Package org.openrefine.model.changes

Class LazyChangeDataStore

java.lang.Object

org.openrefine.model.changes.LazyChangeDataStore

All Implemented Interfaces:

ChangeDataStore

public class LazyChangeDataStore
extends Object
implements ChangeDataStore

A ChangeDataStore which does not persist its change data, meaning that they do not have to be computed explicitly.

The ChangeData objects are simply stored in an in-memory map, to be restored later. This is suitable in contexts where project data must not be persisted and workflows are meant to be run as pipelines from the import to the export stage.

Constructor Summary

Constructors

Constructor	Description
LazyChangeDataStore(Runner runner)

Method Summary

Modifier and Type	Method	Description
void	discardAll(long historyEntryId)	Discards all change data objects which belong to a given history entry id.
void	dispose()	Stops all the processes and shuts down the thread pool.
List<ChangeDataId>	getChangeDataIds(long historyEntryId)	Retrieve the list of change data ids associated with a given history entry.
ProcessManager	getProcessManager()
boolean	needsRefreshing(long historyEntryId)	Returns true when a change data object is being fetched by a process and should therefore be refreshed as the process may have refreshed the contents on disk.
<T> ChangeData<T>	retrieve(ChangeDataId changeDataId, ChangeDataSerializer<T> serializer)	Loads back a ChangeData that has been persisted before.
<T> ChangeData<T>	retrieveOrCompute(ChangeDataId changeDataId, ChangeDataSerializer<T> serializer, Function<Optional<ChangeData<T>>,ChangeData<T>> completionProcess, String description)	Retrieves a change data if it exists already, and if it does not (or is incomplete), start a process to finish computing it.
<T> void	store(ChangeData<T> data, ChangeDataId changeDataId, ChangeDataSerializer<T> serializer, Optional<ProgressReporter> progressReporter)	Stores a ChangeData, which might imply explicitly computing all its values (if the store persists its changes).
<T> ProgressingFuture<Void>	storeAsync(ChangeData<T> data, ChangeDataId changeDataId, ChangeDataSerializer<T> serializer)	Asynchronously stores a ChangeData, which might imply explicitly computing all its values (if the store persists its changes).

Methods inherited from class java.lang.Object

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

Constructor Detail

LazyChangeDataStore

public LazyChangeDataStore(Runner runner)

Method Detail

getProcessManager

public ProcessManager getProcessManager()

Specified by:

getProcessManager in interface ChangeDataStore

store

public <T> void store(ChangeData<T> data,
                      ChangeDataId changeDataId,
                      ChangeDataSerializer<T> serializer,
                      Optional<ProgressReporter> progressReporter)
               throws IOException

Description copied from interface: ChangeDataStore

Stores a ChangeData, which might imply explicitly computing all its values (if the store persists its changes).

Specified by:

store in interface ChangeDataStore

Parameters:

data - the data to store

changeDataId - the id of the change data to store

serializer - to serialize the data to a file, for instance

progressReporter - reports the progress of the change data computation and serialization

Throws:

IOException - if serialization failed

storeAsync

public <T> ProgressingFuture<Void> storeAsync(ChangeData<T> data,
                                              ChangeDataId changeDataId,
                                              ChangeDataSerializer<T> serializer)

Description copied from interface: ChangeDataStore

Asynchronously stores a ChangeData, which might imply explicitly computing all its values (if the store persists its changes).

Specified by:

storeAsync in interface ChangeDataStore

Parameters:

data - the data to store

changeDataId - the id of the change data to store

serializer - to serialize the data to a file, for instance

retrieve

public <T> ChangeData<T> retrieve(ChangeDataId changeDataId,
                                  ChangeDataSerializer<T> serializer)
                           throws IOException

Description copied from interface: ChangeDataStore

Loads back a ChangeData that has been persisted before.

Specified by:

retrieve in interface ChangeDataStore

Parameters:

changeDataId - the id of the change data to retrieve

serializer - the deserializer to read it back from a file

Throws:

IOException

retrieveOrCompute

public <T> ChangeData<T> retrieveOrCompute(ChangeDataId changeDataId,
                                           ChangeDataSerializer<T> serializer,
                                           Function<Optional<ChangeData<T>>,ChangeData<T>> completionProcess,
                                           String description)
                                    throws IOException

Description copied from interface: ChangeDataStore

Retrieves a change data if it exists already, and if it does not (or is incomplete), start a process to finish computing it.

Specified by:

retrieveOrCompute in interface ChangeDataStore

Parameters:

changeDataId - the id of the change data to retrieve

serializer - the serializer to read it back from a file and to write its completion if it is incomplete

completionProcess - a function taking the existing state of the change data and returning the complete version

description - a description of the completion process, to be reported to the user

Throws:

IOException

needsRefreshing

public boolean needsRefreshing(long historyEntryId)

Description copied from interface: ChangeDataStore

Returns true when a change data object is being fetched by a process and should therefore be refreshed as the process may have refreshed the contents on disk.

Specified by:

needsRefreshing in interface ChangeDataStore

discardAll

public void discardAll(long historyEntryId)

Description copied from interface: ChangeDataStore

Discards all change data objects which belong to a given history entry id.

Specified by:

discardAll in interface ChangeDataStore

getChangeDataIds

public List<ChangeDataId> getChangeDataIds(long historyEntryId)

Description copied from interface: ChangeDataStore

Retrieve the list of change data ids associated with a given history entry.

Specified by:

getChangeDataIds in interface ChangeDataStore

dispose

public void dispose()

Description copied from interface: ChangeDataStore

Stops all the processes and shuts down the thread pool.

Specified by:

dispose in interface ChangeDataStore