Package com.clickhouse.client.cache

Class JdkLruCache<K,V>

java.lang.Object

com.clickhouse.client.cache.JdkLruCache<K,V>

All Implemented Interfaces:

ClickHouseCache<K,V>

public class JdkLruCache<K,V>
extends Object
implements ClickHouseCache<K,V>

A simple thread-safe LRU cache based on LinkedHashMap. It's not as effient as the one in Caffeine/Guava, but it requires no extra dependency.

Field Summary

Fields inherited from interface com.clickhouse.client.ClickHouseCache

DEFAULT_CACHE_SIZE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	JdkLruCache(Map<K,V> cache, Function<K,V> loadFunc)

Method Summary

Modifier and Type	Method	Description
static <K,V> ClickHouseCache<K,V>	create(int capacity, Function<K,V> loadFunc)	Creates a cache with given capacity and load function.
V	get(K key)	Gets value from cache if it exists.
<T> T	unwrap(Class<T> clazz)	Gets inner cache object to gain more access.

Methods inherited from class java.lang.Object

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

Constructor Detail

JdkLruCache

protected JdkLruCache(Map<K,V> cache,
                      Function<K,V> loadFunc)

Method Detail

create

public static <K,V> ClickHouseCache<K,V> create(int capacity,
                                                            Function<K,V> loadFunc)

Creates a cache with given capacity and load function.

Type Parameters:

K - type of the key

V - type of the value

Parameters:

capacity - capacity

loadFunc - load function

Returns:

cache

get

public V get(K key)

Description copied from interface: ClickHouseCache

Gets value from cache if it exists.

Specified by:

get in interface ClickHouseCache<K,V>

Parameters:

key - key, in genernal should NOT be null

Returns:

non-null value in general

unwrap

public <T> T unwrap(Class<T> clazz)

Description copied from interface: ClickHouseCache

Gets inner cache object to gain more access.

Specified by:

unwrap in interface ClickHouseCache<K,V>

Type Parameters:

T - type of the cache

Parameters:

clazz - non-null class of the cache

Returns:

inner cache object