Paul Duffin | e236301 | 2015-11-30 16:20:41 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2011 Google Inc. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.google.caliper.util; |
| 18 | |
| 19 | import static com.google.common.base.Preconditions.checkArgument; |
| 20 | import static com.google.common.base.Preconditions.checkNotNull; |
| 21 | |
| 22 | import com.google.common.base.Ascii; |
| 23 | import com.google.common.collect.ImmutableListMultimap; |
| 24 | import com.google.common.collect.ImmutableMap; |
| 25 | import com.google.common.collect.Maps; |
| 26 | import com.google.common.primitives.Longs; |
| 27 | |
| 28 | import java.math.BigDecimal; |
| 29 | import java.math.MathContext; |
| 30 | import java.math.RoundingMode; |
| 31 | import java.util.Collections; |
| 32 | import java.util.Map; |
| 33 | import java.util.concurrent.TimeUnit; |
| 34 | import java.util.regex.Matcher; |
| 35 | import java.util.regex.Pattern; |
| 36 | |
| 37 | import javax.annotation.Nullable; |
| 38 | |
| 39 | /** |
| 40 | * Represents a nonnegative duration from 0 to 100 days, with picosecond precision. |
| 41 | * Contrast with Joda-Time's duration class, which has only millisecond precision but can |
| 42 | * represent durations of millions of years. |
| 43 | */ |
| 44 | public abstract class ShortDuration implements Comparable<ShortDuration> { |
| 45 | // Factories |
| 46 | |
| 47 | public static ShortDuration of(long duration, TimeUnit unit) { |
| 48 | if (duration == 0) { |
| 49 | return ZERO; |
| 50 | } |
| 51 | checkArgument(duration >= 0, "negative duration: %s", duration); |
| 52 | checkArgument(duration <= MAXES.get(unit), |
| 53 | "ShortDuration cannot exceed 100 days: %s %s", duration, unit); |
| 54 | long nanos = TimeUnit.NANOSECONDS.convert(duration, unit); |
| 55 | return new PositiveShortDuration(nanos * 1000); |
| 56 | } |
| 57 | |
| 58 | public static ShortDuration of(BigDecimal duration, TimeUnit unit) { |
| 59 | // convert to picoseconds first, to minimize rounding |
| 60 | BigDecimal picos = duration.multiply(ONE_IN_PICOS.get(unit)); |
| 61 | return ofPicos(toLong(picos, RoundingMode.HALF_UP)); |
| 62 | } |
| 63 | |
| 64 | public static ShortDuration valueOf(String s) { |
| 65 | if ("0".equals(s)) { |
| 66 | return ZERO; |
| 67 | } |
| 68 | Matcher matcher = PATTERN.matcher(s); |
| 69 | checkArgument(matcher.matches(), "Invalid ShortDuration: %s", s); |
| 70 | |
| 71 | BigDecimal value = new BigDecimal(matcher.group(1)); |
| 72 | String abbrev = matcher.group(2); |
| 73 | TimeUnit unit = ABBREV_TO_UNIT.get(abbrev); |
| 74 | checkArgument(unit != null, "Unrecognized time unit: %s", abbrev); |
| 75 | |
| 76 | return of(value, unit); |
| 77 | } |
| 78 | |
| 79 | public static ShortDuration zero() { |
| 80 | return ZERO; |
| 81 | } |
| 82 | |
| 83 | // fortunately no abbreviation starts with 'e', so this should work |
| 84 | private static final Pattern PATTERN = Pattern.compile("^([0-9.eE+-]+) ?(\\S+)$"); |
| 85 | |
| 86 | private static ShortDuration ofPicos(long picos) { |
| 87 | if (picos == 0) { |
| 88 | return ZERO; |
| 89 | } |
| 90 | checkArgument(picos > 0); |
| 91 | return new PositiveShortDuration(picos); |
| 92 | } |
| 93 | |
| 94 | // TODO(kevinb): we sure seem to convert back and forth with BigDecimal a lot. |
| 95 | // Why not just *make* this a BigDecimal? |
| 96 | final long picos; |
| 97 | |
| 98 | ShortDuration(long picos) { |
