org.apache.hadoop.hbase.util

Class CollectionBackedScanner

java.lang.Object

org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner

org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner

org.apache.hadoop.hbase.util.CollectionBackedScanner

All Implemented Interfaces:

KeyValueScanner

@InterfaceAudience.Private
public class CollectionBackedScanner
extends NonReversedNonLazyKeyValueScanner

Utility scanner that wraps a sortable collection and serves as a KeyValueScanner.

Constructor Summary

Constructors

Constructor and Description
CollectionBackedScanner(KeyValue.KVComparator comparator, KeyValue... array)
CollectionBackedScanner(List<KeyValue> list)
CollectionBackedScanner(List<KeyValue> list, KeyValue.KVComparator comparator)
CollectionBackedScanner(SortedSet<KeyValue> set)
CollectionBackedScanner(SortedSet<KeyValue> set, KeyValue.KVComparator comparator)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the KeyValue scanner.
long	getSequenceID() Get the sequence id associated with this KeyValueScanner.
KeyValue	next() Return the next KeyValue in this scanner, iterating the scanner
KeyValue	peek() Look at the next KeyValue in this scanner, but do not iterate scanner.
boolean	reseek(KeyValue seekKv) Reseek the scanner at or after the specified KeyValue.
boolean	seek(KeyValue seekKv) Seek the scanner at or after the specified KeyValue.

Methods inherited from class org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner

backwardSeek, seekToLastRow, seekToPreviousRow

Methods inherited from class org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner

doRealSeek, enforceSeek, isFileScanner, realSeekDone, requestSeek, shouldUseScanner

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionBackedScanner

public CollectionBackedScanner(SortedSet<KeyValue> set)

CollectionBackedScanner

public CollectionBackedScanner(SortedSet<KeyValue> set,
                       KeyValue.KVComparator comparator)

CollectionBackedScanner

public CollectionBackedScanner(List<KeyValue> list)

CollectionBackedScanner

public CollectionBackedScanner(List<KeyValue> list,
                       KeyValue.KVComparator comparator)

CollectionBackedScanner

public CollectionBackedScanner(KeyValue.KVComparator comparator,
                       KeyValue... array)

Method Detail

peek

public KeyValue peek()

Description copied from interface: KeyValueScanner

Look at the next KeyValue in this scanner, but do not iterate scanner.

Returns:

the next KeyValue

next

public KeyValue next()

Description copied from interface: KeyValueScanner

Return the next KeyValue in this scanner, iterating the scanner

Returns:

the next KeyValue

seek

public boolean seek(KeyValue seekKv)

Description copied from interface: KeyValueScanner

Seek the scanner at or after the specified KeyValue.

Parameters:

seekKv - seek value

Returns:

true if scanner has values left, false if end of scanner

reseek

public boolean reseek(KeyValue seekKv)

Description copied from interface: KeyValueScanner

Reseek the scanner at or after the specified KeyValue. This method is guaranteed to seek at or after the required key only if the key comes after the current position of the scanner. Should not be used to seek to a key which may come before the current position.

Parameters:

seekKv - seek value (should be non-null)

Returns:

true if scanner has values left, false if end of scanner

getSequenceID

public long getSequenceID()

Description copied from interface: KeyValueScanner

Get the sequence id associated with this KeyValueScanner. This is required for comparing multiple files to find out which one has the latest data. The default implementation for this would be to return 0. A file having lower sequence id will be considered to be the older one.

close

public void close()

Description copied from interface: KeyValueScanner

Close the KeyValue scanner.