J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved |
| 28 | * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved |
| 29 | * |
| 30 | * The original version of this source code and documentation is copyrighted |
| 31 | * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These |
| 32 | * materials are provided under terms of a License Agreement between Taligent |
| 33 | * and Sun. This technology is protected by multiple US and International |
| 34 | * patents. This notice and attribution to Taligent may not be removed. |
| 35 | * Taligent is a registered trademark of Taligent, Inc. |
| 36 | * |
| 37 | */ |
| 38 | |
| 39 | package java.text; |
| 40 | |
| 41 | import java.math.BigDecimal; |
| 42 | import java.math.BigInteger; |
| 43 | import java.math.RoundingMode; |
| 44 | |
| 45 | /** |
| 46 | * Digit List. Private to DecimalFormat. |
| 47 | * Handles the transcoding |
| 48 | * between numeric values and strings of characters. Only handles |
| 49 | * non-negative numbers. The division of labor between DigitList and |
| 50 | * DecimalFormat is that DigitList handles the radix 10 representation |
| 51 | * issues; DecimalFormat handles the locale-specific issues such as |
| 52 | * positive/negative, grouping, decimal point, currency, and so on. |
| 53 | * |
| 54 | * A DigitList is really a representation of a floating point value. |
| 55 | * It may be an integer value; we assume that a double has sufficient |
| 56 | * precision to represent all digits of a long. |
| 57 | * |
| 58 | * The DigitList representation consists of a string of characters, |
| 59 | * which are the digits radix 10, from '0' to '9'. It also has a radix |
| 60 | * 10 exponent associated with it. The value represented by a DigitList |
| 61 | * object can be computed by mulitplying the fraction f, where 0 <= f < 1, |
| 62 | * derived by placing all the digits of the list to the right of the |
| 63 | * decimal point, by 10^exponent. |
| 64 | * |
| 65 | * @see Locale |
| 66 | * @see Format |
| 67 | * @see NumberFormat |
| 68 | * @see DecimalFormat |
| 69 | * @see ChoiceFormat |
| 70 | * @see MessageFormat |
| 71 | * @author Mark Davis, Alan Liu |
| 72 | */ |
| 73 | final class DigitList implements Cloneable { |
| 74 | /** |
| 75 | * The maximum number of significant digits in an IEEE 754 double, that |
| 76 | * is, in a Java double. This must not be increased, or garbage digits |
| 77 | * will be generated, and should not be decreased, or accuracy will be lost. |
| 78 | */ |
| 79 | public static final int MAX_COUNT = 19; // == Long.toString(Long.MAX_VALUE).length() |
| 80 | |
| 81 | /** |
| 82 | * These data members are intentionally public and can be set directly. |
| 83 | * |
| 84 | * The value represented is given by placing the decimal point before |
| 85 | * digits[decimalAt]. If decimalAt is < 0, then leading zeros between |
| 86 | * the decimal point and the first nonzero digit are implied. If decimalAt |
| 87 | * is > count, then trailing zeros between the digits[count-1] and the |
| 88 | * decimal point are implied. |
| 89 | * |
| 90 | * Equivalently, the represented value is given by f * 10^decimalAt. Here |
| 91 | * f is a value 0.1 <= f < 1 arrived at by placing the digits in Digits to |
| 92 | * the right of the decimal. |
| 93 | * |
| 94 | * DigitList is normalized, so if it is non-zero, figits[0] is non-zero. We |
| 95 | * don't allow denormalized numbers because our exponent is effectively of |
| 96 | * unlimited magnitude. The count value contains the number of significant |
| 97 | * digits present in digits[]. |
| 98 | * |
| 99 | * Zero is represented by any DigitList with count == 0 or with each digits[i] |
| 100 | * for all i <= count == '0'. |
