org.neo4j.index.internal.gbptree

Interface ValueMerger<VALUE>

Type Parameters:

VALUE - type of values to merge.

public interface ValueMerger<VALUE>

Decides what to do when inserting key which already exists in index. Different implementations of ValueMerger can result in unique/non-unique indexes for example.

Method Summary

Modifier and Type	Method and Description
VALUE	merge(VALUE existingValue, VALUE newValue) Merge an existing value with a new value, returning potentially a combination of the two, or null if no merge was done effectively meaning that nothing should be written.

Method Detail

merge

VALUE merge(VALUE existingValue,
            VALUE newValue)

Merge an existing value with a new value, returning potentially a combination of the two, or null if no merge was done effectively meaning that nothing should be written.

Parameters:

existingValue - existing value

newValue - new value

Returns:

value, now merged with withValue, or null if no merge was done.