1 /* 2 * Copyright (c) 2000, 2013, 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 package sun.util.calendar; 27 28 import java.io.IOException; 29 import java.io.ObjectInputStream; 30 import java.util.Date; 31 import java.util.Map; 32 import java.util.SimpleTimeZone; 33 import java.util.TimeZone; 34 35 /** 36 * <code>ZoneInfo</code> is an implementation subclass of {@link 37 * java.util.TimeZone TimeZone} that represents GMT offsets and 38 * daylight saving time transitions of a time zone. 39 * <p> 40 * The daylight saving time transitions are described in the {@link 41 * #transitions transitions} table consisting of a chronological 42 * sequence of transitions of GMT offset and/or daylight saving time 43 * changes. Since all transitions are represented in UTC, in theory, 44 * <code>ZoneInfo</code> can be used with any calendar systems except 45 * for the {@link #getOffset(int,int,int,int,int,int) getOffset} 46 * method that takes Gregorian calendar date fields. 47 * <p> 48 * This table covers transitions from 1900 until 2037 (as of version 49 * 1.4), Before 1900, it assumes that there was no daylight saving 50 * time and the <code>getOffset</code> methods always return the 51 * {@link #getRawOffset} value. No Local Mean Time is supported. If a 52 * specified date is beyond the transition table and this time zone is 53 * supposed to observe daylight saving time in 2037, it delegates 54 * operations to a {@link java.util.SimpleTimeZone SimpleTimeZone} 55 * object created using the daylight saving time schedule as of 2037. 56 * <p> 57 * The date items, transitions, GMT offset(s), etc. are read from a database 58 * file. See {@link ZoneInfoFile} for details. 59 * @see java.util.SimpleTimeZone 60 * @since 1.4 61 */ 62 63 public class ZoneInfo extends TimeZone { 64 65 private static final int UTC_TIME = 0; 66 private static final int STANDARD_TIME = 1; 67 private static final int WALL_TIME = 2; 68 69 private static final long OFFSET_MASK = 0x0fL; 70 private static final long DST_MASK = 0xf0L; 71 private static final int DST_NSHIFT = 4; 72 // this bit field is reserved for abbreviation support 73 private static final long ABBR_MASK = 0xf00L; 74 private static final int TRANSITION_NSHIFT = 12; 75 76 /** 77 * The raw GMT offset in milliseconds between this zone and GMT. 78 * Negative offsets are to the west of Greenwich. To obtain local 79 * <em>standard</em> time, add the offset to GMT time. 80 * @serial 81 */ 82 private int rawOffset; 83 84 /** 85 * Difference in milliseconds from the original GMT offset in case 86 * the raw offset value has been modified by calling {@link 87 * #setRawOffset}. The initial value is 0. 88 * @serial 89 */ 90 private int rawOffsetDiff = 0; 91 92 /** 93 * A CRC32 value of all pairs of transition time (in milliseconds 94 * in <code>long</code>) in local time and its GMT offset (in 95 * seconds in <code>int</code>) in the chronological order. Byte 96 * values of each <code>long</code> and <code>int</code> are taken 97 * in the big endian order (i.e., MSB to LSB). 98 * @serial 99 */ 100 private int checksum; 101 102 /** 103 * The amount of time in milliseconds saved during daylight saving 104 * time. If <code>useDaylight</code> is false, this value is 0. 105 * @serial 106 */ 107 private int dstSavings; 108 109 /** 110 * This array describes transitions of GMT offsets of this time 111 * zone, including both raw offset changes and daylight saving 112 * time changes. 113 * A long integer consists of four bit fields. 114 * <ul> 115 * <li>The most significant 52-bit field represents transition 116 * time in milliseconds from Gregorian January 1 1970, 00:00:00 117 * GMT.</li> 118 * <li>The next 4-bit field is reserved and must be 0.