| 101 | */ |
| 102 | public int decimalAt = 0; |
| 103 | public int count = 0; |
| 104 | public char[] digits = new char[MAX_COUNT]; |
| 105 | |
| 106 | private char[] data; |
| 107 | private RoundingMode roundingMode = RoundingMode.HALF_EVEN; |
| 108 | private boolean isNegative = false; |
| 109 | |
| 110 | /** |
| 111 | * Return true if the represented number is zero. |
| 112 | */ |
| 113 | boolean isZero() { |
| 114 | for (int i=0; i < count; ++i) { |
| 115 | if (digits[i] != '0') { |
| 116 | return false; |
| 117 | } |
| 118 | } |
| 119 | return true; |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * Set the rounding mode |
| 124 | */ |
| 125 | void setRoundingMode(RoundingMode r) { |
| 126 | roundingMode = r; |
| 127 | } |
| 128 | |
| 129 | /** |
| 130 | * Clears out the digits. |
| 131 | * Use before appending them. |
| 132 | * Typically, you set a series of digits with append, then at the point |
| 133 | * you hit the decimal point, you set myDigitList.decimalAt = myDigitList.count; |
| 134 | * then go on appending digits. |
| 135 | */ |
| 136 | public void clear () { |
| 137 | decimalAt = 0; |
| 138 | count = 0; |
| 139 | } |
| 140 | |
| 141 | /** |
| 142 | * Appends a digit to the list, extending the list when necessary. |
| 143 | */ |
| 144 | public void append(char digit) { |
| 145 | if (count == digits.length) { |
| 146 | char[] data = new char[count + 100]; |
| 147 | System.arraycopy(digits, 0, data, 0, count); |
| 148 | digits = data; |
| 149 | } |
| 150 | digits[count++] = digit; |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Utility routine to get the value of the digit list |
| 155 | * If (count == 0) this throws a NumberFormatException, which |
| 156 | * mimics Long.parseLong(). |
| 157 | */ |
| 158 | public final double getDouble() { |
| 159 | if (count == 0) { |
| 160 | return 0.0; |
| 161 | } |
| 162 | |
| 163 | StringBuffer temp = getStringBuffer(); |
| 164 | temp.append('.'); |
| 165 | temp.append(digits, 0, count); |
| 166 | temp.append('E'); |
| 167 | temp.append(decimalAt); |
| 168 | return Double.parseDouble(temp.toString()); |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Utility routine to get the value of the digit list. |
| 173 | * If (count == 0) this returns 0, unlike Long.parseLong(). |
| 174 | */ |
| 175 | public final long getLong() { |
| 176 | // for now, simple implementation; later, do proper IEEE native stuff |
| 177 | |
| 178 | if (count == 0) { |
| 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | // We have to check for this, because this is the one NEGATIVE value |
| 183 | // we represent. If we tried to just pass the digits off to parseLong, |
| 184 | // we'd get a parse failure. |
| 185 | if (isLongMIN_VALUE()) { |
| 186 | return Long.MIN_VALUE; |
| 187 | } |
| 188 | |
| 189 | StringBuffer temp = getStringBuffer(); |
| 190 | temp.append(digits, 0, count); |
| 191 | for (int i = count; i < decimalAt; ++i) { |
| 192 | temp.append('0'); |
| 193 | } |
| 194 | return Long.parseLong(temp.toString()); |
| 195 | } |
| 196 | |
| 197 | public final BigDecimal getBigDecimal() { |
| 198 | if (count == 0) { |
| 199 | if (decimalAt == 0) { |
| 200 | return BigDecimal.ZERO; |
| 201 | } else { |
| 202 | return new BigDecimal("0E" + decimalAt); |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | if (decimalAt == count) { |
| 207 | return new BigDecimal(digits, 0, count); |
| 208 | } else { |
| 209 | return new BigDecimal(digits, 0, count).scaleByPowerOfTen(decimalAt - count); |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Return true if the number represented by this object can fit into |
| 215 | * a long. |
| 216 | * @param isPositive true if this number should be regarded as positive |
