Memory (JNA API)

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JNA API 3.2.7

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com.sun.jna
Class Memory

java.lang.Object
  com.sun.jna.Pointer
      com.sun.jna.Memory

Direct Known Subclasses:: StringArray

public class Memory
extends Pointer
extends Pointer

A Pointer to memory obtained from the native heap via a call to malloc.

In some cases it might be necessary to use memory obtained from malloc. For example, Memory helps accomplish the following idiom:

                void *buf = malloc(BUF_LEN * sizeof(char));
                call_some_function(buf);
                free(buf);

The finalize() method will free allocated memory when this object is no longer referenced.

Author:: Sheng Liang, originator, Todd Fast, suitability modifications, Timothy Wall
See Also:: Pointer

Field Summary
`protected long`	`size`

Fields inherited from class com.sun.jna.Pointer
`NULL, peer, SIZE`

Constructor Summary
`protected`	`Memory()`
	`Memory(long size)` Allocate space in the native heap via a call to C's `malloc`.

Method Summary
`Memory`	`align(int byteBoundary)` Provide a view onto this structure with the given alignment.
`protected void`	`boundsCheck(long off, long sz)` Check that indirection won't cause us to write outside the malloc'ed space.
`void`	`clear()` Zero the full extent of this memory region.
`protected void`	`finalize()`
`protected static void`	`free(long ptr)` Call the real native free
`byte`	`getByte(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getByte`.
`ByteBuffer`	`getByteBuffer(long offset, long length)` Get a ByteBuffer mapped to a portion of this memory.
`char`	`getChar(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getByte`.
`double`	`getDouble(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getDouble`.
`float`	`getFloat(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getFloat`.
`int`	`getInt(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getInt`.
`long`	`getLong(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getLong`.
`Pointer`	`getPointer(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getPointer`.
`short`	`getShort(long offset)` Indirect the native pointer to `malloc` space, a la `Pointer.getShort`.
`long`	`getSize()` Deprecated. use `size()` instead.
`String`	`getString(long offset, boolean wide)` Indirect the native pointer to `malloc` space, a la `Pointer.getString`.
`boolean`	`isValid()` Deprecated. use `valid()` instead.
`protected static long`	`malloc(long size)` Call the real native malloc
`static void`	`purge()` Force cleanup of memory that has associated NIO Buffers which have been GC'd.
`void`	`read(long bOff, byte[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`read(long bOff, char[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`read(long bOff, double[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`read(long bOff, float[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`read(long bOff, int[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`read(long bOff, long[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`read(long bOff, short[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.read`.
`void`	`setByte(long offset, byte value)` Indirect the native pointer to `malloc` space, a la `Pointer.setByte`.
`void`	`setChar(long offset, char value)` Indirect the native pointer to `malloc` space, a la `Pointer.setChar`.
`void`	`setDouble(long offset, double value)` Indirect the native pointer to `malloc` space, a la `Pointer.setDouble`.
`void`	`setFloat(long offset, float value)` Indirect the native pointer to `malloc` space, a la `Pointer.setFloat`.
`void`	`setInt(long offset, int value)` Indirect the native pointer to `malloc` space, a la `Pointer.setInt`.
`void`	`setLong(long offset, long value)` Indirect the native pointer to `malloc` space, a la `Pointer.setLong`.
`void`	`setPointer(long offset, Pointer value)` Indirect the native pointer to `malloc` space, a la `Pointer.setPointer`.
`void`	`setShort(long offset, short value)` Indirect the native pointer to `malloc` space, a la `Pointer.setShort`.
`void`	`setString(long offset, String value, boolean wide)` Indirect the native pointer to `malloc` space, a la `Pointer.setString`.
`Pointer`	`share(long offset)` Provide a view onto this structure from the given offset.
`Pointer`	`share(long offset, long sz)` Provide a view onto this structure from the given offset.
`long`	`size()`
`String`	`toString()`
`boolean`	`valid()` Returns false if the memory has been freed.
`void`	`write(long bOff, byte[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.
`void`	`write(long bOff, char[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.
`void`	`write(long bOff, double[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.
`void`	`write(long bOff, float[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.
`void`	`write(long bOff, int[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.
`void`	`write(long bOff, long[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.
`void`	`write(long bOff, short[] buf, int index, int length)` Indirect the native pointer to `malloc` space, a la `Pointer.write`.

Methods inherited from class com.sun.jna.Pointer
`_setMemory, clear, createConstant, createConstant, equals, getByteArray, getCharArray, getDoubleArray, getFloatArray, getIntArray, getLongArray, getNativeLong, getPointerArray, getPointerArray, getShortArray, getString, getStringArray, getStringArray, getStringArray, getStringArray, getValue, hashCode, indexOf, nativeValue, nativeValue, read, setMemory, setNativeLong, setString, setValue, write`

Methods inherited from class java.lang.Object
`clone, getClass, notify, notifyAll, wait, wait, wait`

Field Detail

size

protected long size

Constructor Detail

Memory

public Memory(long size)

Allocate space in the native heap via a call to C's malloc.

