1 /*

     2  * Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 import java.util.ArrayList;

    27 import java.util.List;

    28 

    29 /**

    30  * Timezone represents all information of a single point of time to

    31  * generate its time zone database.

    32  *

    33  * @since 1.4

    34  */

    35 class Timezone {

    36     /**

    37      * zone name of this time zone

    38      */

    39     private String name;

    40 

    41     /**

    42      * transition time values in UTC (millisecond)

    43      */

    44     private List<Long> transitions;

    45 

    46     /**

    47      * All offset values in millisecond

    48      * @see sun.util.calendar.ZoneInfo

    49      */

    50     private List<Integer> offsets;

    51 

    52     /**

    53      * Indices of GMT offset values (both raw and raw+saving)

    54      * at transitions

    55      */

    56     private List<Integer> gmtOffsets;

    57 

    58     /**

    59      * Indices of regular or "direct" saving time values

    60      * at transitions

    61      */

    62     private List<Integer> dstOffsets;

    63 

    64     /**

    65      * Zone records of this time zone

    66      */

    67     private List<ZoneRec> usedZoneRecs;

    68 

    69     /**

    70      * Rule records referred to by this time zone

    71      */

    72     private List<RuleRec> usedRuleRecs;

    73 

    74     /**

    75      * Type of DST rules in this time zone

    76      */

    77     private int dstType;

    78     static final int UNDEF_DST = 0;     // DST type not set yet

    79     static final int NO_DST = 1;        // never observed DST

    80     static final int LAST_DST = 2;      // last rule ends in DST (all year round DST-only)

    81     static final int X_DST = 3;         // used to observe DST

    82     static final int DST = 4;           // observing DST regularly

    83 

    84     /**

    85      * Raw GMT offset of this time zone in the last rule

    86      */

    87     private int rawOffset;

    88 

    89     /**

    90      * The CRC32 value of the transitions data

    91      */

    92     private int crc32;

    93 

    94     /**

    95      * The last ZoneRec

    96      */

    97     private ZoneRec lastZoneRec;

    98 

    99     /**

   100      * The last DST rules. lastRules[0] is the DST start

   101      * rule. lastRules[1] is the DST end rules.

   102      */

   103     private List<RuleRec> lastRules;

   104 

   105     /**

   106      * The amount of DST saving value (millisecond) in the last DST

   107      * rule.

   108      */

   109     private int lastSaving;

   110 

   111     /**

   112      * true if the raw offset will change in the future time.

   113      */

   114     private boolean willRawOffsetChange = false;

   115 

   116 

   117     /**

   118      * Constracts a Timezone object with the given zone name.

   119      * @param name the zone name

   120      */

   121     Timezone(String name) {

   122         this.name = name;

   123     }

   124 

   125     /**

   126      * @return the number of transitions

   127      */

   128     int getNTransitions() {

   129         if (transitions == null) {

   130             return 0;

   131         }

   132         return transitions.size();

   133     }

   134 

   135     /**

   136      * @return the zone name

   137      */

   138     String getName() {

   139         return name;

   140     }

   141 

   142     /**

   143      * Returns the list of all rule records that have been referred to

   144      * by this time zone.

   145      * @return the rule records list

   146      */

   147     List<RuleRec> getRules() {

   148         return usedRuleRecs;

   149     }

   150 

   151     /**

   152      * Returns the list of all zone records that have been referred to

   153      * by this time zone.

   154      * @return the zone records list

   155      */

   156     List<ZoneRec> getZones() {

   157         return usedZoneRecs;

   158     }

   159 

   160     /**

   161      * @return the transition table (list)

   162      */

   163     List<Long> getTransitions() {

   164         return transitions;

   165     }

   166 

   167     /**

   168      * @return the offsets list

   169      */

   170     List<Integer> getOffsets() {

   171         return offsets;

   172     }

   173 

   174     /**

   175      * @return the DST saving offsets list

   176      */

   177     List<Integer> getDstOffsets() {

   178         return dstOffsets;

   179     }

   180 

   181     /**

   182      * @return the GMT offsets list

   183      */

   184     List<Integer> getGmtOffsets() {

   185         return gmtOffsets;

   186     }

   187 

   188     /**

   189      * @return the checksum (crc32) value of the trasition table

   190      */

   191     int getCRC32() {

   192         return crc32;

   193     }

   194 

   195     /**

   196      * @return true if the GMT offset of this time zone would change

   197      * after the time zone database has been generated, false, otherwise.

