Package org.openrefine.runners.testing

Class TestingGrid

java.lang.Object

org.openrefine.runners.testing.TestingGrid

All Implemented Interfaces:

Grid

public class TestingGrid
extends Object
implements Grid

A massively inefficient but very simple implementation of a Grid, for testing purposes.

Author:

Antonin Delpeuch

Nested Class Summary

Nested classes/interfaces inherited from interface org.openrefine.model.Grid

Grid.ApproxCount, Grid.Metadata, Grid.PartialAggregation<T extends Serializable>

Field Summary

Fields inherited from interface org.openrefine.model.Grid

GRID_PATH, METADATA_PATH

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	TestingGrid(List<IndexedRow> indexedRows, ColumnModel columnModel, Map<String,OverlayModel> overlayModels)
	TestingGrid(ColumnModel columnModel, List<Row> rows, Map<String,OverlayModel> overlayModels)

Method Summary

Modifier and Type	Method	Description
<T extends Serializable> T	aggregateRecords(RecordAggregator<T> aggregator, T initialState)	Computes the result of a row aggregator on the grid.
<T extends Serializable> Grid.PartialAggregation<T>	aggregateRecordsApprox(RecordAggregator<T> aggregator, T initialState, long maxRecords)	Computes the result of a row aggregator on the grid, reading about at most a fixed number of records.
<T extends Serializable> T	aggregateRows(RowAggregator<T> aggregator, T initialState)	Computes the result of a row aggregator on the grid.
<T extends Serializable> Grid.PartialAggregation<T>	aggregateRowsApprox(RowAggregator<T> aggregator, T initialState, long maxRows)	Computes the result of a row aggregator on the grid, reading about at most a fixed number of rows.
boolean	cache()	Attempt to cache this grid in memory.
ProgressingFuture<Boolean>	cacheAsync()	Attempt to cache this grid in memory, in an async way.
List<Record>	collectRecords()	Returns all records in a list.
List<IndexedRow>	collectRows()	Returns all rows in a list.
Grid	concatenate(Grid other)	Creates a new grid containing all rows in this grid, followed by all rows in the other grid supplied.
long	countMatchingRecords(RecordFilter filter)	Return the number of records which are filtered by this filter.
Grid.ApproxCount	countMatchingRecordsApprox(RecordFilter filter, long limit)	Return the number of records matching the given record filter, but by processing about at most a fixed number of records.
long	countMatchingRows(RowFilter filter)	Count the number of rows which match a given filter.
Grid.ApproxCount	countMatchingRowsApprox(RowFilter filter, long limit)	Return the number of rows matching the given row filter, but by processing about at most a fixed number of row.
Grid	flatMapRows(RowFlatMapper mapper, ColumnModel newColumnModel)	Returns a new grid, where the rows have been mapped by the flat mapper.
ColumnModel	getColumnModel()
Map<String,OverlayModel>	getOverlayModels()
Record	getRecord(long id)	Returns a record obtained by its id.
List<Record>	getRecordsAfter(long start, int limit)	Returns a list of records, starting from a given index and defined by a maximum size.
List<Record>	getRecordsAfter(RecordFilter filter, long start, int limit)	Among the filtered subset of records, returns a list of records, starting from a given index and defined by a maximum size.
List<Record>	getRecordsBefore(long end, int limit)	Returns a list of consecutive records, ending at a given index (exclusive) and defined by a maximum size.
List<Record>	getRecordsBefore(RecordFilter filter, long end, int limit)	Among the filtered subset of records, returns a list of records, ending at a given index (exclusive) and defined by a maximum size.
Row	getRow(long id)	Returns a row by index.
