com.yahoo.memory

Class MemoryRegion

java.lang.Object

com.yahoo.memory.MemoryRegion

All Implemented Interfaces:

Memory

public class MemoryRegion
extends Object
implements Memory

The MemoryRegion class implements the Memory interface and provides a means of hierarchically partitioning a large block of native memory into smaller regions of memory, each with their own capacity and offsets. MemoryRegion is immutable.

If asserts are enabled in the JVM, the methods in this class perform bounds checking against the region's defined boundaries and then redirect the call to the parent Memory class. If the parent class is also a MemoryRegion it does a similar check and then calls its parent. The root of this hierarchy will be a NativeMemory class that ultimately performs the desired task. If asserts are not enabled the JIT compiler will eliminate all the asserts and the hierarchical calls should collapse to a call to the NativeMemory method.

Because asserts must be specifically enabled in the JVM, it is incumbent on the user of this class to make sure that their code is thoroughly tested. Violating memory bounds can cause memory segment faults, which takes down the JVM and can be very difficult to debug.

Author:

Lee Rhodes

See Also:

NativeMemory

Constructor Summary

Constructors

Constructor and Description
MemoryRegion(Memory memory, long memOffsetBytes, long capacityBytes) Defines a region of the given parent Memory by defining an offset and capacity that are within the boundaries of the parent.
MemoryRegion(Memory memory, long memOffsetBytes, long capacityBytes, MemoryRequest memReq) Defines a region of the given parent Memory by defining an offset and capacity that are within the boundaries of the parent.

