WALKey (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.wal.WALKey

All Implemented Interfaces:

Comparable<WALKey>, SequenceId

Direct Known Subclasses:

HLogKey
```
@InterfaceAudience.LimitedPrivate(value="Replication")
public class WALKey
extends Object
implements SequenceId, Comparable<WALKey>
```
A Key for an entry in the change log. The log intermingles edits to many tables and rows, so each log entry identifies the appropriate table and row. Within a table and row, they're also sorted.
Some Transactional edits (START, COMMIT, ABORT) will not have an associated row. Note that protected members marked @InterfaceAudience.Private are only protected to support the legacy HLogKey class, which is in a different package.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

protected static class WALKey.Version

Nested Classes
Modifier and Type	Class and Description
`protected static class`	`WALKey.Version`

Field Summary

Fields
Modifier and Type	Field and Description
`protected List<UUID>`	`clusterIds`
`protected CompressionContext`	`compressionContext`
`static List<UUID>`	`EMPTY_UUIDS`
`protected byte[]`	`encodedRegionName`
`private static org.apache.commons.logging.Log`	`LOG`
`protected long`	`logSeqNum`
`private MultiVersionConcurrencyControl`	`mvcc`
`static long`	`NO_SEQUENCE_ID` Used to represent when a particular wal key doesn't know/care about the sequence ordering.
`private long`	`nonce`
`private long`	`nonceGroup`
`private long`	`origLogSeqNum`
`private static String`	`PREFIX_CLUSTER_KEY`
`private NavigableMap<byte[],Integer>`	`scopes`
`private CountDownLatch`	`seqNumAssignedLatch`
`protected TableName`	`tablename`
`protected static WALKey.Version`	`VERSION`
`private MultiVersionConcurrencyControl.WriteEntry`	`writeEntry`
`protected long`	`writeTime`

Constructor Summary

Constructors
Constructor and Description
`WALKey()`
`WALKey(byte[] encodedRegionName, TableName tablename)`
`WALKey(byte[] encodedRegionName, TableName tablename, long now)`
`WALKey(byte[] encodedRegionName, TableName tablename, long now, List<UUID> clusterIds, long nonceGroup, long nonce, MultiVersionConcurrencyControl mvcc)` Create the log key for writing to somewhere.
`WALKey(byte[] encodedRegionName, TableName tablename, long logSeqNum, long now, List<UUID> clusterIds, long nonceGroup, long nonce, MultiVersionConcurrencyControl mvcc)` Create the log key for writing to somewhere.
`WALKey(byte[] encodedRegionName, TableName tablename, long logSeqNum, long nonceGroup, long nonce, MultiVersionConcurrencyControl mvcc)` Create the log key for writing to somewhere.
`WALKey(byte[] encodedRegionName, TableName tablename, long logSeqNum, long now, UUID clusterId)`
`WALKey(byte[] encodedRegionName, TableName tablename, long now, MultiVersionConcurrencyControl mvcc)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addClusterId(UUID clusterId)` Marks that the cluster with the given clusterId has consumed the change
`int`	`compareTo(WALKey o)`
`boolean`	`equals(Object obj)`
`org.apache.hadoop.hbase.protobuf.generated.WALProtos.WALKey.Builder`	`getBuilder(WALCellCodec.ByteStringCompressor compressor)`
`List<UUID>`	`getClusterIds()`
`byte[]`	`getEncodedRegionName()`
`long`	`getLogSeqNum()`
`MultiVersionConcurrencyControl`	`getMvcc()`
`long`	`getNonce()`
`long`	`getNonceGroup()`
`UUID`	`getOriginatingClusterId()`
`long`	`getOrigLogSeqNum()` Return a positive long if current WALKey is created from a replay edit
`NavigableMap<byte[],Integer>`	`getScopes()`
`long`	`getSequenceId()` Wait for sequence number to be assigned & return the assigned value
`long`	`getSequenceId(long maxWaitForSeqId)` Wait for sequence number to be assigned & return the assigned value.
`TableName`	`getTablename()`
`MultiVersionConcurrencyControl.WriteEntry`	`getWriteEntry()` Will block until a write entry has been assigned by they WAL subsystem.
`long`	`getWriteTime()`
`int`	`hashCode()`
`protected void`	`init(byte[] encodedRegionName, TableName tablename, long logSeqNum, long now, List<UUID> clusterIds, long nonceGroup, long nonce, MultiVersionConcurrencyControl mvcc)`
`(package private) void`	`internEncodedRegionName(byte[] encodedRegionName)` Drop this instance's region name byte array and instead hold a reference to the provided region name.
`(package private) void`	`internTableName(TableName tablename)` Drop this instance's tablename byte array and instead hold a reference to the provided tablename.
`void`	`readFieldsFromPb(org.apache.hadoop.hbase.protobuf.generated.WALProtos.WALKey walKey, WALCellCodec.ByteStringUncompressor uncompressor)`
`void`	`readOlderScopes(NavigableMap<byte[],Integer> scopes)`
`void`	`setCompressionContext(CompressionContext compressionContext)`
`void`	`setLogSeqNum(long sequence)` Allow that the log sequence id to be set post-construction Only public for org.apache.hadoop.hbase.regionserver.wal.FSWALEntry
`void`	`setOrigLogSeqNum(long seqId)` Used to set original seq Id for WALKey during wal replay
`void`	`setScopes(NavigableMap<byte[],Integer> scopes)`
`void`	`setWriteEntry(MultiVersionConcurrencyControl.WriteEntry writeEntry)`
`String`	`toString()`
`Map<String,Object>`	`toStringMap()` Produces a string map for this key.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

