org.apache.cassandra.db.commitlog

Class CommitLogSegment

java.lang.Object

org.apache.cassandra.db.commitlog.CommitLogSegment

Direct Known Subclasses:

FileDirectSegment, MemoryMappedSegment

public abstract class CommitLogSegment
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CommitLogSegment.CommitLogSegmentFileComparator

Field Summary

Fields

Modifier and Type	Field and Description
CommitLogDescriptor	descriptor
static int	ENTRY_OVERHEAD_SIZE
long	id

Method Summary

Modifier and Type	Method and Description
protected java.util.Map<java.lang.String,java.lang.String>	additionalHeaderParameters() Provide any additional header data that should be stored in the CommitLogDescriptor.
boolean	contains(ReplayPosition context) Check to see if a certain ReplayPosition is contained by this segment file.
long	contentSize()
java.lang.String	dirtyString()
ReplayPosition	getContext()
java.util.Collection<java.util.UUID>	getDirtyCFIDs()
java.lang.String	getName()
java.lang.String	getPath()
protected void	internalClose() Close the segment file.
boolean	isStillAllocating()
boolean	isUnused()
void	markClean(java.util.UUID cfId, ReplayPosition context) Marks the ColumnFamily specified by cfId as clean for this log segment.
abstract long	onDiskSize()
java.lang.String	toString()
protected void	writeSyncMarker(java.nio.ByteBuffer buffer, int offset, int filePos, int nextMarker) Create a sync marker to delineate sections of the commit log, typically created on each sync of the file.

Methods inherited from class java.lang.Object

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

Field Detail

ENTRY_OVERHEAD_SIZE

public static final int ENTRY_OVERHEAD_SIZE

See Also:

Constant Field Values

id

public final long id

descriptor

public final CommitLogDescriptor descriptor

Method Detail

additionalHeaderParameters

protected java.util.Map<java.lang.String,java.lang.String> additionalHeaderParameters()

Provide any additional header data that should be stored in the CommitLogDescriptor.

writeSyncMarker

protected void writeSyncMarker(java.nio.ByteBuffer buffer,
                               int offset,
                               int filePos,
                               int nextMarker)

Create a sync marker to delineate sections of the commit log, typically created on each sync of the file. The sync marker consists of a file pointer to where the next sync marker should be (effectively declaring the length of this section), as well as a CRC value.

Parameters:

buffer - buffer in which to write out the sync marker.

offset - Offset into the buffer at which to write the sync marker.

filePos - The current position in the target file where the sync marker will be written (most likely different from the buffer position).

nextMarker - The file position of where the next sync marker should be.

isStillAllocating

public boolean isStillAllocating()

getContext

public ReplayPosition getContext()

Returns:

the current ReplayPosition for this log segment

getPath

public java.lang.String getPath()

Returns:

the file path to this segment

getName

public java.lang.String getName()

Returns:

the file name of this segment

internalClose

protected void internalClose()

Close the segment file. Do not call from outside this class, use syncAndClose() instead.

markClean

public void markClean(java.util.UUID cfId,
                      ReplayPosition context)

Marks the ColumnFamily specified by cfId as clean for this log segment. If the given context argument is contained in this file, it will only mark the CF as clean if no newer writes have taken place.

Parameters:

cfId - the column family ID that is now clean

context - the optional clean offset

getDirtyCFIDs

public java.util.Collection<java.util.UUID> getDirtyCFIDs()

Returns:

a collection of dirty CFIDs for this segment file.

isUnused

public boolean isUnused()

Returns:

true if this segment is unused and safe to recycle or delete

contains

public boolean contains(ReplayPosition context)

Check to see if a certain ReplayPosition is contained by this segment file.

Parameters:

context - the replay position to be checked

Returns:

true if the replay position is contained by this segment file.

dirtyString

public java.lang.String dirtyString()

onDiskSize

public abstract long onDiskSize()

contentSize

public long contentSize()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object