org.apache.hadoop.hbase.replication.regionserver

Class WALEntryStream

java.lang.Object

org.apache.hadoop.hbase.replication.regionserver.WALEntryStream

All Implemented Interfaces:

Closeable, AutoCloseable

@InterfaceAudience.Private
 @InterfaceStability.Evolving
class WALEntryStream
extends Object
implements Closeable

Streaming access to WAL entries. This class is given a queue of WAL Path, and continually iterates through all the WAL WAL.Entry in the queue. When it's done reading from a Path, it dequeues it and starts reading from the next.

Field Summary

Fields

Modifier and Type	Field and Description
private org.apache.hadoop.conf.Configuration	conf
private WAL.Entry	currentEntry
private org.apache.hadoop.fs.Path	currentPath
private long	currentPositionOfEntry
private long	currentPositionOfReader
private org.apache.hadoop.fs.FileSystem	fs
private static org.slf4j.Logger	LOG
private PriorityBlockingQueue<org.apache.hadoop.fs.Path>	logQueue
private MetricsSource	metrics
private WAL.Reader	reader
private ServerName	serverName
private WALFileLengthProvider	walFileLengthProvider

Constructor Summary

Constructors

Constructor and Description
WALEntryStream(PriorityBlockingQueue<org.apache.hadoop.fs.Path> logQueue, org.apache.hadoop.conf.Configuration conf, long startPosition, WALFileLengthProvider walFileLengthProvider, ServerName serverName, MetricsSource metrics) Create an entry stream over the given queue at the given start position

Method Summary

Modifier and Type	Method and Description
private boolean	checkAllBytesParsed()
private boolean	checkReader()
void	close()
private void	closeReader()
private long	currentTrailerSize()
private void	dequeueCurrentLog()
private org.apache.hadoop.fs.Path	getArchivedLog(org.apache.hadoop.fs.Path path)
org.apache.hadoop.fs.Path	getCurrentPath()
private String	getCurrentPathStat()
long	getPosition()
private void	handleFileNotFound(org.apache.hadoop.fs.Path path, FileNotFoundException fnfe)
boolean	hasNext()
WAL.Entry	next() Returns the next WAL entry in this stream and advance the stream.
private boolean	openNextLog()
private void	openReader(org.apache.hadoop.fs.Path path)
WAL.Entry	peek() Returns the next WAL entry in this stream but does not advance.
private boolean	readNextEntryAndRecordReaderPosition() Returns whether the file is opened for writing.
private void	recoverLease(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.Path path)
void	reset() Should be called if the stream is to be reused (i.e.
private void	resetReader()
private void	seek()
private void	setCurrentPath(org.apache.hadoop.fs.Path path)
private void	setPosition(long position)
private void	tryAdvanceEntry()

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final org.slf4j.Logger LOG

reader

private WAL.Reader reader

currentPath

private org.apache.hadoop.fs.Path currentPath

currentEntry

private WAL.Entry currentEntry

currentPositionOfEntry

private long currentPositionOfEntry

currentPositionOfReader

private long currentPositionOfReader

logQueue

private final PriorityBlockingQueue<org.apache.hadoop.fs.Path> logQueue

fs

private final org.apache.hadoop.fs.FileSystem fs

conf

private final org.apache.hadoop.conf.Configuration conf

walFileLengthProvider

private final WALFileLengthProvider walFileLengthProvider

serverName

private final ServerName serverName

metrics

private final MetricsSource metrics

Constructor Detail

WALEntryStream

public WALEntryStream(PriorityBlockingQueue<org.apache.hadoop.fs.Path> logQueue,
                      org.apache.hadoop.conf.Configuration conf,
                      long startPosition,
                      WALFileLengthProvider walFileLengthProvider,
                      ServerName serverName,
                      MetricsSource metrics)
               throws IOException

Create an entry stream over the given queue at the given start position

Parameters:

logQueue - the queue of WAL paths

conf - the Configuration to use to create WAL.Reader for this stream

startPosition - the position in the first WAL to start reading at

walFileLengthProvider - provides the length of the WAL file

serverName - the server name which all WALs belong to

metrics - the replication metrics

Throws:

IOException

Method Detail

hasNext

public boolean hasNext()
                throws IOException

Returns:

true if there is another WAL WAL.Entry

Throws:

IOException

peek

public WAL.Entry peek()
               throws IOException

Returns the next WAL entry in this stream but does not advance.

Throws:

IOException

next

public WAL.Entry next()
               throws IOException

Returns the next WAL entry in this stream and advance the stream.

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

getPosition

public long getPosition()

Returns:

the position of the last Entry returned by next()

getCurrentPath

public org.apache.hadoop.fs.Path getCurrentPath()

Returns:

the Path of the current WAL

getCurrentPathStat

private String getCurrentPathStat()

reset

public void reset()
           throws IOException

Should be called if the stream is to be reused (i.e. used again after hasNext() has returned false)

Throws:

IOException

setPosition

private void setPosition(long position)

setCurrentPath

private void setCurrentPath(org.apache.hadoop.fs.Path path)

tryAdvanceEntry

private void tryAdvanceEntry()
                      throws IOException

Throws:

IOException

checkAllBytesParsed

private boolean checkAllBytesParsed()
                             throws IOException

Throws:

IOException

dequeueCurrentLog

private void dequeueCurrentLog()
                        throws IOException

Throws:

IOException

readNextEntryAndRecordReaderPosition

private boolean readNextEntryAndRecordReaderPosition()
                                              throws IOException

Returns whether the file is opened for writing.

Throws:

IOException

closeReader

private void closeReader()
                  throws IOException

Throws:

IOException

checkReader

private boolean checkReader()
                     throws IOException

Throws:

IOException

openNextLog

private boolean openNextLog()
                     throws IOException

Throws:

IOException

getArchivedLog

private org.apache.hadoop.fs.Path getArchivedLog(org.apache.hadoop.fs.Path path)
                                          throws IOException

Throws:

IOException

handleFileNotFound

private void handleFileNotFound(org.apache.hadoop.fs.Path path,
                                FileNotFoundException fnfe)
                         throws IOException

Throws:

IOException

openReader

private void openReader(org.apache.hadoop.fs.Path path)
                 throws IOException

Throws:

IOException

recoverLease

private void recoverLease(org.apache.hadoop.conf.Configuration conf,
                          org.apache.hadoop.fs.Path path)

resetReader

private void resetReader()
                  throws IOException

Throws:

IOException

seek

private void seek()
           throws IOException

Throws:

IOException

currentTrailerSize

private long currentTrailerSize()