| 217 | * @param ignoreNegativeZero true if -0 should be regarded as identical to |
| 218 | * +0; otherwise they are considered distinct |
| 219 | * @return true if this number fits into a Java long |
| 220 | */ |
| 221 | boolean fitsIntoLong(boolean isPositive, boolean ignoreNegativeZero) { |
| 222 | // Figure out if the result will fit in a long. We have to |
| 223 | // first look for nonzero digits after the decimal point; |
| 224 | // then check the size. If the digit count is 18 or less, then |
| 225 | // the value can definitely be represented as a long. If it is 19 |
| 226 | // then it may be too large. |
| 227 | |
| 228 | // Trim trailing zeros. This does not change the represented value. |
| 229 | while (count > 0 && digits[count - 1] == '0') { |
| 230 | --count; |
| 231 | } |
| 232 | |
| 233 | if (count == 0) { |
| 234 | // Positive zero fits into a long, but negative zero can only |
| 235 | // be represented as a double. - bug 4162852 |
| 236 | return isPositive || ignoreNegativeZero; |
| 237 | } |
| 238 | |
| 239 | if (decimalAt < count || decimalAt > MAX_COUNT) { |
| 240 | return false; |
| 241 | } |
| 242 | |
| 243 | if (decimalAt < MAX_COUNT) return true; |
| 244 | |
| 245 | // At this point we have decimalAt == count, and count == MAX_COUNT. |
| 246 | // The number will overflow if it is larger than 9223372036854775807 |
| 247 | // or smaller than -9223372036854775808. |
| 248 | for (int i=0; i<count; ++i) { |
| 249 | char dig = digits[i], max = LONG_MIN_REP[i]; |
| 250 | if (dig > max) return false; |
| 251 | if (dig < max) return true; |
| 252 | } |
| 253 | |
| 254 | // At this point the first count digits match. If decimalAt is less |
| 255 | // than count, then the remaining digits are zero, and we return true. |
| 256 | if (count < decimalAt) return true; |
| 257 | |
| 258 | // Now we have a representation of Long.MIN_VALUE, without the leading |
| 259 | // negative sign. If this represents a positive value, then it does |
| 260 | // not fit; otherwise it fits. |
| 261 | return !isPositive; |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * Set the digit list to a representation of the given double value. |
| 266 | * This method supports fixed-point notation. |
| 267 | * @param isNegative Boolean value indicating whether the number is negative. |
| 268 | * @param source Value to be converted; must not be Inf, -Inf, Nan, |
| 269 | * or a value <= 0. |
| 270 | * @param maximumFractionDigits The most fractional digits which should |
| 271 | * be converted. |
| 272 | */ |
| 273 | public final void set(boolean isNegative, double source, int maximumFractionDigits) { |
| 274 | set(isNegative, source, maximumFractionDigits, true); |
| 275 | } |
| 276 | |
| 277 | /** |
| 278 | * Set the digit list to a representation of the given double value. |
| 279 | * This method supports both fixed-point and exponential notation. |
| 280 | * @param isNegative Boolean value indicating whether the number is negative. |
| 281 | * @param source Value to be converted; must not be Inf, -Inf, Nan, |
| 282 | * or a value <= 0. |
| 283 | * @param maximumDigits The most fractional or total digits which should |
| 284 | * be converted. |
| 285 | * @param fixedPoint If true, then maximumDigits is the maximum |
| 286 | * fractional digits to be converted. If false, total digits. |
| 287 | */ |
| 288 | final void set(boolean isNegative, double source, int maximumDigits, boolean fixedPoint) { |
| 289 | set(isNegative, Double.toString(source), maximumDigits, fixedPoint); |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * Generate a representation of the form DDDDD, DDDDD.DDDDD, or |
| 294 | * DDDDDE+/-DDDDD. |
| 295 | */ |
