org.apache.hadoop.hbase.nio

Class MultiByteBuff

java.lang.Object

org.apache.hadoop.hbase.nio.ByteBuff

org.apache.hadoop.hbase.nio.MultiByteBuff

@InterfaceAudience.Private
public class MultiByteBuff
extends ByteBuff

Provides a unified view of all the underlying ByteBuffers and will look as if a bigger sequential buffer. This class provides similar APIs as in ByteBuffer to put/get int, short, long etc and doing operations like mark, reset, slice etc. This has to be used when data is split across multiple byte buffers and we don't want copy them to single buffer for reading from it.

Constructor Summary

Constructors

Constructor and Description
MultiByteBuff(ByteBuffer... items)

Method Summary

Modifier and Type	Method and Description
byte[]	array()
int	arrayOffset()
ByteBuffer	asSubByteBuffer(int length) Returns bytes from current position till length specified, as a single ByteBuffer.
void	asSubByteBuffer(int offset, int length, ObjectIntPair<ByteBuffer> pair) Returns bytes from given offset till length specified, as a single ByteBuffer.
int	capacity()
MultiByteBuff	duplicate() Returns an MBB which is a duplicate version of this MBB.
boolean	equals(Object obj)
byte	get() A relative method that returns byte at the current position.
void	get(byte[] dst) Copies the content from this MBB's current position to the byte array and fills it.
void	get(byte[] dst, int offset, int length) Copies the specified number of bytes from this MBB's current position to the byte[]'s offset.
void	get(ByteBuffer out, int sourceOffset, int length) Copies the content from an this MBB to a ByteBuffer
byte	get(int index) Fetches the byte at the given index.
void	get(int sourceOffset, byte[] dst, int offset, int length) Copies the specified number of bytes from this ByteBuff's given position to the byte[]'s offset.
byte	getByteAfterPosition(int offset) Fetches the byte at the given offset from current position.
ByteBuffer[]	getEnclosingByteBuffers()
int	getInt() Returns the int value at the current position.
int	getInt(int index) Fetches the int at the given index.
int	getIntAfterPosition(int offset) Fetches the int value at the given offset from current position.
long	getLong() Returns the long value at the current position.
long	getLong(int index) Fetches the long at the given index.
long	getLongAfterPosition(int offset) Fetches the long value at the given offset from current position.
short	getShort() Returns the short value at the current position.
short	getShort(int index) Fetches the short at the given index.
short	getShortAfterPosition(int offset) Fetches the short value at the given offset from current position.
boolean	hasArray()
int	hashCode()
boolean	hasRemaining() Returns true if there are elements between the current position and the limt
int	limit() Returns the limit of this MBB
MultiByteBuff	limit(int limit) Marks the limit of this MBB.
MultiByteBuff	mark() Marks the current position of the MBB
MultiByteBuff	moveBack(int length) Jumps back the current position of this MBB by specified length.
int	position()
MultiByteBuff	position(int position) Sets this MBB's position to the given value.
MultiByteBuff	put(byte b) Writes a byte to this MBB at the current position and increments the position
MultiByteBuff	put(byte[] src) Copies from the given byte[] to this MBB
MultiByteBuff	put(byte[] src, int offset, int length) Copies from the given byte[] to this MBB
MultiByteBuff	put(int index, byte b) Writes a byte to this MBB at the given index
MultiByteBuff	put(int offset, ByteBuff src, int srcOffset, int length) Copies from a src MBB to this MBB.
MultiByteBuff	putInt(int val) Writes an int to this MBB at its current position.
MultiByteBuff	putLong(long val) Writes a long to this MBB at its current position.
int	read(ReadableByteChannel channel) Reads bytes from the given channel into this ByteBuff
int	remaining() Returns the number of elements between the current position and the limit.
MultiByteBuff	reset() Similar to ByteBuffer.reset(), ensures that this MBB is reset back to last marked position.
MultiByteBuff	rewind() Rewinds this MBB and the position is set to 0
MultiByteBuff	skip(int length) Jumps the current position of this MBB by specified length.
MultiByteBuff	slice() Returns an MBB which is a sliced version of this MBB.
byte[]	toBytes(int offset, int length) Copy the content from this MBB to a byte[] based on the given offset and length

