Package com.rabbitmq.client.impl
Class WorkPool<K,W>
java.lang.Object
com.rabbitmq.client.impl.WorkPool<K,W>
- Type Parameters:
K
- Key -- type of clientW
- Work -- type of work item
This is a generic implementation of the channels specification
in Channeling Work, Nov 2010 (channels.pdf).
Objects of type K must be registered, with registerKey(K)
,
and then they become clients and a queue of
items (type W) is stored for each client.
addWorkItem(Object, Object)
.
If the client is dormant it becomes ready thereby. All other states remain unchanged.
The next ready client, together with a collection of its items,
may be retrieved with nextWorkBlock(collection,max)
(making that client in progress).
An in progress client can finish (processing a batch of items) with finishWorkBlock(K)
.
It then becomes either dormant or ready, depending if its queue of work items is empty or no.
If a client has items queued, it is either in progress or ready but cannot be both.
When work is finished it may be marked ready if there is further work,
or dormant if there is not.
There is never any work for a dormant client.
A client may be unregistered, with unregisterKey(K)
, which removes the client from
all parts of the state, and any queue of items stored with it.
All clients may be unregistered with unregisterAllKeys()
.
Concurrent Semantics
This implementation is thread-safe.-
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionboolean
addWorkItem
(K key, W item) Add (enqueue) an item for a specific client.boolean
finishWorkBlock
(K key) Set client no longer in progress.void
nextWorkBlock
(Collection<W> to, int size) Return the next ready client, and transfer a collection of that client's items to process.void
registerKey
(K key) Add clientkey
to pool of item queues, with an empty queue.void
void
Remove all clients from pool and from any other state.void
unregisterKey
(K key) Remove client from pool and from any other state.
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Constructor Details
-
WorkPool
public WorkPool(int queueingTimeout)
-
-
Method Details
-
registerKey
Add clientkey
to pool of item queues, with an empty queue. A client is initially dormant. No-op ifkey
already present.- Parameters:
key
- client to add to pool
-
limit
-
unlimit
-
unregisterKey
Remove client from pool and from any other state. Has no effect if client already absent.- Parameters:
key
- of client to unregister
-
unregisterAllKeys
public void unregisterAllKeys()Remove all clients from pool and from any other state. -
nextWorkBlock
Return the next ready client, and transfer a collection of that client's items to process. Mark client in progress. If there is no ready client, returnnull
.- Parameters:
to
- collection object in which to transfer itemssize
- max number of items to transfer- Returns:
- key of client to whom items belong, or
null
if there is none.
-
addWorkItem
Add (enqueue) an item for a specific client. No change and returnsfalse
if client not registered. If dormant, the client will be marked ready.- Parameters:
key
- the client to add to the work item toitem
- the work item to add to the client queue- Returns:
true
if and only if the client is marked ready — as a result of this work item
-
finishWorkBlock
Set client no longer in progress. Ignore unknown clients (and returnfalse
).- Parameters:
key
- client that has finished work- Returns:
true
if and only if client becomes ready- Throws:
IllegalStateException
- if registered client not in progress
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