2 * Copyright (c) 2015 Pantheon Technologies s.r.o. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.common;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static com.google.common.base.Verify.verify;
13 import com.google.common.annotations.Beta;
14 import com.google.common.annotations.VisibleForTesting;
15 import com.google.common.base.Strings;
16 import java.math.BigDecimal;
17 import java.util.Optional;
18 import org.eclipse.jdt.annotation.NonNullByDefault;
19 import org.eclipse.jdt.annotation.Nullable;
20 import org.opendaylight.yangtools.concepts.Either;
23 * Dedicated type for YANG's 'type decimal64' type. This class is similar to {@link BigDecimal}, but provides more
24 * efficient storage, as it has fixed precision.
26 * @author Robert Varga
30 public class Decimal64 extends Number implements CanonicalValue<Decimal64> {
31 public static final class Support extends AbstractCanonicalValueSupport<Decimal64> {
33 super(Decimal64.class);
37 public Either<Decimal64, CanonicalValueViolation> fromString(final String str) {
38 // https://tools.ietf.org/html/rfc6020#section-9.3.1
40 // A decimal64 value is lexically represented as an optional sign ("+"
41 // or "-"), followed by a sequence of decimal digits, optionally
42 // followed by a period ('.') as a decimal indicator and a sequence of
43 // decimal digits. If no sign is specified, "+" is assumed.
45 return CanonicalValueViolation.variantOf("Empty string is not a valid decimal64 representation");
48 // Deal with optional sign
49 final boolean negative;
51 switch (str.charAt(0)) {
65 // Sanity check length
66 if (idx == str.length()) {
67 return CanonicalValueViolation.variantOf("Missing digits after sign");
70 // Character limit, used for caching and cutting trailing zeroes
71 int limit = str.length() - 1;
73 // Skip any leading zeroes, but leave at least one
74 for (; idx < limit && str.charAt(idx) == '0'; idx++) {
75 final char ch = str.charAt(idx + 1);
76 if (ch < '0' || ch > '9') {
81 // Integer part and its length
85 for (; idx <= limit; idx++, intLen++) {
86 final char ch = str.charAt(idx);
91 if (intLen == MAX_FRACTION_DIGITS) {
92 return CanonicalValueViolation.variantOf(
93 "Integer part is longer than " + MAX_FRACTION_DIGITS + " digits");
96 intPart = 10 * intPart + toInt(ch, idx);
100 // No fraction digits, we are done
101 return Either.ofFirst(new Decimal64((byte)1, intPart, 0, negative));
104 // Bump index to skip over period and check the remainder
107 return CanonicalValueViolation.variantOf("Value '" + str + "' is missing fraction digits");
110 // Trim trailing zeroes, if any
111 while (idx < limit && str.charAt(limit) == '0') {
115 final int fracLimit = MAX_FRACTION_DIGITS - intLen + 1;
118 for (; idx <= limit; idx++, fracLen++) {
119 final char ch = str.charAt(idx);
120 if (fracLen == fracLimit) {
121 return CanonicalValueViolation.variantOf("Fraction part longer than " + fracLimit + " digits");
124 fracPart = 10 * fracPart + toInt(ch, idx);
127 return Either.ofFirst(new Decimal64(fracLen, intPart, fracPart, negative));
130 private static int toInt(final char ch, final int index) {
131 if (ch < '0' || ch > '9') {
132 throw new NumberFormatException("Illegal character at offset " + index);
138 private static final CanonicalValueSupport<Decimal64> SUPPORT = new Support();
139 private static final long serialVersionUID = 1L;
141 private static final int MAX_FRACTION_DIGITS = 18;
143 private static final long[] SCALE = {
165 verify(SCALE.length == MAX_FRACTION_DIGITS);
168 private final byte scaleOffset;
169 private final long value;
172 Decimal64(final int fractionDigits, final long intPart, final long fracPart, final boolean negative) {
173 checkArgument(fractionDigits >= 1 && fractionDigits <= MAX_FRACTION_DIGITS);
174 this.scaleOffset = (byte) (fractionDigits - 1);
176 final long bits = intPart * SCALE[this.scaleOffset] + fracPart;
177 this.value = negative ? -bits : bits;
180 protected Decimal64(final Decimal64 other) {
181 this.scaleOffset = other.scaleOffset;
182 this.value = other.value;
185 public static Decimal64 valueOf(final byte byteVal) {
186 return byteVal < 0 ? new Decimal64(1, -byteVal, 0, true) : new Decimal64(1, byteVal, 0, false);
189 public static Decimal64 valueOf(final short shortVal) {
190 return shortVal < 0 ? new Decimal64(1, -shortVal, 0, true) : new Decimal64(1, shortVal, 0, false);
193 public static Decimal64 valueOf(final int intVal) {
194 return intVal < 0 ? new Decimal64(1, - (long)intVal, 0, true) : new Decimal64(1, intVal, 0, false);
197 public static Decimal64 valueOf(final long longVal) {
198 // XXX: we should be able to do something smarter here
199 return valueOf(Long.toString(longVal));
202 public static Decimal64 valueOf(final double doubleVal) {
203 // XXX: we should be able to do something smarter here
204 return valueOf(Double.toString(doubleVal));
207 public static Decimal64 valueOf(final BigDecimal decimalVal) {
208 // XXX: we should be able to do something smarter here
209 return valueOf(decimalVal.toPlainString());
213 * Attempt to parse a String into a Decimal64. This method uses minimum fraction digits required to hold
216 * @param str String to parser
217 * @return A Decimal64 instance
218 * @throws NullPointerException if value is null.
