Package org.apache.cassandra.db.tries

Interface InMemoryTrie.UpsertTransformer<T,U>

Type Parameters:

T - The content type for this InMemoryTrie.

U - The type of the new content being applied to this InMemoryTrie.

Enclosing class:

InMemoryTrie<T>

public static interface InMemoryTrie.UpsertTransformer<T,U>

Somewhat similar to Trie.MergeResolver, this encapsulates logic to be applied whenever new content is being upserted into a InMemoryTrie. Unlike Trie.MergeResolver, InMemoryTrie.UpsertTransformer will be applied no matter if there's pre-existing content for that trie key/path or not.

Method Summary

Modifier and Type	Method	Description
T	apply(T existing, U update)	Called when there's content in the updating trie.

Method Details

apply

T apply(T existing,
 U update)

Called when there's content in the updating trie.

Parameters:

existing - Existing content for this key, or null if there isn't any.

update - The update, always non-null.

Returns:

The combined value to use. Cannot be null.