| 296 | final void set(boolean isNegative, String s, int maximumDigits, boolean fixedPoint) { |
| 297 | this.isNegative = isNegative; |
| 298 | int len = s.length(); |
| 299 | char[] source = getDataChars(len); |
| 300 | s.getChars(0, len, source, 0); |
| 301 | |
| 302 | decimalAt = -1; |
| 303 | count = 0; |
| 304 | int exponent = 0; |
| 305 | // Number of zeros between decimal point and first non-zero digit after |
| 306 | // decimal point, for numbers < 1. |
| 307 | int leadingZerosAfterDecimal = 0; |
| 308 | boolean nonZeroDigitSeen = false; |
| 309 | |
| 310 | for (int i = 0; i < len; ) { |
| 311 | char c = source[i++]; |
| 312 | if (c == '.') { |
| 313 | decimalAt = count; |
| 314 | } else if (c == 'e' || c == 'E') { |
| 315 | exponent = parseInt(source, i, len); |
| 316 | break; |
| 317 | } else { |
| 318 | if (!nonZeroDigitSeen) { |
| 319 | nonZeroDigitSeen = (c != '0'); |
| 320 | if (!nonZeroDigitSeen && decimalAt != -1) |
| 321 | ++leadingZerosAfterDecimal; |
| 322 | } |
| 323 | if (nonZeroDigitSeen) { |
| 324 | digits[count++] = c; |
| 325 | } |
| 326 | } |
| 327 | } |
| 328 | if (decimalAt == -1) { |
| 329 | decimalAt = count; |
| 330 | } |
| 331 | if (nonZeroDigitSeen) { |
| 332 | decimalAt += exponent - leadingZerosAfterDecimal; |
| 333 | } |
| 334 | |
| 335 | if (fixedPoint) { |
| 336 | // The negative of the exponent represents the number of leading |
| 337 | // zeros between the decimal and the first non-zero digit, for |
| 338 | // a value < 0.1 (e.g., for 0.00123, -decimalAt == 2). If this |
| 339 | // is more than the maximum fraction digits, then we have an underflow |
| 340 | // for the printed representation. |
| 341 | if (-decimalAt > maximumDigits) { |
| 342 | // Handle an underflow to zero when we round something like |
| 343 | // 0.0009 to 2 fractional digits. |
| 344 | count = 0; |
| 345 | return; |
| 346 | } else if (-decimalAt == maximumDigits) { |
| 347 | // If we round 0.0009 to 3 fractional digits, then we have to |
| 348 | // create a new one digit in the least significant location. |
| 349 | if (shouldRoundUp(0)) { |
| 350 | count = 1; |
| 351 | ++decimalAt; |
| 352 | digits[0] = '1'; |
| 353 | } else { |
| 354 | count = 0; |
| 355 | } |
| 356 | return; |
| 357 | } |
| 358 | // else fall through |
| 359 | } |
| 360 | |
| 361 | // Eliminate trailing zeros. |
| 362 | while (count > 1 && digits[count - 1] == '0') { |
| 363 | --count; |
| 364 | } |
| 365 | |
| 366 | // Eliminate digits beyond maximum digits to be displayed. |
| 367 | // Round up if appropriate. |
| 368 | round(fixedPoint ? (maximumDigits + decimalAt) : maximumDigits); |
| 369 | } |
| 370 | |
| 371 | /** |
| 372 | * Round the representation to the given number of digits. |
| 373 | * @param maximumDigits The maximum number of digits to be shown. |
| 374 | * Upon return, count will be less than or equal to maximumDigits. |
| 375 | */ |
| 376 | private final void round(int maximumDigits) { |
| 377 | // Eliminate digits beyond maximum digits to be displayed. |
| 378 | // Round up if appropriate. |
| 379 | if (maximumDigits >= 0 && maximumDigits < count) { |
| 380 | if (shouldRoundUp(maximumDigits)) { |
| 381 | // Rounding up involved incrementing digits from LSD to MSD. |
| 382 | // In most cases this is simple, but in a worst case situation |
| 383 | // (9999..99) we have to adjust the decimalAt value. |
| 384 | for (;;) { |
| 385 | --maximumDigits; |
| 386 | if (maximumDigits < 0) { |
| 387 | // We have all 9's, so we increment to a single digit |
| 388 | // of one and adjust the exponent. |
| 389 | digits[0] = '1'; |
| 390 | ++decimalAt; |
| 391 | maximumDigits = 0; // Adjust the count |
| 392 | break; |
| 393 | } |
| 394 | |
| 395 | ++digits[maximumDigits]; |
