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/*
* Copyright (c) 2015 Pantheon Technologies s.r.o. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.common;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Verify.verify;
import static java.util.Objects.requireNonNull;
import com.google.common.annotations.VisibleForTesting;
import java.io.Serial;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Optional;
import org.eclipse.jdt.annotation.NonNullByDefault;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.yangtools.concepts.Either;
/**
* Dedicated type for YANG's 'type decimal64' type. This class is similar to {@link BigDecimal}, but provides more
* efficient storage, as it has fixed precision.
*/
@NonNullByDefault
public class Decimal64 extends Number implements CanonicalValue {
public static final class Support extends AbstractCanonicalValueSupport {
public Support() {
super(Decimal64.class);
}
@Override
public Either fromString(final String str) {
// https://www.rfc-editor.org/rfc/rfc6020#section-9.3.1
//
// A decimal64 value is lexically represented as an optional sign ("+"
// or "-"), followed by a sequence of decimal digits, optionally
// followed by a period ('.') as a decimal indicator and a sequence of
// decimal digits. If no sign is specified, "+" is assumed.
if (str.isEmpty()) {
return CanonicalValueViolation.variantOf("Empty string is not a valid decimal64 representation");
}
// Deal with optional sign
final boolean negative;
int idx = switch (str.charAt(0)) {
case '-' -> {
negative = true;
yield 1;
}
case '+' -> {
negative = false;
yield 1;
}
default -> {
negative = false;
yield 0;
}
};
// Sanity check length
if (idx == str.length()) {
return CanonicalValueViolation.variantOf("Missing digits after sign");
}
// Character limit, used for caching and cutting trailing zeroes
int limit = str.length() - 1;
// Skip any leading zeroes, but leave at least one
for (; idx < limit && str.charAt(idx) == '0'; idx++) {
final char ch = str.charAt(idx + 1);
if (ch < '0' || ch > '9') {
break;
}
}
// Integer part and its length
int intLen = 0;
long intPart = 0;
for (; idx <= limit; idx++, intLen++) {
final char ch = str.charAt(idx);
if (ch == '.') {
// Fractions are next
break;
}
if (intLen == MAX_SCALE) {
return CanonicalValueViolation.variantOf(
"Integer part is longer than " + MAX_SCALE + " digits");
}
intPart = 10 * intPart + toInt(ch, idx);
}
if (idx > limit) {
// No fraction digits, we are done
return Either.ofFirst(new Decimal64((byte)1, intPart, 0, negative));
}
// Bump index to skip over period and check the remainder
idx++;
if (idx > limit) {
return CanonicalValueViolation.variantOf("Value '" + str + "' is missing fraction digits");
}
// Trim trailing zeroes, if any
while (idx < limit && str.charAt(limit) == '0') {
limit--;
}
final int fracLimit = MAX_SCALE - intLen + 1;
byte fracLen = 0;
long fracPart = 0;
for (; idx <= limit; idx++, fracLen++) {
final char ch = str.charAt(idx);
if (fracLen == fracLimit) {
return CanonicalValueViolation.variantOf("Fraction part longer than " + fracLimit + " digits");
}
fracPart = 10 * fracPart + toInt(ch, idx);
}
return Either.ofFirst(new Decimal64(fracLen, intPart, fracPart, negative));
}
private static int toInt(final char ch, final int index) {
if (ch < '0' || ch > '9') {
throw new NumberFormatException("Illegal character at offset " + index);
}
return ch - '0';
}
}
/**
* Tri-state indicator of how a non-zero remainder is significant to rounding.
*/
private enum RemainderSignificance {
/**
* The remainder is less than the half of the interval.
*/
LT_HALF,
/**
* The remainder is exactly half of the interval.
*/
HALF,
/**
* The remainder is greater than the half of the interval.