   198      */

   199     boolean willGMTOffsetChange() {

   200         return willRawOffsetChange;

   201     }

   202 

   203     /**

   204      * @return the last known GMT offset value in milliseconds

   205      */

   206     int getRawOffset() {

   207         return rawOffset;

   208     }

   209 

   210     /**

   211      * Sets time zone's GMT offset to <code>offset</code>.

   212      * @param offset the GMT offset value in milliseconds

   213      */

   214     void setRawOffset(int offset) {

   215         rawOffset = offset;

   216     }

   217 

   218     /**

   219      * Sets time zone's GMT offset value to <code>offset</code>. If

   220      * <code>startTime</code> is future time, then the {@link

   221      * #willRawOffsetChange} value is set to true.

   222      * @param offset the GMT offset value in milliseconds

   223      * @param startTime the UTC time at which the GMT offset is in effective

   224      */

   225     void setRawOffset(int offset, long startTime) {

   226         // if this rawOffset is for the future time, let the run-time

   227         // look for the current GMT offset.

   228         if (startTime > Time.getCurrentTime()) {

   229             willRawOffsetChange = true;

   230         }

   231         setRawOffset(offset);

   232     }

   233 

   234     /**

   235      * Adds the specified transition information to the end of the transition table.

   236      * @param time the UTC time at which this transition happens

   237      * @param offset the total amount of the offset from GMT in milliseconds

   238      * @param dstOffset the amount of time in milliseconds saved at this transition

   239      */

   240     void addTransition(long time, int offset, int dstOffset) {

   241         if (transitions == null) {

   242             transitions = new ArrayList<Long>();

   243             offsets = new ArrayList<Integer>();

   244             dstOffsets = new ArrayList<Integer>();

   245         }

   246         transitions.add(time);

   247         offsets.add(offset);

   248         dstOffsets.add(dstOffset);

   249     }

   250 

   251     /**

   252      * Sets the type of historical daylight saving time

   253      * observation. For example, China used to observed daylight

   254      * saving time, but it no longer does. Then, X_DST is set to the

   255      * China time zone.

   256      * @param type the type of daylight saving time

   257      */

   258     void setDSTType(int type) {

   259         dstType = type;

   260     }

   261 

   262     /**

   263      * @return the type of historical daylight saving time

   264      * observation.

   265      */

   266     int getDSTType() {

   267         return dstType;

   268     }

   269 

   270     /**

   271      * Adds the specified zone record to the zone records list.

   272      * @param rec the zone record

   273      */

   274     void addUsedRec(ZoneRec rec) {

   275         if (usedZoneRecs == null) {

   276             usedZoneRecs = new ArrayList<ZoneRec>();

   277         }

   278         usedZoneRecs.add(rec);

   279     }

   280 

   281     /**

   282      * Adds the specified rule record to the rule records list.

   283      * @param rec the rule record

   284      */

   285     void addUsedRec(RuleRec rec) {

   286         if (usedRuleRecs == null) {

   287             usedRuleRecs = new ArrayList<RuleRec>();

   288         }

   289         // if the last used rec is the same as the given rec, avoid

   290         // putting the same rule.

   291         int n = usedRuleRecs.size();

   292         for (int i = 0; i < n; i++) {

   293             if (usedRuleRecs.get(i).equals(rec)) {

   294                 return;

   295             }

   296         }

   297         usedRuleRecs.add(rec);

   298     }

   299 

   300     /**

   301      * Sets the last zone record for this time zone.

   302      * @param the last zone record

   303      */

   304     void setLastZoneRec(ZoneRec zrec) {

   305         lastZoneRec = zrec;

   306     }

   307 

   308     /**

   309      * @return the last zone record for this time zone.

   310      */

   311     ZoneRec getLastZoneRec() {

   312         return lastZoneRec;

   313     }

   314 

   315     /**

   316      * Sets the last rule records for this time zone. Those are used

   317      * for generating SimpleTimeZone parameters.

