org.infinispan.loaders

Interface CacheLoader

All Known Subinterfaces:

CacheStore

All Known Implementing Classes:

AbstractCacheLoader, AbstractCacheStore, AbstractDelegatingStore, AsyncStore, BdbjeCacheStore, BucketBasedCacheStore, CassandraCacheStore, ChainingCacheStore, CloudCacheStore, ClusterCacheLoader, FileCacheStore, HBaseCacheStore, JdbcBinaryCacheStore, JdbcMixedCacheStore, JdbcStringBasedCacheStore, JdbmCacheStore, LevelDBCacheStore, LockSupportCacheStore, LuceneCacheLoader, ReadOnlyStore, RemoteCacheStore, RemoteEventCacheStore, SingletonStore

public interface CacheLoader

Responsible for loading cache data from an external source

Since:

4.0

Author:

Manik Surtani

Method Summary

Methods

Modifier and Type	Method and Description
boolean	containsKey(Object key)
Class<? extends CacheLoaderConfig>	getConfigurationClass() This method is used by the configuration parser to get a hold of the CacheLoader implementation's corresponding CacheLoaderConfig type.
void	init(CacheLoaderConfig config, Cache<?,?> cache, StreamingMarshaller m) Used to initialize a cache loader.
Set<InternalCacheEntry>	load(int numEntries) Loads up to a specific number of entries.
InternalCacheEntry	load(Object key) Loads an entry mapped to by a given key.
Set<InternalCacheEntry>	loadAll() Loads all entries in the loader.
Set<Object>	loadAllKeys(Set<Object> keysToExclude) Loads a set of all keys, excluding a filter set.
void	start()
void	stop()

Method Detail

init

void init(CacheLoaderConfig config,
        Cache<?,?> cache,
        StreamingMarshaller m)
          throws CacheLoaderException

Used to initialize a cache loader. Typically invoked by the CacheLoaderManager when setting up cache loaders.

Parameters:

config - the cache loader configuration bean

cache - cache associated with this cache loader. Implementations may use this to determine cache name when selecting where refer to state in storage, for example, a different database table name.

m - marshaller to use when loading state from a stream, if supported by the implementation.

Throws:

CacheLoaderException

load

InternalCacheEntry load(Object key)
                        throws CacheLoaderException

Loads an entry mapped to by a given key. Should return null if the entry does not exist. Expired entries are not returned.

Parameters:

key - key

Returns:

an entry

Throws:

CacheLoaderException - in the event of problems reading from source

loadAll

Set<InternalCacheEntry> loadAll()
                                throws CacheLoaderException

Loads all entries in the loader. Expired entries are not returned.

Returns:

a set of entries, or an empty set if the loader is emptied.

Throws:

CacheLoaderException - in the event of problems reading from source

load

Set<InternalCacheEntry> load(int numEntries)
                             throws CacheLoaderException

Loads up to a specific number of entries. There is no guarantee as to order of entries loaded. The set returned would contain up to a maximum of numEntries entries, and no more.

Parameters:

numEntries - maximum number of entries to load

Returns:

a set of entries, which would contain between 0 and numEntries entries.

Throws:

CacheLoaderException

loadAllKeys

Set<Object> loadAllKeys(Set<Object> keysToExclude)
                        throws CacheLoaderException

Loads a set of all keys, excluding a filter set.

Parameters:

keysToExclude - a set of keys to exclude. An empty set or null will indicate that all keys should be returned.

Returns:

A set containing keys of entries stored. An empty set is returned if the loader is empty.

Throws:

CacheLoaderException

containsKey

boolean containsKey(Object key)
                    throws CacheLoaderException

Parameters:

key - key to test

Returns:

true if the key exists, false otherwise

Throws:

CacheLoaderException - in the event of problems reading from source

start

void start()
           throws CacheLoaderException

Throws:

CacheLoaderException

stop

void stop()
          throws CacheLoaderException

Throws:

CacheLoaderException

getConfigurationClass

Class<? extends CacheLoaderConfig> getConfigurationClass()

This method is used by the configuration parser to get a hold of the CacheLoader implementation's corresponding CacheLoaderConfig type. This is usually done by instantiating the CacheLoader and then calling this method. This may result in 2 instances being created, however, since the instance created to get a hold of the configuration type is then discarded and another instance is created for actual use as a CacheLoader when the cache starts.

Since Infinispan 4.1, you can also annotate your CacheLoader implementation with CacheLoaderMetadata and provide this information via the annotation, which will prevent unnecessary instances being created.

Returns:

the type of the CacheLoaderConfig bean used to configure this implementation of CacheLoader.