Methods inherited from class org.apache.hadoop.hbase.nio.ByteBuff

channelRead, compareTo, readCompressedInt, readLong, readVLong, toBytes, toString, toStringBinary, unsignedBinarySearch

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MultiByteBuff

public MultiByteBuff(ByteBuffer... items)

Method Detail

array

public byte[] array()

Specified by:

array in class ByteBuff

Returns:

the byte[] if the underlying BB has single BB and hasArray true

Throws:

UnsupportedOperationException - MBB does not support array based operations

arrayOffset

public int arrayOffset()

Specified by:

arrayOffset in class ByteBuff

Returns:

the arrayOffset of the byte[] incase of a single BB backed ByteBuff

Throws:

UnsupportedOperationException - MBB does not support array based operations

hasArray

public boolean hasArray()

Specified by:

hasArray in class ByteBuff

Returns:

false. MBB does not support array based operations

capacity

public int capacity()

Specified by:

capacity in class ByteBuff

Returns:

the total capacity of this MultiByteBuffer.

get

public byte get(int index)

Fetches the byte at the given index. Does not change position of the underlying ByteBuffers

Specified by:

get in class ByteBuff

Parameters:

index -

Returns:

the byte at the given index

getByteAfterPosition

public byte getByteAfterPosition(int offset)

Description copied from class: ByteBuff

Fetches the byte at the given offset from current position. Does not change position of the underlying ByteBuffers.

Specified by:

getByteAfterPosition in class ByteBuff

Returns:

the byte value at the given index.

getInt

public int getInt(int index)

Fetches the int at the given index. Does not change position of the underlying ByteBuffers

Specified by:

getInt in class ByteBuff

Parameters:

index -

Returns:

the int value at the given index

getIntAfterPosition

public int getIntAfterPosition(int offset)

Description copied from class: ByteBuff

Fetches the int value at the given offset from current position. Does not change position of the underlying ByteBuffers.

Specified by:

getIntAfterPosition in class ByteBuff

Returns:

the int value at the given index.

getShort

public short getShort(int index)

Fetches the short at the given index. Does not change position of the underlying ByteBuffers

Specified by:

getShort in class ByteBuff

Parameters:

index -

Returns:

the short value at the given index

getShortAfterPosition

public short getShortAfterPosition(int offset)

Description copied from class: ByteBuff

Fetches the short value at the given offset from current position. Does not change position of the underlying ByteBuffers.

Specified by:

getShortAfterPosition in class ByteBuff

Returns:

the short value at the given index.

getLong

public long getLong(int index)

Fetches the long at the given index. Does not change position of the underlying ByteBuffers

Specified by:

getLong in class ByteBuff

Parameters:

index -

Returns:

the long value at the given index

getLongAfterPosition

public long getLongAfterPosition(int offset)

Description copied from class: ByteBuff

Fetches the long value at the given offset from current position. Does not change position of the underlying ByteBuffers.

Specified by:

getLongAfterPosition in class ByteBuff

Returns:

the long value at the given index.

position

public int position()

Specified by:

position in class ByteBuff

Returns:

this MBB's current position

position

public MultiByteBuff position(int position)

Sets this MBB's position to the given value.

Specified by:

position in class ByteBuff

Parameters:

position -

Returns:

this object

rewind

public MultiByteBuff rewind()

Rewinds this MBB and the position is set to 0

Specified by:

rewind in class ByteBuff

Returns:

this object

mark

public MultiByteBuff mark()

Marks the current position of the MBB

Specified by:

mark in class ByteBuff

Returns:

this object

reset

public MultiByteBuff reset()

Similar to ByteBuffer.reset(), ensures that this MBB is reset back to last marked position.

