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JNA API 3.2.7

com.sun.jna
Class Memory

java.lang.Object
  
extended by com.sun.jna.Pointer extended by com.sun.jna.Memory
Direct Known Subclasses:
StringArray

public class Memory
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.


share

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.

share

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)
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 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)
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 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)
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 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)
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 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)
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 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)
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 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)
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 - 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)
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 - 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)
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 - 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)
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 - 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)
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 - 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)
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 - 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)
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:
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

JNA API 3.2.7

Copyright © 2007-2010 Timothy Wall. All Rights Reserved.
 
 
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