Parameters:: size - number of bytes of space to allocate

Memory

protected Memory()

Method Detail

purge

public static void purge()

Force cleanup of memory that has associated NIO Buffers which have been GC'd.

public Pointer share(long offset)

Provide a view onto this structure from the given offset. The returned Pointer will have the same size as the original, reduced by the offset.

Overrides:: share in class Pointer

Throws:: IndexOutOfBoundsException - if the requested memory is outside the allocated bounds.

public Pointer share(long offset,
                     long sz)

Provide a view onto this structure from the given offset.

Overrides:: share in class Pointer

Throws:: IndexOutOfBoundsException - if the requested memory is outside the allocated bounds.

align

public Memory align(int byteBoundary)

Provide a view onto this structure with the given alignment.

Parameters:: byteBoundary - Align memory to this number of bytes; should be a power of two.
Throws:: IndexOutOfBoundsException - if the requested alignment can not be met.; IllegalArgumentException - if the requested alignment is not a positive power of two.

finalize

protected void finalize()

Overrides:: finalize in class Object

clear

public void clear()

Zero the full extent of this memory region.

isValid

public boolean isValid()

Deprecated. use valid() instead.

valid

public boolean valid()

Returns false if the memory has been freed.

size

public long size()

getSize

public long getSize()

Deprecated. use size() instead.

boundsCheck

protected void boundsCheck(long off,
                           long sz)

Check that indirection won't cause us to write outside the malloc'ed space.

read

public void read(long bOff,
                 byte[] buf,
                 int index,
                 int length)

Indirect the native pointer to malloc space, a la Pointer.read. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - byte array into which data is copied; index - array index from which to start copying; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,byte[],int,int)

read

public void read(long bOff,
                 short[] buf,
                 int index,
                 int length)

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer from which data is copied; buf - short array into which data is copied; index - array index to which data is copied; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,short[],int,int)

read

public void read(long bOff,
                 char[] buf,
                 int index,
                 int length)

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer from which data is copied; buf - char array into which data is copied; index - array index to which data is copied; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,char[],int,int)

read

public void read(long bOff,
                 int[] buf,
                 int index,
                 int length)

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer from which data is copied; buf - int array into which data is copied; index - array index to which data is copied; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,int[],int,int)

read

public void read(long bOff,
                 long[] buf,
                 int index,
                 int length)

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer from which data is copied; buf - long array into which data is copied; index - array index to which data is copied; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,long[],int,int)

read

public void read(long bOff,
                 float[] buf,
                 int index,
                 int length)

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer from which data is copied; buf - float array into which data is copied; index - array index to which data is copied; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,float[],int,int)

read

public void read(long bOff,
                 double[] buf,
                 int index,
                 int length)

Overrides:: read in class Pointer

Parameters:: bOff - byte offset from pointer from which data is copied; buf - double array into which data is copied; index - array index to which data is copied; length - number of elements from native pointer that must be copied
See Also:: Pointer.read(long,double[],int,int)

write

public void write(long bOff,
                  byte[] buf,
                  int index,
                  int length)

Indirect the native pointer to malloc space, a la Pointer.write. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - byte array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,byte[],int,int)

write

public void write(long bOff,
                  short[] buf,
                  int index,
                  int length)

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - short array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,short[],int,int)

write

public void write(long bOff,
                  char[] buf,
                  int index,
                  int length)

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - char array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,char[],int,int)

write

public void write(long bOff,
                  int[] buf,
                  int index,
                  int length)

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - int array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,int[],int,int)

write

public void write(long bOff,
                  long[] buf,
                  int index,
                  int length)

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - long array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,long[],int,int)

write

public void write(long bOff,
                  float[] buf,
                  int index,
                  int length)

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - float array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,float[],int,int)

write

public void write(long bOff,
                  double[] buf,
                  int index,
                  int length)

Overrides:: write in class Pointer

Parameters:: bOff - byte offset from pointer into which data is copied; buf - double array from which to copy; index - array index from which to start copying; length - number of elements from buf that must be copied
See Also:: Pointer.write(long,double[],int,int)

getByte

public byte getByte(long offset)

Indirect the native pointer to malloc space, a la Pointer.getByte. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getByte in class Pointer

Parameters:: offset - offset from pointer to perform the indirection
Returns:: the byte value being pointed to
See Also:: Pointer.getByte(long)

getChar

public char getChar(long offset)

Overrides:: getChar in class Pointer

Parameters:: offset - offset from pointer to perform the indirection
Returns:: the wchar_t value being pointed to
See Also:: Pointer.getByte(long)

getShort

public short getShort(long offset)

Indirect the native pointer to malloc space, a la Pointer.getShort. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getShort in class Pointer

Parameters:: offset - byte offset from pointer to perform the indirection
Returns:: the short value being pointed to
See Also:: Pointer.getShort(long)

getInt

public int getInt(long offset)

Indirect the native pointer to malloc space, a la Pointer.getInt. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getInt in class Pointer

Parameters:: offset - byte offset from pointer to perform the indirection
Returns:: the int value being pointed to
See Also:: Pointer.getInt(long)

getLong

public long getLong(long offset)