219 * @throws NumberFormatException if the string does not contain a parsable decimal64.
221 public static Decimal64 valueOf(final String str) {
222 final Either<Decimal64, CanonicalValueViolation> variant = SUPPORT.fromString(str);
223 final Optional<Decimal64> value = variant.tryFirst();
224 if (value.isPresent()) {
227 final Optional<String> message = variant.getSecond().getMessage();
228 throw message.isPresent() ? new NumberFormatException(message.get()) : new NumberFormatException();
231 public final BigDecimal decimalValue() {
232 return BigDecimal.valueOf(value, scaleOffset + 1);
236 public final int intValue() {
237 return (int) intPart();
241 public final long longValue() {
246 public final float floatValue() {
247 return (float) doubleValue();
251 public final double doubleValue() {
252 return 1.0 * value / SCALE[scaleOffset];
256 * Converts this {@code BigDecimal} to a {@code byte}, checking for lost information. If this {@code Decimal64} has
257 * a nonzero fractional part or is out of the possible range for a {@code byte} result then
258 * an {@code ArithmeticException} is thrown.
260 * @return this {@code Decimal64} converted to a {@code byte}.
261 * @throws ArithmeticException if {@code this} has a nonzero fractional part, or will not fit in a {@code byte}.
263 public final byte byteValueExact() {
264 final long val = longValueExact();
265 final byte ret = (byte) val;
267 throw new ArithmeticException("Value " + val + " is outside of byte range");
273 * Converts this {@code BigDecimal} to a {@code short}, checking for lost information. If this {@code Decimal64} has
274 * a nonzero fractional part or is out of the possible range for a {@code short} result then
275 * an {@code ArithmeticException} is thrown.
277 * @return this {@code Decimal64} converted to a {@code short}.
278 * @throws ArithmeticException if {@code this} has a nonzero fractional part, or will not fit in a {@code short}.
280 public final short shortValueExact() {
281 final long val = longValueExact();
282 final short ret = (short) val;
284 throw new ArithmeticException("Value " + val + " is outside of short range");
290 * Converts this {@code BigDecimal} to an {@code int}, checking for lost information. If this {@code Decimal64} has
291 * a nonzero fractional part or is out of the possible range for an {@code int} result then
292 * an {@code ArithmeticException} is thrown.
294 * @return this {@code Decimal64} converted to an {@code int}.
295 * @throws ArithmeticException if {@code this} has a nonzero fractional part, or will not fit in an {@code int}.
297 public final int intValueExact() {
298 final long val = longValueExact();
299 final int ret = (int) val;
301 throw new ArithmeticException("Value " + val + " is outside of integer range");
307 * Converts this {@code BigDecimal} to a {@code long}, checking for lost information. If this {@code Decimal64} has
308 * a nonzero fractional part then an {@code ArithmeticException} is thrown.
310 * @return this {@code Decimal64} converted to a {@code long}.
311 * @throws ArithmeticException if {@code this} has a nonzero fractional part.
313 public final long longValueExact() {
314 if (fracPart() != 0) {
315 throw new ArithmeticException("Conversion of " + this + " would lose fraction");
321 @SuppressWarnings("checkstyle:parameterName")
322 public final int compareTo(final Decimal64 o) {
326 if (scaleOffset == o.scaleOffset) {
327 return Long.compare(value, o.value);
330 // XXX: we could do something smarter here
331 return Double.compare(doubleValue(), o.doubleValue());
335 public final String toCanonicalString() {
336 // https://tools.ietf.org/html/rfc6020#section-9.3.2
338 // The canonical form of a positive decimal64 does not include the sign
339 // "+". The decimal point is required. Leading and trailing zeros are
340 // prohibited, subject to the rule that there MUST be at least one digit
341 // before and after the decimal point. The value zero is represented as
343 final StringBuilder sb = new StringBuilder(21).append(intPart()).append('.');
344 final long fracPart = fracPart();
346 // We may need to zero-pad the fraction part
347 sb.append(Strings.padStart(Long.toString(fracPart), scaleOffset + 1, '0'));
352 return sb.toString();
356 public final CanonicalValueSupport<Decimal64> support() {
361 public final int hashCode() {
362 // We need to normalize the results in order to be consistent with equals()
363 return Long.hashCode(intPart()) * 31 + Long.hashCode(fracPart());
367 public final boolean equals(final @Nullable Object obj) {
368 return this == obj || obj instanceof Decimal64 && equalsImpl((Decimal64) obj);
372 * A slightly faster version of {@link #equals(Object)}.
374 * @param obj Decimal64 object
375 * @return {@code true} if this object is the same as the obj argument; {@code false} otherwise.
377 public final boolean equals(final @Nullable Decimal64 obj) {
378 return this == obj || obj != null && equalsImpl(obj);
382 public final String toString() {
383 return toCanonicalString();
386 private boolean equalsImpl(final Decimal64 other) {
387 return scaleOffset == other.scaleOffset ? value == other.value
388 // We need to normalize both
389 : intPart() == other.intPart() && fracPart() == other.fracPart();
392 private long intPart() {
393 return value / SCALE[scaleOffset];
396 private long fracPart() {
397 return Math.abs(value % SCALE[scaleOffset]);