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 sequenceid (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 boolean	closeRegion Set if this is a meta edit and it is of close region type.
private Set<byte[]>	familyNames
private boolean	inMemstore If false, means this is a meta edit written by the hbase system itself.
private RegionInfo	regionInfo
private 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() Returns the family names which are effected by this edit.
(package private) RegionInfo	getRegionInfo()
(package private) long	getTxid() Returns The transaction id of this edit.
(package private) boolean	isCloseRegion()
(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

If false, means this is a meta edit written by the hbase system itself. It was not in memstore. HBase uses these edit types to note in the log operational transitions such as compactions, flushes, or region open/closes.

closeRegion

private final transient boolean closeRegion

Set if this is a meta edit and it is of close region type.

regionInfo

private final transient RegionInfo regionInfo

familyNames

private final transient Set<byte[]> familyNames

rpcCall

private final transient ServerCall<?> rpcCall

Constructor Detail

FSWALEntry

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

Parameters:

inMemstore - If true, then this is a data edit, one that came from client. If false, it is a meta edit made by the hbase system itself and is for the WAL only.

Method Detail

collectFamilies

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

toString

public String toString()

Overrides:

toString in class WAL.Entry

isInMemStore

boolean isInMemStore()

isCloseRegion

boolean isCloseRegion()

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()