- All Implemented Interfaces:
Constable,MemoryLayout
ByteOrder).
This is a value-based
class; programmers should treat instances that are
equal as interchangeable and should not
use instances for synchronization, or unpredictable behavior may
occur. For example, in a future release, synchronization may fail.
The equals method should be used for comparisons.
Unless otherwise specified, passing a null argument, or an array argument containing one or more null
elements to a method in this class causes a NullPointerException to be thrown.
- Implementation Requirements:
- This class is immutable and thread-safe.
-
Nested Class Summary
Nested classes/interfaces declared in interface jdk.incubator.foreign.MemoryLayout
MemoryLayout.PathElement -
Field Summary
Fields declared in interface jdk.incubator.foreign.MemoryLayout
LAYOUT_NAME -
Method Summary
Modifier and TypeMethodDescriptionReturns the attribute with the given name (if it exists).Returns a stream of the attribute names associated with this layout.final longReturns the alignment constraint associated with this layout, expressed in bits.longbitSize()Computes the layout size, in bits.booleanIndicates whether some other object is "equal to" this one.inthashCode()Returns a hash code value for the object.booleanhasSize()Does this layout have a specified size?booleanIs this a padding layout (e.g. a layout created fromMemoryLayout.paddingLayout(long)) ?name()Return the name (if any) associated with this layout.order()Returns the value's byte order.toString()Returns a string representation of the object.withAttribute(String name, Constable value) Returns a new memory layout which features the same attributes as this layout, plus the newly specified attribute.withBitAlignment(long alignmentBits) Creates a new layout which features the desired alignment constraint.Creates a new layout which features the desired layout name.Returns a new value layout with given byte order.Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, waitMethods declared in interface jdk.incubator.foreign.MemoryLayout
attribute, attributes, bitAlignment, bitOffset, bitOffsetHandle, bitSize, byteAlignment, byteOffset, byteOffsetHandle, byteSize, hasSize, isPadding, map, name, select, sliceHandle, varHandle
-
Method Details
-
order
Returns the value's byte order.- Returns:
- the value's byte order.
-
withOrder
Returns a new value layout with given byte order.- Parameters:
order- the desired byte order.- Returns:
- a new value layout with given byte order.
-
toString
Description copied from class:ObjectReturns a string representation of the object.- Specified by:
toStringin interfaceMemoryLayout- Overrides:
toStringin classObject- Returns:
- a string representation of the object.
-
equals
Description copied from class:ObjectIndicates whether some other object is "equal to" this one.The
equalsmethod implements an equivalence relation on non-null object references:- It is reflexive: for any non-null reference value
x,x.equals(x)should returntrue. - It is symmetric: for any non-null reference values
xandy,x.equals(y)should returntrueif and only ify.equals(x)returnstrue. - It is transitive: for any non-null reference values
x,y, andz, ifx.equals(y)returnstrueandy.equals(z)returnstrue, thenx.equals(z)should returntrue. - It is consistent: for any non-null reference values
xandy, multiple invocations ofx.equals(y)consistently returntrueor consistently returnfalse, provided no information used inequalscomparisons on the objects is modified. - For any non-null reference value
x,x.equals(null)should returnfalse.
An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.
- Specified by:
equalsin interfaceMemoryLayout- Parameters:
other- the reference object with which to compare.- Returns:
trueif this object is the same as the obj argument;falseotherwise.- See Also:
- It is reflexive: for any non-null reference value
-
hashCode
public int hashCode()Description copied from class:ObjectReturns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided byHashMap.The general contract of
hashCodeis:- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
hashCodemethod must consistently return the same integer, provided no information used inequalscomparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. - If two objects are equal according to the
equalsmethod, then calling thehashCodemethod on each of the two objects must produce the same integer result. - It is not required that if two objects are unequal
according to the
equalsmethod, then calling thehashCodemethod on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
- Specified by:
hashCodein interfaceMemoryLayout- Returns:
- a hash code value for this object.
