org.apache.cassandra.db
Class Column

java.lang.Object
  org.apache.cassandra.db.Column

All Implemented Interfaces:

IColumn, OnDiskAtom

Direct Known Subclasses:

CounterColumn, CounterUpdateColumn, DeletedColumn, ExpiringColumn

public class Column
extends java.lang.Object
implements IColumn

Column is immutable, which prevents all kinds of confusion in a multithreaded environment. (TODO: look at making SuperColumn immutable too. This is trickier but is probably doable with something like PCollections -- http://code.google.com

Nested Class Summary

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

OnDiskAtom.Serializer

Field Summary

protected java.nio.ByteBuffer	name
protected long	timestamp
protected java.nio.ByteBuffer	value

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

MAX_NAME_LENGTH

Constructor Summary

Column(java.nio.ByteBuffer name, java.nio.ByteBuffer value)

Column(java.nio.ByteBuffer name, java.nio.ByteBuffer value, long timestamp)

Method Summary

void	addColumn(IColumn column)
void	addColumn(IColumn column, Allocator allocator)
static Column	create(boolean value, long timestamp, java.lang.String... names)
static Column	create(java.nio.ByteBuffer value, long timestamp, java.lang.String... names)
static Column	create(double value, long timestamp, java.lang.String... names)
static Column	create(java.net.InetAddress value, long timestamp, java.lang.String... names)
static Column	create(int value, long timestamp, java.lang.String... names)
static Column	create(java.lang.String value, long timestamp, java.lang.String... names)
int	dataSize() the size of user-provided data, not including internal overhead
IColumn	diff(IColumn column)
boolean	equals(java.lang.Object o)
int	getLocalDeletionTime()
long	getMarkedForDeleteAt()
java.lang.String	getString(AbstractType<?> comparator)
Column	getSubColumn(java.nio.ByteBuffer columnName)
java.util.Collection<IColumn>	getSubColumns()
int	hashCode()
boolean	hasIrrelevantData(int gcBefore)
boolean	isLive() For a simple column, live == !isMarkedForDelete.
boolean	isMarkedForDelete()
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.
long	maxTimestamp() For a standard column, this is the same as timestamp().
long	minTimestamp() For a standard column, this is the same as timestamp().
long	mostRecentLiveChangeAt()
long	mostRecentNonGCableChangeAt(int gcbefore)
java.nio.ByteBuffer	name()
static OnDiskAtom.Serializer	onDiskSerializer()
IColumn	reconcile(IColumn column)
IColumn	reconcile(IColumn column, Allocator allocator)
int	serializationFlags()
int	serializedSize(TypeSizes typeSizes)
long	serializedSizeForSSTable()
static ColumnSerializer	serializer()
long	timestamp()
void	updateDigest(java.security.MessageDigest digest)
void	validateFields(CFMetaData metadata)
protected void	validateName(CFMetaData metadata)
java.nio.ByteBuffer	value()

Methods inherited from class java.lang.Object

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

Field Detail

name

protected final java.nio.ByteBuffer name

value

protected final java.nio.ByteBuffer value

timestamp

protected final long timestamp

Constructor Detail

Column

public Column(java.nio.ByteBuffer name,
              java.nio.ByteBuffer value)

Column

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

Method Detail

serializer

public static ColumnSerializer serializer()

onDiskSerializer

public static OnDiskAtom.Serializer onDiskSerializer()

name

public java.nio.ByteBuffer name()

Specified by:

name in interface OnDiskAtom

getSubColumn

public Column getSubColumn(java.nio.ByteBuffer columnName)

Specified by:

getSubColumn in interface IColumn

value

public java.nio.ByteBuffer value()

Specified by:

value in interface IColumn

getSubColumns

public java.util.Collection<IColumn> getSubColumns()

Specified by:

getSubColumns in interface IColumn

timestamp

public long timestamp()

Specified by:

timestamp in interface IColumn

minTimestamp

public long minTimestamp()

Description copied from interface: OnDiskAtom

For a standard column, this is the same as timestamp(). For a super column, this is the min/max column timestamp of the sub columns.