| 396 | if (digits[maximumDigits] <= '9') break; |
| 397 | // digits[maximumDigits] = '0'; // Unnecessary since we'll truncate this |
| 398 | } |
| 399 | ++maximumDigits; // Increment for use as count |
| 400 | } |
| 401 | count = maximumDigits; |
| 402 | |
| 403 | // Eliminate trailing zeros. |
| 404 | while (count > 1 && digits[count-1] == '0') { |
| 405 | --count; |
| 406 | } |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | |
| 411 | /** |
| 412 | * Return true if truncating the representation to the given number |
| 413 | * of digits will result in an increment to the last digit. This |
| 414 | * method implements the rounding modes defined in the |
| 415 | * java.math.RoundingMode class. |
| 416 | * [bnf] |
| 417 | * @param maximumDigits the number of digits to keep, from 0 to |
| 418 | * <code>count-1</code>. If 0, then all digits are rounded away, and |
| 419 | * this method returns true if a one should be generated (e.g., formatting |
| 420 | * 0.09 with "#.#"). |
| 421 | * @exception ArithmeticException if rounding is needed with rounding |
| 422 | * mode being set to RoundingMode.UNNECESSARY |
| 423 | * @return true if digit <code>maximumDigits-1</code> should be |
| 424 | * incremented |
| 425 | */ |
| 426 | private boolean shouldRoundUp(int maximumDigits) { |
| 427 | if (maximumDigits < count) { |
| 428 | switch(roundingMode) { |
| 429 | case UP: |
| 430 | for (int i=maximumDigits; i<count; ++i) { |
| 431 | if (digits[i] != '0') { |
| 432 | return true; |
| 433 | } |
| 434 | } |
| 435 | break; |
| 436 | case DOWN: |
| 437 | break; |
| 438 | case CEILING: |
| 439 | for (int i=maximumDigits; i<count; ++i) { |
| 440 | if (digits[i] != '0') { |
| 441 | return !isNegative; |
| 442 | } |
| 443 | } |
| 444 | break; |
| 445 | case FLOOR: |
| 446 | for (int i=maximumDigits; i<count; ++i) { |
| 447 | if (digits[i] != '0') { |
| 448 | return isNegative; |
| 449 | } |
| 450 | } |
| 451 | break; |
| 452 | case HALF_UP: |
| 453 | if (digits[maximumDigits] >= '5') { |
| 454 | return true; |
| 455 | } |
| 456 | break; |
| 457 | case HALF_DOWN: |
| 458 | if (digits[maximumDigits] > '5') { |
| 459 | return true; |
| 460 | } else if (digits[maximumDigits] == '5' ) { |
| 461 | for (int i=maximumDigits+1; i<count; ++i) { |
| 462 | if (digits[i] != '0') { |
| 463 | return true; |
| 464 | } |
| 465 | } |
| 466 | } |
| 467 | break; |
| 468 | case HALF_EVEN: |
| 469 | // Implement IEEE half-even rounding |
| 470 | if (digits[maximumDigits] > '5') { |
| 471 | return true; |
| 472 | } else if (digits[maximumDigits] == '5' ) { |
| 473 | for (int i=maximumDigits+1; i<count; ++i) { |
| 474 | if (digits[i] != '0') { |
| 475 | return true; |
| 476 | } |
| 477 | } |
| 478 | return maximumDigits > 0 && (digits[maximumDigits-1] % 2 != 0); |
| 479 | } |
| 480 | break; |
| 481 | case UNNECESSARY: |
| 482 | for (int i=maximumDigits; i<count; ++i) { |
| 483 | if (digits[i] != '0') { |
| 484 | throw new ArithmeticException( |
| 485 | "Rounding needed with the rounding mode being set to RoundingMode.UNNECESSARY"); |
| 486 | } |
| 487 | } |
| 488 | break; |
| 489 | default: |
| 490 | assert false; |
| 491 | } |
| 492 | } |
| 493 | return false; |
| 494 | } |
| 495 | |
| 496 | /** |
| 497 | * Utility routine to set the value of the digit list from a long |
| 498 | */ |
| 499 | public final void set(boolean isNegative, long source) { |
| 500 | set(isNegative, source, 0); |
| 501 | } |
| 502 | |
| 503 | /** |
| 504 | * Set the digit list to a representation of the given long value. |
| 505 | * @param isNegative Boolean value indicating whether the number is negative. |
| 506 | * @param source Value to be converted; must be >= 0 or == |
| 507 | * Long.MIN_VALUE. |