Method Summary

Modifier and Type	Method and Description
int	addAndGetInt(long offsetBytes, int delta) Atomically adds the given value to the integer located at offsetBytes.
long	addAndGetLong(long offsetBytes, long delta) Atomically adds the given value to the long located at offsetBytes.
Object	array() Returns the backing on-heap primitive array if there is one, otherwise returns null
MemoryRegion	asReadOnlyMemory() Returns a read-only version of this memory
ByteBuffer	byteBuffer() Returns the backing ByteBuffer if there is one, otherwise returns null
void	clear() Clears all bytes of this Memory to zero
void	clear(long offsetBytes, long lengthBytes) Clears a portion of this Memory to zero.
void	clearBits(long offsetBytes, byte bitMask) Clears the bits defined by the bitMask
boolean	compareAndSwapInt(long offsetBytes, int expect, int update) Atomically sets the current value at the memory location to the given updated value if and only if the current value == the expected value.
boolean	compareAndSwapLong(long offsetBytes, long expect, long update) Atomically sets the current value at the memory location to the given updated value if and only if the current value == the expected value.
void	copy(long srcOffsetBytes, long dstOffsetBytes, long lengthBytes) Deprecated.
void	copy(long srcOffsetBytes, Memory destination, long dstOffsetBytes, long lengthBytes) Copies bytes from a source range of this Memory to a destination range of the given Memory using the same low-level system copy function as found in System.arraycopy(Object, int, Object, int, int).
void	fill(byte value) Fills all bytes of this Memory region to the given byte value.
void	fill(long offsetBytes, long lengthBytes, byte value) Fills a portion of this Memory region to the given byte value.
void	freeMemory() Because the Memory classes now use the JVM Cleaner, calling freeMemory(), which also calls Cleaner, is optional.
long	getAddress(long offsetBytes) Returns the start address of this Memory relative to its parent plus the offset in bytes.
int	getAndSetInt(long offsetBytes, int newValue) Atomically exchanges the given value with the current value located at offsetBytes.
long	getAndSetLong(long offsetBytes, long newValue) Atomically exchanges the given value with the current value located at offsetBytes.
boolean	getBoolean(long offsetBytes) Gets the boolean value at the given offset
void	getBooleanArray(long offsetBytes, boolean[] dstArray, int dstOffset, int length) Gets the boolean array at the given offset
byte	getByte(long offsetBytes) Gets the byte at the given offset
void	getByteArray(long offsetBytes, byte[] dstArray, int dstOffset, int length) Gets the byte array at the given offset
long	getCapacity() Gets the capacity of this Memory in bytes
char	getChar(long offsetBytes) Gets the char at the given offset
void	getCharArray(long offsetBytes, char[] dstArray, int dstOffset, int length) Gets the char array at the given offset
long	getCumulativeOffset(long offsetBytes) Returns the cumulative offset in bytes of this Memory from the root of the Memory hierarchy including the given offsetBytes.
double	getDouble(long offsetBytes) Gets the double at the given offset
void	getDoubleArray(long offsetBytes, double[] dstArray, int dstOffset, int length) Gets the double array at the given offset
float	getFloat(long offsetBytes) Gets the float at the given offset
void	getFloatArray(long offsetBytes, float[] dstArray, int dstOffset, int length) Gets the float array at the given offset
int	getInt(long offsetBytes) Gets the int at the given offset
void	getIntArray(long offsetBytes, int[] dstArray, int dstOffset, int length) Gets the int array at the given offset
long	getLong(long offsetBytes) Gets the long at the given offset
void	getLongArray(long offsetBytes, long[] dstArray, int dstOffset, int length) Gets the long array at the given offset
MemoryRequest	getMemoryRequest() Returns a MemoryRequest or null
Object	getParent() Gets the parent Memory or backing array.
short	getShort(long offsetBytes) Gets the short at the given offset
void	getShortArray(long offsetBytes, short[] dstArray, int dstOffset, int length) Gets the short array at the given offset
boolean	hasArray() Returns true if this Memory is backed by an on-heap primitive array
boolean	hasByteBuffer() Returns true if this Memory is backed by a ByteBuffer
boolean	isAllBitsClear(long offsetBytes, byte bitMask) Returns true if all bits defined by the bitMask are clear
boolean	isAllBitsSet(long offsetBytes, byte bitMask) Returns true if all bits defined by the bitMask are set
boolean	isAllocated() Returns true if this Memory has a capacity greater than zero
boolean	isAnyBitsClear(long offsetBytes, byte bitMask) Returns true if any bits defined by the bitMask are clear
boolean	isAnyBitsSet(long offsetBytes, byte bitMask) Returns true if any bits defined by the bitMask are set
boolean	isDirect() Returns true if the backing memory is direct (off-heap) memory.
boolean	isReadOnly() Returns true if this Memory is read only
void	putBoolean(long offsetBytes, boolean srcValue) Puts the boolean value at the given offset
void	putBooleanArray(long offsetBytes, boolean[] srcArray, int srcOffset, int length) Puts the boolean array at the given offset
void	putByte(long offsetBytes, byte srcValue) Puts the byte value at the given offset
void	putByteArray(long offsetBytes, byte[] srcArray, int srcOffset, int length) Puts the byte array at the given offset
void	putChar(long offsetBytes, char srcValue) Puts the char value at the given offset
void	putCharArray(long offsetBytes, char[] srcArray, int srcOffset, int length) Puts the char array at the given offset
void	putDouble(long offsetBytes, double srcValue) Puts the double value at the given offset
void	putDoubleArray(long offsetBytes, double[] srcArray, int srcOffset, int length) Puts the double array at the given offset
void	putFloat(long offsetBytes, float srcValue) Puts the float value at the given offset
void	putFloatArray(long offsetBytes, float[] srcArray, int srcOffset, int length) Puts the float array at the given offset
void	putInt(long offsetBytes, int srcValue) Puts the int value at the given offset
void	putIntArray(long offsetBytes, int[] srcArray, int srcOffset, int length) Puts the int array at the given offset
void	putLong(long offsetBytes, long srcValue) Puts the long value at the given offset
void	putLongArray(long offsetBytes, long[] srcArray, int srcOffset, int length) Puts the long array at the given offset
void	putShort(long offsetBytes, short srcValue) Puts the short value at the given offset
void	putShortArray(long offsetBytes, short[] srcArray, int srcOffset, int length) Puts the short array at the given offset
void	reassign(long memOffsetBytes, long capacityBytes) Deprecated. This could have created difficult to diagnose bugs in MemoryRegion hierarchies. This is now deprecated and will throw an exception. MemoryRegion is now immutable.
void	setBits(long offsetBytes, byte bitMask) Sets the bits defined by the bitMask
void	setMemoryRequest(MemoryRequest memReq) Sets a MemoryRequest
String	toHexString(String header, long offsetBytes, int lengthBytes) Returns a formatted hex string of an area of this Memory.

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryRegion

public MemoryRegion(Memory memory,
                    long memOffsetBytes,
                    long capacityBytes)

Defines a region of the given parent Memory by defining an offset and capacity that are within the boundaries of the parent.

Parameters:

memory - the parent Memory

memOffsetBytes - the starting offset in bytes of this region with respect to the start of the parent memory.

capacityBytes - the capacity in bytes of this region.

