Package org.atmosphere.cache

Class BoundedMemoryCache

java.lang.Object

org.atmosphere.cache.BoundedMemoryCache

All Implemented Interfaces:

BroadcasterCache, AtmosphereConfigAware

public class BoundedMemoryCache
extends Object
implements BroadcasterCache

A bounded, in-memory BroadcasterCache that stores recent broadcast messages per client UUID. Messages are automatically evicted when the cache exceeds its maximum size or when entries are older than the configured TTL.

This implementation is suitable for applications that need message replay on reconnect (e.g., AI chat conversation history, real-time collaboration). For distributed deployments, use a Redis-backed cache.

Configuration

• org.atmosphere.cache.maxSize — max messages per broadcaster (default 1000)
• org.atmosphere.cache.ttlSeconds — message TTL in seconds (default 3600)

Since:

4.0.8

Field Summary

Fields inherited from interface org.atmosphere.cpr.BroadcasterCache

DEFAULT, NULL

Constructor Summary

Constructors

Constructor	Description
BoundedMemoryCache()

Method Summary

Modifier and Type	Method	Description
BroadcasterCache	addBroadcasterCacheListener(BroadcasterCacheListener l)	Add a BroadcasterCacheListener
CacheMessage	addToCache(String broadcasterId, String uuid, BroadcastMessage message)	Start tracking messages associated with AtmosphereResource from the cache.
BroadcasterCache	cacheCandidate(String broadcasterId, String uuid)	Add a AtmosphereResource.uuid() to the list of active AtmosphereResource Message will be cached for the resource associated with the uuid.
void	cleanup()	Clean resources associated with this instance.
BroadcasterCache	clearCache(String broadcasterId, String uuid, CacheMessage cacheMessage)	Remove the previously cached message.
void	configure(AtmosphereConfig config)	Configure an AtmosphereFramework object.
BroadcasterCache	excludeFromCache(String broadcasterId, AtmosphereResource r)	Allow an application to exclude, or block, an AtmosphereResource to received cached message.
BroadcasterCache	inspector(BroadcasterCacheInspector interceptor)	Add a BroadcasterCacheInspector that will be invoked before a message gets added to the cache.
BroadcasterCache	removeBroadcasterCacheListener(BroadcasterCacheListener l)	Remove a BroadcasterCacheListener
List<Object>	retrieveFromCache(String broadcasterId, String uuid)	Retrieve messages associated with AtmosphereResource.
int	size(String broadcasterId)	Returns the current number of cached messages for the given broadcaster.
void	start()	This method is invoked when the Broadcaster is started.
void	stop()	This method is invoked when the Broadcaster is stopped.
int	totalSize()	Returns the total number of cached messages across all broadcasters.

Methods inherited from class java.lang.Object

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

Constructor Details

BoundedMemoryCache

public BoundedMemoryCache()

Method Details

configure

public void configure(AtmosphereConfig config)

Description copied from interface: AtmosphereConfigAware

Configure an AtmosphereFramework object.

Specified by:

configure in interface AtmosphereConfigAware

Parameters:

config - AtmosphereConfig

start

public void start()

Description copied from interface: BroadcasterCache

This method is invoked when the Broadcaster is started.

Specified by:

start in interface BroadcasterCache

stop

public void stop()

Description copied from interface: BroadcasterCache

This method is invoked when the Broadcaster is stopped.

Specified by:

stop in interface BroadcasterCache

cleanup

public void cleanup()

Description copied from interface: BroadcasterCache

Clean resources associated with this instance. This method is useful when ExecutorServices are shared and some future must be cancelled. This method will always be invoked when a Broadcaster gets destroyed.

Specified by:

cleanup in interface BroadcasterCache

addToCache

public CacheMessage addToCache(String broadcasterId,
 String uuid,
 BroadcastMessage message)

Description copied from interface: BroadcasterCache

Start tracking messages associated with AtmosphereResource from the cache.

Specified by:

addToCache in interface BroadcasterCache

Parameters:

broadcasterId - The associated

invalid @link

{@link Broadcaster#addAtmosphereResource(AtmosphereResource).getID

}

uuid - AtmosphereResource.uuid()

message - BroadcastMessage.

Returns:

The CacheMessage

retrieveFromCache

public List<Object> retrieveFromCache(String broadcasterId,
 String uuid)

Description copied from interface: BroadcasterCache

Retrieve messages associated with AtmosphereResource.

Specified by:

retrieveFromCache in interface BroadcasterCache

Parameters:

broadcasterId - The associated

invalid @link

{@link org.atmosphere.cpr.Broadcaster#addAtmosphereResource(org.atmosphere.cpr.AtmosphereResource).getID

}

uuid - AtmosphereResource

Returns:

a List of messages (String).

clearCache

public BroadcasterCache clearCache(String broadcasterId,
 String uuid,
 CacheMessage cacheMessage)

Description copied from interface: BroadcasterCache

Remove the previously cached message.

Specified by:

clearCache in interface BroadcasterCache

Parameters:

broadcasterId - The Broadcaster.getID()

uuid - an AtmosphereResource.uuid()

cacheMessage - the CacheMessage

excludeFromCache

public BroadcasterCache excludeFromCache(String broadcasterId,
 AtmosphereResource r)

Description copied from interface: BroadcasterCache

Allow an application to exclude, or block, an AtmosphereResource to received cached message. No new message will get sent to this client except the ones already cached.

Specified by:

excludeFromCache in interface BroadcasterCache

Parameters:

broadcasterId - The Broadcaster.getID()

r - an AtmosphereResource

Returns:

this

cacheCandidate

public BroadcasterCache cacheCandidate(String broadcasterId,
 String uuid)

Description copied from interface: BroadcasterCache

Add a AtmosphereResource.uuid() to the list of active AtmosphereResource Message will be cached for the resource associated with the uuid.

Specified by:

cacheCandidate in interface BroadcasterCache

Parameters:

broadcasterId - The Broadcaster.getID()

uuid - an AtmosphereResource.uuid()

Returns:

this

inspector

public BroadcasterCache inspector(BroadcasterCacheInspector interceptor)

Description copied from interface: BroadcasterCache

Add a BroadcasterCacheInspector that will be invoked before a message gets added to the cache.

Specified by:

inspector in interface BroadcasterCache

Parameters:

interceptor - an instance of BroadcasterCacheInspector

Returns:

this

addBroadcasterCacheListener

public BroadcasterCache addBroadcasterCacheListener(BroadcasterCacheListener l)

Description copied from interface: BroadcasterCache

Add a BroadcasterCacheListener

Specified by:

addBroadcasterCacheListener in interface BroadcasterCache

Parameters:

l - a BroadcasterCacheListener

Returns:

this

removeBroadcasterCacheListener

public BroadcasterCache removeBroadcasterCacheListener(BroadcasterCacheListener l)

Description copied from interface: BroadcasterCache

Remove a BroadcasterCacheListener

Specified by:

removeBroadcasterCacheListener in interface BroadcasterCache

Parameters:

l - a BroadcasterCacheListener

Returns:

this

size

public int size(String broadcasterId)

Returns the current number of cached messages for the given broadcaster.

totalSize

public int totalSize()

Returns the total number of cached messages across all broadcasters.