diff --git a/src/java.base/share/classes/java/lang/Long.java b/src/java.base/share/classes/java/lang/Long.java
index fb5e4cecca8..813837020fb 100644
--- a/src/java.base/share/classes/java/lang/Long.java
+++ b/src/java.base/share/classes/java/lang/Long.java
@@ -445,39 +445,6 @@ public final class Long extends Number
} while (charPos > offset);
}
- static String fastUUID(long lsb, long msb) {
- if (COMPACT_STRINGS) {
- byte[] buf = new byte[36];
- formatUnsignedLong0(lsb, 4, buf, 24, 12);
- formatUnsignedLong0(lsb >>> 48, 4, buf, 19, 4);
- formatUnsignedLong0(msb, 4, buf, 14, 4);
- formatUnsignedLong0(msb >>> 16, 4, buf, 9, 4);
- formatUnsignedLong0(msb >>> 32, 4, buf, 0, 8);
-
- buf[23] = '-';
- buf[18] = '-';
- buf[13] = '-';
- buf[8] = '-';
-
- return new String(buf, LATIN1);
- } else {
- byte[] buf = new byte[72];
-
- formatUnsignedLong0UTF16(lsb, 4, buf, 24, 12);
- formatUnsignedLong0UTF16(lsb >>> 48, 4, buf, 19, 4);
- formatUnsignedLong0UTF16(msb, 4, buf, 14, 4);
- formatUnsignedLong0UTF16(msb >>> 16, 4, buf, 9, 4);
- formatUnsignedLong0UTF16(msb >>> 32, 4, buf, 0, 8);
-
- StringUTF16.putChar(buf, 23, '-');
- StringUTF16.putChar(buf, 18, '-');
- StringUTF16.putChar(buf, 13, '-');
- StringUTF16.putChar(buf, 8, '-');
-
- return new String(buf, UTF16);
- }
- }
-
/**
* Returns a {@code String} object representing the specified
* {@code long}. The argument is converted to signed decimal
diff --git a/src/java.base/share/classes/java/lang/System.java b/src/java.base/share/classes/java/lang/System.java
index 9d9dbf886e6..31a830782c3 100644
--- a/src/java.base/share/classes/java/lang/System.java
+++ b/src/java.base/share/classes/java/lang/System.java
@@ -2395,9 +2395,6 @@ public final class System {
public Package definePackage(ClassLoader cl, String name, Module module) {
return cl.definePackage(name, module);
}
- public String fastUUID(long lsb, long msb) {
- return Long.fastUUID(lsb, msb);
- }
@SuppressWarnings("removal")
public void addNonExportedPackages(ModuleLayer layer) {
SecurityManager.addNonExportedPackages(layer);
diff --git a/src/java.base/share/classes/java/util/HexDigits.java b/src/java.base/share/classes/java/util/HexDigits.java
index 3ac843aa4a8..7cae4b731f8 100644
--- a/src/java.base/share/classes/java/util/HexDigits.java
+++ b/src/java.base/share/classes/java/util/HexDigits.java
@@ -35,6 +35,44 @@ import jdk.internal.vm.annotation.Stable;
* @since 21
*/
final class HexDigits implements Digits {
+ /**
+ * Each element of the array represents the ascii encoded
+ * hex relative to its index, for example:
+ *
+ * 0 -> '00' -> ('0' << 8) | '0' -> 12336
+ * 1 -> '01' -> ('0' << 8) | '1' -> 12337
+ * 2 -> '02' -> ('0' << 8) | '2' -> 12338
+ *
+ * ...
+ *
+ * 10 -> '0a' -> ('0' << 8) | 'a' -> 12385
+ * 11 -> '0b' -> ('0' << 8) | 'b' -> 12386
+ * 12 -> '0c' -> ('0' << 8) | 'b' -> 12387
+ *
+ * ...
+ *
+ * 26 -> '1a' -> ('1' << 8) | 'a' -> 12641
+ * 27 -> '1b' -> ('1' << 8) | 'b' -> 12642
+ * 28 -> '1c' -> ('1' << 8) | 'c' -> 12643
+ *
+ * ...
