com.linecorp.armeria.client.limit

Class AbstractConcurrencyLimitingClient<I extends Request,O extends Response>

java.lang.Object

com.linecorp.armeria.common.util.AbstractUnwrappable<Client<T_I,T_O>>

com.linecorp.armeria.client.DecoratingClient<I,O,I,O>

com.linecorp.armeria.client.SimpleDecoratingClient<I,O>

com.linecorp.armeria.client.limit.AbstractConcurrencyLimitingClient<I,O>

Type Parameters:

I - the Request type

O - the Response type

All Implemented Interfaces:

Client<I,O>, Unwrappable

Direct Known Subclasses:

ConcurrencyLimitingClient

public abstract class AbstractConcurrencyLimitingClient<I extends Request,O extends Response>
extends SimpleDecoratingClient<I,O>

An abstract Client decorator that limits the concurrent number of active requests.

numActiveRequests() increases when Client.execute(ClientRequestContext, Request) is invoked and decreases when the Response returned by the Client.execute(ClientRequestContext, Request) is closed. When numActiveRequests() reaches at the configured maxConcurrency the Requests are deferred until the currently active Requests are completed.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractConcurrencyLimitingClient(Client<I,O> delegate, int maxConcurrency) Creates a new instance that decorates the specified delegate to limit the concurrent number of active requests to maxConcurrency, with the default timeout of milliseconds.
protected	AbstractConcurrencyLimitingClient(Client<I,O> delegate, int maxConcurrency, long timeout, TimeUnit unit) Creates a new instance that decorates the specified delegate to limit the concurrent number of active requests to maxConcurrency.

Method Summary

Modifier and Type	Method and Description
O	execute(ClientRequestContext ctx, I req) Sends a Request to a remote Endpoint, as specified in ClientRequestContext.endpoint().
protected abstract O	newDeferredResponse(ClientRequestContext ctx, CompletionStage<O> resFuture) Implement this method to return a new Response which delegates to the Response the specified CompletionStage is completed with.
int	numActiveRequests() Returns the number of the Requests that are being executed.

Methods inherited from class com.linecorp.armeria.common.util.AbstractUnwrappable

as, delegate, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.linecorp.armeria.client.Client

as

Constructor Detail

AbstractConcurrencyLimitingClient

protected AbstractConcurrencyLimitingClient(Client<I,O> delegate,
                                            int maxConcurrency)

Creates a new instance that decorates the specified delegate to limit the concurrent number of active requests to maxConcurrency, with the default timeout of milliseconds.

Parameters:

delegate - the delegate Client

maxConcurrency - the maximum number of concurrent active requests. 0 to disable the limit.

AbstractConcurrencyLimitingClient

protected AbstractConcurrencyLimitingClient(Client<I,O> delegate,
                                            int maxConcurrency,
                                            long timeout,
                                            TimeUnit unit)

Creates a new instance that decorates the specified delegate to limit the concurrent number of active requests to maxConcurrency.

Parameters:

delegate - the delegate Client

maxConcurrency - the maximum number of concurrent active requests. 0 to disable the limit.

timeout - the amount of time until this decorator fails the request if the request was not delegated to the delegate before then

Method Detail

numActiveRequests

public int numActiveRequests()

Returns the number of the Requests that are being executed.

execute

public O execute(ClientRequestContext ctx,
                 I req)
          throws Exception

Description copied from interface: Client

Sends a Request to a remote Endpoint, as specified in ClientRequestContext.endpoint().

Returns:

the Response to the specified Request

Throws:

Exception

newDeferredResponse

protected abstract O newDeferredResponse(ClientRequestContext ctx,
                                         CompletionStage<O> resFuture)
                                  throws Exception

Implement this method to return a new Response which delegates to the Response the specified CompletionStage is completed with. For example, you could use HttpResponse.from(CompletionStage, EventExecutor):

 protected HttpResponse newDeferredResponse(
         ClientRequestContext ctx, CompletionStage<HttpResponse> resFuture) {
     return HttpResponse.from(resFuture, ctx.eventLoop());
 }
 

Throws:

Exception