Specified by:

minTimestamp in interface OnDiskAtom

maxTimestamp

public long maxTimestamp()

Description copied from interface: IColumn

For a standard column, this is the same as timestamp(). For a super column, this is the max column timestamp of the sub columns.

Specified by:

maxTimestamp in interface IColumn

Specified by:

maxTimestamp in interface OnDiskAtom

isMarkedForDelete

public boolean isMarkedForDelete()

Specified by:

isMarkedForDelete in interface IColumn

Returns:

true if the column has been deleted (is a tombstone). This depends on comparing the server clock with getLocalDeletionTime, so it can change during a single request if you're not careful.

getMarkedForDeleteAt

public long getMarkedForDeleteAt()

Specified by:

getMarkedForDeleteAt in interface IColumn

mostRecentLiveChangeAt

public long mostRecentLiveChangeAt()

Specified by:

mostRecentLiveChangeAt in interface IColumn

mostRecentNonGCableChangeAt

public long mostRecentNonGCableChangeAt(int gcbefore)

Specified by:

mostRecentNonGCableChangeAt in interface IColumn

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

serializedSize

public int serializedSize(TypeSizes typeSizes)

Specified by:

serializedSize in interface OnDiskAtom

serializedSizeForSSTable

public long serializedSizeForSSTable()

Specified by:

serializedSizeForSSTable in interface OnDiskAtom

serializationFlags

public int serializationFlags()

Specified by:

serializationFlags in interface IColumn

addColumn

public void addColumn(IColumn column)

Specified by:

addColumn in interface IColumn

addColumn

public void addColumn(IColumn column,
                      Allocator allocator)

Specified by:

addColumn in interface IColumn

diff

public IColumn diff(IColumn column)

Specified by:

diff in interface IColumn

updateDigest

public void updateDigest(java.security.MessageDigest digest)

Specified by:

updateDigest in interface OnDiskAtom

getLocalDeletionTime

public int getLocalDeletionTime()

Specified by:

getLocalDeletionTime in interface OnDiskAtom

reconcile

public IColumn reconcile(IColumn column)

Specified by:

reconcile in interface IColumn

reconcile

public IColumn reconcile(IColumn column,
                         Allocator allocator)

Specified by:

reconcile in interface IColumn

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

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

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

getString

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

Specified by:

getString in interface IColumn

isLive

public boolean isLive()

Description copied from interface: IColumn

For a simple column, live == !isMarkedForDelete. For a supercolumn, live means it has at least one subcolumn whose timestamp is greater than the supercolumn deleted-at time.

Specified by:

isLive in interface IColumn

validateName

protected void validateName(CFMetaData metadata)
                     throws MarshalException

Throws:

MarshalException

validateFields

public void validateFields(CFMetaData metadata)
                    throws MarshalException

Specified by:

validateFields in interface IColumn

Specified by:

validateFields in interface OnDiskAtom

Throws:

MarshalException

hasIrrelevantData

public boolean hasIrrelevantData(int gcBefore)

Specified by:

hasIrrelevantData in interface IColumn

Returns:

true if the column or any its subcolumns is no longer relevant after @param gcBefore

create

public static Column create(java.lang.String value,
                            long timestamp,
                            java.lang.String... names)

create

public static Column create(int value,
                            long timestamp,
                            java.lang.String... names)

create

public static Column create(boolean value,
                            long timestamp,
                            java.lang.String... names)

create

public static Column create(double value,
                            long timestamp,
                            java.lang.String... names)

create

public static Column create(java.nio.ByteBuffer value,
                            long timestamp,
                            java.lang.String... names)

create

public static Column create(java.net.InetAddress value,
                            long timestamp,
                            java.lang.String... names)