io.druid.query.extraction

Interface LookupExtractor

All Known Implementing Classes:

MapLookupExtractor, NamespacedExtractor

public interface LookupExtractor

Method Summary

Methods

Modifier and Type	Method and Description
String	apply(String key) Apply a particular lookup methodology to the input string
byte[]	getCacheKey() Create a cache key for use in results caching

Method Detail

apply

@Nullable
String apply(@NotNull
                    String key)

Apply a particular lookup methodology to the input string

Parameters:

key - The value to apply the lookup to. May not be null

Returns:

The lookup, or null key cannot have the lookup applied to it and should be treated as missing.

getCacheKey

@NotNull
byte[] getCacheKey()

Create a cache key for use in results caching

Returns:

A byte array that can be used to uniquely identify if results of a prior lookup can use the cached values