| 508 | * @param maximumDigits The most digits which should be converted. |
| 509 | * If maximumDigits is lower than the number of significant digits |
| 510 | * in source, the representation will be rounded. Ignored if <= 0. |
| 511 | */ |
| 512 | public final void set(boolean isNegative, long source, int maximumDigits) { |
| 513 | this.isNegative = isNegative; |
| 514 | |
| 515 | // This method does not expect a negative number. However, |
| 516 | // "source" can be a Long.MIN_VALUE (-9223372036854775808), |
| 517 | // if the number being formatted is a Long.MIN_VALUE. In that |
| 518 | // case, it will be formatted as -Long.MIN_VALUE, a number |
| 519 | // which is outside the legal range of a long, but which can |
| 520 | // be represented by DigitList. |
| 521 | if (source <= 0) { |
| 522 | if (source == Long.MIN_VALUE) { |
| 523 | decimalAt = count = MAX_COUNT; |
| 524 | System.arraycopy(LONG_MIN_REP, 0, digits, 0, count); |
| 525 | } else { |
| 526 | decimalAt = count = 0; // Values <= 0 format as zero |
| 527 | } |
| 528 | } else { |
| 529 | // Rewritten to improve performance. I used to call |
| 530 | // Long.toString(), which was about 4x slower than this code. |
| 531 | int left = MAX_COUNT; |
| 532 | int right; |
| 533 | while (source > 0) { |
| 534 | digits[--left] = (char)('0' + (source % 10)); |
| 535 | source /= 10; |
| 536 | } |
| 537 | decimalAt = MAX_COUNT - left; |
| 538 | // Don't copy trailing zeros. We are guaranteed that there is at |
| 539 | // least one non-zero digit, so we don't have to check lower bounds. |
| 540 | for (right = MAX_COUNT - 1; digits[right] == '0'; --right) |
| 541 | ; |
| 542 | count = right - left + 1; |
| 543 | System.arraycopy(digits, left, digits, 0, count); |
| 544 | } |
| 545 | if (maximumDigits > 0) round(maximumDigits); |
| 546 | } |
| 547 | |
| 548 | /** |
| 549 | * Set the digit list to a representation of the given BigDecimal value. |
| 550 | * This method supports both fixed-point and exponential notation. |
| 551 | * @param isNegative Boolean value indicating whether the number is negative. |
| 552 | * @param source Value to be converted; must not be a value <= 0. |
| 553 | * @param maximumDigits The most fractional or total digits which should |
| 554 | * be converted. |
| 555 | * @param fixedPoint If true, then maximumDigits is the maximum |
| 556 | * fractional digits to be converted. If false, total digits. |
| 557 | */ |
| 558 | final void set(boolean isNegative, BigDecimal source, int maximumDigits, boolean fixedPoint) { |
| 559 | String s = source.toString(); |
| 560 | extendDigits(s.length()); |
| 561 | |
| 562 | set(isNegative, s, maximumDigits, fixedPoint); |
| 563 | } |
| 564 | |
| 565 | /** |
| 566 | * Set the digit list to a representation of the given BigInteger value. |
| 567 | * @param isNegative Boolean value indicating whether the number is negative. |
| 568 | * @param source Value to be converted; must be >= 0. |
| 569 | * @param maximumDigits The most digits which should be converted. |
| 570 | * If maximumDigits is lower than the number of significant digits |
| 571 | * in source, the representation will be rounded. Ignored if <= 0. |
| 572 | */ |
| 573 | final void set(boolean isNegative, BigInteger source, int maximumDigits) { |
| 574 | this.isNegative = isNegative; |
| 575 | String s = source.toString(); |
| 576 | int len = s.length(); |
| 577 | extendDigits(len); |
| 578 | s.getChars(0, len, digits, 0); |
| 579 | |
| 580 | decimalAt = len; |
| 581 | int right; |
| 582 | for (right = len - 1; right >= 0 && digits[right] == '0'; --right) |
| 583 | ; |
| 584 | count = right + 1; |
| 585 | |
| 586 | if (maximumDigits > 0) { |
| 587 | round(maximumDigits); |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | /** |
