io.druid.server.lookup

Class PollingLookup

java.lang.Object

io.druid.query.lookup.LookupExtractor

io.druid.server.lookup.PollingLookup

public class PollingLookup
extends LookupExtractor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	PollingLookup.CacheRefKeeper

Constructor Summary

Constructors

Constructor and Description
PollingLookup(long pollPeriodMs, DataFetcher dataFetcher, PollingCacheFactory cacheFactory)

Method Summary

Modifier and Type	Method and Description
String	apply(String key) Apply a particular lookup methodology to the input string
void	close()
boolean	equals(Object o)
byte[]	getCacheKey() Create a cache key for use in results caching
int	hashCode()
boolean	isOpen()
String	toString()
List<String>	unapply(String value) Provide the reverse mapping from a given value to a list of keys

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

applyAll, isOneToOne, unapplyAll

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

PollingLookup

public PollingLookup(long pollPeriodMs,
                     DataFetcher dataFetcher,
                     PollingCacheFactory cacheFactory)

Method Detail

close

public void close()

apply

public String apply(@NotNull
                    String key)

Description copied from class: LookupExtractor

Apply a particular lookup methodology to the input string

Specified by:

apply in class LookupExtractor

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.

unapply

public List<String> unapply(String value)

Description copied from class: LookupExtractor

Provide the reverse mapping from a given value to a list of keys

Specified by:

unapply in class LookupExtractor

Parameters:

value - the value to apply the reverse lookup Null and empty are considered to be the same value = nullToEmpty(value)

Returns:

the list of keys that maps to value or empty list. Note that for the case of a none existing value in the lookup we have to cases either return an empty list OR list with null element. returning an empty list implies that user want to ignore such a lookup value. In the other hand returning a list with the null element implies user want to map the none existing value to the key null.

getCacheKey

public byte[] getCacheKey()

Description copied from class: LookupExtractor

Create a cache key for use in results caching

Specified by:

getCacheKey in class LookupExtractor

Returns:

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

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

isOpen

public boolean isOpen()

toString

public String toString()

Overrides:

toString in class Object