LOG

private static final org.apache.commons.logging.Log LOG

PREFIX_CLUSTER_KEY

private static final String PREFIX_CLUSTER_KEY

See Also:: Constant Field Values

VERSION

@InterfaceAudience.Private
protected static final WALKey.Version VERSION

NO_SEQUENCE_ID
```
public static final long NO_SEQUENCE_ID
```
Used to represent when a particular wal key doesn't know/care about the sequence ordering.

See Also:
Constant Field Values

encodedRegionName

@InterfaceAudience.Private
protected byte[] encodedRegionName

tablename

@InterfaceAudience.Private
protected TableName tablename

logSeqNum

@InterfaceAudience.Private
protected long logSeqNum

origLogSeqNum
```
private long origLogSeqNum
```

seqNumAssignedLatch

private CountDownLatch seqNumAssignedLatch

writeTime

@InterfaceAudience.Private
protected long writeTime

clusterIds

@InterfaceAudience.Private
protected List<UUID> clusterIds

scopes

private NavigableMap<byte[],Integer> scopes

nonceGroup
```
private long nonceGroup
```

nonce
```
private long nonce
```

mvcc

private MultiVersionConcurrencyControl mvcc

writeEntry

private MultiVersionConcurrencyControl.WriteEntry writeEntry

EMPTY_UUIDS

public static final List<UUID> EMPTY_UUIDS

compressionContext

@InterfaceAudience.Private
protected CompressionContext compressionContext

Constructor Detail
- WALKey
```
public WALKey()
```
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename,
      long logSeqNum,
      long now,
      UUID clusterId)
```
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename)
```
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename,
      long now)
```
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename,
      long now,
      MultiVersionConcurrencyControl mvcc)
```
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename,
      long logSeqNum,
      long now,
      List<UUID> clusterIds,
      long nonceGroup,
      long nonce,
      MultiVersionConcurrencyControl mvcc)
```
  Create the log key for writing to somewhere. We maintain the tablename mainly for debugging purposes. A regionName is always a sub-table object.
  Used by log splitting and snapshots.
  
  Parameters:
  encodedRegionName - Encoded name of the region as returned by HRegionInfo#getEncodedNameAsBytes().
  tablename - - name of table
  logSeqNum - - log sequence number
  now - Time at which this edit was written.
  clusterIds - the clusters that have consumed the change(used in Replication)
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename,
      long now,
      List<UUID> clusterIds,
      long nonceGroup,
      long nonce,
      MultiVersionConcurrencyControl mvcc)
```
  Create the log key for writing to somewhere. We maintain the tablename mainly for debugging purposes. A regionName is always a sub-table object.
  