MemoryRegion

public MemoryRegion(Memory memory,
                    long memOffsetBytes,
                    long capacityBytes,
                    MemoryRequest memReq)

Defines a region of the given parent Memory by defining an offset and capacity that are within the boundaries of the parent.

Parameters:

memory - the parent Memory

memOffsetBytes - the starting offset in bytes of this region with respect to the start of the parent memory.

capacityBytes - the capacity in bytes of this region.

memReq - a MemoryRequest object

Method Detail

reassign

@Deprecated
public void reassign(long memOffsetBytes,
                                 long capacityBytes)

Deprecated. This could have created difficult to diagnose bugs in MemoryRegion hierarchies. This is now deprecated and will throw an exception. MemoryRegion is now immutable.

Reassign the offset and capacity of this MemoryRegion. This is now deprecated and will throw an exception. MemoryRegion is now immutable.

Parameters:

memOffsetBytes - the given offset from the parent's start

capacityBytes - the given capacity of this region

getBoolean

public boolean getBoolean(long offsetBytes)

Description copied from interface: Memory

Gets the boolean value at the given offset

Specified by:

getBoolean in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the boolean at the given offset

getBooleanArray

public void getBooleanArray(long offsetBytes,
                            boolean[] dstArray,
                            int dstOffset,
                            int length)

Description copied from interface: Memory

Gets the boolean array at the given offset

Specified by:

getBooleanArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getByte

public byte getByte(long offsetBytes)

Description copied from interface: Memory

Gets the byte at the given offset

Specified by:

getByte in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the byte at the given offset

getByteArray

public void getByteArray(long offsetBytes,
                         byte[] dstArray,
                         int dstOffset,
                         int length)

Description copied from interface: Memory

Gets the byte array at the given offset

Specified by:

getByteArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getChar

public char getChar(long offsetBytes)

Description copied from interface: Memory

Gets the char at the given offset

Specified by:

getChar in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the char at the given offset

getCharArray

public void getCharArray(long offsetBytes,
                         char[] dstArray,
                         int dstOffset,
                         int length)

Description copied from interface: Memory

Gets the char array at the given offset

Specified by:

getCharArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getDouble

public double getDouble(long offsetBytes)

Description copied from interface: Memory

Gets the double at the given offset

Specified by:

getDouble in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the double at the given offset

getDoubleArray

public void getDoubleArray(long offsetBytes,
                           double[] dstArray,
                           int dstOffset,
                           int length)

Description copied from interface: Memory

Gets the double array at the given offset

Specified by:

getDoubleArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getFloat

public float getFloat(long offsetBytes)

Description copied from interface: Memory

Gets the float at the given offset

Specified by:

getFloat in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the float at the given offset

getFloatArray

public void getFloatArray(long offsetBytes,
                          float[] dstArray,
                          int dstOffset,
                          int length)

Description copied from interface: Memory

Gets the float array at the given offset

Specified by:

getFloatArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getInt

public int getInt(long offsetBytes)

Description copied from interface: Memory

Gets the int at the given offset

Specified by:

getInt in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the int at the given offset

getIntArray

public void getIntArray(long offsetBytes,
                        int[] dstArray,
                        int dstOffset,
                        int length)

Description copied from interface: Memory

Gets the int array at the given offset

Specified by:

getIntArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getLong

public long getLong(long offsetBytes)

Description copied from interface: Memory

Gets the long at the given offset

Specified by:

getLong in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the long at the given offset

getLongArray

public void getLongArray(long offsetBytes,
                         long[] dstArray,
                         int dstOffset,
                         int length)

Description copied from interface: Memory

Gets the long array at the given offset

Specified by:

getLongArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

getShort

public short getShort(long offsetBytes)

Description copied from interface: Memory

Gets the short at the given offset

Specified by:

getShort in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

Returns:

the short at the given offset

getShortArray

public void getShortArray(long offsetBytes,
                          short[] dstArray,
                          int dstOffset,
                          int length)

Description copied from interface: Memory

Gets the short array at the given offset

Specified by:

getShortArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

dstArray - The preallocated destination array.

dstOffset - offset in array units

length - number of array units to transfer

isAllBitsClear

public boolean isAllBitsClear(long offsetBytes,
                              byte bitMask)