List<IndexedRow>	getRowsAfter(long start, int limit)	Returns a list of rows, starting from a given index and defined by a maximum size.
List<IndexedRow>	getRowsAfter(RowFilter filter, long start, int limit)	Among the subset of filtered rows, return a list of rows, starting from a given index and defined by a maximum size.
List<IndexedRow>	getRowsBefore(long end, int limit)	Returns a list of consecutive rows, just before the given row index (not included) and up to a maximum size.
List<IndexedRow>	getRowsBefore(RowFilter filter, long end, int limit)	Among the subset of filtered rows, return a list of rows, just before the row with a given index (excluded) and defined by a maximum size.
Runner	getRunner()
static List<Record>	groupRowsIntoRecords(List<IndexedRow> rows, int keyCellIndex)
boolean	isCached()	Is this grid cached in memory?
CloseableIterator<Record>	iterateRecords(RecordFilter filter)	Iterate over records matched by a filter.
CloseableIterator<IndexedRow>	iterateRows(RowFilter filter)	Iterate over rows matched by a filter, in the order determined by a sorting configuration.
<T> Grid	join(ChangeData<T> changeData, RecordChangeDataJoiner<T> recordJoiner, ColumnModel newColumnModel)	Joins pre-computed change data with the current grid data, record by record.
<T> Grid	join(ChangeData<T> changeData, RowChangeDataFlatJoiner<T> rowJoiner, ColumnModel newColumnModel)	Joins pre-computed change data with the current grid data, with a joiner function that can return multiple rows for a given original row.
<T> Grid	join(ChangeData<T> changeData, RowChangeDataJoiner<T> rowJoiner, ColumnModel newColumnModel)	Joins pre-computed change data with the current grid data, row by row.
<T> ChangeData<T>	mapRecords(RecordFilter filter, RecordChangeDataProducer<T> recordMapper, Optional<ChangeData<T>> incompleteChangeData)	Extract change data by applying a function to each filtered record.
Grid	mapRecords(RecordMapper mapper, ColumnModel newColumnModel)	Returns a new grid, where the records have been mapped by the mapper
<T> ChangeData<T>	mapRows(RowFilter filter, RowChangeDataProducer<T> rowMapper, Optional<ChangeData<T>> incompleteChangeData)	Extract change data by applying a function to each filtered row.
Grid	mapRows(RowMapper mapper, ColumnModel newColumnModel)	Returns a new grid, where the rows have been mapped by the mapper.
<S extends Serializable> Grid	mapRows(RowScanMapper<S> mapper, ColumnModel newColumnModel)	Returns a new grid where the rows have been mapped by the stateful mapper.
long	recordCount()
Grid	removeRecords(RecordFilter filter)	Removes all records selected by a filter
Grid	removeRows(RowFilter filter)	Removes all rows selected by a filter
Grid	reorderRecords(SortingConfig sortingConfig, boolean permanent)	Returns a new grid where records have been reordered according to the configuration supplied.
Grid	reorderRows(SortingConfig sortingConfig, boolean permanent)	Returns a new grid where rows have been reordered according to the configuration supplied.
long	rowCount()
void	saveToFile(File file)	Saves the grid to a specified directory, following OpenRefine's format for grid storage.
protected void	saveToFile(File file, Optional<ProgressReporter> progressReporter)
ProgressingFuture<Void>	saveToFileAsync(File file)	Saves the grid to a specified directory, in an asynchronous fashion.
void	uncache()	Free up any memory used to cache this grid in memory.
Grid	withColumnModel(ColumnModel newColumnModel)
Grid	withOverlayModels(Map<String,OverlayModel> overlayModel)	Returns a new grid where the overlay models have changed.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openrefine.model.Grid