  Parameters:
  encodedRegionName - Encoded name of the region as returned by HRegionInfo#getEncodedNameAsBytes().
  tablename -
  now - Time at which this edit was written.
  clusterIds - the clusters that have consumed the change(used in Replication)
  nonceGroup -
  nonce -
  mvcc - mvcc control used to generate sequence numbers and control read/write points
- WALKey
```
public WALKey(byte[] encodedRegionName,
      TableName tablename,
      long logSeqNum,
      long nonceGroup,
      long nonce,
      MultiVersionConcurrencyControl mvcc)
```
  Create the log key for writing to somewhere. We maintain the tablename mainly for debugging purposes. A regionName is always a sub-table object.
  
  Parameters:
  encodedRegionName - Encoded name of the region as returned by HRegionInfo#getEncodedNameAsBytes().
  tablename -
  logSeqNum -
  nonceGroup -
  nonce -

Method Detail
- getMvcc
```
@InterfaceAudience.Private
public MultiVersionConcurrencyControl getMvcc()
```
- getWriteEntry
```
@InterfaceAudience.Private
public MultiVersionConcurrencyControl.WriteEntry getWriteEntry()
                                                        throws InterruptedIOException
```
  Will block until a write entry has been assigned by they WAL subsystem.
  
  Returns:
  A WriteEntry gotten from local WAL subsystem. Must be completed by calling mvcc#complete or mvcc#completeAndWait.
  
  Throws:
  
  InterruptedIOException
  See Also:
  setWriteEntry(org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl.WriteEntry)
- setWriteEntry
```
@InterfaceAudience.Private
public void setWriteEntry(MultiVersionConcurrencyControl.WriteEntry writeEntry)
```
- init
```
@InterfaceAudience.Private
protected void init(byte[] encodedRegionName,
                                  TableName tablename,
                                  long logSeqNum,
                                  long now,
                                  List<UUID> clusterIds,
                                  long nonceGroup,
                                  long nonce,
                                  MultiVersionConcurrencyControl mvcc)
```
- setCompressionContext
```
public void setCompressionContext(CompressionContext compressionContext)
```
  Parameters:
  compressionContext - Compression context to use
- getEncodedRegionName
```
public byte[] getEncodedRegionName()
```
  Returns:
  encoded region name
- getTablename
```
public TableName getTablename()
```
  Returns:
  table name
- getLogSeqNum
```
public long getLogSeqNum()
```
  Returns:
  log sequence number
- setLogSeqNum
```
@InterfaceAudience.Private
public void setLogSeqNum(long sequence)
```
  Allow that the log sequence id to be set post-construction Only public for org.apache.hadoop.hbase.regionserver.wal.FSWALEntry
  
  Parameters:
  sequence -
- setOrigLogSeqNum
```
public void setOrigLogSeqNum(long seqId)
```
  Used to set original seq Id for WALKey during wal replay
  
  Parameters:
  seqId -
- getOrigLogSeqNum
```
public long getOrigLogSeqNum()
```
  Return a positive long if current WALKey is created from a replay edit
  
  Returns:
  original sequence number of the WALEdit
- getSequenceId
```
public long getSequenceId()
                   throws IOException
```
  Wait for sequence number to be assigned & return the assigned value
  
  Specified by:
  
  getSequenceId in interface SequenceId
  
  Returns:
  long the new assigned sequence number
  
  Throws:
  
  IOException
- getSequenceId
```
public long getSequenceId(long maxWaitForSeqId)
                   throws IOException
```
  Wait for sequence number to be assigned & return the assigned value.
  