*/
GT_HALF;
static RemainderSignificance of(final long remainder, final long interval) {
final long absRemainder = Math.abs(remainder);
final long half = interval / 2;
if (absRemainder > half) {
return GT_HALF;
} else if (absRemainder < half) {
return LT_HALF;
} else {
return HALF;
}
}
}
private static final CanonicalValueSupport SUPPORT = new Support();
@Serial
private static final long serialVersionUID = 1L;
private static final int MAX_SCALE = 18;
private static final long[] FACTOR = {
10,
100,
1000,
10000,
100000,
1000000,
10000000,
100000000,
1000000000,
10000000000L,
100000000000L,
1000000000000L,
10000000000000L,
100000000000000L,
1000000000000000L,
10000000000000000L,
100000000000000000L,
1000000000000000000L
};
private static final Decimal64Conversion[] CONVERSION = Decimal64Conversion.values();
private static final Decimal64[] MIN_VALUE;
private static final Decimal64[] MAX_VALUE;
static {
verify(CONVERSION.length == MAX_SCALE);
verify(FACTOR.length == MAX_SCALE);
MIN_VALUE = new Decimal64[MAX_SCALE];
MAX_VALUE = new Decimal64[MAX_SCALE];
for (byte i = 0; i < MAX_SCALE; ++i) {
MIN_VALUE[i] = new Decimal64(i, Long.MIN_VALUE);
MAX_VALUE[i] = new Decimal64(i, Long.MAX_VALUE);
}
}
private final byte offset;
private final long value;
@VisibleForTesting
Decimal64(final int scale, final long intPart, final long fracPart, final boolean negative) {
offset = offsetOf(scale);
final long bits = intPart * FACTOR[offset] + fracPart;
value = negative ? -bits : bits;
}
private Decimal64(final byte offset, final long intPart, final boolean negative) {
this.offset = offset;
final long bits = intPart * FACTOR[offset];
value = negative ? -bits : bits;
}
private Decimal64(final byte offset, final long value) {
this.offset = offset;
this.value = value;
}
protected Decimal64(final Decimal64 other) {
this(other.offset, other.value);
}
/**
* Return a {@link Decimal64} with specified scale and unscaled value.
*
* @param scale scale to use
* @param unscaledValue unscaled value to use
* @return A Decimal64 instance
* @throws IllegalArgumentException if {@code scale} is not in range {@code [1..18]}
*/
public static Decimal64 of(final int scale, final long unscaledValue) {
return new Decimal64(offsetOf(scale), unscaledValue);
}
/**
* Return the minimum value supported in specified scale.
*
* @param scale scale to use
* @return Minimum value in that scale
* @throws IllegalArgumentException if {@code scale} is not in range {@code [1..18]}
*/
public static Decimal64 minValueIn(final int scale) {
return MIN_VALUE[offsetOf(scale)];
}
/**
* Return the maximum value supported in specified scale.
*
* @param scale scale to use
* @return Maximum value in that scale
* @throws IllegalArgumentException if {@code scale} is not in range {@code [1..18]}
*/
public static Decimal64 maxValueIn(final int scale) {
return MAX_VALUE[offsetOf(scale)];
}
// >>> FIXME: these need truncating counterparts
public static Decimal64 valueOf(final int scale, final byte byteVal) {
final byte offset = offsetOf(scale);
final var conv = CONVERSION[offset];
if (byteVal < conv.minByte || byteVal > conv.maxByte) {
throw iae(scale, byteVal, conv);
}
return byteVal < 0 ? new Decimal64(offset, -byteVal, true) : new Decimal64(offset, byteVal, false);
}
public static Decimal64 valueOf(final int scale, final short shortVal) {
final byte offset = offsetOf(scale);
final var conv = CONVERSION[offset];
if (shortVal < conv.minShort || shortVal > conv.maxShort) {
throw iae(scale, shortVal, conv);
}
return shortVal < 0 ? new Decimal64(offset, -shortVal, true) : new Decimal64(offset, shortVal, false);
}
public static Decimal64 valueOf(final int scale, final int intVal) {
final byte offset = offsetOf(scale);
final var conv = CONVERSION[offset];
if (intVal < conv.minInt || intVal > conv.maxInt) {
throw iae(scale, intVal, conv);
}
return intVal < 0 ? new Decimal64(offset, - (long)intVal, true) : new Decimal64(offset, intVal, false);
}
public static Decimal64 valueOf(final int scale, final long longVal) {
final byte offset = offsetOf(scale);
final var conv = CONVERSION[offset];
if (longVal < conv.minLong || longVal > conv.maxLong) {
throw iae(scale, longVal, conv);
}
return longVal < 0 ? new Decimal64(offset, -longVal, true) : new Decimal64(offset, longVal, false);
}
// <<< FIXME
// FIXME: this should take a RoundingMode and perform rounding
// FIXME: this should have a truncating counterpart
public static Decimal64 valueOf(final float floatVal, final RoundingMode rounding) {
// XXX: we should be able to do something smarter here
return valueOf(Float.toString(floatVal));
}
// FIXME: this should take a RoundingMode and perform rounding
// FIXME: this should have a truncating counterpart
public static Decimal64 valueOf(final double doubleVal, final RoundingMode rounding) {
// XXX: we should be able to do something smarter here
return valueOf(Double.toString(doubleVal));
}
public static Decimal64 valueOf(final BigDecimal decimalVal) {
// FIXME: we should be able to do something smarter here using BigDecimal.unscaledValue() and BigDecimal.scale()
return valueOf(decimalVal.toPlainString());
}
/**
* Attempt to parse a String into a Decimal64. This method uses minimum fraction digits required to hold
* the entire value.
*
* @param str String to parser
* @return A Decimal64 instance
* @throws NullPointerException if value is null.
* @throws NumberFormatException if the string does not contain a parsable decimal64.
