org.apache.http.impl.client.cache.memcached
Class PrefixKeyHashingScheme

java.lang.Object
  org.apache.http.impl.client.cache.memcached.PrefixKeyHashingScheme

All Implemented Interfaces:

KeyHashingScheme

public class PrefixKeyHashingScheme
extends Object
implements KeyHashingScheme

This is a KeyHashingScheme decorator that simply adds a known prefix to the results of another KeyHashingScheme. Primarily useful for namespacing a shared memcached cluster, for example.

Constructor Summary

PrefixKeyHashingScheme(String prefix, KeyHashingScheme backingScheme)
Creates a new KeyHashingScheme that prepends the given prefix to the results of hashes from the given backing scheme.

Method Summary

String

hash(String storageKey) Maps a storage key to a cache key.

Methods inherited from class java.lang.Object

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

Constructor Detail

PrefixKeyHashingScheme

public PrefixKeyHashingScheme(String prefix,
                              KeyHashingScheme backingScheme)

Creates a new KeyHashingScheme that prepends the given prefix to the results of hashes from the given backing scheme. Users should be aware that memcached has a fixed maximum key length, so the combination of this prefix plus the results of the backing hashing scheme must still fit within these limits.

Parameters:

prefix -

backingScheme -

Method Detail

hash

public String hash(String storageKey)

Description copied from interface: KeyHashingScheme

Maps a storage key to a cache key. The storage key is what the higher-level HTTP cache uses as a key; the cache key is what we use as a key for talking to memcached.

Specified by:

hash in interface KeyHashingScheme

Parameters:

storageKey - what the higher-level HTTP cache wants to use as its key for looking up cache entries

Returns:

a cache key suitable for use with memcached