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

java.lang.Object
  extended by 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


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