com.sleepycat.je.cleaner

Class UtilizationTracker

java.lang.Object

com.sleepycat.je.cleaner.BaseUtilizationTracker

com.sleepycat.je.cleaner.UtilizationTracker

public class UtilizationTracker
extends BaseUtilizationTracker

Tracks changes to the utilization profile since the last checkpoint. This is the "global" tracker for an environment that tracks changes as they occur in live operations. Other "local" tracker classes are used to count utilization locally and then later transfer the information to the global tracker, this tracker.

All changes to this object occur must under the log write latch. It is possible to read tracked info without holding the latch. This is done by the cleaner when selecting a file and by the checkpointer when determining what FileSummaryLNs need to be written. To read tracked info outside the log write latch, call getTrackedFile or getTrackedFiles. activateCleaner can also be called outside the latch.

Field Summary

Fields inherited from class com.sleepycat.je.cleaner.BaseUtilizationTracker

bytesSinceActivate, cleaner, env

Constructor Summary

Constructors

Constructor and Description
UtilizationTracker(EnvironmentImpl env) Creates an empty tracker.
UtilizationTracker(EnvironmentImpl env, Cleaner cleaner) Constructor used by the cleaner constructor, prior to setting the cleaner field of the environment.

Method Summary

Methods

Modifier and Type	Method and Description
void	activateCleaner() Wakeup the cleaner thread and reset the log byte counter.
boolean	countNewLogEntry(long lsn, LogEntryType type, int size, DatabaseImpl db) Counts the addition of all new log entries including LNs, and returns whether the cleaner should be woken.
void	countObsoleteNode(long lsn, LogEntryType type, int size, DatabaseImpl db) Counts a node that has become obsolete and tracks the LSN offset, if non-zero, to avoid a lookup during cleaning.
void	countObsoleteNodeInexact(long lsn, LogEntryType type, int size, DatabaseImpl db) Counts as countObsoleteNode does, but since the LSN may be inexact, does not track the obsolete LSN offset.
long	evictMemory() Evicts tracked detail if the budget for the tracker is exceeded.
(package private) DbFileSummary	getDbFileSummary(java.lang.Object databaseKey, long fileNum) Allocates DbFileSummary information in the DatabaseImpl, which is the database key.
EnvironmentImpl	getEnvironment()
TrackedFileSummary	getUnflushableTrackedSummary(long fileNum) Returns a tracked summary for the given file which will not be flushed.

Methods inherited from class com.sleepycat.je.cleaner.BaseUtilizationTracker

close, countNew, countObsolete, countObsoleteDb, getFileSummary, getTrackedFile, getTrackedFiles, isFileUncounted, isLNType, isNodeType, resetFile

Methods inherited from class java.lang.Object

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

Constructor Detail

UtilizationTracker

public UtilizationTracker(EnvironmentImpl env)
                   throws DatabaseException

Creates an empty tracker. The cleaner field of the environment object must be initialized before using this constructor.

Throws:

DatabaseException

UtilizationTracker

UtilizationTracker(EnvironmentImpl env,
                  Cleaner cleaner)
             throws DatabaseException

Constructor used by the cleaner constructor, prior to setting the cleaner field of the environment.

Throws:

DatabaseException

Method Detail

getEnvironment

public EnvironmentImpl getEnvironment()

Overrides:

getEnvironment in class BaseUtilizationTracker

evictMemory

public long evictMemory()
                 throws DatabaseException

Evicts tracked detail if the budget for the tracker is exceeded. Evicts only one file summary LN at most to keep eviction batches small. Returns the number of bytes freed.

When flushFileSummary is called, the TrackedFileSummary is cleared via its reset method, which is called by FileSummaryLN.writeToLog. This is how memory is subtracted from the budget.

Throws:

DatabaseException

activateCleaner

public void activateCleaner()

Wakeup the cleaner thread and reset the log byte counter.

countNewLogEntry

public boolean countNewLogEntry(long lsn,
                       LogEntryType type,
                       int size,
                       DatabaseImpl db)

Counts the addition of all new log entries including LNs, and returns whether the cleaner should be woken.

Must be called under the log write latch.

countObsoleteNode

public void countObsoleteNode(long lsn,
                     LogEntryType type,
                     int size,
                     DatabaseImpl db)

Counts a node that has become obsolete and tracks the LSN offset, if non-zero, to avoid a lookup during cleaning.

A zero LSN offset is used as a special value when obsolete offset tracking is not desired. [#15365] The file header entry (at offset zero) is never counted as obsolete, it is assumed to be obsolete by the cleaner.

This method should only be called for LNs and INs (i.e, only for nodes). If type is null we assume it is an LN.

Must be called under the log write latch.

countObsoleteNodeInexact

public void countObsoleteNodeInexact(long lsn,
                            LogEntryType type,
                            int size,
                            DatabaseImpl db)

Counts as countObsoleteNode does, but since the LSN may be inexact, does not track the obsolete LSN offset.

This method should only be called for LNs and INs (i.e, only for nodes). If type is null we assume it is an LN.

Must be called under the log write latch.

getUnflushableTrackedSummary

public TrackedFileSummary getUnflushableTrackedSummary(long fileNum)
                                                throws DatabaseException

Returns a tracked summary for the given file which will not be flushed. Used for watching changes that occur while a file is being cleaned.

Throws:

DatabaseException

getDbFileSummary

DbFileSummary getDbFileSummary(java.lang.Object databaseKey,
                             long fileNum)

Allocates DbFileSummary information in the DatabaseImpl, which is the database key.

Must be called under the log write latch.

Specified by:

getDbFileSummary in class BaseUtilizationTracker

Returns:

the summary, or null if the DB should not be tracked because the file has been deleted, or null if the databaseKey param is null.