Description copied from interface: Memory

Returns true if all bits defined by the bitMask are clear

Specified by:

isAllBitsClear in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

bitMask - bits set to one will be checked

Returns:

true if all bits defined by the bitMask are clear

isAllBitsSet

public boolean isAllBitsSet(long offsetBytes,
                            byte bitMask)

Description copied from interface: Memory

Returns true if all bits defined by the bitMask are set

Specified by:

isAllBitsSet in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

bitMask - bits set to one will be checked

Returns:

true if all bits defined by the bitMask are set

isAnyBitsClear

public boolean isAnyBitsClear(long offsetBytes,
                              byte bitMask)

Description copied from interface: Memory

Returns true if any bits defined by the bitMask are clear

Specified by:

isAnyBitsClear in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

bitMask - bits set to one will be checked

Returns:

true if any bits defined by the bitMask are clear

isAnyBitsSet

public boolean isAnyBitsSet(long offsetBytes,
                            byte bitMask)

Description copied from interface: Memory

Returns true if any bits defined by the bitMask are set

Specified by:

isAnyBitsSet in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

bitMask - bits set to one will be checked

Returns:

true if any bits defined by the bitMask are set

putBoolean

public void putBoolean(long offsetBytes,
                       boolean srcValue)

Description copied from interface: Memory

Puts the boolean value at the given offset

Specified by:

putBoolean in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putBooleanArray

public void putBooleanArray(long offsetBytes,
                            boolean[] srcArray,
                            int srcOffset,
                            int length)

Description copied from interface: Memory

Puts the boolean array at the given offset

Specified by:

putBooleanArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putByte

public void putByte(long offsetBytes,
                    byte srcValue)

Description copied from interface: Memory

Puts the byte value at the given offset

Specified by:

putByte in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putByteArray

public void putByteArray(long offsetBytes,
                         byte[] srcArray,
                         int srcOffset,
                         int length)

Description copied from interface: Memory

Puts the byte array at the given offset

Specified by:

putByteArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putChar

public void putChar(long offsetBytes,
                    char srcValue)

Description copied from interface: Memory

Puts the char value at the given offset

Specified by:

putChar in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putCharArray

public void putCharArray(long offsetBytes,
                         char[] srcArray,
                         int srcOffset,
                         int length)

Description copied from interface: Memory

Puts the char array at the given offset

Specified by:

putCharArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putDouble

public void putDouble(long offsetBytes,
                      double srcValue)

Description copied from interface: Memory

Puts the double value at the given offset

Specified by:

putDouble in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putDoubleArray

public void putDoubleArray(long offsetBytes,
                           double[] srcArray,
                           int srcOffset,
                           int length)

Description copied from interface: Memory

Puts the double array at the given offset

Specified by:

putDoubleArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putFloat

public void putFloat(long offsetBytes,
                     float srcValue)

Description copied from interface: Memory

Puts the float value at the given offset

Specified by:

putFloat in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putFloatArray

public void putFloatArray(long offsetBytes,
                          float[] srcArray,
                          int srcOffset,
                          int length)

Description copied from interface: Memory

Puts the float array at the given offset

Specified by:

putFloatArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putInt

public void putInt(long offsetBytes,
                   int srcValue)

Description copied from interface: Memory

Puts the int value at the given offset

Specified by:

putInt in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putIntArray

public void putIntArray(long offsetBytes,
                        int[] srcArray,
                        int srcOffset,
                        int length)

Description copied from interface: Memory

Puts the int array at the given offset

Specified by:

putIntArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putLong

public void putLong(long offsetBytes,
                    long srcValue)

Description copied from interface: Memory

Puts the long value at the given offset

Specified by:

putLong in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putLongArray

public void putLongArray(long offsetBytes,
                         long[] srcArray,
                         int srcOffset,
                         int length)

Description copied from interface: Memory

Puts the long array at the given offset

Specified by:

putLongArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

putShort

public void putShort(long offsetBytes,
                     short srcValue)

Description copied from interface: Memory

Puts the short value at the given offset

Specified by:

putShort in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcValue - the value to put

putShortArray

public void putShortArray(long offsetBytes,
                          short[] srcArray,
                          int srcOffset,
                          int length)

Description copied from interface: Memory

Puts the short array at the given offset

Specified by:

putShortArray in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

srcArray - The source array.

srcOffset - offset in array units

length - number of array units to transfer

setBits

public void setBits(long offsetBytes,
                    byte bitMask)

Description copied from interface: Memory

Sets the bits defined by the bitMask

Specified by:

setBits in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

bitMask - the bits set to one will be set

addAndGetInt

public int addAndGetInt(long offsetBytes,
                        int delta)

Description copied from interface: Memory

Atomically adds the given value to the integer located at offsetBytes.

