Package jnr.ffi

Class Struct

java.lang.Object

jnr.ffi.Struct

Direct Known Subclasses:

Union

public abstract class Struct
extends Object

Representation of C structures in java. Note: This class is not threadsafe.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	Struct.AbstractBoolean	Base class for Boolean fields
protected class	Struct.AbstractMember	Base implementation of Member
class	Struct.Address	Represents a native memory address.
static class	Struct.Alignment
class	Struct.AsciiString
class	Struct.AsciiStringRef
class	Struct.blkcnt_t
class	Struct.blksize_t
class	Struct.BOOL16
class	Struct.Boolean	A normal C boolean - 1 byte in size
class	Struct.BYTE
class	Struct.caddr_t
class	Struct.cc_t
class	Struct.clock_t
class	Struct.dev_t
class	Struct.Double
class	Struct.DWORD
class	Struct.Enum<T extends Enum<T>>
class	Struct.Enum16<E extends Enum<E>>
class	Struct.Enum32<E extends Enum<E>>
class	Struct.Enum64<E extends Enum<E>>
class	Struct.Enum8<E extends Enum<E>>	An 8 bit enum field.
protected class	Struct.EnumField<E>	Base for all the Enum fields.
class	Struct.EnumLong<E extends Enum<E>>
class	Struct.Float
class	Struct.fsblkcnt_t
class	Struct.fsfilcnt_t
class	Struct.Function<T>
class	Struct.gid_t
class	Struct.id_t
class	Struct.in_addr_t
class	Struct.in_port_t
class	Struct.ino_t
class	Struct.ino64_t
class	Struct.int16_t
class	Struct.int32_t
class	Struct.int64_t
class	Struct.int8_t
class	Struct.IntegerAlias
class	Struct.intptr_t
class	Struct.key_t
class	Struct.LONG
protected class	Struct.Member	Interface all Struct members must implement.
class	Struct.mode_t
class	Struct.nlink_t
class	Struct.NumberField	Base class for all Number structure fields.
class	Struct.off_t
static class	Struct.Offset
protected class	Struct.Padding	Specialized padding fields for structs.
class	Struct.pid_t
class	Struct.Pointer	Represents a native memory address.
class	Struct.PointerField
class	Struct.rlim_t
class	Struct.sa_family_t
class	Struct.Signed16	A 16 bit signed integer field.
class	Struct.Signed32	A 32 bit signed integer field.
class	Struct.Signed64	A 64 bit signed integer field.
class	Struct.Signed8	An 8 bit signed integer
class	Struct.SignedLong	A native long integer field.
class	Struct.size_t
class	Struct.socklen_t
class	Struct.speed_t
class	Struct.ssize_t
class	Struct.String
class	Struct.StructRef<T extends Struct>	Represents a reference to a Struct or and array of Structs
class	Struct.swblk_t
class	Struct.tcflag_t
class	Struct.time_t
class	Struct.u_int16_t
class	Struct.u_int32_t
class	Struct.u_int64_t
class	Struct.u_int8_t
class	Struct.uid_t
class	Struct.uintptr_t
class	Struct.Unsigned16	A 16 bit signed integer field.
class	Struct.Unsigned32	A 32 bit signed integer field.
class	Struct.Unsigned64	A 64 bit unsigned integer field.
class	Struct.Unsigned8	An 8 bit unsigned integer
class	Struct.UnsignedLong	A native long integer field.
class	Struct.UTF8String
class	Struct.UTF8StringRef
class	Struct.UTFString
class	Struct.UTFStringRef
class	Struct.WBOOL	A Windows BOOL - 4 bytes
class	Struct.WORD

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Struct(Runtime runtime)	Creates a new Struct.
protected	Struct(Runtime runtime, boolean isUnion)	Creates a new Struct.
protected	Struct(Runtime runtime, Struct enclosing)
protected	Struct(Runtime runtime, Struct.Alignment alignment)

