Jim Laskey 4aa65cbeef 8285932: Implementation of JEP 430 String Templates (Preview)
Reviewed-by: mcimadamore, rriggs, darcy
2023-05-10 11:34:01 +00:00

284 lines
8.1 KiB
Java

/*
* Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.util;
import java.lang.invoke.MethodHandle;
import jdk.internal.vm.annotation.Stable;
/**
* Digits provides a fast methodology for converting integers and longs to
* ASCII strings.
*
* @since 21
*/
sealed interface Digits permits Digits.DecimalDigits, Digits.HexDigits, Digits.OctalDigits {
/**
* Insert digits for long value in buffer from high index to low index.
*
* @param value value to convert
* @param buffer byte buffer to copy into
* @param index insert point + 1
* @param putCharMH method to put character
*
* @return the last index used
*
* @throws Throwable if putCharMH fails (unusual).
*/
int digits(long value, byte[] buffer, int index,
MethodHandle putCharMH) throws Throwable;
/**
* Calculate the number of digits required to represent the long.
*
* @param value value to convert
*
* @return number of digits
*/
int size(long value);
/**
* Digits class for decimal digits.
*/
final class DecimalDigits implements Digits {
@Stable
private static final short[] DIGITS;
/**
* Singleton instance of DecimalDigits.
*/
static final Digits INSTANCE = new DecimalDigits();
static {
short[] digits = new short[10 * 10];
for (int i = 0; i < 10; i++) {
short hi = (short) ((i + '0') << 8);
for (int j = 0; j < 10; j++) {
short lo = (short) (j + '0');
digits[i * 10 + j] = (short) (hi | lo);
}
}
DIGITS = digits;
}
/**
* Constructor.
*/
private DecimalDigits() {
}
@Override
public int digits(long value, byte[] buffer, int index,
MethodHandle putCharMH) throws Throwable {
boolean negative = value < 0;
if (!negative) {
value = -value;
}
long q;
int r;
while (value <= Integer.MIN_VALUE) {
q = value / 100;
r = (int)((q * 100) - value);
value = q;
int digits = DIGITS[r];
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
int iq, ivalue = (int)value;
while (ivalue <= -100) {
iq = ivalue / 100;
r = (iq * 100) - ivalue;
ivalue = iq;
int digits = DIGITS[r];
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
if (ivalue < 0) {
ivalue = -ivalue;
}
int digits = DIGITS[ivalue];
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
if (9 < ivalue) {
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
if (negative) {
putCharMH.invokeExact(buffer, --index, (int)'-');
}
return index;
}
@Override
public int size(long value) {
boolean negative = value < 0;
int sign = negative ? 1 : 0;
if (!negative) {
value = -value;
}
long precision = -10;
for (int i = 1; i < 19; i++) {
if (value > precision)
return i + sign;
precision = 10 * precision;
}
return 19 + sign;
}
}
/**
* Digits class for hexadecimal digits.
*/
final class HexDigits implements Digits {
@Stable
private static final short[] DIGITS;
/**
* Singleton instance of HexDigits.
*/
static final Digits INSTANCE = new HexDigits();
static {
short[] digits = new short[16 * 16];
for (int i = 0; i < 16; i++) {
short hi = (short) ((i < 10 ? i + '0' : i - 10 + 'a') << 8);
for (int j = 0; j < 16; j++) {
short lo = (short) (j < 10 ? j + '0' : j - 10 + 'a');
digits[(i << 4) + j] = (short) (hi | lo);
}
}
DIGITS = digits;
}
/**
* Constructor.
*/
private HexDigits() {
}
@Override
public int digits(long value, byte[] buffer, int index,
MethodHandle putCharMH) throws Throwable {
while ((value & ~0xFF) != 0) {
int digits = DIGITS[(int) (value & 0xFF)];
value >>>= 8;
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
int digits = DIGITS[(int) (value & 0xFF)];
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
if (0xF < value) {
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
return index;
}
@Override
public int size(long value) {
return value == 0 ? 1 :
67 - Long.numberOfLeadingZeros(value) >> 2;
}
}
/**
* Digits class for octal digits.
*/
final class OctalDigits implements Digits {
@Stable
private static final short[] DIGITS;
/**
* Singleton instance of OctalDigits.
*/
static final Digits INSTANCE = new OctalDigits();
static {
short[] digits = new short[8 * 8];
for (int i = 0; i < 8; i++) {
short hi = (short) ((i + '0') << 8);
for (int j = 0; j < 8; j++) {
short lo = (short) (j + '0');
digits[(i << 3) + j] = (short) (hi | lo);
}
}
DIGITS = digits;
}
/**
* Constructor.
*/
private OctalDigits() {
}
@Override
public int digits(long value, byte[] buffer, int index,
MethodHandle putCharMH) throws Throwable {
while ((value & ~0x3F) != 0) {
int digits = DIGITS[(int) (value & 0x3F)];
value >>>= 6;
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
int digits = DIGITS[(int) (value & 0x3F)];
putCharMH.invokeExact(buffer, --index, digits & 0xFF);
if (7 < value) {
putCharMH.invokeExact(buffer, --index, digits >> 8);
}
return index;
}
@Override
public int size(long value) {
return (66 - Long.numberOfLeadingZeros(value)) / 3;
}
}
}