</li> 119 * <li>The next 4-bit field is an index value to {@link #offsets 120 * offsets[]} for the amount of daylight saving at the 121 * transition. If this value is zero, it means that no daylight 122 * saving, not the index value zero.</li> 123 * <li>The least significant 4-bit field is an index value to 124 * {@link #offsets offsets[]} for <em>total</em> GMT offset at the 125 * transition.</li> 126 * </ul> 127 * If this time zone doesn't observe daylight saving time and has 128 * never changed any GMT offsets in the past, this value is null. 129 * @serial 130 */ 131 private long[] transitions; 132 133 /** 134 * This array holds all unique offset values in 135 * milliseconds. Index values to this array are stored in the 136 * transitions array elements. 137 * @serial 138 */ 139 private int[] offsets; 140 141 /** 142 * SimpleTimeZone parameter values. It has to have either 8 for 143 * {@link java.util.SimpleTimeZone#SimpleTimeZone(int, String, 144 * int, int , int , int , int , int , int , int , int) the 145 * 11-argument SimpleTimeZone constructor} or 10 for {@link 146 * java.util.SimpleTimeZone#SimpleTimeZone(int, String, int, int, 147 * int , int , int , int , int , int , int, int, int) the 148 * 13-argument SimpleTimeZone constructor} parameters. 149 * @serial 150 */ 151 private int[] simpleTimeZoneParams; 152 153 /** 154 * True if the raw GMT offset value would change after the time 155 * zone data has been generated; false, otherwise. The default 156 * value is false. 157 * @serial 158 */ 159 private boolean willGMTOffsetChange = false; 160 161 /** 162 * True if the object has been modified after its instantiation. 163 */ 164 private transient boolean dirty = false; 165 166 private static final long serialVersionUID = 2653134537216586139L; 167 168 /** 169 * A constructor. 170 */ 171 public ZoneInfo() { 172 } 173 174 /** 175 * A Constructor for CustomID. 176 */ 177 public ZoneInfo(String ID, int rawOffset) { 178 this(ID, rawOffset, 0, 0, null, null, null, false); 179 } 180 181 /** 182 * Constructs a ZoneInfo instance. 183 * 184 * @param ID time zone name 185 * @param rawOffset GMT offset in milliseconds 186 * @param dstSavings daylight saving value in milliseconds or 0 187 * (zero) if this time zone doesn't observe Daylight Saving Time. 188 * @param checksum CRC32 value with all transitions table entry 189 * values 190 * @param transitions transition table 191 * @param offsets offset value table 192 * @param simpleTimeZoneParams parameter values for constructing 193 * SimpleTimeZone 194 * @param willGMTOffsetChange the value of willGMTOffsetChange 195 */ 196 ZoneInfo(String ID, 197 int rawOffset, 198 int dstSavings, 199 int checksum, 200 long[] transitions, 201 int[] offsets, 202 int[] simpleTimeZoneParams, 203 boolean willGMTOffsetChange) { 204 setID(ID); 205 this.rawOffset = rawOffset; 206 this.dstSavings = dstSavings; 207 this.checksum = checksum; 208 this.transitions = transitions; 209 this.offsets = offsets; 210 this.simpleTimeZoneParams = simpleTimeZoneParams; 211 this.willGMTOffsetChange = willGMTOffsetChange; 212 } 213 214 /** 215 * Returns the difference in milliseconds between local time and UTC 216 * of given time, taking into account both the raw offset and the 217 * effect of daylight savings. 218 * 219 * @param date the milliseconds in UTC 220 * @return the milliseconds to add to UTC to get local wall time 221 */ 222 public int getOffset(long date) { 223 return getOffsets(date, null, UTC_TIME); 224 } 225 226 public int getOffsets(long utc, int[] offsets) { 227 return getOffsets(utc, offsets, UTC_TIME); 228 } 229 230 public int getOffsetsByStandard(long standard, int[] offsets) { 231 return getOffsets(standard, offsets, STANDARD_TIME); 232 } 233 234 public int getOffsetsByWall(long wall, int[] offsets) { 235 return getOffsets(wall, offsets, WALL_TIME); 236 } 237 238 private int getOffsets(long date, int[] offsets, int type) { 239 // if dst is never observed, there is no transition. 