Specified by:

reset in class ByteBuff

Returns:

This MBB

remaining

public int remaining()

Returns the number of elements between the current position and the limit.

Specified by:

remaining in class ByteBuff

Returns:

the remaining elements in this MBB

hasRemaining

public final boolean hasRemaining()

Returns true if there are elements between the current position and the limt

Specified by:

hasRemaining in class ByteBuff

Returns:

true if there are elements, false otherwise

get

public byte get()

A relative method that returns byte at the current position. Increments the current position by the size of a byte.

Specified by:

get in class ByteBuff

Returns:

the byte at the current position

getShort

public short getShort()

Returns the short value at the current position. Also advances the position by the size of short

Specified by:

getShort in class ByteBuff

Returns:

the short value at the current position

getInt

public int getInt()

Returns the int value at the current position. Also advances the position by the size of int

Specified by:

getInt in class ByteBuff

Returns:

the int value at the current position

getLong

public long getLong()

Returns the long value at the current position. Also advances the position by the size of long

Specified by:

getLong in class ByteBuff

Returns:

the long value at the current position

get

public void get(byte[] dst)

Copies the content from this MBB's current position to the byte array and fills it. Also advances the position of the MBB by the length of the byte[].

Specified by:

get in class ByteBuff

Parameters:

dst -

get

public void get(byte[] dst,
                int offset,
                int length)

Copies the specified number of bytes from this MBB's current position to the byte[]'s offset. Also advances the position of the MBB by the given length.

Specified by:

get in class ByteBuff

Parameters:

dst -

offset - within the current array

length - upto which the bytes to be copied

get

public void get(int sourceOffset,
                byte[] dst,
                int offset,
                int length)

Description copied from class: ByteBuff

Copies the specified number of bytes from this ByteBuff's given position to the byte[]'s offset. The position of the ByteBuff remains in the current position only

Specified by:

get in class ByteBuff

Parameters:

sourceOffset - the offset in this ByteBuff from where the copy should happen

dst - the byte[] to which the ByteBuff's content is to be copied

offset - within the current array

length - upto which the bytes to be copied

limit

public MultiByteBuff limit(int limit)

Marks the limit of this MBB.

Specified by:

limit in class ByteBuff

Parameters:

limit -

Returns:

This MBB

limit

public int limit()

Returns the limit of this MBB

Specified by:

limit in class ByteBuff

Returns:

limit of the MBB

slice

public MultiByteBuff slice()

Returns an MBB which is a sliced version of this MBB. The position, limit and mark of the new MBB will be independent than that of the original MBB. The content of the new MBB will start at this MBB's current position

Specified by:

slice in class ByteBuff

Returns:

a sliced MBB

duplicate

public MultiByteBuff duplicate()

Returns an MBB which is a duplicate version of this MBB. The position, limit and mark of the new MBB will be independent than that of the original MBB. The content of the new MBB will start at this MBB's current position The position, limit and mark of the new MBB would be identical to this MBB in terms of values.

Specified by:

duplicate in class ByteBuff

Returns:

a sliced MBB

put

public MultiByteBuff put(byte b)

Writes a byte to this MBB at the current position and increments the position

Specified by:

put in class ByteBuff

Parameters:

b -

Returns:

this object

put

public MultiByteBuff put(int index,
                         byte b)

Writes a byte to this MBB at the given index

Specified by:

put in class ByteBuff

Parameters:

index -

b -

Returns:

this object

put

public MultiByteBuff put(int offset,
                         ByteBuff src,
                         int srcOffset,
                         int length)

Copies from a src MBB to this MBB.