| 592 | * equality test between two digit lists. |
| 593 | */ |
| 594 | public boolean equals(Object obj) { |
| 595 | if (this == obj) // quick check |
| 596 | return true; |
| 597 | if (!(obj instanceof DigitList)) // (1) same object? |
| 598 | return false; |
| 599 | DigitList other = (DigitList) obj; |
| 600 | if (count != other.count || |
| 601 | decimalAt != other.decimalAt) |
| 602 | return false; |
| 603 | for (int i = 0; i < count; i++) |
| 604 | if (digits[i] != other.digits[i]) |
| 605 | return false; |
| 606 | return true; |
| 607 | } |
| 608 | |
| 609 | /** |
| 610 | * Generates the hash code for the digit list. |
| 611 | */ |
| 612 | public int hashCode() { |
| 613 | int hashcode = decimalAt; |
| 614 | |
| 615 | for (int i = 0; i < count; i++) { |
| 616 | hashcode = hashcode * 37 + digits[i]; |
| 617 | } |
| 618 | |
| 619 | return hashcode; |
| 620 | } |
| 621 | |
| 622 | /** |
| 623 | * Creates a copy of this object. |
| 624 | * @return a clone of this instance. |
| 625 | */ |
| 626 | public Object clone() { |
| 627 | try { |
| 628 | DigitList other = (DigitList) super.clone(); |
| 629 | char[] newDigits = new char[digits.length]; |
| 630 | System.arraycopy(digits, 0, newDigits, 0, digits.length); |
| 631 | other.digits = newDigits; |
| 632 | other.tempBuffer = null; |
| 633 | return other; |
| 634 | } catch (CloneNotSupportedException e) { |
| 635 | throw new InternalError(); |
| 636 | } |
| 637 | } |
| 638 | |
| 639 | /** |
| 640 | * Returns true if this DigitList represents Long.MIN_VALUE; |
| 641 | * false, otherwise. This is required so that getLong() works. |
| 642 | */ |
| 643 | private boolean isLongMIN_VALUE() { |
| 644 | if (decimalAt != count || count != MAX_COUNT) { |
| 645 | return false; |
| 646 | } |
| 647 | |
| 648 | for (int i = 0; i < count; ++i) { |
| 649 | if (digits[i] != LONG_MIN_REP[i]) return false; |
| 650 | } |
| 651 | |
| 652 | return true; |
| 653 | } |
| 654 | |
| 655 | private static final int parseInt(char[] str, int offset, int strLen) { |
| 656 | char c; |
| 657 | boolean positive = true; |
| 658 | if ((c = str[offset]) == '-') { |
| 659 | positive = false; |
| 660 | offset++; |
| 661 | } else if (c == '+') { |
| 662 | offset++; |
| 663 | } |
| 664 | |
| 665 | int value = 0; |
| 666 | while (offset < strLen) { |
| 667 | c = str[offset++]; |
| 668 | if (c >= '0' && c <= '9') { |
| 669 | value = value * 10 + (c - '0'); |
| 670 | } else { |
| 671 | break; |
| 672 | } |
| 673 | } |
| 674 | return positive ? value : -value; |
| 675 | } |
| 676 | |
| 677 | // The digit part of -9223372036854775808L |
| 678 | private static final char[] LONG_MIN_REP = "9223372036854775808".toCharArray(); |
| 679 | |
| 680 | public String toString() { |
| 681 | if (isZero()) { |
| 682 | return "0"; |
| 683 | } |
| 684 | StringBuffer buf = getStringBuffer(); |
| 685 | buf.append("0."); |
| 686 | buf.append(digits, 0, count); |
| 687 | buf.append("x10^"); |
| 688 | buf.append(decimalAt); |
| 689 | return buf.toString(); |
| 690 | } |
| 691 | |
| 692 | private StringBuffer tempBuffer; |
| 693 | |
| 694 | private StringBuffer getStringBuffer() { |
| 695 | if (tempBuffer == null) { |
| 696 | tempBuffer = new StringBuffer(MAX_COUNT); |
| 697 | } else { |
| 698 | tempBuffer.setLength(0); |
| 699 | } |
| 700 | return tempBuffer; |
| 701 | } |
| 702 | |
| 703 | private void extendDigits(int len) { |
| 704 | if (len > digits.length) { |
| 705 | digits = new char[len]; |
| 706 | } |
| 707 | } |
| 708 | |
| 709 | private final char[] getDataChars(int length) { |
| 710 | if (data == null || data.length < length) { |
| 711 | data = new char[length]; |
| 712 | } |
| 713 | return data; |
| 714 | } |
| 715 | } |