Specified by:

addAndGetInt in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

delta - the amount to add

Returns:

the modified value

addAndGetLong

public long addAndGetLong(long offsetBytes,
                          long delta)

Description copied from interface: Memory

Atomically adds the given value to the long located at offsetBytes.

Specified by:

addAndGetLong in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

delta - the amount to add

Returns:

the modified value

compareAndSwapInt

public boolean compareAndSwapInt(long offsetBytes,
                                 int expect,
                                 int update)

Description copied from interface: Memory

Atomically sets the current value at the memory location to the given updated value if and only if the current value == the expected value.

Specified by:

compareAndSwapInt in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

expect - the expected value

update - the new value

Returns:

true if successful. False return indicates that the current value at the memory location was not equal to the expected value.

compareAndSwapLong

public boolean compareAndSwapLong(long offsetBytes,
                                  long expect,
                                  long update)

Description copied from interface: Memory

Atomically sets the current value at the memory location to the given updated value if and only if the current value == the expected value.

Specified by:

compareAndSwapLong in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

expect - the expected value

update - the new value

Returns:

true if successful. False return indicates that the current value at the memory location was not equal to the expected value.

getAndSetInt

public int getAndSetInt(long offsetBytes,
                        int newValue)

Description copied from interface: Memory

Atomically exchanges the given value with the current value located at offsetBytes.

Specified by:

getAndSetInt in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

newValue - new value

Returns:

the previous value

getAndSetLong

public long getAndSetLong(long offsetBytes,
                          long newValue)

Description copied from interface: Memory

Atomically exchanges the given value with the current value located at offsetBytes.

Specified by:

getAndSetLong in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

newValue - new value

Returns:

the previous value

array

public Object array()

Description copied from interface: Memory

Returns the backing on-heap primitive array if there is one, otherwise returns null

Specified by:

array in interface Memory

Returns:

the backing on-heap primitive array if there is one, otherwise returns null

asReadOnlyMemory

public MemoryRegion asReadOnlyMemory()

Description copied from interface: Memory

Returns a read-only version of this memory

Specified by:

asReadOnlyMemory in interface Memory

Returns:

a read-only version of this memory

byteBuffer

public ByteBuffer byteBuffer()

Description copied from interface: Memory

Returns the backing ByteBuffer if there is one, otherwise returns null

Specified by:

byteBuffer in interface Memory

Returns:

the backing ByteBuffer if there is one, otherwise returns null

clear

public void clear()

Description copied from interface: Memory

Clears all bytes of this Memory to zero

Specified by:

clear in interface Memory

clear

public void clear(long offsetBytes,
                  long lengthBytes)

Description copied from interface: Memory

Clears a portion of this Memory to zero.

Specified by:

clear in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

lengthBytes - the length in bytes

clearBits

public void clearBits(long offsetBytes,
                      byte bitMask)

Description copied from interface: Memory

Clears the bits defined by the bitMask

Specified by:

clearBits in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start.

bitMask - the bits set to one will be cleared

copy

@Deprecated
public void copy(long srcOffsetBytes,
                             long dstOffsetBytes,
                             long lengthBytes)

Deprecated.

Description copied from interface: Memory

Copies bytes from a source range of this Memory to a destination range of the given Memory using the same low-level system copy function as found in System.arraycopy(Object, int, Object, int, int). These regions may not overlap. This will be checked if asserts are enabled in the JVM.

Specified by:

copy in interface Memory

Parameters:

srcOffsetBytes - the source offset

dstOffsetBytes - the destintaion offset

lengthBytes - the number of bytes to copy

copy

public void copy(long srcOffsetBytes,
                 Memory destination,
                 long dstOffsetBytes,
                 long lengthBytes)

Description copied from interface: Memory

Copies bytes from a source range of this Memory to a destination range of the given Memory using the same low-level system copy function as found in System.arraycopy(Object, int, Object, int, int).

Specified by:

copy in interface Memory

Parameters:

srcOffsetBytes - the source offset for this Memory

destination - the destination Memory, which may not be Read-Only.

dstOffsetBytes - the destintaion offset

lengthBytes - the number of bytes to copy

fill

public void fill(byte value)

Description copied from interface: Memory

Fills all bytes of this Memory region to the given byte value.

