Package io.deephaven.engine.table.impl.remote

Interface ConstructSnapshot.UsePreviousValues

All Known Subinterfaces:

ConstructSnapshot.SnapshotControl

All Known Implementing Classes:

ConstructSnapshot.StaticSnapshotControl, OperationSnapshotControl, OperationSnapshotControlEx

Enclosing class:

ConstructSnapshot

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface ConstructSnapshot.UsePreviousValues

Interface for usePreviousValues(long).

Method Summary

Modifier and Type	Method	Description
Boolean	usePreviousValues(long beforeClockValue)	Determine if previous values should be used in table data access for the given clock value.

Method Details

usePreviousValues

Boolean usePreviousValues(long beforeClockValue)

Determine if previous values should be used in table data access for the given clock value.

Expected to never request previous values during the idle phase of a cycle.

Must never request previous values for a source that has already been updated on the current cycle, unless it can be proven that that source was not instantiated on the current cycle.

Must be safe to call more than once, exactly once per snapshot attempt.

Parameters:

beforeClockValue - The current clock value before the snapshot function will be invoked

Returns:

A Boolean with the following meaning:

• true if previous values should be used
• false if they should not
• null if a clock discrepancy was detected and we must retry with a new beforeClockValue