Package io.deephaven.engine.table

Interface DataIndex

All Superinterfaces:

BasicDataIndex, LivenessReferent

All Known Implementing Classes:

AbstractDataIndex, RemappedDataIndex, TableBackedDataIndex

public interface DataIndex
extends BasicDataIndex

Expansion of BasicDataIndex to include methods for transforming the index and fast retrieval of row keys from lookup keys.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	DataIndex.RowKeyLookup	Provides a lookup function from a lookup key to the row key in the index table.

Method Summary

Modifier and Type	Method	Description
DataIndex	remapKeyColumns(@NotNull Map<ColumnSource<?>,ColumnSource<?>> oldToNewColumnMap)	Create a new DataIndex using the same index BasicDataIndex.table(), with the indexed columns in BasicDataIndex.keyColumnNamesByIndexedColumn() remapped according to oldToNewColumnMap.
@NotNull DataIndex.RowKeyLookup	rowKeyLookup()	Build a lookup function of row keys for this index.
default @NotNull DataIndex.RowKeyLookup	rowKeyLookup(@NotNull ColumnSource<?>[] lookupColumns)	Return a lookup function function of index row keys for this index.
@NotNull BasicDataIndex	transform(@NotNull DataIndexTransformer transformer)	Transform and return a new BasicDataIndex with the provided transform operations applied.

Methods inherited from interface io.deephaven.engine.table.BasicDataIndex

isRefreshing, keyColumnNames, keyColumnNamesByIndexedColumn, keyColumns, keyColumns, rowSetColumn, rowSetColumnName, table

Methods inherited from interface io.deephaven.engine.liveness.LivenessReferent

dropReference, getReferentDescription, getWeakReference, retainReference, tryRetainReference

Method Details

rowKeyLookup

@NotNull
@NotNull DataIndex.RowKeyLookup rowKeyLookup()

Build a lookup function of row keys for this index. If BasicDataIndex.isRefreshing() is true, this lookup function is only guaranteed to be accurate for the current cycle. Lookup keys should be in the order of the index's key columns.

Returns:

A function that provides map-like lookup of index BasicDataIndex.table() row keys from an index lookup key

rowKeyLookup

@NotNull
@FinalDefault
default @NotNull DataIndex.RowKeyLookup rowKeyLookup(@NotNull
 @NotNull ColumnSource<?>[] lookupColumns)

Return a lookup function function of index row keys for this index. If BasicDataIndex.isRefreshing() is true, this lookup function is only guaranteed to be accurate for the current cycle. Lookup keys should be in the order of lookupColumns.

Parameters:

lookupColumns - The ColumnSources to use for the lookup key

Returns:

A function that provides map-like lookup of index BasicDataIndex.table() row keys from an index lookup key. The result must not be used concurrently by more than one thread.

transform

@NotNull
@NotNull BasicDataIndex transform(@NotNull
 @NotNull DataIndexTransformer transformer)

Transform and return a new BasicDataIndex with the provided transform operations applied. Some transformations will force the result to be a static snapshot even when this DataIndex is refreshing.

Parameters:

transformer - The DataIndexTransformer specifying the desired transformations

Returns:

The transformed BasicDataIndex

remapKeyColumns

DataIndex remapKeyColumns(@NotNull
 @NotNull Map<ColumnSource<?>,ColumnSource<?>> oldToNewColumnMap)

Create a new DataIndex using the same index BasicDataIndex.table(), with the indexed columns in BasicDataIndex.keyColumnNamesByIndexedColumn() remapped according to oldToNewColumnMap. This is used when it is known that an operation has produced new columns that are equivalent to the old indexed columns. The result index may keep this index reachable and live for its own lifetime, if necessary.

Parameters:

oldToNewColumnMap - Map from the old indexed ColumnSources to the new indexed ColumnSources

Returns:

The remapped DataIndex