com.almworks.jira.structure.api.attribute

Class VersionedRowValues.EmptyVersionedRowValues

java.lang.Object

com.almworks.jira.structure.api.attribute.VersionedRowValues.EmptyVersionedRowValues

All Implemented Interfaces:

RowValues, VersionedRowValues

Enclosing interface:

VersionedRowValues

public static final class VersionedRowValues.EmptyVersionedRowValues
extends Object
implements VersionedRowValues

Empty result implementation

Nested Class Summary

Nested classes/interfaces inherited from interface com.almworks.jira.structure.api.attribute.VersionedRowValues

VersionedRowValues.EmptyVersionedRowValues

Field Summary

Fields inherited from interface com.almworks.jira.structure.api.attribute.VersionedRowValues

EMPTY

Constructor Summary

Constructors

Constructor and Description
EmptyVersionedRowValues()

Method Summary

Modifier and Type	Method and Description
<T> T	get(Long row, AttributeSpec<T> attribute) Returns a value for the given row and attribute.
DataVersion	getForestVersion() Returns the version of the forest (defined by ForestSpec), which was used to calculate the values.
DataVersion	getItemsVersion() Returns the global version of items, which was current when the values were calculated.
AttributeTrail	getTrail(AttributeSpec<?> attribute) Returns an object that can be used to implement correct value invalidation, in case the value is cached.

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyVersionedRowValues

public EmptyVersionedRowValues()

Method Detail

getForestVersion

@NotNull
public DataVersion getForestVersion()

Description copied from interface: VersionedRowValues

Returns the version of the forest (defined by ForestSpec), which was used to calculate the values. Forest version is important for "aggregate" and "propagate" values.

When values are requested for arbitrary forest (not defined by a ForestSpec), this method always returns DataVersion.ZERO.

Specified by:

getForestVersion in interface VersionedRowValues

getItemsVersion

@NotNull
public DataVersion getItemsVersion()

Description copied from interface: VersionedRowValues

Returns the global version of items, which was current when the values were calculated. When items change, the global items version increases, so it can be used to implement caching with invalidation.

Specified by:

getItemsVersion in interface VersionedRowValues

See Also:

ItemTracker

getTrail

@NotNull
public AttributeTrail getTrail(AttributeSpec<?> attribute)

Description copied from interface: RowValues

Returns an object that can be used to implement correct value invalidation, in case the value is cached.

Specified by:

getTrail in interface RowValues

Parameters:

attribute - attribute that was requested for value calculation

Returns:

the attribute's trail (a trail for non-requested attribute will be empty, but not null)

get

public <T> T get(Long row,
                 AttributeSpec<T> attribute)

Description copied from interface: RowValues

Returns a value for the given row and attribute.

Specified by:

get in interface RowValues

Type Parameters:

T - value type

Parameters:

row - row ID

attribute - attribute specification

Returns:

value or null if the value is missing