| 99 | this.picos = picos; |
| 100 | } |
| 101 | |
| 102 | public long toPicos() { |
| 103 | return picos; |
| 104 | } |
| 105 | |
| 106 | public long to(TimeUnit unit) { |
| 107 | return to(unit, RoundingMode.HALF_UP); |
| 108 | } |
| 109 | |
| 110 | public abstract long to(TimeUnit unit, RoundingMode roundingMode); |
| 111 | |
| 112 | /* |
| 113 | * In Guava, this will probably implement an interface called Quantity, and the following methods |
| 114 | * will come from there, so they won't have to be defined here. |
| 115 | */ |
| 116 | |
| 117 | /** |
| 118 | * Returns an instance of this type that represents the sum of this value and {@code |
| 119 | * addend}. |
| 120 | */ |
| 121 | public abstract ShortDuration plus(ShortDuration addend); |
| 122 | |
| 123 | /** |
| 124 | * Returns an instance of this type that represents the difference of this value and |
| 125 | * {@code subtrahend}. |
| 126 | */ |
| 127 | public abstract ShortDuration minus(ShortDuration subtrahend); |
| 128 | |
| 129 | /** |
| 130 | * Returns an instance of this type that represents the product of this value and the |
| 131 | * integral value {@code multiplicand}. |
| 132 | */ |
| 133 | public abstract ShortDuration times(long multiplicand); |
| 134 | |
| 135 | /** |
| 136 | * Returns an instance of this type that represents the product of this value and {@code |
| 137 | * multiplicand}, rounded according to {@code roundingMode} if necessary. |
| 138 | * |
| 139 | * <p>If this class represents an amount that is "continuous" rather than discrete, the |
| 140 | * implementation of this method may simply ignore the rounding mode. |
| 141 | */ |
| 142 | public abstract ShortDuration times(BigDecimal multiplicand, RoundingMode roundingMode); |
| 143 | |
| 144 | /** |
| 145 | * Returns an instance of this type that represents this value divided by the integral |
| 146 | * value {@code divisor}, rounded according to {@code roundingMode} if necessary. |
| 147 | * |
| 148 | * <p>If this class represents an amount that is "continuous" rather than discrete, the |
| 149 | * implementation of this method may simply ignore the rounding mode. |
| 150 | */ |
| 151 | public abstract ShortDuration dividedBy(long divisor, RoundingMode roundingMode); |
| 152 | |
| 153 | /** |
| 154 | * Returns an instance of this type that represents this value divided by {@code |
| 155 | * divisor}, rounded according to {@code roundingMode} if necessary. |
| 156 | * |
| 157 | * <p>If this class represents an amount that is "continuous" rather than discrete, the |
| 158 | * implementation of this method may simply ignore the rounding mode. |
| 159 | */ |
| 160 | public abstract ShortDuration dividedBy(BigDecimal divisor, RoundingMode roundingMode); |
| 161 | |
| 162 | // Zero |
| 163 | |
| 164 | private static ShortDuration ZERO = new ShortDuration(0) { |
| 165 | @Override public long to(TimeUnit unit, RoundingMode roundingMode) { |
| 166 | return 0; |
| 167 | } |
| 168 | @Override public ShortDuration plus(ShortDuration addend) { |
| 169 | return addend; |
| 170 | } |
| 171 | @Override public ShortDuration minus(ShortDuration subtrahend) { |
| 172 | checkArgument(this == subtrahend); |
| 173 | return this; |
| 174 | } |
| 175 | @Override public ShortDuration times(long multiplicand) { |
| 176 | return this; |
| 177 | } |
| 178 | @Override public ShortDuration times(BigDecimal multiplicand, RoundingMode roundingMode) { |
| 179 | return this; |
