com.sleepycat.je.log

Class FileReader

java.lang.Object

com.sleepycat.je.log.FileReader

Direct Known Subclasses:

CheckpointFileReader, CleanerFileReader, DumpFileReader, INFileReader, LastFileReader, LNFileReader, ScavengerFileReader, SearchFileReader, UtilizationFileReader

public abstract class FileReader
extends java.lang.Object

A FileReader is an abstract class that traverses the log files, reading in chunks of the file at a time. Concrete subclasses perform a particular action to each entry.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	anticipateChecksumErrors
protected ChecksumValidator	cksumValidator
protected LogEntryHeader	currentEntryHeader
protected long	currentEntryOffset
protected long	currentEntryPrevOffset
protected EnvironmentImpl	envImpl
protected boolean	eof
protected FileManager	fileManager
protected long	nextEntryOffset
protected long	readBufferFileEnd
protected long	readBufferFileNum
protected long	readBufferFileStart
protected long	startLsn

Constructor Summary

Constructors

Constructor and Description
FileReader(EnvironmentImpl envImpl, int readBufferSize, boolean forward, long startLsn, java.lang.Long singleFileNumber, long endOfFileLsn, long finishLsn) A FileReader just needs to know what size chunks to read in.

Method Summary

Methods

Modifier and Type	Method and Description
int	getAndResetNReads() Returns the number of reads since the last time this method was called.
int	getLastEntrySize() Returns the total size (including header) of the last entry read.
long	getLastLsn() Get LSN of the last entry read.
long	getNRepeatIteratorReads()
int	getNumRead()
protected void	initStartingPosition(long endOfFileLsn, java.lang.Long ignoreSingleFileNumber) Helper for determining the starting position and opening up a file at the desired location.
protected boolean	isTargetEntry()
protected abstract boolean	processEntry(java.nio.ByteBuffer entryBuffer) Each file reader implements this method to process the entry data.
boolean	readNextEntry() readNextEntry scans the log files until either it's reached the end of the log or has hit an invalid portion.
protected boolean	resyncReader(long nextGoodRecordPostCorruption, boolean dumpCorruptedBounds)
void	setAlwaysValidateChecksum(boolean validate) Whether to always validate the checksum, even for non-target entries.
(package private) int	threadSafeBufferPosition(java.nio.ByteBuffer buffer)
(package private) java.nio.Buffer	threadSafeBufferPosition(java.nio.ByteBuffer buffer, int newPosition)

Methods inherited from class java.lang.Object

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

Field Detail

envImpl

protected EnvironmentImpl envImpl

fileManager

protected FileManager fileManager

eof

protected boolean eof

readBufferFileNum

protected long readBufferFileNum

readBufferFileStart

protected long readBufferFileStart

readBufferFileEnd

protected long readBufferFileEnd

currentEntryHeader

protected LogEntryHeader currentEntryHeader

currentEntryPrevOffset

protected long currentEntryPrevOffset

currentEntryOffset

protected long currentEntryOffset

nextEntryOffset

protected long nextEntryOffset

startLsn

protected long startLsn

cksumValidator

protected ChecksumValidator cksumValidator

anticipateChecksumErrors

protected boolean anticipateChecksumErrors

Constructor Detail

FileReader

public FileReader(EnvironmentImpl envImpl,
          int readBufferSize,
          boolean forward,
          long startLsn,
          java.lang.Long singleFileNumber,
          long endOfFileLsn,
          long finishLsn)
           throws java.io.IOException,
                  DatabaseException

A FileReader just needs to know what size chunks to read in.

Parameters:

endOfFileLsn - indicates the end of the log file

Throws:

java.io.IOException

DatabaseException

Method Detail

initStartingPosition

protected void initStartingPosition(long endOfFileLsn,
                        java.lang.Long ignoreSingleFileNumber)
                             throws java.io.IOException,
                                    DatabaseException

Helper for determining the starting position and opening up a file at the desired location.

Throws:

java.io.IOException

DatabaseException

setAlwaysValidateChecksum

public void setAlwaysValidateChecksum(boolean validate)

Whether to always validate the checksum, even for non-target entries.

getNumRead

public int getNumRead()

Returns:

the number of entries processed by this reader.

getNRepeatIteratorReads

public long getNRepeatIteratorReads()

getLastLsn

public long getLastLsn()

Get LSN of the last entry read.

getLastEntrySize

public int getLastEntrySize()

Returns the total size (including header) of the last entry read.

readNextEntry

public boolean readNextEntry()
                      throws DatabaseException,
                             java.io.IOException

readNextEntry scans the log files until either it's reached the end of the log or has hit an invalid portion. It then returns false.

Returns:

true if an element has been read

Throws:

DatabaseException

java.io.IOException

resyncReader

protected boolean resyncReader(long nextGoodRecordPostCorruption,
                   boolean dumpCorruptedBounds)
                        throws DatabaseException,
                               java.io.IOException

Throws:

DatabaseException

java.io.IOException

getAndResetNReads

public int getAndResetNReads()

Returns the number of reads since the last time this method was called.

isTargetEntry

protected boolean isTargetEntry()
                         throws DatabaseException

Returns:

true if this reader should process this entry, or just skip over it.

Throws:

DatabaseException

processEntry

protected abstract boolean processEntry(java.nio.ByteBuffer entryBuffer)
                                 throws DatabaseException

Each file reader implements this method to process the entry data.

Parameters:

enteryBuffer - contains the entry data and is positioned at the data

Returns:

true if this entry should be returned

Throws:

DatabaseException

threadSafeBufferPosition

int threadSafeBufferPosition(java.nio.ByteBuffer buffer)

threadSafeBufferPosition

java.nio.Buffer threadSafeBufferPosition(java.nio.ByteBuffer buffer,
                                       int newPosition)