Top Description Fields Constructors Methods
jnr.ffi.byref

public final Class NativeLongByReference

extends AbstractNumberReference<NativeLong>
Class Inheritance
Imports
jnr.ffi.NativeLong, .Pointer, .Runtime
NativeLongByReference is used when the address of a primitive C long must be passed as a parameter to a function.

For example, the following C code, 

extern void get_a(long * ap);

long foo(void) {
    long a;
    // pass a reference to 'a' so get_a() can fill it out
    get_a(&a);

    return a;
}

Would be declared in java as 

interface Lib {
    void get_a(@Out NativeLongByReference ap);
}

and used like this 

NativeLongByReference ap = new NativeLongByReference();
lib.get_a(ap);
System.out.printf("a from lib=%d\n", a.longValue());

Field Summary

Inherited from jnr.ffi.byref.AbstractNumberReference:
value

Constructor Summary

AccessConstructor and Description
public
NativeLongByReference()

Creates a new reference to a native long value initialized to zero.

public
NativeLongByReference(NativeLong
the initial native value
value)

Creates a new reference to a native long value

public
NativeLongByReference(long
the initial native value
value)

Creates a new reference to a native long value

Method Summary

Modifier and TypeMethod and Description
public void
fromNative(Runtime
the current runtime.
runtime, Pointer
the native memory buffer.
memory, long
the memory offset.
offset)

Implements jnr.ffi.byref.ByReference.fromNative.

Copies the long value from native memory
public final int

Returns:

the size of a byte in bytes
nativeSize(Runtime
the current runtime.
runtime)

Implements jnr.ffi.byref.ByReference.nativeSize.

Gets the native size of type of reference in bytes.
public void
toNative(Runtime
the current runtime.
runtime, Pointer
the native memory buffer.
memory, long
the memory offset.
offset)

Implements jnr.ffi.byref.ByReference.toNative.

Copies the long value to native memory
Inherited from jnr.ffi.byref.AbstractNumberReference:
byteValuecheckNulldoubleValuefloatValuegetValueintValuelongValueshortValue

Constructor Detail

NativeLongByReferenceback to summary
public NativeLongByReference()

Creates a new reference to a native long value initialized to zero.

NativeLongByReferenceback to summary
public NativeLongByReference(NativeLong value)

Creates a new reference to a native long value

Parameters
value:NativeLong

the initial native value

NativeLongByReferenceback to summary
public NativeLongByReference(long value)

Creates a new reference to a native long value

Parameters
value:long

the initial native value

Method Detail

fromNativeback to summary
public void fromNative(Runtime runtime, Pointer memory, long offset)

Implements jnr.ffi.byref.ByReference.fromNative.

Copies the long value from native memory

Parameters
runtime:Runtime

the current runtime.

memory:Pointer

the native memory buffer.

offset:long

the memory offset.

nativeSizeback to summary
public final int nativeSize(Runtime runtime)

Implements jnr.ffi.byref.ByReference.nativeSize.

Gets the native size of type of reference in bytes.

Parameters
runtime:Runtime

the current runtime.

Returns:int

the size of a byte in bytes

toNativeback to summary
public void toNative(Runtime runtime, Pointer memory, long offset)

Implements jnr.ffi.byref.ByReference.toNative.

Copies the long value to native memory

Parameters
runtime:Runtime

the current runtime.

memory:Pointer

the native memory buffer.

offset:long

the memory offset.