+ *
+ * 253 -> 'fd' -> ('f' << 8) | 'd' -> 26212
+ * 254 -> 'fe' -> ('f' << 8) | 'e' -> 26213
+ * 255 -> 'ff' -> ('f' << 8) | 'f' -> 26214
+ *
+ * use like this:
+ *
+ * int v = 254;
+ *
+ * char[] chars = new char[2];
+ *
+ * short i = DIGITS[v]; // 26213
+ *
+ * chars[0] = (char) (byte) (i >> 8); // 'f'
+ * chars[1] = (char) (byte) i; // 'e'
+ *
+ */
@Stable
private static final short[] DIGITS;
@@ -64,6 +102,23 @@ final class HexDigits implements Digits {
private HexDigits() {
}
+ /**
+ * Combine two hex shorts into one int based on big endian
+ */
+ static int digit(int b0, int b1) {
+ return (DIGITS[b0 & 0xff] << 16) | DIGITS[b1 & 0xff];
+ }
+
+ /**
+ * Combine four hex shorts into one long based on big endian
+ */
+ static long digit(int b0, int b1, int b2, int b3) {
+ return (((long) DIGITS[b0 & 0xff]) << 48)
+ | (((long) DIGITS[b1 & 0xff]) << 32)
+ | (DIGITS[b2 & 0xff] << 16)
+ | DIGITS[b3 & 0xff];
+ }
+
@Override
public int digits(long value, byte[] buffer, int index,
MethodHandle putCharMH) throws Throwable {
diff --git a/src/java.base/share/classes/java/util/UUID.java b/src/java.base/share/classes/java/util/UUID.java
index 2f5ad22653d..78846ba48c2 100644
--- a/src/java.base/share/classes/java/util/UUID.java
+++ b/src/java.base/share/classes/java/util/UUID.java
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 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
@@ -25,10 +25,13 @@
package java.util;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.StandardCharsets;
import java.security.*;
import jdk.internal.access.JavaLangAccess;
import jdk.internal.access.SharedSecrets;
+import jdk.internal.util.ByteArray;
/**
* A class that represents an immutable universally unique identifier (UUID).
@@ -463,7 +466,43 @@ public final class UUID implements java.io.Serializable, Comparable {
*/
@Override
public String toString() {
- return jla.fastUUID(leastSigBits, mostSigBits);
+ long lsb = leastSigBits;
+ long msb = mostSigBits;
+ byte[] buf = new byte[36];
+ ByteArray.setLong(
+ buf,
+ 0,
+ HexDigits.digit((int) (msb >> 56), (int) (msb >> 48), (int) (msb >> 40), (int) (msb >> 32)));
+ buf[8] = '-';
+ ByteArray.setInt(
+ buf,
+ 9,
+ HexDigits.digit(((int) msb) >> 24, ((int) msb) >> 16));
+ buf[13] = '-';
+ ByteArray.setInt(
+ buf,
+ 14,
+ HexDigits.digit(((int) msb) >> 8, (int) msb));
+ buf[18] = '-';
+ ByteArray.setInt(
+ buf,
+ 19,
+ HexDigits.digit((int) (lsb >> 56), (int) (lsb >> 48)));
+ buf[23] = '-';
+ ByteArray.setLong(
+ buf,
+ 24,
+ HexDigits.digit(((int) (lsb >> 40)), (int) (lsb >> 32), ((int) lsb) >> 24, ((int) lsb) >> 16));
+ ByteArray.setInt(
+ buf,
+ 32,
+ HexDigits.digit(((int) lsb) >> 8, (int) lsb));
+
+ try {
+ return jla.newStringNoRepl(buf, StandardCharsets.ISO_8859_1);
+ } catch (CharacterCodingException cce) {
+ throw new AssertionError(cce);
+ }
}
/**
diff --git a/src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java b/src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java
index babc1940e78..6ea7abf6b95 100644
--- a/src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java
+++ b/src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java
@@ -176,11 +176,6 @@ public interface JavaLangAccess {
*/
Package definePackage(ClassLoader cl, String name, Module module);
- /**
- * Invokes Long.fastUUID
- */
- String fastUUID(long lsb, long msb);
-
/**
* Record the non-exported packages of the modules in the given layer
*/