com.yahoo.bard.webservice.data.cache

Class MemTupleDataCache<T extends Serializable,V extends Serializable>

java.lang.Object

com.yahoo.bard.webservice.data.cache.MemDataCache<TupleDataCache.DataEntry<String,T,V>>

com.yahoo.bard.webservice.data.cache.MemTupleDataCache<T,V>

Type Parameters:

T - The meta data type of the cache.

V - The raw data type of the cache.

All Implemented Interfaces:

DataCache<TupleDataCache.DataEntry<String,T,V>>, TupleDataCache<String,T,V>

@Singleton
public class MemTupleDataCache<T extends Serializable,V extends Serializable>
extends MemDataCache<TupleDataCache.DataEntry<String,T,V>>
implements TupleDataCache<String,T,V>

Memcached client implementation of TupleDataCache.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MemTupleDataCache.DataEntry<T extends Serializable,V extends Serializable> Memcached implementation of the data cache entry of the tuple data cache.

Constructor Summary

Constructors

Constructor and Description
MemTupleDataCache() Constructor using a default memcached client.
MemTupleDataCache(net.spy.memcached.MemcachedClient client) Constructor.

Method Summary

Modifier and Type	Method and Description
TupleDataCache.DataEntry<String,T,V>	get(String key) Read data from cache.
V	getDataValue(String key) Read the raw data from cache.
protected String	hash(String key) Get the hash encoding of a key string.
boolean	set(String key, T meta, V value) Given a key, put a complete data entry in the data cache.

Methods inherited from class com.yahoo.bard.webservice.data.cache.MemDataCache

clear, set

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.yahoo.bard.webservice.data.cache.DataCache

clear, set

Constructor Detail

MemTupleDataCache

public MemTupleDataCache()
                  throws IOException

Constructor using a default memcached client.

Throws:

IOException - if the memcached client fails to start.

MemTupleDataCache

public MemTupleDataCache(net.spy.memcached.MemcachedClient client)

Constructor.

Parameters:

client - The memcached client to support this cache.

Method Detail

hash

protected String hash(String key)

Get the hash encoding of a key string.

Parameters:

key - The input string to encode.

Returns:

The hash encoding of the key as string. Returns null if the method fails to produce a hash.

getDataValue

public V getDataValue(String key)

Description copied from interface: TupleDataCache

Read the raw data from cache.

Specified by:

getDataValue in interface TupleDataCache<String,T extends Serializable,V extends Serializable>

Parameters:

key - The key whose associated value is to be returned

Returns:

the value to which the specified key is mapped, or null if this map contains no mapping for the key

get

public TupleDataCache.DataEntry<String,T,V> get(String key)

Description copied from interface: DataCache

Read data from cache.

Specified by:

get in interface DataCache<TupleDataCache.DataEntry<String,T extends Serializable,V extends Serializable>>

Specified by:

get in interface TupleDataCache<String,T extends Serializable,V extends Serializable>

Overrides:

get in class MemDataCache<TupleDataCache.DataEntry<String,T extends Serializable,V extends Serializable>>

Parameters:

key - the key whose associated value is to be returned

Returns:

the value to which the specified key is mapped, or null if this map contains no mapping for the key

set

public boolean set(String key,
                   T meta,
                   V value)

Description copied from interface: TupleDataCache

Given a key, put a complete data entry in the data cache.

Specified by:

set in interface TupleDataCache<String,T extends Serializable,V extends Serializable>

Parameters:

key - The key of the cache entry.

meta - The metadata associated with the raw data.

value - The raw data to store in to the cache.

Returns:

true if the entry is stored successfully; false otherwise.