Package org.eclipse.californium.core.observe

Interface ObservationStore

All Known Implementing Classes:

InMemoryObservationStore

public interface ObservationStore

A registry for keeping information about resources observed on other peers.

The information kept in this registry is particularly intended to be shared with other instances (running on other nodes) to support failing over the processing of notifications received by another node after the original node (that initially registered the observation) has crashed.

Method Summary

Modifier and Type	Method	Description
Observation	get(Token token)	Gets the observation initiated by the request with the given token.
Observation	put(Token token, Observation obs)	Adds an observation to the store using the provided token.
Observation	putIfAbsent(Token token, Observation obs)	Adds an observation to the store using the provided token, if not already added with that token.
void	remove(Token token)	Removes the observation initiated by the request with the given token.
void	setContext(Token token, org.eclipse.californium.elements.EndpointContext endpointContext)	Sets the endpoint context on the observation initiated by the request with the given token.
void	setExecutor(ScheduledExecutorService executor)	Set executor for this store.
void	start()
void	stop()

Method Details

putIfAbsent

Observation putIfAbsent(Token token,
 Observation obs)

Adds an observation to the store using the provided token, if not already added with that token. Preserve previous stored observation with that token.

Parameters:

token - unique token to add the provided observation.

obs - The observation to add.

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key.

Throws:

NullPointerException - if token or observation is null.

ObservationStoreException - if observation isn't stored.

put

Observation put(Token token,
 Observation obs)

Adds an observation to the store using the provided token. Potentially replaces previous stored observation with that token.

Parameters:

token - unique token to add the provided observation.

obs - The observation to add.

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key.

Throws:

NullPointerException - if token or observation is null.

ObservationStoreException - if observation isn't stored.

remove

void remove(Token token)

Removes the observation initiated by the request with the given token.

Parameters:

token - The token of the observation to remove.

get

Observation get(Token token)

Gets the observation initiated by the request with the given token.

Parameters:

token - The token of the initiating request.

Returns:

The corresponding observation or null if no observation is registered for the given token.

setContext

void setContext(Token token,
 org.eclipse.californium.elements.EndpointContext endpointContext)

Sets the endpoint context on the observation initiated by the request with the given token.

This method is necessary because the endpoint context may not be known when the observation is originally registered. This is due to the fact that the information contained in the endpoint context is gathered by the transport layer when the request establishing the observation is sent to the peer.

Parameters:

token - The token of the observation to set the context on.

endpointContext - The context to set.

setExecutor

void setExecutor(ScheduledExecutorService executor)

Set executor for this store. Executor is not managed by the store, it must be shutdown externally, if the resource should be freed.

Parameters:

executor - intended to be used for rare executing timers (e.g. cleanup tasks).

start

void start()

stop

void stop()