*/
public static Decimal64 valueOf(final String str) {
final Either variant = SUPPORT.fromString(str);
final Optional value = variant.tryFirst();
if (value.isPresent()) {
return value.orElseThrow();
}
final Optional message = variant.getSecond().getMessage();
throw message.isPresent() ? new NumberFormatException(message.orElseThrow()) : new NumberFormatException();
}
/**
* Return the scale of this decimal. This is the number of fraction digits, in range {@code [1..18]}.
*
* @return This decimal's scale
*/
public final int scale() {
return offset + 1;
}
/**
* Return the unscaled value of this decimal.
*
* @return This decimal's unscaled value
*/
public final long unscaledValue() {
return value;
}
/**
* Return this decimal in the specified scale.
*
* @param scale target scale
* @return Scaled number
* @throws ArithmeticException if the conversion would overflow or require rounding
*/
public Decimal64 scaleTo(final int scale) {
return scaleTo(scale, RoundingMode.UNNECESSARY);
}
/**
* Return this decimal in the specified scale.
*
* @param scale scale
* @param roundingMode rounding mode
* @return Scaled number
* @throws ArithmeticException if the conversion would overflow or require rounding and {@code roundingMode} is
* {@link RoundingMode#UNNECESSARY}.
* @throws IllegalArgumentException if {@code scale} is not valid
* @throws NullPointerException if {@code roundingMode} is {@code null}
*/
public Decimal64 scaleTo(final int scale, final RoundingMode roundingMode) {
final var mode = requireNonNull(roundingMode);
final byte scaleOffset = offsetOf(scale);
final int diff = scaleOffset - offset;
if (diff == 0) {
// Same scale, no-op
return this;
} else if (value == 0) {
// Zero is special, as it has the same unscaled value in all scales
return new Decimal64(scaleOffset, 0);
}
if (diff > 0) {
// Increasing scale is simple, as we have pre-calculated min/max boundaries and then it's just
// factor multiplication
final int diffOffset = diff - 1;
final var conv = CONVERSION[diffOffset];
if (value < conv.minLong || value > conv.maxLong) {
throw new ArithmeticException("Increasing scale of " + this + " to " + scale + " would overflow");
}
return new Decimal64(scaleOffset, value * FACTOR[diffOffset]);
}
// Decreasing scale is hard, as we need to deal with rounding
final int diffOffset = -diff - 1;
final long factor = FACTOR[diffOffset];
final long trunc = value / factor;
final long remainder = value - trunc * factor;
// No remainder, we do not need to involve rounding
if (remainder == 0) {
return new Decimal64(scaleOffset, trunc);
}
final long increment = switch (mode) {
case UP -> Long.signum(trunc);
case DOWN -> 0;
case CEILING -> Long.signum(trunc) > 0 ? 1 : 0;
case FLOOR -> Long.signum(trunc) < 0 ? -1 : 0;
case HALF_UP -> switch (RemainderSignificance.of(remainder, factor)) {
case LT_HALF -> 0;
case HALF, GT_HALF -> Long.signum(trunc);
};
case HALF_DOWN -> switch (RemainderSignificance.of(remainder, factor)) {
case LT_HALF, HALF -> 0;
case GT_HALF -> Long.signum(trunc);
};
case HALF_EVEN -> switch (RemainderSignificance.of(remainder, factor)) {
case LT_HALF -> 0;
case HALF -> (trunc & 0x1) != 0 ? Long.signum(trunc) : 0;
case GT_HALF -> Long.signum(trunc);
};
case UNNECESSARY ->
throw new ArithmeticException("Decreasing scale of " + this + " to " + scale + " requires rounding");
};
return new Decimal64(scaleOffset, trunc + increment);
}
public final BigDecimal decimalValue() {
return BigDecimal.valueOf(value, scale());
}
@Override
public final int intValue() {
return (int) intPart();
}
@Override
public final long longValue() {
return intPart();
}
@Override
public final float floatValue() {
return (float) doubleValue();
}
@Override
public final double doubleValue() {
return 1.0 * value / FACTOR[offset];
}
/**
* Converts this {@code BigDecimal} to a {@code byte}, checking for lost information. If this {@code Decimal64} has
* a nonzero fractional part or is out of the possible range for a {@code byte} result then
* an {@code ArithmeticException} is thrown.
*
* @return this {@code Decimal64} converted to a {@code byte}.
* @throws ArithmeticException if {@code this} has a nonzero fractional part, or will not fit in a {@code byte}.
*/
public final byte byteValueExact() {
final long val = longValueExact();
final byte ret = (byte) val;
if (val != ret) {
throw ae("byte", val);
}
return ret;
}
/**
* Converts this {@code BigDecimal} to a {@code short}, checking for lost information. If this {@code Decimal64} has
* a nonzero fractional part or is out of the possible range for a {@code short} result then
* an {@code ArithmeticException} is thrown.
