org.apache.cassandra.db.rows

Class Rows

java.lang.Object

org.apache.cassandra.db.rows.Rows

public abstract class Rows
extends java.lang.Object

Static utilities to work on Row objects.

Field Summary

Fields

Modifier and Type	Field and Description
static Row	EMPTY_STATIC_ROW

Method Summary

Modifier and Type	Method and Description
static int	collectStats(Row row, PartitionStatisticsCollector collector) Collect statistics on a given row.
static Row.Builder	copy(Row row, Row.Builder builder)
static void	diff(RowDiffListener diffListener, Row merged, Row... inputs) Given the result (merged) of merging multiple inputs, signals the difference between each input and merged to diffListener.
static Row	merge(Row row1, Row row2)
static long	merge(Row existing, Row update, Row.Builder builder) Merges two rows into the given builder, mainly for merging memtable rows.
static Row	removeShadowedCells(Row existing, Row update, DeletionTime rangeDeletion) Returns a row that is obtained from the given existing row by removing everything that is shadowed by data in the update row.
static Row.SimpleBuilder	simpleBuilder(TableMetadata metadata, java.lang.Object... clusteringValues) Creates a new simple row builder.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_STATIC_ROW

public static final Row EMPTY_STATIC_ROW

Method Detail

copy

public static Row.Builder copy(Row row,
                               Row.Builder builder)

simpleBuilder

public static Row.SimpleBuilder simpleBuilder(TableMetadata metadata,
                                              java.lang.Object... clusteringValues)

Creates a new simple row builder.

Parameters:

metadata - the metadata of the table this is a row of.

clusteringValues - the value for the clustering columns of the row to add to this build. There may be no values if either the table has no clustering column, or if you want to edit the static row. Note that as a shortcut it is also allowed to pass a Clustering object directly, in which case that should be the only argument.

Returns:

a newly created builder.

collectStats

public static int collectStats(Row row,
                               PartitionStatisticsCollector collector)

Collect statistics on a given row.

Parameters:

row - the row for which to collect stats.

collector - the stats collector.

Returns:

the total number of cells in row.

diff

public static void diff(RowDiffListener diffListener,
                        Row merged,
                        Row... inputs)

Given the result (merged) of merging multiple inputs, signals the difference between each input and merged to diffListener.

Note that this method doesn't only emit cells etc where there's a difference. The listener is informed of every corresponding entity between the merged and input rows, including those that are equal.

Parameters:

diffListener - the listener to which to signal the differences between the inputs and the merged result.

merged - the result of merging inputs.

inputs - the inputs whose merge yielded merged.

merge

public static Row merge(Row row1,
                        Row row2)

merge

public static long merge(Row existing,
                         Row update,
                         Row.Builder builder)

Merges two rows into the given builder, mainly for merging memtable rows. In addition to reconciling the cells in each row, the liveness info, and deletion times for the row and complex columns are also merged.

Note that this method assumes that the provided rows can meaningfully be reconciled together. That is, that the rows share the same clustering value, and belong to the same partition.

Parameters:

existing -

update -

builder - the row build to which the result of the reconciliation is written.

Returns:

the smallest timestamp delta between corresponding rows from existing and update. A timestamp delta being computed as the difference between the cells and DeletionTimes from existing and those in existing.

removeShadowedCells

public static Row removeShadowedCells(Row existing,
                                      Row update,
                                      DeletionTime rangeDeletion)

Returns a row that is obtained from the given existing row by removing everything that is shadowed by data in the update row. In other words, produces the smallest result row such that merge(result, update, nowInSec) == merge(existing, update, nowInSec) after filtering by rangeDeletion.

Parameters:

existing - source row

update - shadowing row

rangeDeletion - extra DeletionTime from covering tombstone