concatenate, dropRows, getRows, limitRows

Constructor Detail

TestingGrid

public TestingGrid(ColumnModel columnModel,
                   List<Row> rows,
                   Map<String,OverlayModel> overlayModels)

TestingGrid

protected TestingGrid(List<IndexedRow> indexedRows,
                      ColumnModel columnModel,
                      Map<String,OverlayModel> overlayModels)

Method Detail

groupRowsIntoRecords

public static List<Record> groupRowsIntoRecords(List<IndexedRow> rows,
                                                int keyCellIndex)

getColumnModel

public ColumnModel getColumnModel()

Specified by:

getColumnModel in interface Grid

Returns:

the column metadata at this stage of the workflow

getRow

public Row getRow(long id)

Description copied from interface: Grid

Returns a row by index. Repeatedly calling this method to obtain multiple rows might be inefficient compared to fetching them by batch, depending on the implementation.

Specified by:

getRow in interface Grid

Parameters:

id - the row index. This refers to the current position of the row in the grid, which corresponds to IndexedRow.getIndex().

Returns:

the row at the given index

getRowsAfter

public List<IndexedRow> getRowsAfter(long start,
                                     int limit)

Description copied from interface: Grid

Returns a list of rows, starting from a given index and defined by a maximum size.

Specified by:

getRowsAfter in interface Grid

Parameters:

start - the first row id to fetch (inclusive)

limit - the maximum number of rows to fetch

Returns:

the list of rows with their ids (if any)

getRowsAfter

public List<IndexedRow> getRowsAfter(RowFilter filter,
                                     long start,
                                     int limit)

Description copied from interface: Grid

Among the subset of filtered rows, return a list of rows, starting from a given index and defined by a maximum size.

Specified by:

getRowsAfter in interface Grid

Parameters:

filter - the subset of rows to paginate through. This object and its dependencies are required to be serializable.

start - the first row id to fetch (inclusive)

limit - the maximum number of rows to fetch

Returns:

the list of rows with their ids (if any)

See Also:

Grid.getRowsBefore(long, int)

getRowsBefore

public List<IndexedRow> getRowsBefore(long end,
                                      int limit)

Description copied from interface: Grid

Returns a list of consecutive rows, just before the given row index (not included) and up to a maximum size.

Specified by:

getRowsBefore in interface Grid

Parameters:

end - the last row id to fetch (exclusive)

limit - the maximum number of rows to fetch

Returns:

the list of rows with their ids (if any)

See Also:

Grid.getRowsAfter(long, int)

getRowsBefore

public List<IndexedRow> getRowsBefore(RowFilter filter,
                                      long end,
                                      int limit)

Description copied from interface: Grid

Among the subset of filtered rows, return a list of rows, just before the row with a given index (excluded) and defined by a maximum size.

Specified by:

getRowsBefore in interface Grid

Parameters:

filter - the subset of rows to paginate through. This object and its dependencies are required to be serializable.

end - the last row id to fetch (exclusive)

limit - the maximum number of rows to fetch

Returns:

the list of rows with their ids (if any)

collectRows

public List<IndexedRow> collectRows()

Description copied from interface: Grid

Returns all rows in a list. This is inefficient for large datasets as it forces the entire grid to be loaded in memory.

Specified by:

collectRows in interface Grid

getRecord

public Record getRecord(long id)

Description copied from interface: Grid

Returns a record obtained by its id. Repeatedly calling this method to obtain multiple records might be inefficient depending on the implementation.

Specified by:

getRecord in interface Grid

Parameters:

id - the row id of the first row in the record. This refers to the current position of the record in the grid, which corresponds to Record.getStartRowId().

Returns:

the corresponding record

getRecordsAfter

public List<Record> getRecordsAfter(long start,
                                    int limit)

Description copied from interface: Grid

Returns a list of records, starting from a given index and defined by a maximum size.

Specified by:

getRecordsAfter in interface Grid

Parameters:

start - the first record id to fetch (inclusive)

limit - the maximum number of records to fetch

Returns:

the list of records (if any)

See Also:

Grid.getRecordsBefore(long, int)

getRecordsAfter

public List<Record> getRecordsAfter(RecordFilter filter,
                                    long start,
                                    int limit)

Description copied from interface: Grid

Among the filtered subset of records, returns a list of records, starting from a given index and defined by a maximum size.

Specified by:

getRecordsAfter in interface Grid

Parameters:

filter - the filter which defines the subset of records to paginate through This object and its dependencies are required to be serializable.

start - the first record id to fetch (inclusive)

limit - the maximum number of records to fetch

Returns:

the list of records (if any)

getRecordsBefore

public List<Record> getRecordsBefore(long end,
                                     int limit)

Description copied from interface: Grid

Returns a list of consecutive records, ending at a given index (exclusive) and defined by a maximum size.

Specified by:

getRecordsBefore in interface Grid

Parameters:

end - the last record id to fetch (exclusive)

limit - the maximum number of records to fetch

Returns:

the list of records (if any)

See Also:

Grid.getRecordsAfter(long, int)

getRecordsBefore

public List<Record> getRecordsBefore(RecordFilter filter,
                                     long end,
                                     int limit)

Description copied from interface: Grid

Among the filtered subset of records, returns a list of records, ending at a given index (exclusive) and defined by a maximum size.