Specified by:

put in class ByteBuff

Parameters:

offset - the position in this MBB to which the copy should happen

src - the src MBB

srcOffset - the offset in the src MBB from where the elements should be read

length - the length upto which the copy should happen

putInt

public MultiByteBuff putInt(int val)

Writes an int to this MBB at its current position. Also advances the position by size of int

Specified by:

putInt in class ByteBuff

Parameters:

val - Int value to write

Returns:

this object

put

public final MultiByteBuff put(byte[] src)

Copies from the given byte[] to this MBB

Specified by:

put in class ByteBuff

Parameters:

src -

Returns:

this MBB

put

public MultiByteBuff put(byte[] src,
                         int offset,
                         int length)

Copies from the given byte[] to this MBB

Specified by:

put in class ByteBuff

Parameters:

src -

offset - the position in the byte array from which the copy should be done

length - the length upto which the copy should happen

Returns:

this MBB

putLong

public MultiByteBuff putLong(long val)

Writes a long to this MBB at its current position. Also advances the position by size of long

Specified by:

putLong in class ByteBuff

Parameters:

val - Long value to write

Returns:

this object

skip

public MultiByteBuff skip(int length)

Jumps the current position of this MBB by specified length.

Specified by:

skip in class ByteBuff

Parameters:

length -

moveBack

public MultiByteBuff moveBack(int length)

Jumps back the current position of this MBB by specified length.

Specified by:

moveBack in class ByteBuff

Parameters:

length -

asSubByteBuffer

public ByteBuffer asSubByteBuffer(int length)

Returns bytes from current position till length specified, as a single ByteBuffer. When all these bytes happen to be in a single ByteBuffer, which this object wraps, that ByteBuffer item as such will be returned. So users are warned not to change the position or limit of this returned ByteBuffer. The position of the returned byte buffer is at the begin of the required bytes. When the required bytes happen to span across multiple ByteBuffers, this API will copy the bytes to a newly created ByteBuffer of required size and return that.

Specified by:

asSubByteBuffer in class ByteBuff

Parameters:

length - number of bytes required.

Returns:

bytes from current position till length specified, as a single ByteButter.

asSubByteBuffer

public void asSubByteBuffer(int offset,
                            int length,
                            ObjectIntPair<ByteBuffer> pair)

Returns bytes from given offset till length specified, as a single ByteBuffer. When all these bytes happen to be in a single ByteBuffer, which this object wraps, that ByteBuffer item as such will be returned (with offset in this ByteBuffer where the bytes starts). So users are warned not to change the position or limit of this returned ByteBuffer. When the required bytes happen to span across multiple ByteBuffers, this API will copy the bytes to a newly created ByteBuffer of required size and return that.

Specified by:

asSubByteBuffer in class ByteBuff

Parameters:

offset - the offset in this MBB from where the subBuffer should be created

length - the length of the subBuffer

pair - a pair that will have the bytes from the current position till length specified, as a single ByteBuffer and offset in that Buffer where the bytes starts. The method would set the values on the pair that is passed in by the caller

get

public void get(ByteBuffer out,
                int sourceOffset,
                int length)

Copies the content from an this MBB to a ByteBuffer

Specified by:

get in class ByteBuff

Parameters:

out - the ByteBuffer to which the copy has to happen

sourceOffset - the offset in the MBB from which the elements has to be copied

length - the length in the MBB upto which the elements has to be copied

toBytes

public byte[] toBytes(int offset,
                      int length)

Copy the content from this MBB to a byte[] based on the given offset and length

Specified by:

toBytes in class ByteBuff

Parameters:

offset - the position from where the copy should start

length - the length upto which the copy has to be done

Returns:

byte[] with the copied contents from this MBB.

read

public int read(ReadableByteChannel channel)
         throws IOException

Description copied from class: ByteBuff

Reads bytes from the given channel into this ByteBuff

Specified by:

read in class ByteBuff

Returns:

The number of bytes read from the channel

Throws:

IOException

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

getEnclosingByteBuffers

public ByteBuffer[] getEnclosingByteBuffers()

Returns:

the ByteBuffers which this wraps.