240 if (transitions == null) { 241 int offset = getLastRawOffset(); 242 if (offsets != null) { 243 offsets[0] = offset; 244 offsets[1] = 0; 245 } 246 return offset; 247 } 248 249 date -= rawOffsetDiff; 250 int index = getTransitionIndex(date, type); 251 252 // prior to the transition table, returns the raw offset. 253 // FIXME: should support LMT. 254 if (index < 0) { 255 int offset = getLastRawOffset(); 256 if (offsets != null) { 257 offsets[0] = offset; 258 offsets[1] = 0; 259 } 260 return offset; 261 } 262 263 if (index < transitions.length) { 264 long val = transitions[index]; 265 int offset = this.offsets[(int)(val & OFFSET_MASK)] + rawOffsetDiff; 266 if (offsets != null) { 267 int dst = (int)((val >>> DST_NSHIFT) & 0xfL); 268 int save = (dst == 0) ? 0 : this.offsets[dst]; 269 offsets[0] = offset - save; 270 offsets[1] = save; 271 } 272 return offset; 273 } 274 275 // beyond the transitions, delegate to SimpleTimeZone if there 276 // is a rule; otherwise, return the offset of the last transition. 277 SimpleTimeZone tz = getLastRule(); 278 if (tz != null) { 279 int rawoffset = tz.getRawOffset(); 280 long msec = date; 281 if (type != UTC_TIME) { 282 msec -= rawOffset; 283 } 284 int dstoffset = tz.getOffset(msec) - rawOffset; 285 286 // Check if it's in a standard-to-daylight transition. 287 if (dstoffset > 0 && tz.getOffset(msec - dstoffset) == rawoffset) { 288 dstoffset = 0; 289 } 290 291 if (offsets != null) { 292 offsets[0] = rawoffset; 293 offsets[1] = dstoffset; 294 } 295 return rawoffset + dstoffset; 296 } else { 297 // use the last transition 298 long val = transitions[transitions.length - 1]; 299 int offset = this.offsets[(int)(val & OFFSET_MASK)] + rawOffsetDiff; 300 if (offsets != null) { 301 int dst = (int)((val >>> DST_NSHIFT) & 0xfL); 302 int save = (dst == 0) ? 0 : this.offsets[dst]; 303 offsets[0] = offset - save; 304 offsets[1] = save; 305 } 306 return offset; 307 } 308 } 309 310 private int getTransitionIndex(long date, int type) { 311 int low = 0; 312 int high = transitions.length - 1; 313 314 while (low <= high) { 315 int mid = (low + high) / 2; 316 long val = transitions[mid]; 317 long midVal = val >> TRANSITION_NSHIFT; // sign extended 318 if (type != UTC_TIME) { 319 midVal += offsets[(int)(val & OFFSET_MASK)]; // wall time 320 } 321 if (type == STANDARD_TIME) { 322 int dstIndex = (int)((val >>> DST_NSHIFT) & 0xfL); 323 if (dstIndex != 0) { 324 midVal -= offsets[dstIndex]; // make it standard time 325 } 326 } 327 328 if (midVal < date) { 329 low = mid + 1; 330 } else if (midVal > date) { 331 high = mid - 1; 332 } else { 333 return mid; 334 } 335 } 336 337 // if beyond the transitions, returns that index. 338 if (low >= transitions.length) { 339 return low; 340 } 341 return low - 1; 342 } 343 344 /** 345 * Returns the difference in milliseconds between local time and 346 * UTC, taking into account both the raw offset and the effect of 347 * daylight savings, for the specified date and time. This method 348 * assumes that the start and end month are distinct. This method 349 * assumes a Gregorian calendar for calculations. 350 * <p> 351 * <em>Note: In general, clients should use 352 * {@link Calendar#ZONE_OFFSET Calendar.get(ZONE_OFFSET)} + 353 * {@link Calendar#DST_OFFSET Calendar.get(DST_OFFSET)} 354 * instead of calling this method.