Class MemoryLayouts

java.lang.Object

jdk.incubator.foreign.MemoryLayouts

public final class MemoryLayouts extends Object

This class defines useful layout constants. Some of the constants defined in this class are explicit in both size and byte order (see BITS_64_BE), and can therefore be used to explicitly and unambiguously specify the contents of a memory segment. Other constants make implicit byte order assumptions (see JAVA_INT); as such, these constants make it easy to work with other serialization-centric APIs, such as ByteBuffer.

Field Summary

Modifier and Type	Field	Description
`static final ValueLayout`	`ADDRESS`	A value layout constant whose size is the same as that of a machine address (e.g.
`static final ValueLayout`	`BITS_16_BE`	A value layout constant with size of two bytes, and byte order set to `ByteOrder.BIG_ENDIAN`.
`static final ValueLayout`	`BITS_16_LE`	A value layout constant with size of two bytes, and byte order set to `ByteOrder.LITTLE_ENDIAN`.
`static final ValueLayout`	`BITS_32_BE`	A value layout constant with size of four bytes, and byte order set to `ByteOrder.BIG_ENDIAN`.
`static final ValueLayout`	`BITS_32_LE`	A value layout constant with size of four bytes, and byte order set to `ByteOrder.LITTLE_ENDIAN`.
`static final ValueLayout`	`BITS_64_BE`	A value layout constant with size of eight bytes, and byte order set to `ByteOrder.BIG_ENDIAN`.
`static final ValueLayout`	`BITS_64_LE`	A value layout constant with size of eight bytes, and byte order set to `ByteOrder.LITTLE_ENDIAN`.
`static final ValueLayout`	`BITS_8_BE`	A value layout constant with size of one byte, and byte order set to `ByteOrder.BIG_ENDIAN`.
`static final ValueLayout`	`BITS_8_LE`	A value layout constant with size of one byte, and byte order set to `ByteOrder.LITTLE_ENDIAN`.
`static final ValueLayout`	`JAVA_BYTE`	A value layout constant whose size is the same as that of a Java `byte`, and byte order set to `ByteOrder.nativeOrder()`.
`static final ValueLayout`	`JAVA_CHAR`	A value layout constant whose size is the same as that of a Java `char`, and byte order set to `ByteOrder.nativeOrder()`.
`static final ValueLayout`	`JAVA_DOUBLE`	A value layout constant whose size is the same as that of a Java `double`, and byte order set to `ByteOrder.nativeOrder()`.
`static final ValueLayout`	`JAVA_FLOAT`	A value layout constant whose size is the same as that of a Java `float`, and byte order set to `ByteOrder.nativeOrder()`.
`static final ValueLayout`	`JAVA_INT`	A value layout constant whose size is the same as that of a Java `int`, and byte order set to `ByteOrder.nativeOrder()`.
`static final ValueLayout`	`JAVA_LONG`	A value layout constant whose size is the same as that of a Java `long`, and byte order set to `ByteOrder.nativeOrder()`.
`static final ValueLayout`	`JAVA_SHORT`	A value layout constant whose size is the same as that of a Java `short`, and byte order set to `ByteOrder.nativeOrder()`.
`static final MemoryLayout`	`PAD_16`	A padding layout constant with size of two bytes.
`static final MemoryLayout`	`PAD_32`	A padding layout constant with size of four bytes.
`static final MemoryLayout`	`PAD_64`	A padding layout constant with size of eight bytes.
`static final MemoryLayout`	`PAD_8`	A padding layout constant with size of one byte.

Method Summary

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BITS_8_LE

public static final ValueLayout BITS_8_LE

A value layout constant with size of one byte, and byte order set to ByteOrder.LITTLE_ENDIAN.

BITS_16_LE

public static final ValueLayout BITS_16_LE

A value layout constant with size of two bytes, and byte order set to ByteOrder.LITTLE_ENDIAN.

BITS_32_LE

public static final ValueLayout BITS_32_LE

A value layout constant with size of four bytes, and byte order set to ByteOrder.LITTLE_ENDIAN.

BITS_64_LE

public static final ValueLayout BITS_64_LE

A value layout constant with size of eight bytes, and byte order set to ByteOrder.LITTLE_ENDIAN.

BITS_8_BE

public static final ValueLayout BITS_8_BE

A value layout constant with size of one byte, and byte order set to ByteOrder.BIG_ENDIAN.

BITS_16_BE

public static final ValueLayout BITS_16_BE

A value layout constant with size of two bytes, and byte order set to ByteOrder.BIG_ENDIAN.

BITS_32_BE

public static final ValueLayout BITS_32_BE

A value layout constant with size of four bytes, and byte order set to ByteOrder.BIG_ENDIAN.

BITS_64_BE

public static final ValueLayout BITS_64_BE

A value layout constant with size of eight bytes, and byte order set to ByteOrder.BIG_ENDIAN.

PAD_8

public static final MemoryLayout PAD_8

A padding layout constant with size of one byte.

PAD_16

public static final MemoryLayout PAD_16

A padding layout constant with size of two bytes.

PAD_32

public static final MemoryLayout PAD_32

A padding layout constant with size of four bytes.

PAD_64

public static final MemoryLayout PAD_64

A padding layout constant with size of eight bytes.

ADDRESS

public static final ValueLayout ADDRESS

A value layout constant whose size is the same as that of a machine address (e.g. size_t), and byte order set to ByteOrder.nativeOrder().

JAVA_BYTE

public static final ValueLayout JAVA_BYTE

A value layout constant whose size is the same as that of a Java byte, and byte order set to ByteOrder.nativeOrder().

JAVA_CHAR

public static final ValueLayout JAVA_CHAR

A value layout constant whose size is the same as that of a Java char, and byte order set to ByteOrder.nativeOrder().

JAVA_SHORT

public static final ValueLayout JAVA_SHORT

A value layout constant whose size is the same as that of a Java short, and byte order set to ByteOrder.nativeOrder().

JAVA_INT

public static final ValueLayout JAVA_INT

A value layout constant whose size is the same as that of a Java int, and byte order set to ByteOrder.nativeOrder().

JAVA_LONG

public static final ValueLayout JAVA_LONG

A value layout constant whose size is the same as that of a Java long, and byte order set to ByteOrder.nativeOrder(). The alignment of this layout (see MemoryLayout.byteAlignment() is platform-dependent, so that the following invariant holds:


    MemoryLayouts.JAVA_LONG.byteAlignment() == MemoryLayouts.ADDRESS.byteSize();

JAVA_FLOAT

public static final ValueLayout JAVA_FLOAT

A value layout constant whose size is the same as that of a Java float, and byte order set to ByteOrder.nativeOrder().

JAVA_DOUBLE

public static final ValueLayout JAVA_DOUBLE

A value layout constant whose size is the same as that of a Java double, and byte order set to ByteOrder.nativeOrder(). The alignment of this layout (see MemoryLayout.byteAlignment() is platform-dependent, so that the following invariant holds:


    MemoryLayouts.JAVA_DOUBLE.byteAlignment() == MemoryLayouts.ADDRESS.byteSize();

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https://docs.oracle.com/en/java/javase/17/docs/api/jdk.incubator.foreign/jdk/incubator/foreign/MemoryLayouts.html