co.cask.cdap.data2.dataset2.lib.table

Class FuzzyRowFilter

java.lang.Object

co.cask.cdap.data2.dataset2.lib.table.FuzzyRowFilter

All Implemented Interfaces:

co.cask.cdap.api.dataset.table.Filter

public final class FuzzyRowFilter
extends Object
implements co.cask.cdap.api.dataset.table.Filter

This is inspired by HBase's FuzzyRowFilter. Filters data based on fuzzy row key. Performs fast-forwards during scanning. It takes pairs (row key, fuzzy info) to match row keys. Where fuzzy info is a byte array with 0 or 1 as its values:

• 0 - means that this byte in provided row key is fixed, i.e. row key's byte at same position must match
• 1 - means that this byte in provided row key is NOT fixed, i.e. row key's byte at this position can be different from the one in provided row key

Example: Let's assume row key format is userId_actionId_year_month. Length of userId is fixed and is 4, length of actionId is 2 and year and month are 4 and 2 bytes long respectively. Let's assume that we need to fetch all users that performed certain action (encoded as "99") in Jan of any year. Then the pair (row key, fuzzy info) would be the following: row key = "????_99_????_01" (one can use any value instead of "?") fuzzy info = "\x01\x01\x01\x01\x00\x00\x00\x00\x01\x01\x01\x01\x00\x00\x00" I.e. fuzzy info tells the matching mask is "????_99_????_01", where at ? can be any value.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FuzzyRowFilter.ReturnCode Return codes for filterRow().

Constructor Summary

Constructors

Constructor and Description
FuzzyRowFilter(List<ImmutablePair<byte[],byte[]>> fuzzyKeysData)

Method Summary

Methods

Modifier and Type	Method and Description
FuzzyRowFilter.ReturnCode	filterRow(byte[] rowKey)
List<ImmutablePair<byte[],byte[]>>	getFuzzyKeysData()
byte[]	getNextRowHint(byte[] rowKey)
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

FuzzyRowFilter

public FuzzyRowFilter(List<ImmutablePair<byte[],byte[]>> fuzzyKeysData)

Method Detail

getFuzzyKeysData

public List<ImmutablePair<byte[],byte[]>> getFuzzyKeysData()

filterRow

public FuzzyRowFilter.ReturnCode filterRow(byte[] rowKey)

getNextRowHint

public byte[] getNextRowHint(byte[] rowKey)

toString

public String toString()

Overrides:

toString in class Object