Method Summary

Modifier and Type	Method	Description
static int	alignment(Struct struct)
protected Struct.Address[]	array(Struct.Address[] array)	Creates an array of Address instances.
protected Struct.Double[]	array(Struct.Double[] array)	Creates an array of Double instances.
protected <T extends Enum<T>> Struct.Enum<T>[]	array(Struct.Enum<T>[] array, Class<T> enumClass)	Creates an array of Enum instances.
protected <T extends Enum<T>> Struct.Enum16<T>[]	array(Struct.Enum16<T>[] array, Class<T> enumClass)	Creates an array of Enum16 instances.
protected <T extends Enum<T>> Struct.Enum32<T>[]	array(Struct.Enum32<T>[] array, Class<T> enumClass)	Creates an array of Enum32 instances.
protected <T extends Enum<T>> Struct.Enum64<T>[]	array(Struct.Enum64<T>[] array, Class<T> enumClass)	Creates an array of Enum64 instances.
protected <T extends Enum<T>> Struct.Enum8<T>[]	array(Struct.Enum8<T>[] array, Class<T> enumClass)	Creates an array of Enum8 instances.
protected Struct.Float[]	array(Struct.Float[] array)	Creates an array of Float instances.
protected Struct.Pointer[]	array(Struct.Pointer[] array)	Creates an array of Pointer instances.
protected Struct.Signed16[]	array(Struct.Signed16[] array)	Creates an array of Signed16 instances.
protected Struct.Signed32[]	array(Struct.Signed32[] array)	Creates an array of Signed32 instances.
protected Struct.Signed64[]	array(Struct.Signed64[] array)	Creates an array of Signed64 instances.
protected Struct.Signed8[]	array(Struct.Signed8[] array)	Creates an array of Signed8 instances.
protected Struct.SignedLong[]	array(Struct.SignedLong[] array)	Creates an array of SignedLong instances.
protected Struct.Unsigned16[]	array(Struct.Unsigned16[] array)	Creates an array of Unsigned16 instances.
protected Struct.Unsigned32[]	array(Struct.Unsigned32[] array)	Creates an array of Unsigned32 instances.
protected Struct.Unsigned64[]	array(Struct.Unsigned64[] array)	Creates an array of Unsigned64 instances.
protected Struct.Unsigned8[]	array(Struct.Unsigned8[] array)	Creates an array of Unsigned8 instances.
protected Struct.UnsignedLong[]	array(Struct.UnsignedLong[] array)	Creates an array of UnsignedLong instances.
protected Struct.UTF8String[]	array(Struct.UTF8String[] array, int stringLength)	Creates an array of UTF8String instances.
protected <T extends Struct.Member> T[]	array(T[] array)	Creates an array of Member instances.
protected void	arrayBegin()	Starts an array construction session
protected void	arrayEnd()	Ends an array construction session
static <T extends Struct> T[]	arrayOf(Runtime runtime, Class<T> type, int length)
protected <T> Struct.Function<T>	function(Class<T> closureClass)
static Pointer	getMemory(Struct struct)
static Pointer	getMemory(Struct struct, int flags)
Runtime	getRuntime()
protected <T extends Struct> T	inner(Class<T> structClass)	Creates inner Structs in Struct definitions.
protected <T extends Struct> T	inner(T struct)	Creates inner Structs in Struct definitions.
static boolean	isDirect(Struct struct)
static <T extends Struct> int	size(Class<T> structClass)	Gets the size of a Struct type in bytes
static <T extends Struct> int	size(Class<T> structClass, Runtime runtime)	Gets the size of a Struct type in bytes
static int	size(Struct struct)	Gets the size of a Struct instance in bytes
String	toString()	Returns a human readable String representation of the structure.
void	useMemory(Pointer address)	Uses the specified memory address as the backing store for this structure.

Methods inherited from class java.lang.Object

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

Constructor Detail

Struct

protected Struct(Runtime runtime)

Creates a new Struct.

Parameters:

runtime - The current runtime.

Struct

protected Struct(Runtime runtime,
                 Struct.Alignment alignment)

Struct

protected Struct(Runtime runtime,
                 Struct enclosing)

Struct

protected Struct(Runtime runtime,
                 boolean isUnion)

Creates a new Struct.

Parameters:

runtime - the current jnr-ffi runtime

isUnion - if this Struct is a Union

Method Detail

getRuntime

public final Runtime getRuntime()

useMemory

public final void useMemory(Pointer address)

Uses the specified memory address as the backing store for this structure.

Parameters:

address - the native memory area.

getMemory

public static Pointer getMemory(Struct struct)

getMemory

public static Pointer getMemory(Struct struct,
                                int flags)

size

public static int size(Struct struct)

Gets the size of a Struct instance in bytes

Parameters:

struct - the Struct instance

Returns:

the size of the Struct in bytes

size

public static <T extends Struct> int size(Class<T> structClass,
                                          Runtime runtime)

Gets the size of a Struct type in bytes

Type Parameters:

T - the Struct type

Parameters:

structClass - the Class of the Struct

runtime - the Runtime that will be used to create an instance of the Struct

Returns:

the size of the Struct in bytes

size

public static <T extends Struct> int size(Class<T> structClass)

Gets the size of a Struct type in bytes

Type Parameters:

T - the Struct type

Parameters:

structClass - the Class of the Struct

Returns:

the size of the Struct in bytes

alignment

public static int alignment(Struct struct)

isDirect

public static boolean isDirect(Struct struct)

arrayOf

public static <T extends Struct> T[] arrayOf(Runtime runtime,
                                             Class<T> type,
                                             int length)

toString

public String toString()

Returns a human readable String representation of the structure.

Overrides:

toString in class Object

Returns:

a String representation of this structure.

arrayBegin

protected final void arrayBegin()

Starts an array construction session

arrayEnd

protected final void arrayEnd()

Ends an array construction session

array

protected <T extends Struct.Member> T[] array(T[] array)

Creates an array of Member instances.

Type Parameters:

T - The type of the Member subclass to create.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected <T extends Enum<T>> Struct.Enum8<T>[] array(Struct.Enum8<T>[] array,
                                                      Class<T> enumClass)

Creates an array of Enum8 instances.