   318      * @param rules the last rule records

   319      */

   320     void setLastRules(List<RuleRec> rules) {

   321         int n = rules.size();

   322         if (n > 0) {

   323             lastRules = rules;

   324             RuleRec rec = rules.get(0);

   325             int offset = rec.getSave();

   326             if (offset > 0) {

   327                 setLastDSTSaving(offset);

   328             } else {

   329                 System.err.println("\t    No DST starting rule in the last rules.");

   330             }

   331         }

   332     }

   333 

   334     /**

   335      * @return the last rule records for this time zone.

   336      */

   337     List<RuleRec> getLastRules() {

   338         return lastRules;

   339     }

   340 

   341     /**

   342      * Sets the last daylight saving amount.

   343      * @param the daylight saving amount

   344      */

   345     void setLastDSTSaving(int offset) {

   346         lastSaving = offset;

   347     }

   348 

   349     /**

   350      * @return the last daylight saving amount.

   351      */

   352     int getLastDSTSaving() {

   353         return lastSaving;

   354     }

   355 

   356     /**

   357      * Calculates the CRC32 value from the transition table and sets

   358      * the value to <code>crc32</code>.

   359      */

   360     void checksum() {

   361         if (transitions == null) {

   362             crc32 = 0;

   363             return;

   364         }

   365         Checksum sum = new Checksum();

   366         for (int i = 0; i < transitions.size(); i++) {

   367             int offset = offsets.get(i);

   368             // adjust back to make the transition in local time

   369             sum.update(transitions.get(i) + offset);

   370             sum.update(offset);

   371             sum.update(dstOffsets.get(i));

   372         }

   373         crc32 = (int)sum.getValue();

   374     }

   375 

   376     /**

   377      * Removes unnecessary transitions for Java time zone support.

   378      */

   379     void optimize() {

   380         // if there is only one offset, delete all transitions. This

   381         // could happen if only time zone abbreviations changed.

   382         if (gmtOffsets.size() == 1) {

   383             transitions = null;

   384             usedRuleRecs =  null;

   385             setDSTType(NO_DST);

   386             return;

   387         }

   388         for (int i = 0; i < (transitions.size() - 2); i++) { // don't remove the last one

   389             if (transitions.get(i) == transitions.get(i+1)) {

   390                 transitions.remove(i);

   391                 offsets.remove(i);

   392                 dstOffsets.remove(i);

   393                 i--;

   394             }

   395         }

   396 

   397         for (int i = 0; i < (transitions.size() - 2); i++) { // don't remove the last one

   398             if (offsets.get(i) == offsets.get(i+1)

   399                 && dstOffsets.get(i) == dstOffsets.get(i+1)) {

   400                 transitions.remove(i+1);

   401                 offsets.remove(i+1);

   402                 dstOffsets.remove(i+1);

   403                 i--;

   404             }

   405         }

   406     }

   407 

   408     /**

   409      * Stores the specified offset value from GMT in the GMT offsets

   410      * table and returns its index. The offset value includes the base

   411      * GMT offset and any additional daylight saving if applicable. If

   412      * the same value as the specified offset is already in the table,

   413      * its index is returned.

   414      * @param offset the offset value in milliseconds

   415      * @return the index to the offset value in the GMT offsets table.

   416      */

   417     int getOffsetIndex(int offset) {

   418         return getOffsetIndex(offset, 0);

   419     }

   420 

   421     /**

   422      * Stores the specified daylight saving value in the GMT offsets

   423      * table and returns its index. If the same value as the specified

   424      * offset is already in the table, its index is returned. If 0 is

   425      * specified, it's not stored in the table and -1 is returned.

   426      * @param offset the offset value in milliseconds

   427      * @return the index to the specified offset value in the GMT

   428      * offsets table, or -1 if 0 is specified.

   429      */

   430     int getDstOffsetIndex(int offset) {

   431         if (offset == 0) {

   432             return -1;

   433         }

   434         return getOffsetIndex(offset, 1);

   435     }

   436 

   437     private int getOffsetIndex(int offset, int index) {

   438         if (gmtOffsets == null) {

   439             gmtOffsets = new ArrayList<Integer>();

   440         }

   441         for (int i = index; i < gmtOffsets.size(); i++) {

   442             if (offset == gmtOffsets.get(i)) {

   443                 return i;

   444             }

   445         }

   446         if (gmtOffsets.size() < index) {

   447             gmtOffsets.add(0);

   448         }

   449         gmtOffsets.add(offset);

   450         return gmtOffsets.size() - 1;

   451     }

   452 }