com.sleepycat.je.log

Class UtilizationFileReader

java.lang.Object

com.sleepycat.je.log.FileReader

com.sleepycat.je.log.UtilizationFileReader

public class UtilizationFileReader
extends FileReader

Summarizes the utilized and unutilized portion of each log file by examining each log entry. Does not use the Cleaner UtilizationProfile information in order to provide a second measure against which to evaluation the UtilizationProfile accuracy. Limitations =========== BIN-deltas are all considered obsolete, as an implementation short cut and for efficiency. 90% (by default) of deltas are obsolete anyway, and it would be expensive to fetch the parent BIN to find the lookup key. Assumes that any currently open transactions will be committed. For example, if a deletion or update has been performed but not yet committed, the old record will be considered obsolete. Perhaps this behavior could be changed in the future by attempting to lock a record (non-blocking) and considering a locked record to be non-obsolete; this might make it match live utilization counting more closely. Accesses the Btree, using JE cache memory if necessary and contending with other accessors, to check whether an entry is active. Historical note: This implementation, which uses the Btree to determine whether a node is active, replaced an earlier implementation that attempted to duplicate the Btree in memory and read the entire log. This older implementation had inaccuracies and was less efficient. With the new implementation it is also possible to calculation utilization for a range of LSNs, reading only that portion of the log. [#22208]

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

Method Summary

Modifier and Type	Method and Description
static Map<Long,FileSummary>	calcFileSummaryMap(EnvironmentImpl envImpl) Creates a UtilizationReader, reads the log, and returns the resulting Map of Long file number to FileSummary.
static Map<Long,FileSummary>	calcFileSummaryMap(EnvironmentImpl envImpl, long startLsn, long finishLsn)
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) Each file reader implements this method to process the entry data.

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

Method Detail

isTargetEntry

protected boolean isTargetEntry()

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().

processEntry

protected boolean processEntry(ByteBuffer entryBuffer)
                        throws DatabaseException

Description copied from class: FileReader

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

Specified by:

processEntry in class FileReader

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().

Throws:

DatabaseException

calcFileSummaryMap

public static Map<Long,FileSummary> calcFileSummaryMap(EnvironmentImpl envImpl)

Creates a UtilizationReader, reads the log, and returns the resulting Map of Long file number to FileSummary.

calcFileSummaryMap

public static Map<Long,FileSummary> calcFileSummaryMap(EnvironmentImpl envImpl,
                                                       long startLsn,
                                                       long finishLsn)