APIdia Launch Partner
Top Description Fields Constructors Methods
jdk.internal.util

public final Class ModifiedUtf

extends Object
Class Inheritance
Imports
jdk.internal.vm.annotation.ForceInline
Utilities for string encoding and decoding with the Modified UTF-8 format.

Field Summary

Modifier and TypeField and Description
public static final int
CONSTANT_POOL_UTF8_MAX_BYTES

Maximum number of bytes allowed for a Modified UTF-8 encoded string in a java.lang.classfile.constantpool.Utf8Entry or a hotspot Symbol.

Constructor Summary

AccessConstructor and Description
private
ModifiedUtf()

Method Summary

Modifier and TypeMethod and Description
public static boolean
isValidLengthInConstantPool(String
input string
str)

Checks whether an input String can be encoded in a java.lang.classfile.constantpool.Utf8Entry, or represented as a hotspot Symbol (which has the same length limit).

public static int
putChar(byte[] buf, int offset, char c)

Writes a char to the pre-sized modified UTF buffer.

public static long
utfLen(String
input string
str)

Calculate the encoded length of an input String.

public static long
utfLen(String
input string
str, int
the number of non-zero ascii characters in the prefix calculated by JLA.countNonZeroAscii(str)
countNonZeroAscii)

Calculate the encoded length of trailing parts of an input String, after jdk.internal.access.JavaLangAccess#countNonZeroAscii(String) calculates the number of contiguous single-byte characters in the beginning of the string.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

CONSTANT_POOL_UTF8_MAX_BYTESback to summary
public static final int CONSTANT_POOL_UTF8_MAX_BYTES

Maximum number of bytes allowed for a Modified UTF-8 encoded string in a java.lang.classfile.constantpool.Utf8Entry or a hotspot Symbol.

Constructor Detail

ModifiedUtfback to summary
private ModifiedUtf()

Method Detail

isValidLengthInConstantPoolback to summary
public static boolean isValidLengthInConstantPool(String str)

Checks whether an input String can be encoded in a java.lang.classfile.constantpool.Utf8Entry, or represented as a hotspot Symbol (which has the same length limit).

Parameters
str:String

input string

Annotations
@ForceInline
putCharback to summary
public static int putChar(byte[] buf, int offset, char c)

Writes a char to the pre-sized modified UTF buffer.

Annotations
@ForceInline
utfLenback to summary
public static long utfLen(String str)

Calculate the encoded length of an input String. For many workloads that have fast paths for ASCII-only prefixes, utfLen(String, int) skips scanning that prefix.

Parameters
str:String

input string

utfLenback to summary
public static long utfLen(String str, int countNonZeroAscii)

Calculate the encoded length of trailing parts of an input String, after jdk.internal.access.JavaLangAccess#countNonZeroAscii(String) calculates the number of contiguous single-byte characters in the beginning of the string.

Parameters
str:String

input string

countNonZeroAscii:int

the number of non-zero ascii characters in the prefix calculated by JLA.countNonZeroAscii(str)

Annotations
@ForceInline