org.apache.cassandra.db.rows

Class Cell

java.lang.Object

org.apache.cassandra.db.rows.ColumnData

org.apache.cassandra.db.rows.Cell

Direct Known Subclasses:

AbstractCell

public abstract class Cell
extends ColumnData

A cell is our atomic unit for a single value of a single column.

A cell always holds at least a timestamp that gives us how the cell reconcile. We then have 3 main types of cells: 1) live regular cells: those will also have a value and, if for a complex column, a path. 2) expiring cells: on top of regular cells, those have a ttl and a local deletion time (when they are expired). 3) tombstone cells: those won't have value, but they have a local deletion time (when the tombstone was created).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Cell.Serializer

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Comparator<Cell>	comparator
static int	NO_DELETION_TIME
static int	NO_TTL
static Cell.Serializer	serializer

Fields inherited from class org.apache.cassandra.db.rows.ColumnData

column

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Cell(ColumnDefinition column)

Method Summary

Modifier and Type	Method and Description
abstract Cell	copy(AbstractAllocator allocator)
abstract boolean	isCounterCell() Whether the cell is a counter cell or not.
abstract boolean	isExpiring() Whether the cell is an expiring one or not.
abstract boolean	isLive(int nowInSec) Whether the cell is live or not given the current time.
abstract boolean	isTombstone() Whether the cell is a tombstone or not.
abstract int	localDeletionTime() The cell local deletion time.
abstract Cell	markCounterLocalToBeCleared()
abstract CellPath	path() For cells belonging to complex types (non-frozen collection and UDT), the path to the cell.
abstract Cell	purge(DeletionPurger purger, int nowInSec)
abstract long	timestamp() The cell timestamp.
abstract int	ttl() The cell ttl.
abstract java.nio.ByteBuffer	value() The cell value.
abstract Cell	withUpdatedColumn(ColumnDefinition newColumn)
abstract Cell	withUpdatedValue(java.nio.ByteBuffer newValue)

Methods inherited from class org.apache.cassandra.db.rows.ColumnData

column, dataSize, digest, maxTimestamp, unsharedHeapSizeExcludingData, updateAllTimestamp, validate

Methods inherited from class java.lang.Object

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

Field Detail

NO_TTL

public static final int NO_TTL

See Also:

Constant Field Values

NO_DELETION_TIME

public static final int NO_DELETION_TIME

See Also:

Constant Field Values

comparator

public static final java.util.Comparator<Cell> comparator

serializer

public static final Cell.Serializer serializer

Constructor Detail

Cell

protected Cell(ColumnDefinition column)

Method Detail

isCounterCell

public abstract boolean isCounterCell()

Whether the cell is a counter cell or not.

Returns:

whether the cell is a counter cell or not.

value

public abstract java.nio.ByteBuffer value()

The cell value.

Returns:

the cell value.

timestamp

public abstract long timestamp()

The cell timestamp.

Returns:

the cell timestamp.

ttl

public abstract int ttl()

The cell ttl.

Returns:

the cell ttl, or NO_TTL if the cell isn't an expiring one.

localDeletionTime

public abstract int localDeletionTime()

The cell local deletion time.

Returns:

the cell local deletion time, or NO_DELETION_TIME if the cell is neither a tombstone nor an expiring one.

isTombstone

public abstract boolean isTombstone()

Whether the cell is a tombstone or not.

Returns:

whether the cell is a tombstone or not.

isExpiring

public abstract boolean isExpiring()

Whether the cell is an expiring one or not.

Note that this only correspond to whether the cell liveness info have a TTL or not, but doesn't tells whether the cell is already expired or not. You should use isLive(int) for that latter information.

Returns:

whether the cell is an expiring one or not.

isLive

public abstract boolean isLive(int nowInSec)

Whether the cell is live or not given the current time.

Parameters:

nowInSec - the current time in seconds. This is used to decide if an expiring cell is expired or live.

Returns:

whether the cell is live or not at nowInSec.

path

public abstract CellPath path()

For cells belonging to complex types (non-frozen collection and UDT), the path to the cell.

Returns:

the cell path for cells of complex column, and null for other cells.

withUpdatedColumn

public abstract Cell withUpdatedColumn(ColumnDefinition newColumn)

withUpdatedValue

public abstract Cell withUpdatedValue(java.nio.ByteBuffer newValue)

copy

public abstract Cell copy(AbstractAllocator allocator)

markCounterLocalToBeCleared

public abstract Cell markCounterLocalToBeCleared()

Specified by:

markCounterLocalToBeCleared in class ColumnData

purge

public abstract Cell purge(DeletionPurger purger,
                           int nowInSec)

Specified by:

purge in class ColumnData