Specified by:

fill in interface Memory

Parameters:

value - the given byte value

fill

public void fill(long offsetBytes,
                 long lengthBytes,
                 byte value)

Description copied from interface: Memory

Fills a portion of this Memory region to the given byte value.

Specified by:

fill in interface Memory

Parameters:

offsetBytes - offset bytes relative to this Memory start

lengthBytes - the length in bytes

value - the given byte value

getAddress

public long getAddress(long offsetBytes)

Description copied from interface: Memory

Returns the start address of this Memory relative to its parent plus the offset in bytes. Note that the parent could be native memory or some backing object.

Specified by:

getAddress in interface Memory

Parameters:

offsetBytes - the given offset in bytes from the start address of this Memory relative to its parent.

Returns:

the start address of this Memory relative to its parent plus the offset in bytes.

getCapacity

public long getCapacity()

Description copied from interface: Memory

Gets the capacity of this Memory in bytes

Specified by:

getCapacity in interface Memory

Returns:

the capacity of this Memory in bytes

getCumulativeOffset

public long getCumulativeOffset(long offsetBytes)

Description copied from interface: Memory

Returns the cumulative offset in bytes of this Memory from the root of the Memory hierarchy including the given offsetBytes.

Specified by:

getCumulativeOffset in interface Memory

Parameters:

offsetBytes - the given offset in bytes

Returns:

the cumulative offset in bytes of this Memory from the root of the Memory hierarchy including the given offsetBytes.

getMemoryRequest

public MemoryRequest getMemoryRequest()

Description copied from interface: Memory

Returns a MemoryRequest or null

Specified by:

getMemoryRequest in interface Memory

Returns:

a MemoryRequest or null

getParent

public Object getParent()

Description copied from interface: Memory

Gets the parent Memory or backing array. Used internally.

Specified by:

getParent in interface Memory

Returns:

the parent Memory.

hasArray

public boolean hasArray()

Description copied from interface: Memory

Returns true if this Memory is backed by an on-heap primitive array

Specified by:

hasArray in interface Memory

Returns:

true if this Memory is backed by an on-heap primitive array

hasByteBuffer

public boolean hasByteBuffer()

Description copied from interface: Memory

Returns true if this Memory is backed by a ByteBuffer

Specified by:

hasByteBuffer in interface Memory

Returns:

true if this Memory is backed by a ByteBuffer

isAllocated

public boolean isAllocated()

Description copied from interface: Memory

Returns true if this Memory has a capacity greater than zero

Specified by:

isAllocated in interface Memory

Returns:

true if this Memory has a capacity greater than zero

isDirect

public boolean isDirect()

Description copied from interface: Memory

Returns true if the backing memory is direct (off-heap) memory.

Specified by:

isDirect in interface Memory

Returns:

true if the backing memory is direct (off-heap) memory.

isReadOnly

public boolean isReadOnly()

Description copied from interface: Memory

Returns true if this Memory is read only

Specified by:

isReadOnly in interface Memory

Returns:

true if this Memory is read only

setMemoryRequest

public void setMemoryRequest(MemoryRequest memReq)

Description copied from interface: Memory

Sets a MemoryRequest

Specified by:

setMemoryRequest in interface Memory

Parameters:

memReq - the MemoryRequest

toHexString

public String toHexString(String header,
                          long offsetBytes,
                          int lengthBytes)

Description copied from interface: Memory

Returns a formatted hex string of an area of this Memory. Used primarily for testing.

Specified by:

toHexString in interface Memory

Parameters:

header - descriptive header

offsetBytes - offset bytes relative to this Memory start

lengthBytes - number of bytes to convert to a hex string

Returns:

a formatted hex string in a human readable array

freeMemory

public void freeMemory()

Description copied from interface: Memory

Because the Memory classes now use the JVM Cleaner, calling freeMemory(), which also calls Cleaner, is optional. In any case, calling freeMemory() is only relevant for Memory objects that have actually allocated native memory, which are those that have been allocated using AllocMemory or MemoryMappedFile.

Preemptively calling freeMemory() may reduce the load on the JVM GarbageCollector, but the significance of this will have to be verified in the target system environment. Calling freeMemory() always disables the current instance by setting the capacity to zero.

Specified by:

freeMemory in interface Memory