io.druid.server.lookup

Class LoadingLookup

java.lang.Object

io.druid.query.lookup.LookupExtractor

io.druid.server.lookup.LoadingLookup

public class LoadingLookup
extends LookupExtractor

Loading lookup will load the key\value pair upon request on the key it self, the general algorithm is load key if absent. Once the key/value pair is loaded eviction will occur according to the cache eviction policy. This module comes with two loading cache implementations, the first OnHeapLoadingCacheis onheap backed by a Guava cache implementation, the second OffHeapLoadingCacheis MapDB offheap implementation. Both implementations offer various eviction strategies.

Constructor Summary

Constructors

Constructor and Description
LoadingLookup(DataFetcher dataFetcher, LoadingCache<String,String> loadingCache, LoadingCache<String,List<String>> reverseLoadingCache)

Method Summary

Modifier and Type	Method and Description
String	apply(String key)
void	close()
byte[]	getCacheKey()
boolean	isOpen()
String	toString()
List<String>	unapply(String value)

Methods inherited from class io.druid.query.lookup.LookupExtractor

applyAll, isOneToOne, unapplyAll

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LoadingLookup

public LoadingLookup(DataFetcher dataFetcher,
                     LoadingCache<String,String> loadingCache,
                     LoadingCache<String,List<String>> reverseLoadingCache)

Method Detail

apply

public String apply(String key)

Specified by:

apply in class LookupExtractor

unapply

public List<String> unapply(String value)

Specified by:

unapply in class LookupExtractor

close

public void close()

isOpen

public boolean isOpen()

getCacheKey

public byte[] getCacheKey()

Specified by:

getCacheKey in class LookupExtractor

toString

public String toString()

Overrides:

toString in class Object