  Parameters:
  maxWaitForSeqId - maximum time to wait in milliseconds for sequenceid
  
  Returns:
  long the new assigned sequence number
  
  Throws:
  
  IOException
- getWriteTime
```
public long getWriteTime()
```
  Returns:
  the write time
- getScopes
```
public NavigableMap<byte[],Integer> getScopes()
```
- getNonceGroup
```
public long getNonceGroup()
```
  Returns:
  The nonce group
- getNonce
```
public long getNonce()
```
  Returns:
  The nonce
- setScopes
```
public void setScopes(NavigableMap<byte[],Integer> scopes)
```
- readOlderScopes
```
public void readOlderScopes(NavigableMap<byte[],Integer> scopes)
```
- addClusterId
```
public void addClusterId(UUID clusterId)
```
  Marks that the cluster with the given clusterId has consumed the change
- getClusterIds
```
public List<UUID> getClusterIds()
```
  Returns:
  the set of cluster Ids that have consumed the change
- getOriginatingClusterId
```
public UUID getOriginatingClusterId()
```
  Returns:
  the cluster id on which the change has originated. It there is no such cluster, it returns DEFAULT_CLUSTER_ID (cases where replication is not enabled)
- toString
```
public String toString()
```
  Overrides:
  
  toString in class Object
- toStringMap
```
public Map<String,Object> toStringMap()
```
  Produces a string map for this key. Useful for programmatic use and manipulation of the data stored in an WALKey, for example, printing as JSON.
  
  Returns:
  a Map containing data from this key
- equals
```
public boolean equals(Object obj)
```
  Overrides:
  
  equals in class Object
- hashCode
```
public int hashCode()
```
  Overrides:
  
  hashCode in class Object
- compareTo
```
public int compareTo(WALKey o)
```
  Specified by:
  
  compareTo in interface Comparable<WALKey>
- internTableName
```
void internTableName(TableName tablename)
```
  Drop this instance's tablename byte array and instead hold a reference to the provided tablename. This is not meant to be a general purpose setter - it's only used to collapse references to conserve memory.
- internEncodedRegionName
```
void internEncodedRegionName(byte[] encodedRegionName)
```
  Drop this instance's region name byte array and instead hold a reference to the provided region name. This is not meant to be a general purpose setter - it's only used to collapse references to conserve memory.
- getBuilder
```
public org.apache.hadoop.hbase.protobuf.generated.WALProtos.WALKey.Builder getBuilder(WALCellCodec.ByteStringCompressor compressor)
                                                                               throws IOException
```
  Throws:
  
  IOException
- readFieldsFromPb
```
public void readFieldsFromPb(org.apache.hadoop.hbase.protobuf.generated.WALProtos.WALKey walKey,
                    WALCellCodec.ByteStringUncompressor uncompressor)
                      throws IOException
```
  Throws:
  
  IOException

Class WALKey

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

PREFIX_CLUSTER_KEY

VERSION

NO_SEQUENCE_ID

encodedRegionName

tablename

logSeqNum

origLogSeqNum

seqNumAssignedLatch

writeTime

clusterIds

scopes

nonceGroup

nonce

mvcc

writeEntry

EMPTY_UUIDS

compressionContext

Constructor Detail

WALKey

WALKey

WALKey

WALKey

WALKey

WALKey

WALKey

WALKey

Method Detail

getMvcc

getWriteEntry

setWriteEntry

init

setCompressionContext

getEncodedRegionName

getTablename

getLogSeqNum

setLogSeqNum

setOrigLogSeqNum

getOrigLogSeqNum

getSequenceId

getSequenceId

getWriteTime

getScopes

getNonceGroup

getNonce

setScopes

readOlderScopes

addClusterId

getClusterIds

getOriginatingClusterId

toString

toStringMap

equals

hashCode

compareTo

internTableName

internEncodedRegionName

getBuilder

readFieldsFromPb