MemoryLayoutPREVIEWpublic sealed interface SequenceLayout extends MemoryLayoutPREVIEW
SequenceLayout is a preview API of the Java platform. MemoryLayout.sequenceLayout(3, ValueLayout.JAVA_INT.withOrder(ByteOrder.BIG_ENDIAN));
MemoryLayout.structLayout(
ValueLayout.JAVA_INT.withOrder(ByteOrder.BIG_ENDIAN),
ValueLayout.JAVA_INT.withOrder(ByteOrder.BIG_ENDIAN),
ValueLayout.JAVA_INT.withOrder(ByteOrder.BIG_ENDIAN));
MemoryLayout.PathElementPREVIEW
| Modifier and Type | Method | Description |
|---|---|---|
long |
elementCount() |
Returns the element count of this sequence layout. |
MemoryLayoutPREVIEW |
elementLayout() |
Returns the element layout of this sequence layout. |
SequenceLayoutPREVIEW |
flatten() |
Returns a flattened sequence layout. |
SequenceLayoutPREVIEW |
reshape |
Rearranges the elements in this sequence layout into a multi-dimensional sequence layout. |
SequenceLayoutPREVIEW |
withByteAlignment |
Returns a memory layout with the same characteristics as this layout, but with the given alignment constraint (in bytes). |
SequenceLayoutPREVIEW |
withElementCount |
Returns a sequence layout with the same characteristics of this layout, but with the given element count. |
SequenceLayoutPREVIEW |
withName |
Returns a memory layout with the same characteristics as this layout, but with the given name. |
byteAlignment, byteOffset, byteOffsetHandle, byteSize, equals, hashCode, name, select, sliceHandle, toString, varHandle, withoutName
MemoryLayoutPREVIEW elementLayout()
long elementCount()
SequenceLayoutPREVIEW withElementCount(long elementCount)
elementCount - the new element count.IllegalArgumentException - if elementCount is negative.IllegalArgumentException - if elementLayout.bitSize() * elementCount overflows.SequenceLayoutPREVIEW reshape(long... elementCounts)
For instance, given a sequence layout of the kind:
var seq = MemoryLayout.sequenceLayout(4, MemoryLayout.sequenceLayout(3, ValueLayout.JAVA_INT));
seq.reshape(2, 6) will yield the following sequence layout: var reshapeSeq = MemoryLayout.sequenceLayout(2, MemoryLayout.sequenceLayout(6, ValueLayout.JAVA_INT));
If one of the provided element count is the special value -1, then the element count in that position will be inferred from the remaining element counts and the element count of the flattened projection of this layout. For instance, a layout equivalent to the above reshapeSeq can also be computed in the following ways:
var reshapeSeqImplicit1 = seq.reshape(-1, 6);
var reshapeSeqImplicit2 = seq.reshape(2, -1);
elementCounts - an array of element counts, of which at most one can be -1.flatten()) are re-arranged into one or more nested sequence layouts.IllegalArgumentException - if two or more element counts are set to -1, or if one or more element count is <= 0 (but other than -1) or, if, after any required inference, multiplying the element counts does not yield the same element count as the flattened projection of this sequence layout.SequenceLayoutPREVIEW flatten()
MemoryLayout flatElementLayout(SequenceLayout sequenceLayout) {
return switch (sequenceLayout.elementLayout()) {
case SequenceLayout nestedSequenceLayout -> flatElementLayout(nestedSequenceLayout);
case MemoryLayout layout -> layout;
};
}
This transformation preserves the layout size; nested sequence layout in this sequence layout will be dropped and their element counts will be incorporated into that of the returned sequence layout. For instance, given a sequence layout of the kind:
var seq = MemoryLayout.sequenceLayout(4, MemoryLayout.sequenceLayout(3, ValueLayout.JAVA_INT));
seq.flatten() will yield the following sequence layout: var flattenedSeq = MemoryLayout.sequenceLayout(12, ValueLayout.JAVA_INT);
SequenceLayoutPREVIEW withName(String name)
withName in interface MemoryLayoutPREVIEW
name - the layout name.SequenceLayoutPREVIEW withByteAlignment(long byteAlignment)
withByteAlignment in interface MemoryLayoutPREVIEW
byteAlignment - the layout alignment constraint, expressed in bytes.IllegalArgumentException - if byteAlignment is not a power of two.IllegalArgumentException - if byteAlignment < elementLayout().byteAlignment().
© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/foreign/SequenceLayout.html
SequenceLayoutwhen preview features are enabled.