Specified by:

getRecordsBefore in interface Grid

Parameters:

filter - the filter which defines the subset of records to paginate through This object and its dependencies are required to be serializable.

end - the last record id to fetch (exclusive)

limit - the maximum number of records to fetch

Returns:

the list of records (if any)

collectRecords

public List<Record> collectRecords()

Description copied from interface: Grid

Returns all records in a list. This is inefficient for large datasets as it forces all records to be loaded in memory.

Specified by:

collectRecords in interface Grid

rowCount

public long rowCount()

Specified by:

rowCount in interface Grid

Returns:

the number of rows in the table

recordCount

public long recordCount()

Specified by:

recordCount in interface Grid

Returns:

the number of records in the table

countMatchingRows

public long countMatchingRows(RowFilter filter)

Description copied from interface: Grid

Count the number of rows which match a given filter.

Specified by:

countMatchingRows in interface Grid

Parameters:

filter - the row filter

Returns:

the number of rows for which this filter returns true

countMatchingRowsApprox

public Grid.ApproxCount countMatchingRowsApprox(RowFilter filter,
                                                long limit)

Description copied from interface: Grid

Return the number of rows matching the given row filter, but by processing about at most a fixed number of row.

Specified by:

countMatchingRowsApprox in interface Grid

Parameters:

filter - counts the number of records on which it returns true

limit - maximum number of records to process

countMatchingRecords

public long countMatchingRecords(RecordFilter filter)

Description copied from interface: Grid

Return the number of records which are filtered by this filter.

Specified by:

countMatchingRecords in interface Grid

Parameters:

filter - the filter to evaluate

Returns:

the number of records for which this filter evaluates to true

countMatchingRecordsApprox

public Grid.ApproxCount countMatchingRecordsApprox(RecordFilter filter,
                                                   long limit)

Description copied from interface: Grid

Return the number of records matching the given record filter, but by processing about at most a fixed number of records.

Specified by:

countMatchingRecordsApprox in interface Grid

Parameters:

filter - counts the number of records on which it returns true

limit - maximum number of records to process

getOverlayModels

public Map<String,OverlayModel> getOverlayModels()

Specified by:

getOverlayModels in interface Grid

Returns:

the overlay models in this state

saveToFile

public void saveToFile(File file)
                throws IOException

Description copied from interface: Grid

Saves the grid to a specified directory, following OpenRefine's format for grid storage.

Specified by:

saveToFile in interface Grid

Parameters:

file - the directory where to save the grid

Throws:

IOException

saveToFileAsync

public ProgressingFuture<Void> saveToFileAsync(File file)

Description copied from interface: Grid

Saves the grid to a specified directory, in an asynchronous fashion.

Specified by:

saveToFileAsync in interface Grid

Parameters:

file - the directory where to save the grid

Returns:

a future which completes once the save is complete

saveToFile

protected void saveToFile(File file,
                          Optional<ProgressReporter> progressReporter)
                   throws IOException

Throws:

IOException

aggregateRows

public <T extends Serializable> T aggregateRows(RowAggregator<T> aggregator,
                                                T initialState)

Description copied from interface: Grid

Computes the result of a row aggregator on the grid.

Specified by:

aggregateRows in interface Grid

aggregateRecords

public <T extends Serializable> T aggregateRecords(RecordAggregator<T> aggregator,
                                                   T initialState)

Description copied from interface: Grid

Computes the result of a row aggregator on the grid.

Specified by:

aggregateRecords in interface Grid

aggregateRowsApprox

public <T extends Serializable> Grid.PartialAggregation<T> aggregateRowsApprox(RowAggregator<T> aggregator,
                                                                               T initialState,
                                                                               long maxRows)

Description copied from interface: Grid

Computes the result of a row aggregator on the grid, reading about at most a fixed number of rows. The rows read should be deterministic for a given implementation.

Specified by:

aggregateRowsApprox in interface Grid

aggregateRecordsApprox

public <T extends Serializable> Grid.PartialAggregation<T> aggregateRecordsApprox(RecordAggregator<T> aggregator,
                                                                                  T initialState,
                                                                                  long maxRecords)

Description copied from interface: Grid

Computes the result of a row aggregator on the grid, reading about at most a fixed number of records. The records read should be deterministic for a given implementation.

Specified by:

aggregateRecordsApprox in interface Grid

mapRows

public Grid mapRows(RowMapper mapper,
                    ColumnModel newColumnModel)

Description copied from interface: Grid

Returns a new grid, where the rows have been mapped by the mapper.

