Package com.clickhouse.client

Interface ClickHouseCache<K,V>

All Known Implementing Classes:

CaffeineCache, JdkLruCache

public interface ClickHouseCache<K,V>

Wrapper interface depicts essential methods required by a client-side cache.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_CACHE_SIZE	Default cache size.

Method Summary

Modifier and Type	Method	Description
static <K,V> ClickHouseCache<K,V>	create(int capacity, long expireSeconds, Function<K,V> loadFunc)	Creates a cache with specific 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.

Field Detail

DEFAULT_CACHE_SIZE

static final int DEFAULT_CACHE_SIZE

Default cache size.

See Also:

Constant Field Values

Method Detail

create

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

Creates a cache with specific capacity and load function.

Type Parameters:

K - type of key

V - type of value

Parameters:

capacity - capacity of the cache, zero or negative number will be treated as DEFAULT_CACHE_SIZE

expireSeconds - seconds to expire after access

loadFunc - non-null load function

Returns:

cache

get

V get(K key)

Gets value from cache if it exists.

Parameters:

key - key, in genernal should NOT be null

Returns:

non-null value in general

unwrap

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

Gets inner cache object to gain more access.

Type Parameters:

T - type of the cache

Parameters:

clazz - non-null class of the cache

Returns:

inner cache object

Throws:

NullPointerException - when clazz is null