| 180 | } |
| 181 | @Override public ShortDuration dividedBy(long divisor, RoundingMode roundingMode) { |
| 182 | return dividedBy(new BigDecimal(divisor), roundingMode); |
| 183 | } |
| 184 | @Override public ShortDuration dividedBy(BigDecimal divisor, RoundingMode roundingMode) { |
| 185 | checkArgument(divisor.compareTo(BigDecimal.ZERO) != 0); |
| 186 | return this; |
| 187 | } |
| 188 | @Override public int compareTo(ShortDuration that) { |
| 189 | if (this == that) { |
| 190 | return 0; |
| 191 | } |
| 192 | checkNotNull(that); |
| 193 | return -1; |
| 194 | } |
| 195 | @Override public boolean equals(@Nullable Object that) { |
| 196 | return this == that; |
| 197 | } |
| 198 | @Override public int hashCode() { |
| 199 | return 0; |
| 200 | } |
| 201 | @Override public String toString() { |
| 202 | return "0s"; |
| 203 | } |
| 204 | }; |
| 205 | |
| 206 | // Non-zero |
| 207 | |
| 208 | private static class PositiveShortDuration extends ShortDuration { |
| 209 | private PositiveShortDuration(long picos) { |
| 210 | super(picos); |
| 211 | checkArgument(picos > 0); |
| 212 | } |
| 213 | |
| 214 | @Override public long to(TimeUnit unit, RoundingMode roundingMode) { |
| 215 | BigDecimal divisor = ONE_IN_PICOS.get(unit); |
| 216 | return toLong(new BigDecimal(picos).divide(divisor), roundingMode); |
| 217 | } |
| 218 | |
| 219 | @Override public ShortDuration plus(ShortDuration addend) { |
| 220 | return new PositiveShortDuration(picos + addend.picos); |
| 221 | } |
| 222 | |
| 223 | @Override public ShortDuration minus(ShortDuration subtrahend) { |
| 224 | return ofPicos(picos - subtrahend.picos); |
| 225 | } |
| 226 | |
| 227 | @Override public ShortDuration times(long multiplicand) { |
| 228 | if (multiplicand == 0) { |
| 229 | return ZERO; |
| 230 | } |
| 231 | checkArgument(multiplicand >= 0, "negative multiplicand: %s", multiplicand); |
| 232 | checkArgument(multiplicand <= Long.MAX_VALUE / picos, |
| 233 | "product of %s and %s would overflow", this, multiplicand); |
| 234 | return new PositiveShortDuration(picos * multiplicand); |
| 235 | } |
| 236 | |
| 237 | @Override public ShortDuration times(BigDecimal multiplicand, RoundingMode roundingMode) { |
| 238 | BigDecimal product = BigDecimal.valueOf(picos).multiply(multiplicand); |
| 239 | return ofPicos(toLong(product, roundingMode)); |
| 240 | } |
| 241 | |
| 242 | @Override public ShortDuration dividedBy(long divisor, RoundingMode roundingMode) { |
| 243 | return dividedBy(new BigDecimal(divisor), roundingMode); |
| 244 | } |
| 245 | |
| 246 | @Override public ShortDuration dividedBy(BigDecimal divisor, RoundingMode roundingMode) { |
| 247 | BigDecimal product = BigDecimal.valueOf(picos).divide(divisor, roundingMode); |
| 248 | return ofPicos(product.longValueExact()); |
| 249 | } |
| 250 | |
| 251 | @Override public int compareTo(ShortDuration that) { |
| 252 | return Longs.compare(this.picos, that.picos); |
| 253 | } |
| 254 | |
| 255 | @Override public boolean equals(Object object) { |
| 256 | if (object instanceof PositiveShortDuration) { |
| 257 | PositiveShortDuration that = (PositiveShortDuration) object; |
| 258 | return this.picos == that.picos; |
| 259 | } |
| 260 | return false; |
| 261 | } |
| 262 | |
| 263 | @Override public int hashCode() { |
| 264 | return Longs.hashCode(picos); |
| 265 | } |
| 266 | |
| 267 | @Override public String toString() { |
| 268 | TimeUnit bestUnit = TimeUnit.NANOSECONDS; |