- See Also:
- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
-
describeConstable
Description copied from interface:MemoryLayoutReturns anOptionalcontaining the nominal descriptor for this layout, if one can be constructed, or an emptyOptionalif one cannot be constructed.- Specified by:
describeConstablein interfaceConstable- Specified by:
describeConstablein interfaceMemoryLayout- Returns:
- An
Optionalcontaining the resulting nominal descriptor, or an emptyOptionalif one cannot be constructed.
-
withName
Creates a new layout which features the desired layout name.This is equivalent to the following code:
withAttribute(LAYOUT_NAME, name);- Specified by:
withNamein interfaceMemoryLayout- Parameters:
name- the layout name.- Returns:
- a new layout which is the same as this layout, except for the name associated with it.
- See Also:
-
withBitAlignment
Creates a new layout which features the desired alignment constraint.- Specified by:
withBitAlignmentin interfaceMemoryLayout- Parameters:
alignmentBits- the layout alignment constraint, expressed in bits.- Returns:
- a new layout which is the same as this layout, except for the alignment constraint associated with it.
-
withAttribute
Returns a new memory layout which features the same attributes as this layout, plus the newly specified attribute. If this layout already contains an attribute with the same name, the existing attribute value is overwritten in the returned layout.- Specified by:
withAttributein interfaceMemoryLayout- Parameters:
name- the attribute name.value- the attribute value.- Returns:
- a new memory layout which features the same attributes as this layout, plus the newly specified attribute.
-
name
Description copied from interface:MemoryLayoutReturn the name (if any) associated with this layout.This is equivalent to the following code:
attribute(LAYOUT_NAME).map(String.class::cast);- Specified by:
namein interfaceMemoryLayout- Returns:
- the layout name (if any).
- See Also:
-
attribute
Description copied from interface:MemoryLayoutReturns the attribute with the given name (if it exists).- Specified by:
attributein interfaceMemoryLayout- Parameters:
name- the attribute name- Returns:
- the attribute with the given name (if it exists).
-
attributes
Description copied from interface:MemoryLayoutReturns a stream of the attribute names associated with this layout.- Specified by:
attributesin interfaceMemoryLayout- Returns:
- a stream of the attribute names associated with this layout.
-
bitAlignment
public final long bitAlignment()Description copied from interface:MemoryLayoutReturns the alignment constraint associated with this layout, expressed in bits. Layout alignment defines a power of twoAwhich is the bit-wise alignment of the layout. IfA <= 8thenA/8is the number of bytes that must be aligned for any pointer that correctly points to this layout. Thus:A=8means unaligned (in the usual sense), which is common in packets.A=64means word aligned (on LP64),A=32int aligned,A=16short aligned, etc.A=512is the most strict alignment required by the x86/SV ABI (for AVX-512 data).
MemoryLayout.withBitAlignment(long)), then this method returns the natural alignment constraint (in bits) associated with this layout.- Specified by:
bitAlignmentin interfaceMemoryLayout- Returns:
- the layout alignment constraint, in bits.
-
hasSize
public boolean hasSize()Description copied from interface:MemoryLayoutDoes this layout have a specified size? A layout does not have a specified size if it is (or contains) a sequence layout whose size is unspecified (seeSequenceLayout.elementCount()). Value layouts (seeValueLayout) and padding layouts (seeMemoryLayout.paddingLayout(long)) always have a specified size, therefore this method always returnstruein these cases.- Specified by:
hasSizein interfaceMemoryLayout- Returns:
true, if this layout has a specified size.
-
bitSize
public long bitSize()Description copied from interface:MemoryLayoutComputes the layout size, in bits.- Specified by:
bitSizein interfaceMemoryLayout- Returns:
- the layout size, in bits.
-
isPadding
public boolean isPadding()Description copied from interface:MemoryLayoutIs this a padding layout (e.g. a layout created fromMemoryLayout.paddingLayout(long)) ?- Specified by:
isPaddingin interfaceMemoryLayout- Returns:
- true, if this layout is a padding layout.
-