org.apache.hadoop.hbase.regionserver.wal

Class FSWALEntry

java.lang.Object

org.apache.hadoop.hbase.wal.WAL.Entry

org.apache.hadoop.hbase.regionserver.wal.FSWALEntry

@InterfaceAudience.Private
class FSWALEntry
extends WAL.Entry

A WAL Entry for AbstractFSWAL implementation. Immutable. A subclass of WAL.Entry that carries extra info across the ring buffer such as region sequence id (we want to use this later, just before we write the WAL to ensure region edits maintain order). The extra info added here is not 'serialized' as part of the WALEdit hence marked 'transient' to underline this fact. It also adds mechanism so we can wait on the assign of the region sequence id. See #stampRegionSequenceId().

Field Summary

Fields

Modifier and Type	Field and Description
private Set<byte[]>	familyNames
private boolean	inMemstore
private RegionInfo	regionInfo
private Optional<ServerCall<?>>	rpcCall
private long	txid

Constructor Summary

Constructors

Constructor and Description
FSWALEntry(long txid, WALKeyImpl key, WALEdit edit, RegionInfo regionInfo, boolean inMemstore, ServerCall<?> rpcCall)

Method Summary

Modifier and Type	Method and Description
(package private) static Set<byte[]>	collectFamilies(List<Cell> cells)
(package private) Set<byte[]>	getFamilyNames()
(package private) RegionInfo	getRegionInfo()
(package private) long	getTxid()
(package private) boolean	isInMemStore()
(package private) void	release()
(package private) long	stampRegionSequenceId(MultiVersionConcurrencyControl.WriteEntry we) Here is where a WAL edit gets its sequenceid.
String	toString()

Methods inherited from class org.apache.hadoop.hbase.wal.WAL.Entry

getEdit, getKey, setCompressionContext

Methods inherited from class java.lang.Object

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

Field Detail

txid

private final transient long txid

inMemstore

private final transient boolean inMemstore

regionInfo

private final transient RegionInfo regionInfo

familyNames

private final transient Set<byte[]> familyNames

rpcCall

private final transient Optional<ServerCall<?>> rpcCall

Constructor Detail

FSWALEntry

FSWALEntry(long txid,
           WALKeyImpl key,
           WALEdit edit,
           RegionInfo regionInfo,
           boolean inMemstore,
           ServerCall<?> rpcCall)

Method Detail

collectFamilies

static Set<byte[]> collectFamilies(List<Cell> cells)

toString

public String toString()

Overrides:

toString in class WAL.Entry

isInMemStore

boolean isInMemStore()

getRegionInfo

RegionInfo getRegionInfo()

getTxid

long getTxid()

Returns:

The transaction id of this edit.

stampRegionSequenceId

long stampRegionSequenceId(MultiVersionConcurrencyControl.WriteEntry we)
                    throws IOException

Here is where a WAL edit gets its sequenceid. SIDE-EFFECT is our stamping the sequenceid into every Cell AND setting the sequenceid into the MVCC WriteEntry!!!!

Returns:

The sequenceid we stamped on this edit.

Throws:

IOException

getFamilyNames

Set<byte[]> getFamilyNames()

Returns:

the family names which are effected by this edit.

release

void release()