| 269 | for (TimeUnit unit : TimeUnit.values()) { |
| 270 | if (picosIn(unit) > picos) { |
| 271 | break; |
| 272 | } |
| 273 | bestUnit = unit; |
| 274 | } |
| 275 | BigDecimal divisor = ONE_IN_PICOS.get(bestUnit); |
| 276 | |
| 277 | return new BigDecimal(picos).divide(divisor, ROUNDER) + preferredAbbrev(bestUnit); |
| 278 | } |
| 279 | |
| 280 | private static final MathContext ROUNDER = new MathContext(4); |
| 281 | } |
| 282 | |
| 283 | // Private parts |
| 284 | |
| 285 | private static String preferredAbbrev(TimeUnit bestUnit) { |
| 286 | return ABBREVIATIONS.get(bestUnit).get(0); |
| 287 | } |
| 288 | |
| 289 | private static final ImmutableListMultimap<TimeUnit, String> ABBREVIATIONS = |
| 290 | createAbbreviations(); |
| 291 | |
| 292 | private static ImmutableListMultimap<TimeUnit, String> createAbbreviations() { |
| 293 | ImmutableListMultimap.Builder<TimeUnit, String> builder = ImmutableListMultimap.builder(); |
| 294 | builder.putAll(TimeUnit.NANOSECONDS, "ns", "nanos"); |
| 295 | builder.putAll(TimeUnit.MICROSECONDS, "\u03bcs" /*μs*/, "us", "micros"); |
| 296 | builder.putAll(TimeUnit.MILLISECONDS, "ms", "millis"); |
| 297 | builder.putAll(TimeUnit.SECONDS, "s", "sec"); |
| 298 | |
| 299 | // Do the rest in a JDK5-safe way |
| 300 | TimeUnit[] allUnits = TimeUnit.values(); |
| 301 | if (allUnits.length >= 7) { |
| 302 | builder.putAll(allUnits[4], "m", "min"); |
| 303 | builder.putAll(allUnits[5], "h", "hr"); |
| 304 | builder.putAll(allUnits[6], "d"); |
| 305 | } |
| 306 | |
| 307 | for (TimeUnit unit : TimeUnit.values()) { |
| 308 | builder.put(unit, Ascii.toLowerCase(unit.name())); |
| 309 | } |
| 310 | return builder.build(); |
| 311 | } |
| 312 | |
| 313 | private static final Map<String, TimeUnit> ABBREV_TO_UNIT = createAbbrevToUnitMap(); |
| 314 | |
| 315 | private static Map<String, TimeUnit> createAbbrevToUnitMap() { |
| 316 | ImmutableMap.Builder<String, TimeUnit> builder = ImmutableMap.builder(); |
| 317 | for (Map.Entry<TimeUnit, String> entry : ABBREVIATIONS.entries()) { |
| 318 | builder.put(entry.getValue(), entry.getKey()); |
| 319 | } |
| 320 | return builder.build(); |
| 321 | } |
| 322 | |
| 323 | private static final Map<TimeUnit, BigDecimal> ONE_IN_PICOS = createUnitToPicosMap(); |
| 324 | |
| 325 | private static Map<TimeUnit, BigDecimal> createUnitToPicosMap() { |
| 326 | Map<TimeUnit, BigDecimal> map = Maps.newEnumMap(TimeUnit.class); |
| 327 | for (TimeUnit unit : TimeUnit.values()) { |
| 328 | map.put(unit, new BigDecimal(picosIn(unit))); |
| 329 | } |
| 330 | return Collections.unmodifiableMap(map); |
| 331 | } |
| 332 | |
| 333 | private static final Map<TimeUnit, Long> MAXES = createMaxesMap(); |
| 334 | |
| 335 | private static Map<TimeUnit, Long> createMaxesMap() { |
| 336 | Map<TimeUnit, Long> map = Maps.newEnumMap(TimeUnit.class); |
| 337 | for (TimeUnit unit : TimeUnit.values()) { |
| 338 | // Max is 100 days |
| 339 | map.put(unit, unit.convert(100L * 24 * 60 * 60, TimeUnit.SECONDS)); |
| 340 | } |
| 341 | return Collections.unmodifiableMap(map); |
| 342 | } |
| 343 | |
| 344 | private static long toLong(BigDecimal bd, RoundingMode roundingMode) { |
| 345 | // setScale does not really mutate the BigDecimal |
| 346 | return bd.setScale(0, roundingMode).longValueExact(); |
| 347 | } |
| 348 | |
| 349 | private static long picosIn(TimeUnit unit) { |
| 350 | return unit.toNanos(1000); |
| 351 | } |
| 352 | } |