Package ch.tocco.nice2.persist.core.api.exec

Class PartitionedTask<I,O,X,Y>

java.lang.Object

ch.tocco.nice2.persist.core.api.exec.PartitionedTask<I,O,X,Y>

Type Parameters:

I - parameter type of the PartitionedTask

O - return type of the PartitionedTask

X - parameter type of the nested task

Y - return type of the nested task

All Implemented Interfaces:

PersistTask<Iterable<I>,Iterable<O>>, PersistTaskIterable<Iterable<I>,O>

public class PartitionedTask<I,O,X,Y>
extends Object
implements PersistTaskIterable<Iterable<I>,O>

A PersistTaskIterable that takes an Iterable of parameters. The nested task is executed once for each partition (and given an Iterable of parameters). For each partition a new context (and transaction) is created to limit the size of the context. As Entity instances can only be used with the Context they are associated to, they should typically not be used as parameter or return types of the outer PersistTaskIterable (I, O) (use PrimaryKey or EntityId instead!). In addition this would defeat the purpose of using multiple contexts to save memory. The inner task can use Entity as parameter or return type though. A converter function that has to be passed to the constructor will convert the parameters and return values of the outer task to inner task and vice versa. (see entityToPrimaryKey() for example).

Constructor Summary

Constructors

Constructor	Description
PartitionedTask(AbstractPartitionedPersistTask<X,Y,?> task, BiFunction<Iterable<I>,PersistenceService,Iterable<X>> inputConverter, Function<Iterable<Y>,Iterable<O>> outputConverter, int batchSize, boolean transactional)

Method Summary

Modifier and Type	Method	Description
static <T> BiFunction<Iterable<T>,PersistenceService,Iterable<T>>	emptyBiFunction(Class<T> clazz)	Does not do anything - can be used for parameters that are independent of the Context.
static <T> Function<Iterable<T>,Iterable<T>>	emptyFunction(Class<T> clazz)	Does not do anything - can be used for parameters that are independent of the Context.
static Function<Iterable<Entity>,Iterable<EntityId>>	entityToEntityId()
static Function<Iterable<Entity>,Iterable<PrimaryKey>>	entityToPrimaryKey()	Converts an Entity to a PrimaryKey.
static Function<Iterable<Entity>,Iterable<SimpleEntityId>>	entityToSimpleEntityId()
static BiFunction<Iterable<EntityId>,PersistenceService,Iterable<Entity>>	loadEntities()
static BiFunction<Iterable<PrimaryKey>,PersistenceService,Iterable<Entity>>	loadEntities(EntityModel entityModel, boolean keepOrder)
static BiFunction<Iterable<PrimaryKey>,PersistenceService,Iterable<Entity>>	loadEntities(String entityModel)	Loads entities based on a list of private keys.
@Nullable Iterable<O>	run(Optional<Iterable<I>> args, CommandContext commandContext)

Methods inherited from class java.lang.Object

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

Methods inherited from interface ch.tocco.nice2.persist.core.api.exec.PersistTask

andThenDo, compose, compose2, composeWhen, discardResult, expand, expand, getDescription, ifElse, logTime, orWhen, orWhenNot, passWhen, passWhenNot, skipErrors, unwrap

Methods inherited from interface ch.tocco.nice2.persist.core.api.exec.PersistTaskIterable

filter, find, flatMap, forEach, get, get, get, getOnlyElement, getOnlyElement, getOnlyElement, map

Constructor Details

PartitionedTask

public PartitionedTask(AbstractPartitionedPersistTask<X,Y,?> task,
 BiFunction<Iterable<I>,PersistenceService,Iterable<X>> inputConverter,
 Function<Iterable<Y>,Iterable<O>> outputConverter,
 int batchSize,
 boolean transactional)

Method Details

run

@Nullable
public @Nullable Iterable<O> run(Optional<Iterable<I>> args,
 CommandContext commandContext)
                          throws Exception

Specified by:

run in interface PersistTask<I,O>

Throws:

Exception

entityToPrimaryKey

public static Function<Iterable<Entity>,Iterable<PrimaryKey>> entityToPrimaryKey()

Converts an Entity to a PrimaryKey.

entityToEntityId

public static Function<Iterable<Entity>,Iterable<EntityId>> entityToEntityId()

entityToSimpleEntityId

public static Function<Iterable<Entity>,Iterable<SimpleEntityId>> entityToSimpleEntityId()

emptyFunction

public static <T> Function<Iterable<T>,Iterable<T>> emptyFunction(Class<T> clazz)

Does not do anything - can be used for parameters that are independent of the Context.

emptyBiFunction

public static <T>
BiFunction<Iterable<T>,PersistenceService,Iterable<T>> emptyBiFunction(Class<T> clazz)

Does not do anything - can be used for parameters that are independent of the Context.

loadEntities

public static BiFunction<Iterable<PrimaryKey>,PersistenceService,Iterable<Entity>> loadEntities(String entityModel)

Loads entities based on a list of private keys.

loadEntities

public static BiFunction<Iterable<PrimaryKey>,PersistenceService,Iterable<Entity>> loadEntities(EntityModel entityModel,
 boolean keepOrder)

loadEntities

public static BiFunction<Iterable<EntityId>,PersistenceService,Iterable<Entity>> loadEntities()