io.vertx.core.shareddata

Interface SharedData

public interface SharedData

Shared data allows you to share data safely between different parts of your application in a safe way.

Shared data provides:

• synchronous shared maps (local)
• asynchronous maps (local or cluster-wide)
• asynchronous locks (local or cluster-wide)
• asynchronous counters (local or cluster-wide)

WARNING: In clustered mode, asynchronous maps/locks/counters rely on distributed data structures provided by the cluster manager. Beware that the latency relative to asynchronous maps/locks/counters operations can be much higher in clustered than in local mode.

Please see the documentation for more information.

Author:

Tim Fox

Method Summary

Modifier and Type	Method and Description
<K,V> void	getAsyncMap(String name, Handler<AsyncResult<AsyncMap<K,V>>> resultHandler) Get the AsyncMap with the specified name.
<K,V> void	getClusterWideMap(String name, Handler<AsyncResult<AsyncMap<K,V>>> resultHandler) Get the cluster wide map with the specified name.
void	getCounter(String name, Handler<AsyncResult<Counter>> resultHandler) Get an asynchronous counter.
<K,V> void	getLocalAsyncMap(String name, Handler<AsyncResult<AsyncMap<K,V>>> resultHandler) Get the AsyncMap with the specified name.
void	getLocalCounter(String name, Handler<AsyncResult<Counter>> resultHandler) Get an asynchronous local counter.
void	getLocalLock(String name, Handler<AsyncResult<Lock>> resultHandler) Get an asynchronous local lock with the specified name.
void	getLocalLockWithTimeout(String name, long timeout, Handler<AsyncResult<Lock>> resultHandler) Like getLocalLock(String, Handler) but specifying a timeout.
<K,V> LocalMap<K,V>	getLocalMap(String name) Return a LocalMap with the specific name.
void	getLock(String name, Handler<AsyncResult<Lock>> resultHandler) Get an asynchronous lock with the specified name.
void	getLockWithTimeout(String name, long timeout, Handler<AsyncResult<Lock>> resultHandler) Like getLock(String, Handler) but specifying a timeout.

Method Detail

getClusterWideMap

<K,V> void getClusterWideMap(String name,
                             Handler<AsyncResult<AsyncMap<K,V>>> resultHandler)

Get the cluster wide map with the specified name. The map is accessible to all nodes in the cluster and data put into the map from any node is visible to to any other node.

Parameters:

name - the name of the map

resultHandler - the map will be returned asynchronously in this handler

Throws:

IllegalStateException - if the parent Vertx instance is not clustered

getAsyncMap

<K,V> void getAsyncMap(String name,
                       Handler<AsyncResult<AsyncMap<K,V>>> resultHandler)

Get the AsyncMap with the specified name. When clustered, the map is accessible to all nodes in the cluster and data put into the map from any node is visible to to any other node.

WARNING: In clustered mode, asynchronous shared maps rely on distributed data structures provided by the cluster manager. Beware that the latency relative to asynchronous shared maps operations can be much higher in clustered than in local mode.

Parameters:

name - the name of the map

resultHandler - the map will be returned asynchronously in this handler

getLocalAsyncMap

<K,V> void getLocalAsyncMap(String name,
                            Handler<AsyncResult<AsyncMap<K,V>>> resultHandler)

Get the AsyncMap with the specified name.

When clustered, the map is NOT accessible to all nodes in the cluster. Only the instance which created the map can put and retrieve data from this map.

Parameters:

name - the name of the map

resultHandler - the map will be returned asynchronously in this handler

getLock

void getLock(String name,
             Handler<AsyncResult<Lock>> resultHandler)

Get an asynchronous lock with the specified name. The lock will be passed to the handler when it is available.

In general lock acquision is unordered, so that sequential attempts to acquire a lock, even from a single thread, can happen in non-sequential order.

Parameters:

name - the name of the lock

resultHandler - the handler

getLockWithTimeout

void getLockWithTimeout(String name,
                        long timeout,
                        Handler<AsyncResult<Lock>> resultHandler)

Like getLock(String, Handler) but specifying a timeout. If the lock is not obtained within the timeout a failure will be sent to the handler.

In general lock acquision is unordered, so that sequential attempts to acquire a lock, even from a single thread, can happen in non-sequential order.

Parameters:

name - the name of the lock

timeout - the timeout in ms

resultHandler - the handler

getLocalLock

void getLocalLock(String name,
                  Handler<AsyncResult<Lock>> resultHandler)

Get an asynchronous local lock with the specified name. The lock will be passed to the handler when it is available.

In general lock acquision is unordered, so that sequential attempts to acquire a lock, even from a single thread, can happen in non-sequential order.

Parameters:

name - the name of the lock

resultHandler - the handler

getLocalLockWithTimeout

void getLocalLockWithTimeout(String name,
                             long timeout,
                             Handler<AsyncResult<Lock>> resultHandler)

Like getLocalLock(String, Handler) but specifying a timeout. If the lock is not obtained within the timeout a failure will be sent to the handler.

In general lock acquision is unordered, so that sequential attempts to acquire a lock, even from a single thread, can happen in non-sequential order.

Parameters:

name - the name of the lock

timeout - the timeout in ms

resultHandler - the handler

getCounter

void getCounter(String name,
                Handler<AsyncResult<Counter>> resultHandler)

Get an asynchronous counter. The counter will be passed to the handler.

Parameters:

name - the name of the counter.

resultHandler - the handler

getLocalCounter

void getLocalCounter(String name,
                     Handler<AsyncResult<Counter>> resultHandler)

Get an asynchronous local counter. The counter will be passed to the handler.

Parameters:

name - the name of the counter.

resultHandler - the handler

getLocalMap

<K,V> LocalMap<K,V> getLocalMap(String name)

Return a LocalMap with the specific name.

Parameters:

name - the name of the map

Returns:

the msp