</em> 355 * 356 * @param era The era of the given date. The value must be either 357 * GregorianCalendar.AD or GregorianCalendar.BC. 358 * @param year The year in the given date. 359 * @param month The month in the given date. Month is 0-based. e.g., 360 * 0 for January. 361 * @param day The day-in-month of the given date. 362 * @param dayOfWeek The day-of-week of the given date. 363 * @param milliseconds The milliseconds in day in <em>standard</em> local time. 364 * @return The milliseconds to add to UTC to get local time. 365 */ 366 public int getOffset(int era, int year, int month, int day, 367 int dayOfWeek, int milliseconds) { 368 if (milliseconds < 0 || milliseconds >= AbstractCalendar.DAY_IN_MILLIS) { 369 throw new IllegalArgumentException(); 370 } 371 372 if (era == java.util.GregorianCalendar.BC) { // BC 373 year = 1 - year; 374 } else if (era != java.util.GregorianCalendar.AD) { 375 throw new IllegalArgumentException(); 376 } 377 378 Gregorian gcal = CalendarSystem.getGregorianCalendar(); 379 CalendarDate date = gcal.newCalendarDate(null); 380 date.setDate(year, month + 1, day); 381 if (gcal.validate(date) == false) { 382 throw new IllegalArgumentException(); 383 } 384 385 // bug-for-bug compatible argument checking 386 if (dayOfWeek < java.util.GregorianCalendar.SUNDAY 387 || dayOfWeek > java.util.GregorianCalendar.SATURDAY) { 388 throw new IllegalArgumentException(); 389 } 390 391 if (transitions == null) { 392 return getLastRawOffset(); 393 } 394 395 long dateInMillis = gcal.getTime(date) + milliseconds; 396 dateInMillis -= (long) rawOffset; // make it UTC 397 return getOffsets(dateInMillis, null, UTC_TIME); 398 } 399 400 /** 401 * Sets the base time zone offset from GMT. This operation 402 * modifies all the transitions of this ZoneInfo object, including 403 * historical ones, if applicable. 404 * 405 * @param offsetMillis the base time zone offset to GMT. 406 * @see getRawOffset 407 */ 408 public synchronized void setRawOffset(int offsetMillis) { 409 if (offsetMillis == rawOffset + rawOffsetDiff) { 410 return; 411 } 412 rawOffsetDiff = offsetMillis - rawOffset; 413 if (lastRule != null) { 414 lastRule.setRawOffset(offsetMillis); 415 } 416 dirty = true; 417 } 418 419 /** 420 * Returns the GMT offset of the current date. This GMT offset 421 * value is not modified during Daylight Saving Time. 422 * 423 * @return the GMT offset value in milliseconds to add to UTC time 424 * to get local standard time 425 */ 426 public int getRawOffset() { 427 if (!willGMTOffsetChange) { 428 return rawOffset + rawOffsetDiff; 429 } 430 431 int[] offsets = new int[2]; 432 getOffsets(System.currentTimeMillis(), offsets, UTC_TIME); 433 return offsets[0]; 434 } 435 436 public boolean isDirty() { 437 return dirty; 438 } 439 440 private int getLastRawOffset() { 441 return rawOffset + rawOffsetDiff; 442 } 443 444 /** 445 * Queries if this time zone uses Daylight Saving Time in the last known rule. 446 */ 447 public boolean useDaylightTime() { 448 return (simpleTimeZoneParams != null); 449 } 450 451 @Override 452 public boolean observesDaylightTime() { 453 if (simpleTimeZoneParams != null) { 454 return true; 455 } 456 if (transitions == null) { 457 return false; 458 } 459 460 // Look up the transition table to see if it's in DST right 461 // now or if there's any standard-to-daylight transition at 462 // any future. 463 long utc = System.currentTimeMillis() - rawOffsetDiff; 464 int index = getTransitionIndex(utc, UTC_TIME); 465 466 // before transitions in the transition table 467 if (index < 0) { 468 return false; 469 } 470 471 // the time is in the table range. 472 for (int i = index; i < transitions.length; i++) { 473 if ((transitions[i] & DST_MASK) != 0) { 474 return true; 475 } 476 } 477 // No further DST is observed. 