com.sleepycat.je.cleaner

Class ExpirationProfile

java.lang.Object

com.sleepycat.je.cleaner.ExpirationProfile

public class ExpirationProfile
extends Object

A cache of the histograms for all files, except for the last file. Also caches the number of bytes expired in the current interval. No memory budgeting is performed because the size of these data structures is small compared to the Btree they represent. The serialized form of the histogram is cached, which is a small number of bytes per file. If no data in a file expires, it will not have a cache entry. Possible future optimization: If there is contention on this data structure, the refresh method could create a read-only map containing the current number of expired bytes, for access by getExpiredBytes without synchronization.

Constructor Summary

Constructors

Constructor and Description
ExpirationProfile(EnvironmentImpl env)
ExpirationProfile(ExpirationProfile other) Make a copy for use in utilities, etc.

Method Summary

Modifier and Type	Method and Description
void	addCompletedTracker(ExpirationTracker tracker) Called after a file flip.
int	getExpiredBytes(long fileNum) Returns the number of expired bytes for the given file.
Pair<Integer,Integer>	getExpiredBytes(long fileNum, long time) Returns the number of expired bytes for the given file.
void	populateCache(StartupTracker.Counter counter, ProgressListener<RecoveryProgress> listener) Called at the end of recovery to open the expiration DB, and cache its records in the profile's map.
void	refresh(long time) Updates the expired bytes in the expiration profile according to the data that has expired at the given time.
String	toString(long fileNum)

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpirationProfile

public ExpirationProfile(EnvironmentImpl env)

ExpirationProfile

public ExpirationProfile(ExpirationProfile other)

Make a copy for use in utilities, etc.

Method Detail

populateCache

public void populateCache(StartupTracker.Counter counter,
                          ProgressListener<RecoveryProgress> listener)

Called at the end of recovery to open the expiration DB, and cache its records in the profile's map. Also collects expiration info for any complete file having expiration info that was not written to the DB earlier, due to a crash for example. Also initializes the tracker for the current file in the log manager, reading/tracking the existing entries in that file.

addCompletedTracker

public void addCompletedTracker(ExpirationTracker tracker)

Called after a file flip. The tracker is completed in the sense that the file is completely written, but there may be pending calls to ExpirationTracker.track(int, boolean, int) for some writing threads. This is because track is not called under the LWL.

refresh

public void refresh(long time)

Updates the expired bytes in the expiration profile according to the data that has expired at the given time. The recalculation is only actually performed once per hour, on hour boundaries, since data expires on (at most) hour boundaries.

Also calls processCompletedTrackers to process any completed trackers by adding them to the DB and to the histogram map.

Should be called periodically (more than once per file written), and before calling getExpiredBytes(long).

getExpiredBytes

public int getExpiredBytes(long fileNum)

Returns the number of expired bytes for the given file. Uses the value calculated by the last call to refresh(long).

getExpiredBytes

public Pair<Integer,Integer> getExpiredBytes(long fileNum,
                                             long time)

Returns the number of expired bytes for the given file. Two values are returned: the total expired at the given time, and a potentially smaller amount that gradually expires over the current hour or day interval. Uses the values calculated by the last call to refresh(long). The amount that gradually expires is the amount that expires in the current time interval, which is one day if all data in the profile expires on day boundaries, and otherwise is one hour. If this is the first interval for the file (after a restart or a revisal run), all expired bytes are considered expired in the current interval and expire gradually.

Returns:

pair of {allExpiredBytes, gradualExpiredBytes}.

toString

public String toString(long fileNum)