org.apache.cassandra.db.commitlog

Class CommitLogSegmentManager

java.lang.Object

org.apache.cassandra.db.commitlog.CommitLogSegmentManager

public class CommitLogSegmentManager
extends java.lang.Object

Performs eager-creation of commit log segments in a background thread. All the public methods are thread safe.

Constructor Summary

Constructors

Constructor and Description
CommitLogSegmentManager()

Method Summary

Methods

Modifier and Type	Method and Description
org.apache.cassandra.db.commitlog.CommitLogSegment.Allocation	allocate(Mutation mutation, int size) Reserve space in the current segment for the provided mutation or, if there isn't space available, create a new segment.
void	awaitTermination() Returns when the management thread terminates.
long	bytesUsed()
void	enableReserveSegmentCreation() Throws a flag that enables the behavior of keeping at least one spare segment available at all times.
boolean	manages(java.lang.String name)
void	resetUnsafe() Resets all the segments, for testing purposes.
void	shutdown() Initiates the shutdown process for the management thread.

Methods inherited from class java.lang.Object

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

Constructor Detail

CommitLogSegmentManager

public CommitLogSegmentManager()

Method Detail

allocate

public org.apache.cassandra.db.commitlog.CommitLogSegment.Allocation allocate(Mutation mutation,
                                                                     int size)

Reserve space in the current segment for the provided mutation or, if there isn't space available, create a new segment.

Returns:

the provided Allocation object

bytesUsed

public long bytesUsed()

Returns:

the space (in bytes) used by all segment files.

manages

public boolean manages(java.lang.String name)

Parameters:

name - the filename to check

Returns:

true if file is managed by this manager.

enableReserveSegmentCreation

public void enableReserveSegmentCreation()

Throws a flag that enables the behavior of keeping at least one spare segment available at all times.

resetUnsafe

public void resetUnsafe()

Resets all the segments, for testing purposes. DO NOT USE THIS OUTSIDE OF TESTS.

shutdown

public void shutdown()

Initiates the shutdown process for the management thread.

awaitTermination

public void awaitTermination()
                      throws java.lang.InterruptedException

Returns when the management thread terminates.

Throws:

java.lang.InterruptedException