478 return false; 479 } 480 481 /** 482 * Queries if the specified date is in Daylight Saving Time. 483 */ 484 public boolean inDaylightTime(Date date) { 485 if (date == null) { 486 throw new NullPointerException(); 487 } 488 489 if (transitions == null) { 490 return false; 491 } 492 493 long utc = date.getTime() - rawOffsetDiff; 494 int index = getTransitionIndex(utc, UTC_TIME); 495 496 // before transitions in the transition table 497 if (index < 0) { 498 return false; 499 } 500 501 // the time is in the table range. 502 if (index < transitions.length) { 503 return (transitions[index] & DST_MASK) != 0; 504 } 505 506 // beyond the transition table 507 SimpleTimeZone tz = getLastRule(); 508 if (tz != null) { 509 return tz.inDaylightTime(date); 510 } else { 511 // use the last transition 512 return (transitions[transitions.length - 1] & DST_MASK) != 0; 513 } 514 } 515 516 /** 517 * Returns the amount of time in milliseconds that the clock is advanced 518 * during daylight saving time is in effect in its last daylight saving time rule. 519 * 520 * @return the number of milliseconds the time is advanced with respect to 521 * standard time when daylight saving time is in effect. 522 */ 523 public int getDSTSavings() { 524 return dstSavings; 525 } 526 527 // /** 528 // * @return the last year in the transition table or -1 if this 529 // * time zone doesn't observe any daylight saving time. 530 // */ 531 // public int getMaxTransitionYear() { 532 // if (transitions == null) { 533 // return -1; 534 // } 535 // long val = transitions[transitions.length - 1]; 536 // int offset = this.offsets[(int)(val & OFFSET_MASK)] + rawOffsetDiff; 537 // val = (val >> TRANSITION_NSHIFT) + offset; 538 // CalendarDate lastDate = Gregorian.getCalendarDate(val); 539 // return lastDate.getYear(); 540 // } 541 542 /** 543 * Returns a string representation of this time zone. 544 * @return the string 545 */ 546 public String toString() { 547 return getClass().getName() + 548 "[id=\"" + getID() + "\"" + 549 ",offset=" + getLastRawOffset() + 550 ",dstSavings=" + dstSavings + 551 ",useDaylight=" + useDaylightTime() + 552 ",transitions=" + ((transitions != null) ? transitions.length : 0) + 553 ",lastRule=" + (lastRule == null ? getLastRuleInstance() : lastRule) + 554 "]"; 555 } 556 557 /** 558 * Gets all available IDs supported in the Java run-time. 559 * 560 * @return an array of time zone IDs. 561 */ 562 public static String[] getAvailableIDs() { 563 return ZoneInfoFile.getZoneIds(); 564 } 565 566 /** 567 * Gets all available IDs that have the same value as the 568 * specified raw GMT offset. 569 * 570 * @param rawOffset the GMT offset in milliseconds. This 571 * value should not include any daylight saving time. 572 * 573 * @return an array of time zone IDs. 574 */ 575 public static String[] getAvailableIDs(int rawOffset) { 576 return ZoneInfoFile.getZoneIds(rawOffset); 577 } 578 579 /** 580 * Gets the ZoneInfo for the given ID. 581 * 582 * @param ID the ID for a ZoneInfo. See TimeZone for detail. 583 * 584 * @return the specified ZoneInfo object, or null if there is no 585 * time zone of the ID. 586 */ 587 public static TimeZone getTimeZone(String ID) { 588 return ZoneInfoFile.getZoneInfo(ID); 589 } 590 591 private transient SimpleTimeZone lastRule; 592 593 /** 594 * Returns a SimpleTimeZone object representing the last GMT 595 * offset and DST schedule or null if this time zone doesn't 596 * observe DST. 597 */ 598 private synchronized SimpleTimeZone getLastRule() { 599 if (lastRule == null) { 600 lastRule = getLastRuleInstance(); 601 } 602 return lastRule; 603 } 604 605 /** 606 * Returns a SimpleTimeZone object that represents the last 607 * known daylight saving time rules. 