com.sleepycat.je.rep.stream

Class FeederSyncupReader

java.lang.Object

com.sleepycat.je.log.FileReader

com.sleepycat.je.rep.stream.FeederSyncupReader

public class FeederSyncupReader
extends FileReader

The FeederSyncupReader scans the log backwards for requested log entries. It uses the vlsnIndex to optimize its search, repositioning when a concrete vlsn->lsn mapping is available. The FeederSyncupReader is not thread safe, and can only be used serially. It will stop at the finishLsn, which should be set using the GlobalCBVLSN.

Nested Class Summary

Nested classes/interfaces inherited from class com.sleepycat.je.log.FileReader

FileReader.EOFException, FileReader.ReadWindow

Field Summary

Fields inherited from class com.sleepycat.je.log.FileReader

cksumValidator, currentEntryHeader, currentEntryOffset, currentEntryPrevOffset, envImpl, eof, fileManager, forward, logger, nextEntryOffset, startLsn, window

Constructor Summary

Constructors

Constructor and Description
FeederSyncupReader(EnvironmentImpl envImpl, VLSNIndex vlsnIndex, long endOfLogLsn, int readBufferSize, VLSN startVLSN, long finishLsn)

Method Summary

Modifier and Type	Method and Description
protected boolean	isTargetEntry() This method is called by readNextEntry() after the header of the current logrec has been de-serialized, but not the body.
protected boolean	processEntry(ByteBuffer entryBuffer) Instantiate a WireRecord to house this log entry.
OutputWireRecord	scanBackwards(VLSN vlsn) Backward scanning for records for the feeder's part in syncup.

Methods inherited from class com.sleepycat.je.log.FileReader

entryIsReplicated, getAndResetNReads, getLastEntrySize, getLastLsn, getLastVlsn, getLogVersion, getNRepeatIteratorReads, getNumRead, handleGapInBackwardsScan, initStartingPosition, makeWindow, readNextEntry, readNextEntryAllowExceptions, setAlwaysValidateChecksum, setBackwardPosition, setForwardPosition, skipData, skipEntry

Methods inherited from class java.lang.Object

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

Constructor Detail

FeederSyncupReader

public FeederSyncupReader(EnvironmentImpl envImpl,
                          VLSNIndex vlsnIndex,
                          long endOfLogLsn,
                          int readBufferSize,
                          VLSN startVLSN,
                          long finishLsn)
                   throws IOException,
                          DatabaseException

Throws:

IOException

DatabaseException

Method Detail

scanBackwards

public OutputWireRecord scanBackwards(VLSN vlsn)
                               throws FileNotFoundException,
                                      ChecksumException

Backward scanning for records for the feeder's part in syncup.

Throws:

ChecksumException

FileNotFoundException

isTargetEntry

protected boolean isTargetEntry()
                         throws DatabaseException

Description copied from class: FileReader

This method is called by readNextEntry() after the header of the current logrec has been de-serialized, but not the body. Based on header info only, it may perform some actions and then decide whether the rest of the logrec should be de-serialized or just skipped.

Overrides:

isTargetEntry in class FileReader

Returns:

true if this reader should process the current logrec further, via the processEntry() method. A logrec must be passed to processEntry if the full logrec (not just the header) must be de-serialized for further processing. Return false if no further processing is needed, in which case the current logrec will be skipped (i.e, not returned to the caller of readNextEntry().

Throws:

DatabaseException - from subclasses.

processEntry

protected boolean processEntry(ByteBuffer entryBuffer)

Instantiate a WireRecord to house this log entry.

Parameters:

entryBuffer - A ByteBuffer that the logrec data and is positioned at the start of the logrec body (i.e., just after the logrec header).

Returns:

true if this entry should be returned to the caller of readNextEntry().