org.apache.hadoop.hbase

Class ArrayBackedTag

java.lang.Object

org.apache.hadoop.hbase.ArrayBackedTag

All Implemented Interfaces:

Tag

@InterfaceAudience.Private
 @InterfaceStability.Evolving
public class ArrayBackedTag
extends Object
implements Tag

This is a Tag implementation in which value is backed by an on heap byte array.

Field Summary

Fields inherited from interface org.apache.hadoop.hbase.Tag

CUSTOM_TAG_TYPE_RANGE, INFRASTRUCTURE_SIZE, MAX_TAG_LENGTH, TAG_LENGTH_SIZE, TYPE_LENGTH_SIZE

Constructor Summary

Constructors

Constructor and Description
ArrayBackedTag(byte[] bytes, int offset) Creates a Tag from the specified byte array and offset.
ArrayBackedTag(byte[] bytes, int offset, int length) Creates a Tag from the specified byte array, starting at offset, and for length length.
ArrayBackedTag(byte tagType, byte[] tag) Format for a tag : <length of tag - 2 bytes><type code - 1 byte><tag> tag length is serialized using 2 bytes only but as this will be unsigned, we can have max tag length of (Short.MAX_SIZE * 2) +1.
ArrayBackedTag(byte tagType, String tag) The special tag will write the length of each tag and that will be followed by the type and then the actual tag.

Method Summary

Modifier and Type	Method and Description
byte	getType() Returns the tag type
byte[]	getValueArray() Returns The byte array backing this Tag.
ByteBuffer	getValueByteBuffer() Returns The ByteBuffer containing the value bytes.
int	getValueLength() Returns Length of actual tag bytes within the backed buffer
int	getValueOffset() Returns Offset of actual tag bytes within the backed buffer
boolean	hasArray() Tells whether or not this Tag is backed by a byte array.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.hbase.Tag

cloneValue, copyValueTo, getValueAsByte, getValueAsLong, getValueAsString, matchingValue

Constructor Detail

ArrayBackedTag

public ArrayBackedTag(byte tagType,
                      String tag)

The special tag will write the length of each tag and that will be followed by the type and then the actual tag. So every time the length part is parsed we need to add + 1 byte to it to get the type and then get the actual tag.

ArrayBackedTag

public ArrayBackedTag(byte tagType,
                      byte[] tag)

Format for a tag : <length of tag - 2 bytes><type code - 1 byte><tag> tag length is serialized using 2 bytes only but as this will be unsigned, we can have max tag length of (Short.MAX_SIZE * 2) +1. It includes 1 byte type length and actual tag bytes length.

ArrayBackedTag

public ArrayBackedTag(byte[] bytes,
                      int offset)

Creates a Tag from the specified byte array and offset. Presumes bytes content starting at offset is formatted as a Tag blob. The bytes to include the tag type, tag length and actual tag bytes.

Parameters:

offset - offset to start of Tag

ArrayBackedTag

public ArrayBackedTag(byte[] bytes,
                      int offset,
                      int length)

Creates a Tag from the specified byte array, starting at offset, and for length length. Presumes bytes content starting at offset is formatted as a Tag blob.

Method Detail

getValueArray

public byte[] getValueArray()

Returns The byte array backing this Tag.

Specified by:

getValueArray in interface Tag

Returns:

The array containing the value bytes. when Tag.hasArray() return false. Use Tag.getValueByteBuffer() in such situation

getType

public byte getType()

Returns the tag type

Specified by:

getType in interface Tag

getValueLength

public int getValueLength()

Returns Length of actual tag bytes within the backed buffer

Specified by:

getValueLength in interface Tag

getValueOffset

public int getValueOffset()

Returns Offset of actual tag bytes within the backed buffer

Specified by:

getValueOffset in interface Tag

hasArray

public boolean hasArray()

Description copied from interface: Tag

Tells whether or not this Tag is backed by a byte array.

Specified by:

hasArray in interface Tag

Returns:

true when this Tag is backed by byte array

getValueByteBuffer

public ByteBuffer getValueByteBuffer()

Description copied from interface: Tag

Returns The ByteBuffer containing the value bytes.

Specified by:

getValueByteBuffer in interface Tag

toString

public String toString()

Overrides:

toString in class Object