Package org.apache.cassandra.db.rows

Class Cell<V>

java.lang.Object
org.apache.cassandra.db.rows.ColumnData
org.apache.cassandra.db.rows.Cell<V>
All Implemented Interfaces:
IMeasurableMemory
Direct Known Subclasses:
AbstractCell, CellWithSource
public abstract class Cell<V> 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).

  • Field Details

    • NO_TTL

      public static final int NO_TTL
      See Also:

    • NO_DELETION_TIME

      public static final long NO_DELETION_TIME
      See Also:

    • NO_DELETION_TIME_UNSIGNED_INTEGER

      public static final int NO_DELETION_TIME_UNSIGNED_INTEGER

    • MAX_DELETION_TIME

      public static final long MAX_DELETION_TIME

    • MAX_DELETION_TIME_UNSIGNED_INTEGER

      public static final int MAX_DELETION_TIME_UNSIGNED_INTEGER

    • INVALID_DELETION_TIME

      public static final long INVALID_DELETION_TIME

    • MAX_DELETION_TIME_2038_LEGACY_CAP

      public static final int MAX_DELETION_TIME_2038_LEGACY_CAP
      See Also:

    • comparator

      public static final Comparator<Cell<?>> comparator

    • serializer

      public static final org.apache.cassandra.db.rows.Cell.Serializer serializer

  • Constructor Details

  • Method Details

    • deletionTimeLongToUnsignedInteger

      public static int deletionTimeLongToUnsignedInteger(long deletionTime)

    • deletionTimeUnsignedIntegerToLong

      public static long deletionTimeUnsignedIntegerToLong(int deletionTimeUnsignedInteger)

    • getVersionedMaxDeletiontionTime

      public static long getVersionedMaxDeletiontionTime()

    • isCounterCell

      public abstract boolean isCounterCell()
      Whether the cell is a counter cell or not.CassandraUInt
      Returns:
      whether the cell is a counter cell or not.

    • value

      public abstract V value()

    • accessor

      public abstract ValueAccessor<V> accessor()

    • valueSize

      public int valueSize()

    • buffer

      public ByteBuffer buffer()

    • 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 long 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(long) for that latter information.

      Returns:
      whether the cell is an expiring one or not.

    • isLive

      public abstract boolean isLive(long 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(ColumnMetadata newColumn)

    • withUpdatedValue

      public abstract Cell<?> withUpdatedValue(ByteBuffer newValue)

    • withUpdatedTimestampAndLocalDeletionTime

      public abstract Cell<?> withUpdatedTimestampAndLocalDeletionTime(long newTimestamp, long newLocalDeletionTime)

    • withSkippedValue

      public abstract Cell<?> withSkippedValue()
      Used to apply the same optimization as in Cell.Serializer.deserialize(org.apache.cassandra.io.util.DataInputPlus, org.apache.cassandra.db.LivenessInfo, org.apache.cassandra.schema.ColumnMetadata, org.apache.cassandra.db.SerializationHeader, org.apache.cassandra.db.rows.DeserializationHelper, org.apache.cassandra.db.marshal.ValueAccessor<V>) when the column is not queried but eventhough it's used for digest calculation.
      Returns:
      a cell with an empty buffer as value

    • clone

      public final Cell<?> clone(Cloner cloner)
      Specified by:
      clone in class ColumnData

    • clone

      public abstract Cell<?> clone(ByteBufferCloner cloner)

    • markCounterLocalToBeCleared

      public abstract Cell<?> markCounterLocalToBeCleared()
      Specified by:
      markCounterLocalToBeCleared in class ColumnData

    • purge

      public abstract Cell<?> purge(DeletionPurger purger, long nowInSec)
      Specified by:
      purge in class ColumnData

    • purgeDataOlderThan

      public abstract Cell<?> purgeDataOlderThan(long timestamp)
      Specified by:
      purgeDataOlderThan in class ColumnData

    • localDeletionTimeAsUnsignedInt

      protected abstract int localDeletionTimeAsUnsignedInt()

    • decodeLocalDeletionTime

      public static long decodeLocalDeletionTime(long localDeletionTime, int ttl, DeserializationHelper helper)
      Handle unsigned encoding and potentially invalid localDeletionTime.