608 * 609 * @return a SimpleTimeZone object or null if this time zone 610 * doesn't observe DST. 611 */ 612 public SimpleTimeZone getLastRuleInstance() { 613 if (simpleTimeZoneParams == null) { 614 return null; 615 } 616 if (simpleTimeZoneParams.length == 10) { 617 return new SimpleTimeZone(getLastRawOffset(), getID(), 618 simpleTimeZoneParams[0], 619 simpleTimeZoneParams[1], 620 simpleTimeZoneParams[2], 621 simpleTimeZoneParams[3], 622 simpleTimeZoneParams[4], 623 simpleTimeZoneParams[5], 624 simpleTimeZoneParams[6], 625 simpleTimeZoneParams[7], 626 simpleTimeZoneParams[8], 627 simpleTimeZoneParams[9], 628 dstSavings); 629 } 630 return new SimpleTimeZone(getLastRawOffset(), getID(), 631 simpleTimeZoneParams[0], 632 simpleTimeZoneParams[1], 633 simpleTimeZoneParams[2], 634 simpleTimeZoneParams[3], 635 simpleTimeZoneParams[4], 636 simpleTimeZoneParams[5], 637 simpleTimeZoneParams[6], 638 simpleTimeZoneParams[7], 639 dstSavings); 640 } 641 642 /** 643 * Returns a copy of this <code>ZoneInfo</code>. 644 */ 645 public Object clone() { 646 ZoneInfo zi = (ZoneInfo) super.clone(); 647 zi.lastRule = null; 648 return zi; 649 } 650 651 /** 652 * Returns a hash code value calculated from the GMT offset and 653 * transitions. 654 * @return a hash code of this time zone 655 */ 656 public int hashCode() { 657 return getLastRawOffset() ^ checksum; 658 } 659 660 /** 661 * Compares the equity of two ZoneInfo objects. 662 * 663 * @param obj the object to be compared with 664 * @return true if given object is same as this ZoneInfo object, 665 * false otherwise. 666 */ 667 public boolean equals(Object obj) { 668 if (this == obj) { 669 return true; 670 } 671 if (!(obj instanceof ZoneInfo)) { 672 return false; 673 } 674 ZoneInfo that = (ZoneInfo) obj; 675 return (getID().equals(that.getID()) 676 && (getLastRawOffset() == that.getLastRawOffset()) 677 && (checksum == that.checksum)); 678 } 679 680 /** 681 * Returns true if this zone has the same raw GMT offset value and 682 * transition table as another zone info. If the specified 683 * TimeZone object is not a ZoneInfo instance, this method returns 684 * true if the specified TimeZone object has the same raw GMT 685 * offset value with no daylight saving time. 686 * 687 * @param other the ZoneInfo object to be compared with 688 * @return true if the given <code>TimeZone</code> has the same 689 * GMT offset and transition information; false, otherwise. 690 */ 691 public boolean hasSameRules(TimeZone other) { 692 if (this == other) { 693 return true; 694 } 695 if (other == null) { 696 return false; 697 } 698 if (!(other instanceof ZoneInfo)) { 699 if (getRawOffset() != other.getRawOffset()) { 700 return false; 701 } 702 // if both have the same raw offset and neither observes 703 // DST, they have the same rule. 704 if ((transitions == null) 705 && (useDaylightTime() == false) 706 && (other.useDaylightTime() == false)) { 707 return true; 708 } 709 return false; 710 } 711 if (getLastRawOffset() != ((ZoneInfo)other).getLastRawOffset()) { 712 return false; 713 } 714 return (checksum == ((ZoneInfo)other).checksum); 715 } 716 717 /** 718 * Returns a Map from alias time zone IDs to their standard 719 * time zone IDs. 720 * 721 * @return the Map that holds the mappings from alias time zone IDs 722 * to their standard time zone IDs, or null if 723 * <code>ZoneInfoMappings</code> file is not available. 724 */ 725 public static Map<String, String> getAliasTable() { 726 return ZoneInfoFile.getAliasMap(); 727 } 728 729 private void readObject(ObjectInputStream stream) 730 throws IOException, ClassNotFoundException { 731 stream.defaultReadObject(); 732 // We don't know how this object from 1.4.x or earlier has 733 // been mutated. So it should always be marked as `dirty'. 734 dirty = true; 735 } 736 }