Indirect the native pointer to malloc space, a la Pointer.getLong. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getLong in class Pointer

Parameters:: offset - byte offset from pointer to perform the indirection
Returns:: the long value being pointed to
See Also:: Pointer.getLong(long)

getFloat

public float getFloat(long offset)

Indirect the native pointer to malloc space, a la Pointer.getFloat. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getFloat in class Pointer

Parameters:: offset - byte offset from pointer to perform the indirection
Returns:: the float value being pointed to
See Also:: Pointer.getFloat(long)

getDouble

public double getDouble(long offset)

Indirect the native pointer to malloc space, a la Pointer.getDouble. But this method performs a bounds check to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getDouble in class Pointer

Parameters:: offset - byte offset from pointer to perform the indirection
Returns:: the double value being pointed to
See Also:: Pointer.getDouble(long)

getPointer

public Pointer getPointer(long offset)

Indirect the native pointer to malloc space, a la Pointer.getPointer. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getPointer in class Pointer

Parameters:: offset - byte offset from pointer to perform the indirection
Returns:: a Pointer equivalent of the pointer value being pointed to, or null if the pointer value is NULL;
See Also:: Pointer.getPointer(long)

getByteBuffer

public ByteBuffer getByteBuffer(long offset,
                                long length)

Get a ByteBuffer mapped to a portion of this memory.

Overrides:: getByteBuffer in class Pointer

Parameters:: offset - byte offset from pointer to start the buffer; length - Length of ByteBuffer
Returns:: a direct ByteBuffer that accesses the memory being pointed to,

getString

public String getString(long offset,
                        boolean wide)

Indirect the native pointer to malloc space, a la Pointer.getString. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: getString in class Pointer

Parameters:: offset - byte offset from pointer to obtain the native string v * @param wide whether to convert from a wide or standard C string
Returns:: the String value being pointed to
See Also:: Pointer.getString(long, boolean)

setByte

public void setByte(long offset,
                    byte value)

Indirect the native pointer to malloc space, a la Pointer.setByte. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setByte in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - byte value to set
See Also:: Pointer.setByte(long, byte)

setChar

public void setChar(long offset,
                    char value)

Indirect the native pointer to malloc space, a la Pointer.setChar. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setChar in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - char value to set
See Also:: Pointer.setChar(long, char)

setShort

public void setShort(long offset,
                     short value)

Indirect the native pointer to malloc space, a la Pointer.setShort. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setShort in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - short value to set
See Also:: Pointer.setShort(long, short)

setInt

public void setInt(long offset,
                   int value)

Indirect the native pointer to malloc space, a la Pointer.setInt. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setInt in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - int value to set
See Also:: Pointer.setInt(long, int)

setLong

public void setLong(long offset,
                    long value)

Indirect the native pointer to malloc space, a la Pointer.setLong. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setLong in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - long value to set
See Also:: Pointer.setLong(long, long)

setFloat

public void setFloat(long offset,
                     float value)

Indirect the native pointer to malloc space, a la Pointer.setFloat. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setFloat in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - float value to set
See Also:: Pointer.setFloat(long, float)

setDouble

public void setDouble(long offset,
                      double value)

Indirect the native pointer to malloc space, a la Pointer.setDouble. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setDouble in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - double value to set
See Also:: Pointer.setDouble(long, double)

setPointer

public void setPointer(long offset,
                       Pointer value)

Indirect the native pointer to malloc space, a la Pointer.setPointer. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setPointer in class Pointer

Parameters:: offset - byte offset from pointer at which value must be set; value - Pointer holding the actual pointer value to set, which may be null to indicate a NULL pointer.
See Also:: Pointer.setPointer(long, com.sun.jna.Pointer)

setString

public void setString(long offset,
                      String value,
                      boolean wide)

Indirect the native pointer to malloc space, a la Pointer.setString. But this method performs a bounds checks to ensure that the indirection does not cause memory outside the malloced space to be accessed.

Overrides:: setString in class Pointer

Parameters:: offset - byte offset from pointer at which characters in value must be set; value - java.lang.String value to set; wide - whether to write the native string as an array of wchar_t. If false, writes as a NUL-terminated array of char using the default platform encoding.
See Also:: Pointer.setString(long,String,boolean)

malloc

protected static long malloc(long size)

Call the real native malloc

free

protected static void free(long ptr)

Call the real native free

toString

public String toString()

Overrides:: toString in class Pointer

Overview

Package

Class

Tree

Deprecated

Index

Help

JNA API 3.2.7

PREV CLASS NEXT CLASS

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SUMMARY: NESTED | FIELD | CONSTR | METHOD

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com.sun.jna Class Memory

size

Memory

Memory

purge

share

share

align

finalize

clear

isValid

valid

size

getSize

boundsCheck

read

read

read

read

read

read

read

write

write

write

write

write

write

write

getByte

getChar

getShort

getInt

getLong

getFloat

getDouble

getPointer

getByteBuffer

getString

setByte

setChar

setShort

setInt

setLong

setFloat

setDouble

setPointer

setString

malloc

free

toString

com.sun.jna
Class Memory