Type Parameters:

T - The type of the java.lang.Enum

Parameters:

array - the array to store the instances in

enumClass - class of java.lang.Enum, these Enum8 instances will represent

Returns:

the array that was passed in

array

protected <T extends Enum<T>> Struct.Enum16<T>[] array(Struct.Enum16<T>[] array,
                                                       Class<T> enumClass)

Creates an array of Enum16 instances.

Type Parameters:

T - The type of the java.lang.Enum

Parameters:

array - the array to store the instances in

enumClass - class of java.lang.Enum, these Enum16 instances will represent

Returns:

the array that was passed in

array

protected <T extends Enum<T>> Struct.Enum32<T>[] array(Struct.Enum32<T>[] array,
                                                       Class<T> enumClass)

Creates an array of Enum32 instances.

Type Parameters:

T - The type of the java.lang.Enum

Parameters:

array - the array to store the instances in

enumClass - class of java.lang.Enum, these Enum32 instances will represent

Returns:

the array that was passed in

array

protected <T extends Enum<T>> Struct.Enum64<T>[] array(Struct.Enum64<T>[] array,
                                                       Class<T> enumClass)

Creates an array of Enum64 instances.

Type Parameters:

T - The type of the java.lang.Enum

Parameters:

array - the array to store the instances in

enumClass - class of java.lang.Enum, these Enum64 instances will represent

Returns:

the array that was passed in

array

protected <T extends Enum<T>> Struct.Enum<T>[] array(Struct.Enum<T>[] array,
                                                     Class<T> enumClass)

Creates an array of Enum instances.

Type Parameters:

T - The type of the java.lang.Enum

Parameters:

array - the array to store the instances in

enumClass - class of java.lang.Enum, these Enum instances will represent

Returns:

the array that was passed in

array

protected <T extends Struct> T[] array(T[] array)

Creates an array of Struct instances.

Type Parameters:

T - the type of Struct

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Signed8[] array(Struct.Signed8[] array)

Creates an array of Signed8 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Unsigned8[] array(Struct.Unsigned8[] array)

Creates an array of Unsigned8 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Signed16[] array(Struct.Signed16[] array)

Creates an array of Signed16 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Unsigned16[] array(Struct.Unsigned16[] array)

Creates an array of Unsigned16 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Signed32[] array(Struct.Signed32[] array)

Creates an array of Signed32 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Unsigned32[] array(Struct.Unsigned32[] array)

Creates an array of Unsigned32 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Signed64[] array(Struct.Signed64[] array)

Creates an array of Signed64 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Unsigned64[] array(Struct.Unsigned64[] array)

Creates an array of Unsigned64 instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.SignedLong[] array(Struct.SignedLong[] array)

Creates an array of SignedLong instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.UnsignedLong[] array(Struct.UnsignedLong[] array)

Creates an array of UnsignedLong instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Float[] array(Struct.Float[] array)

Creates an array of Float instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Double[] array(Struct.Double[] array)

Creates an array of Double instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Address[] array(Struct.Address[] array)

Creates an array of Address instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected final Struct.Pointer[] array(Struct.Pointer[] array)

Creates an array of Pointer instances.

Parameters:

array - the array to store the instances in

Returns:

the array that was passed in

array

protected Struct.UTF8String[] array(Struct.UTF8String[] array,
                                    int stringLength)

Creates an array of UTF8String instances.

Parameters:

array - the array to store the instances in

stringLength - length of each string in array

Returns:

the array that was passed in

inner

protected final <T extends Struct> T inner(T struct)

Creates inner Structs in Struct definitions. Example:

     public class InnerStruct extends Struct {
         public final Signed32 innerInt32 = new Signed32();
         public final Double innerDouble = new Double();

         public InnerStruct(Runtime runtime) {super(runtime);}
     }

     public class MyStruct extends Struct {
         public final Signed32 myInt32 = new Signed32();
         public final InnerStruct myInnerStruct = inner(new InnerStruct());

         public MyStruct(Runtime runtime) {super(runtime);}
     }

Type Parameters:

T - the type of the inner Struct

Parameters:

struct - an instance of the inner Struct

Returns:

the instance of the inner Struct of type Struct

inner

protected final <T extends Struct> T inner(Class<T> structClass)

Creates inner Structs in Struct definitions. Example:

     public class InnerStruct extends Struct {
         public final Signed32 innerInt32 = new Signed32();
         public final Double innerDouble = new Double();

         public InnerStruct(Runtime runtime) {super(runtime);}
     }

     public class MyStruct extends Struct {
         public final Signed32 myInt32 = new Signed32();
         public final InnerStruct myInnerStruct = inner(InnerStruct.class);

         public MyStruct(Runtime runtime) {super(runtime);}
     }

Type Parameters:

T - the type of the inner Struct

Parameters:

structClass - the Class of the inner Struct

Returns:

the newly created inner Struct of type Struct

function

protected final <T> Struct.Function<T> function(Class<T> closureClass)