Specified by:

mapRows in interface Grid

Parameters:

mapper - the function used to transform rows This object and its dependencies are required to be serializable.

newColumnModel - the column model of the resulting grid

Returns:

the resulting grid

flatMapRows

public Grid flatMapRows(RowFlatMapper mapper,
                        ColumnModel newColumnModel)

Description copied from interface: Grid

Returns a new grid, where the rows have been mapped by the flat mapper.

Specified by:

flatMapRows in interface Grid

Parameters:

mapper - the function used to transform rows This object and its dependencies are required to be serializable.

newColumnModel - the column model of the resulting grid

Returns:

the resulting grid

mapRows

public <S extends Serializable> Grid mapRows(RowScanMapper<S> mapper,
                                             ColumnModel newColumnModel)

Description copied from interface: Grid

Returns a new grid where the rows have been mapped by the stateful mapper. This can be significantly less efficient than a stateless mapper, so only use this if you really need to rely on state.

Specified by:

mapRows in interface Grid

Type Parameters:

S - the type of state kept by the mapper

Parameters:

mapper - the mapper to apply to the grid

newColumnModel - the column model to apply to the new grid

mapRecords

public Grid mapRecords(RecordMapper mapper,
                       ColumnModel newColumnModel)

Description copied from interface: Grid

Returns a new grid, where the records have been mapped by the mapper

Specified by:

mapRecords in interface Grid

Parameters:

mapper - the function used to transform records This object and its dependencies are required to be serializable.

newColumnModel - the column model of the resulting grid

Returns:

the resulting grid

iterateRows

public CloseableIterator<IndexedRow> iterateRows(RowFilter filter)

Description copied from interface: Grid

Iterate over rows matched by a filter, in the order determined by a sorting configuration. This might not require loading all rows in memory at once, but might be less efficient than Grid.collectRows() if all rows are to be stored in memory downstream.

Specified by:

iterateRows in interface Grid

iterateRecords

public CloseableIterator<Record> iterateRecords(RecordFilter filter)

Description copied from interface: Grid

Iterate over records matched by a filter. This might not require loading all records in memory at once, but might be less efficient than Grid.collectRecords() if all records are to be stored in memory downstream.

Specified by:

iterateRecords in interface Grid

withOverlayModels

public Grid withOverlayModels(Map<String,OverlayModel> overlayModel)

Description copied from interface: Grid

Returns a new grid where the overlay models have changed.

Specified by:

withOverlayModels in interface Grid

Parameters:

overlayModel - the new overlay models to apply to the grid

Returns:

the changed grid

withColumnModel

public Grid withColumnModel(ColumnModel newColumnModel)

Specified by:

withColumnModel in interface Grid

Parameters:

newColumnModel - the column model to apply to the grid

Returns:

a copy of this grid with a modified column model.

reorderRows

public Grid reorderRows(SortingConfig sortingConfig,
                        boolean permanent)

Description copied from interface: Grid

Returns a new grid where rows have been reordered according to the configuration supplied.

Specified by:

reorderRows in interface Grid

Parameters:

sortingConfig - the criteria to sort rows

permanent - if true, forget the original row ids. If false, store them in the corresponding IndexedRow.getOriginalIndex().

Returns:

the resulting grid

reorderRecords

public Grid reorderRecords(SortingConfig sortingConfig,
                           boolean permanent)

Description copied from interface: Grid

Returns a new grid where records have been reordered according to the configuration supplied.

Specified by:

reorderRecords in interface Grid

Parameters:

sortingConfig - the criteria to sort records

permanent - if true, forget the original record ids. If false, store them in the corresponding Record.getOriginalStartRowId().

Returns:

the resulting grid

getRunner

public Runner getRunner()

Specified by:

getRunner in interface Grid

Returns:

the runner which created this grid

removeRows

public Grid removeRows(RowFilter filter)

Description copied from interface: Grid

Removes all rows selected by a filter

Specified by:

removeRows in interface Grid

Parameters:

filter - which returns true when we should delete the row

Returns:

the grid where the matching rows have been removed

removeRecords

public Grid removeRecords(RecordFilter filter)

Description copied from interface: Grid

Removes all records selected by a filter

Specified by:

removeRecords in interface Grid

Parameters:

filter - which returns true when we should delete the record

Returns:

the grid where the matching record have been removed

mapRows

public <T> ChangeData<T> mapRows(RowFilter filter,
                                 RowChangeDataProducer<T> rowMapper,
                                 Optional<ChangeData<T>> incompleteChangeData)

Description copied from interface: Grid

Extract change data by applying a function to each filtered row. The calls to the change data producer are batched if requested by the producer.