*
* @return this {@code Decimal64} converted to a {@code short}.
* @throws ArithmeticException if {@code this} has a nonzero fractional part, or will not fit in a {@code short}.
*/
public final short shortValueExact() {
final long val = longValueExact();
final short ret = (short) val;
if (val != ret) {
throw ae("short", val);
}
return ret;
}
/**
* Converts this {@code BigDecimal} to an {@code int}, checking for lost information. If this {@code Decimal64} has
* a nonzero fractional part or is out of the possible range for an {@code int} result then
* an {@code ArithmeticException} is thrown.
*
* @return this {@code Decimal64} converted to an {@code int}.
* @throws ArithmeticException if {@code this} has a nonzero fractional part, or will not fit in an {@code int}.
*/
public final int intValueExact() {
final long val = longValueExact();
final int ret = (int) val;
if (val != ret) {
throw ae("integer", val);
}
return ret;
}
/**
* Converts this {@code BigDecimal} to a {@code long}, checking for lost information. If this {@code Decimal64} has
* a nonzero fractional part then an {@code ArithmeticException} is thrown.
*
* @return this {@code Decimal64} converted to a {@code long}.
* @throws ArithmeticException if {@code this} has a nonzero fractional part.
*/
public final long longValueExact() {
if (fracPart() != 0) {
throw new ArithmeticException("Conversion of " + this + " would lose fraction");
}
return intPart();
}
@Override
@SuppressWarnings("checkstyle:parameterName")
public final int compareTo(final Decimal64 o) {
if (this == o) {
return 0;
}
if (offset == o.offset) {
return Long.compare(value, o.value);
}
// XXX: we could do something smarter here
return Double.compare(doubleValue(), o.doubleValue());
}
@Override
public final String toCanonicalString() {
// https://www.rfc-editor.org/rfc/rfc6020#section-9.3.2
//
// The canonical form of a positive decimal64 does not include the sign
// "+". The decimal point is required. Leading and trailing zeros are
// prohibited, subject to the rule that there MUST be at least one digit
// before and after the decimal point. The value zero is represented as
// "0.0".
// Pad unscaled value to scale + 1 size string starting after optional '-' sign
final var builder = new StringBuilder(21).append(value);
final int start = value < 0 ? 1 : 0;
final int scale = scale();
final int padding = scale + 1 + start - builder.length();
if (padding > 0) {
builder.insert(start, "0".repeat(padding));
}
// The first digit of the fraction part is now 'scale' from the end. We will insert the decimal point there,
// but also we it is the digit we never trim.
final int length = builder.length();
final int firstDecimal = length - scale;
// Remove trailing '0's from decimal part. We walk backwards from the last character stop at firstDecimal
int significantLength = length;
for (int i = length - 1; i > firstDecimal && builder.charAt(i) == '0'; --i) {
significantLength = i;
}
if (significantLength != length) {
builder.setLength(significantLength);
}
// Insert '.' before the first decimal and we're done
return builder.insert(firstDecimal, '.').toString();
}
@Override
public final CanonicalValueSupport support() {
return SUPPORT;
}
@Override
public final int hashCode() {
// We need to normalize the results in order to be consistent with equals()
return Long.hashCode(intPart()) * 31 + Long.hashCode(fracPart());
}
@Override
public final boolean equals(final @Nullable Object obj) {
return this == obj || obj instanceof Decimal64 other && equalsImpl(other);
}
/**
* A slightly faster version of {@link #equals(Object)}.
*
* @param obj Decimal64 object
* @return {@code true} if this object is the same as the obj argument; {@code false} otherwise.
*/
public final boolean equals(final @Nullable Decimal64 obj) {
return this == obj || obj != null && equalsImpl(obj);
}
@Override
public final String toString() {
return toCanonicalString();
}
private boolean equalsImpl(final Decimal64 other) {
return offset == other.offset ? value == other.value
// We need to normalize both
: intPart() == other.intPart() && fracPart() == other.fracPart();
}
private long intPart() {
return value / FACTOR[offset];
}
private long fracPart() {
return value % FACTOR[offset];
}
private static byte offsetOf(final int scale) {
checkArgument(scale >= 1 && scale <= MAX_SCALE, "Scale %s is not in range [1..%s]", scale, MAX_SCALE);
return (byte) (scale - 1);
}
private static ArithmeticException ae(final String type, final long val) {
return new ArithmeticException("Value " + val + " is outside of " + type + " range");
}
private static IllegalArgumentException iae(final int scale, final long longVal, final Decimal64Conversion conv) {
return new IllegalArgumentException("Value " + longVal + " is not in range ["
+ conv.minLong + ".." + conv.maxLong + "] to fit scale " + scale);
}
}