org.apache.cassandra.db

Class CounterColumn

java.lang.Object

org.apache.cassandra.db.Column

org.apache.cassandra.db.CounterColumn

All Implemented Interfaces:

IColumn, OnDiskAtom

public class CounterColumn
extends Column

A column that represents a partitioned counter.

Nested Class Summary

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

OnDiskAtom.Serializer

Field Summary

Fields

Modifier and Type	Field and Description
protected static CounterContext	contextManager

Fields inherited from class org.apache.cassandra.db.Column

name, timestamp, value

Fields inherited from interface org.apache.cassandra.db.IColumn

MAX_NAME_LENGTH

Constructor Summary

Constructors

Constructor and Description
CounterColumn(java.nio.ByteBuffer name, java.nio.ByteBuffer value, long timestamp)
CounterColumn(java.nio.ByteBuffer name, java.nio.ByteBuffer value, long timestamp, long timestampOfLastDelete)
CounterColumn(java.nio.ByteBuffer name, long value, long timestamp)
CounterColumn(java.nio.ByteBuffer name, long value, long timestamp, long timestampOfLastDelete)

Method Summary

Methods

Modifier and Type	Method and Description
static CounterColumn	create(java.nio.ByteBuffer name, java.nio.ByteBuffer value, long timestamp, long timestampOfLastDelete, IColumnSerializer.Flag flag)
int	dataSize() the size of user-provided data, not including internal overhead
IColumn	diff(IColumn column)
boolean	equals(java.lang.Object o)
java.lang.String	getString(AbstractType<?> comparator)
boolean	hasCounterId(CounterId id) Check if a given counterId is found in this CounterColumn context.
int	hashCode()
IColumn	localCopy(ColumnFamilyStore cfs) clones the column for the row cache, interning column names and making copies of other underlying byte buffers
IColumn	localCopy(ColumnFamilyStore cfs, Allocator allocator) clones the column for the memtable, interning column names and making copies of other underlying byte buffers.
IColumn	markDeltaToBeCleared()
static void	mergeAndRemoveOldShards(DecoratedKey key, ColumnFamily cf, int gcBefore, int mergeBefore)
static void	mergeAndRemoveOldShards(DecoratedKey key, ColumnFamily cf, int gcBefore, int mergeBefore, boolean sendToOtherReplica) There is two phase to the removal of old shards.
IColumn	reconcile(IColumn column, Allocator allocator)
int	serializationFlags()
int	serializedSize(TypeSizes typeSizes)
long	timestampOfLastDelete()
long	total()
void	updateDigest(java.security.MessageDigest digest)
void	validateFields(CFMetaData metadata)

Methods inherited from class org.apache.cassandra.db.Column

addColumn, addColumn, create, create, create, create, create, create, getLocalDeletionTime, getMarkedForDeleteAt, getSubColumn, getSubColumns, hasIrrelevantData, isLive, isMarkedForDelete, maxTimestamp, minTimestamp, mostRecentLiveChangeAt, mostRecentNonGCableChangeAt, name, onDiskSerializer, reconcile, serializedSizeForSSTable, serializer, timestamp, validateName, value

Methods inherited from class java.lang.Object

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

Field Detail

contextManager

protected static final CounterContext contextManager

Constructor Detail

CounterColumn

public CounterColumn(java.nio.ByteBuffer name,
             long value,
             long timestamp)

CounterColumn

public CounterColumn(java.nio.ByteBuffer name,
             long value,
             long timestamp,
             long timestampOfLastDelete)

CounterColumn

public CounterColumn(java.nio.ByteBuffer name,
             java.nio.ByteBuffer value,
             long timestamp)

CounterColumn

public CounterColumn(java.nio.ByteBuffer name,
             java.nio.ByteBuffer value,
             long timestamp,
             long timestampOfLastDelete)

Method Detail

create

public static CounterColumn create(java.nio.ByteBuffer name,
                   java.nio.ByteBuffer value,
                   long timestamp,
                   long timestampOfLastDelete,
                   IColumnSerializer.Flag flag)

timestampOfLastDelete

public long timestampOfLastDelete()

total

public long total()

dataSize

public int dataSize()

Description copied from interface: IColumn

the size of user-provided data, not including internal overhead

Specified by:

dataSize in interface IColumn

Overrides:

dataSize in class Column

serializedSize

public int serializedSize(TypeSizes typeSizes)

Specified by:

serializedSize in interface OnDiskAtom

Overrides:

serializedSize in class Column

diff

public IColumn diff(IColumn column)

Specified by:

diff in interface IColumn

Overrides:

diff in class Column

updateDigest

public void updateDigest(java.security.MessageDigest digest)

Specified by:

updateDigest in interface OnDiskAtom

Overrides:

updateDigest in class Column

reconcile

public IColumn reconcile(IColumn column,
                Allocator allocator)

Specified by:

reconcile in interface IColumn

Overrides:

reconcile in class Column

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class Column

hashCode

public int hashCode()

Overrides:

hashCode in class Column

localCopy

public IColumn localCopy(ColumnFamilyStore cfs)

Description copied from interface: IColumn

clones the column for the row cache, interning column names and making copies of other underlying byte buffers

Specified by:

localCopy in interface IColumn

Overrides:

localCopy in class Column

localCopy

public IColumn localCopy(ColumnFamilyStore cfs,
                Allocator allocator)

Description copied from interface: IColumn

clones the column for the memtable, interning column names and making copies of other underlying byte buffers. Unlike the other localCopy, this uses Allocator to allocate values in contiguous memory regions, which helps avoid heap fragmentation.

Specified by:

localCopy in interface IColumn

Overrides:

localCopy in class Column

getString

public java.lang.String getString(AbstractType<?> comparator)

Specified by:

getString in interface IColumn

Overrides:

getString in class Column

serializationFlags

public int serializationFlags()

Specified by:

serializationFlags in interface IColumn

Overrides:

serializationFlags in class Column

validateFields

public void validateFields(CFMetaData metadata)
                    throws MarshalException

Specified by:

validateFields in interface IColumn

Specified by:

validateFields in interface OnDiskAtom

Overrides:

validateFields in class Column

Throws:

MarshalException

hasCounterId

public boolean hasCounterId(CounterId id)

Check if a given counterId is found in this CounterColumn context.

mergeAndRemoveOldShards

public static void mergeAndRemoveOldShards(DecoratedKey key,
                           ColumnFamily cf,
                           int gcBefore,
                           int mergeBefore)

mergeAndRemoveOldShards

public static void mergeAndRemoveOldShards(DecoratedKey key,
                           ColumnFamily cf,
                           int gcBefore,
                           int mergeBefore,
                           boolean sendToOtherReplica)

There is two phase to the removal of old shards. First phase: we merge the old shard value to the current shard and 'nulify' the old one. We then send the counter context with the old shard nulified to all other replica. Second phase: once an old shard has been nulified for longer than gc_grace (to be sure all other replica had been aware of the merge), we simply remove that old shard from the context (it's value is 0). This method does both phases. (Note that the sendToOtherReplica flag is here only to facilitate testing. It should be true in real code so use the method above preferably)

markDeltaToBeCleared

public IColumn markDeltaToBeCleared()