Specified by:

mapRows in interface Grid

Type Parameters:

T - the type of change data that is serialized to disk for each row

Parameters:

filter - a filter to select which rows to map

rowMapper - produces the change data for each row

incompleteChangeData - a previously, incompletely fetched version of the same change data, from which the computation should be resumed, to avoid recomputing the items already in the incomplete change data

mapRecords

public <T> ChangeData<T> mapRecords(RecordFilter filter,
                                    RecordChangeDataProducer<T> recordMapper,
                                    Optional<ChangeData<T>> incompleteChangeData)

Description copied from interface: Grid

Extract change data by applying a function to each filtered record. The calls to the change data producer are batched if requested by the producer.

Specified by:

mapRecords in interface Grid

Type Parameters:

T - the type of change data that is serialized to disk for each row

Parameters:

filter - a filter to select which rows to map

recordMapper - produces the change data for each record

incompleteChangeData - a previously, incompletely fetched version of the same change data, from which the computation should be resumed, to avoid recomputing the items already in the incomplete change data

join

public <T> Grid join(ChangeData<T> changeData,
                     RowChangeDataJoiner<T> rowJoiner,
                     ColumnModel newColumnModel)

Description copied from interface: Grid

Joins pre-computed change data with the current grid data, row by row.

Specified by:

join in interface Grid

Type Parameters:

T - the type of change data that was serialized to disk for each row

Parameters:

changeData - the serialized change data

rowJoiner - produces the new row by joining the old row with change data

newColumnModel - the column model to apply to the new grid

join

public <T> Grid join(ChangeData<T> changeData,
                     RowChangeDataFlatJoiner<T> rowJoiner,
                     ColumnModel newColumnModel)

Description copied from interface: Grid

Joins pre-computed change data with the current grid data, with a joiner function that can return multiple rows for a given original row.

Specified by:

join in interface Grid

Type Parameters:

T - the type of change data that was serialized to disk for each row

Parameters:

changeData - the serialized change data

rowJoiner - produces the new row by joining the old row with change data

newColumnModel - the column model to apply to the new grid

join

public <T> Grid join(ChangeData<T> changeData,
                     RecordChangeDataJoiner<T> recordJoiner,
                     ColumnModel newColumnModel)

Description copied from interface: Grid

Joins pre-computed change data with the current grid data, record by record.

Specified by:

join in interface Grid

Type Parameters:

T - the type of change data that was serialized to disk for each record

Parameters:

changeData - the serialized change data

recordJoiner - produces the new list of rows by joining the old record with change data

newColumnModel - the column model to apply to the new grid

concatenate

public Grid concatenate(Grid other)

Description copied from interface: Grid

Creates a new grid containing all rows in this grid, followed by all rows in the other grid supplied. The overlay models of this grid have priority over the others.

The two grids are required to have the same number of columns.

Specified by:

concatenate in interface Grid

Parameters:

other - the grid to concatenate to this one

Returns:

a new grid, union of the two

isCached

public boolean isCached()

Description copied from interface: Grid

Is this grid cached in memory? If not, its contents are stored on disk.

Specified by:

isCached in interface Grid

uncache

public void uncache()

Description copied from interface: Grid

Free up any memory used to cache this grid in memory.

Specified by:

uncache in interface Grid

cacheAsync

public ProgressingFuture<Boolean> cacheAsync()

Description copied from interface: Grid

Attempt to cache this grid in memory, in an async way.

Specified by:

cacheAsync in interface Grid

Returns:

a future to keep track of the status of the caching process. The future returns whether the caching succeeded.

cache

public boolean cache()

Description copied from interface: Grid

Attempt to cache this grid in memory. If the grid is too big, this can fail.

Specified by:

cache in interface Grid

Returns:

whether the grid was actually cached in memory.