Package org.apache.hadoop.hbase

Class TagUtil

java.lang.Object

org.apache.hadoop.hbase.TagUtil

@Private
public final class TagUtil
extends Object

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final Iterator<Tag>	EMPTY_TAGS_ITR	Iterator returned when no Tags.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	TagUtil()

Method Summary

Modifier and Type	Method	Description
static List<Tag>	asList(byte[] b, int offset, int length)	Creates list of tags from given byte array, expected that it is in the expected tag format.
static List<Tag>	carryForwardTags(List<Tag> tagsOrNull, Cell cell)	Add to tagsOrNull any Tags cell is carrying or null if none.
static List<Tag>	carryForwardTags(Cell cell)	Returns A List<Tag> of any Tags found in cell else null.
static List<Tag>	carryForwardTTLTag(List<Tag> tagsOrNull, long ttl)	Returns Carry forward the TTL tag.
static byte[]	concatTags(byte[] tags, Cell cell)
static byte[]	fromList(List<Tag> tags)	Write a list of tags into a byte array Note : these are all purely internal APIs.
static Pair<Integer,Integer>	readVIntValuePart(Tag tag, int offset)	Reads an int value stored as a VInt at tag's given offset.

Methods inherited from class java.lang.Object

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

Field Details

EMPTY_TAGS_ITR

static final Iterator<Tag> EMPTY_TAGS_ITR

Iterator returned when no Tags. Used by CellUtil too.

Constructor Details

TagUtil

private TagUtil()

Method Details

asList

public static List<Tag> asList(byte[] b,
 int offset,
 int length)

Creates list of tags from given byte array, expected that it is in the expected tag format.

Parameters:

b - The byte array

offset - The offset in array where tag bytes begin

length - Total length of all tags bytes

Returns:

List of tags

readVIntValuePart

public static Pair<Integer,Integer> readVIntValuePart(Tag tag,
 int offset)
                                               throws IOException

Reads an int value stored as a VInt at tag's given offset.

Parameters:

tag - The Tag

offset - The offset where VInt bytes begin

Returns:

A pair of the int value and number of bytes taken to store VInt

Throws:

IOException - When varint is malformed and not able to be read correctly

carryForwardTags

public static List<Tag> carryForwardTags(Cell cell)

Returns A List<Tag> of any Tags found in cell else null.

carryForwardTags

public static List<Tag> carryForwardTags(List<Tag> tagsOrNull,
 Cell cell)

Add to tagsOrNull any Tags cell is carrying or null if none.

concatTags

public static byte[] concatTags(byte[] tags,
 Cell cell)

carryForwardTTLTag

public static List<Tag> carryForwardTTLTag(List<Tag> tagsOrNull,
 long ttl)

Returns Carry forward the TTL tag.

fromList

public static byte[] fromList(List<Tag> tags)

Write a list of tags into a byte array Note : these are all purely internal APIs. It helps in cases where we have set of tags and we would want to create a cell out of it. Say in Mobs we create a reference tags to indicate the presence of mob data. Also note that these are not exposed to CPs also

Parameters:

tags - The list of tags

Returns:

the serialized tag data as bytes