // Add up all the distances between transitions that are less than
1697            // about two years.
1698            double distances = 0;
1699            int count = 0;
1700
1701            for (int i=1; i<transitions.length; i++) {
1702                long diff = transitions[i] - transitions[i - 1];
1703                if (diff < ((366L + 365) * 24 * 60 * 60 * 1000)) {
1704                    distances += (double)diff;
1705                    count++;
1706                }
1707            }
1708
1709            if (count > 0) {
1710                double avg = distances / count;
1711                avg /= 24 * 60 * 60 * 1000;
1712                if (avg >= 25) {
1713                    // Only bother caching if average distance between
1714                    // transitions is at least 25 days. Why 25?
1715                    // CachedDateTimeZone is more efficient if the distance
1716                    // between transitions is large. With an average of 25, it
1717                    // will on average perform about 2 tests per cache
1718                    // hit. (49.7 / 25) is approximately 2.
1719                    return true;
1720                }
1721            }
1722
1723            return false;
1724        }
1725    }
1726}