org.apache.cassandra.db.memtable

Class AbstractMemtableWithCommitlog

java.lang.Object

org.apache.cassandra.db.memtable.AbstractMemtable

org.apache.cassandra.db.memtable.AbstractMemtableWithCommitlog

All Implemented Interfaces:

java.lang.Comparable<Memtable>, Memtable, UnfilteredSource

Direct Known Subclasses:

AbstractAllocatorMemtable

public abstract class AbstractMemtableWithCommitlog
extends AbstractMemtable

Memtable that uses a commit log for persistence. Provides methods of tracking the commit log positions covered by it and safely switching between memtables.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.cassandra.db.memtable.AbstractMemtable

AbstractMemtable.AbstractFlushablePartitionSet<P extends Partition>, AbstractMemtable.ColumnsCollector, AbstractMemtable.StatsCollector

Nested classes/interfaces inherited from interface org.apache.cassandra.db.memtable.Memtable

Memtable.Factory, Memtable.FlushablePartitionSet<P extends Partition>, Memtable.LastCommitLogPosition, Memtable.MemoryUsage, Memtable.Owner

Field Summary

Fields inherited from class org.apache.cassandra.db.memtable.AbstractMemtable

columnsCollector, currentOperations, metadata, minLocalDeletionTime, minTimestamp, statsCollector

Fields inherited from interface org.apache.cassandra.db.memtable.Memtable

NO_MIN_TIMESTAMP

Constructor Summary

Constructors

Constructor and Description
AbstractMemtableWithCommitlog(TableMetadataRef metadataRef, java.util.concurrent.atomic.AtomicReference<CommitLogPosition> commitLogLowerBound)

Method Summary

Modifier and Type	Method and Description
boolean	accepts(OpOrder.Group opGroup, CommitLogPosition commitLogPosition) Decide if this memtable should take a write with the given parameters, or if the write should go to the next memtable.
void	discard() This memtable is no longer in use or required for outstanding flushes or operations.
CommitLogPosition	getApproximateCommitLogLowerBound() Approximate commit log lower bound, <= getCommitLogLowerBound, used as a time stamp for ordering
CommitLogPosition	getCommitLogLowerBound() The commit log position at the time that this memtable was created
Memtable.LastCommitLogPosition	getFinalCommitLogUpperBound() The commit log position at the time that this memtable was switched out
boolean	mayContainDataBefore(CommitLogPosition position) True if the memtable can contain any data that was written before the given commit log position
void	switchOut(OpOrder.Barrier writeBarrier, java.util.concurrent.atomic.AtomicReference<CommitLogPosition> commitLogUpperBound) Called to tell the memtable that it is being switched out and will be flushed (or dropped) and discarded.

Methods inherited from class org.apache.cassandra.db.memtable.AbstractMemtable

getMinLocalDeletionTime, getMinTimestamp, metadata, operationCount, updateMin, updateMin

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.db.memtable.Memtable

addMemoryUsageTo, compareTo, getFlushSet, getLiveDataSize, getMemoryUsage, isClean, localRangesUpdated, markExtraOffHeapUsed, markExtraOnHeapUsed, metadataUpdated, newMemoryUsage, partitionCount, performSnapshot, put, shouldSwitch

Methods inherited from interface org.apache.cassandra.db.rows.UnfilteredSource

partitionIterator, rowIterator, rowIterator

Constructor Detail

AbstractMemtableWithCommitlog

public AbstractMemtableWithCommitlog(TableMetadataRef metadataRef,
                                     java.util.concurrent.atomic.AtomicReference<CommitLogPosition> commitLogLowerBound)

Method Detail

getApproximateCommitLogLowerBound

public CommitLogPosition getApproximateCommitLogLowerBound()

Description copied from interface: Memtable

Approximate commit log lower bound, <= getCommitLogLowerBound, used as a time stamp for ordering

switchOut

public void switchOut(OpOrder.Barrier writeBarrier,
                      java.util.concurrent.atomic.AtomicReference<CommitLogPosition> commitLogUpperBound)

Description copied from interface: Memtable

Called to tell the memtable that it is being switched out and will be flushed (or dropped) and discarded. Will be followed by a Memtable.getFlushSet(org.apache.cassandra.db.PartitionPosition, org.apache.cassandra.db.PartitionPosition) call (if the table is not truncated or dropped), and a Memtable.discard().

Parameters:

writeBarrier - The barrier that will signal that all writes to this memtable have completed. That is, the point after which writes cannot be accepted by this memtable (it is permitted for writes before this barrier to go into the next; see Memtable.accepts(org.apache.cassandra.utils.concurrent.OpOrder.Group, org.apache.cassandra.db.commitlog.CommitLogPosition)).

commitLogUpperBound - The upper commit log position for this memtable. The value may be modified after this call and will match the next memtable's lower commit log bound.

discard

public void discard()

Description copied from interface: Memtable

This memtable is no longer in use or required for outstanding flushes or operations. All held memory must be released.

accepts

public boolean accepts(OpOrder.Group opGroup,
                       CommitLogPosition commitLogPosition)

Description copied from interface: Memtable

Decide if this memtable should take a write with the given parameters, or if the write should go to the next memtable. This enforces that no writes after the barrier set by Memtable.switchOut(org.apache.cassandra.utils.concurrent.OpOrder.Barrier, java.util.concurrent.atomic.AtomicReference<org.apache.cassandra.db.commitlog.CommitLogPosition>) can be accepted, and is also used to define a shared commit log bound as the upper for this memtable and lower for the next.

getCommitLogLowerBound

public CommitLogPosition getCommitLogLowerBound()

Description copied from interface: Memtable

The commit log position at the time that this memtable was created

getFinalCommitLogUpperBound

public Memtable.LastCommitLogPosition getFinalCommitLogUpperBound()

Description copied from interface: Memtable

The commit log position at the time that this memtable was switched out

mayContainDataBefore

public boolean mayContainDataBefore(CommitLogPosition position)

Description copied from interface: Memtable

True if the memtable can contain any data that was written before the given commit log position