gobblin.util.limiter

Class PoolBasedLimiter

java.lang.Object

gobblin.util.limiter.PoolBasedLimiter

All Implemented Interfaces:

Limiter

public class PoolBasedLimiter
extends Object
implements Limiter

An implementation of Limiter that ony allows permits to be acquired from a pool.

This implementation uses a Semaphore as a permit pool. acquirePermits(long) is blocking and will always return true after the permits are successfully acquired (probably after being blocked for some amount of time). Permit refills are supported by this implementation using Semaphore.release(int). Also acquirePermits(long) only accepts input arguments that can be safely casted to an integer bounded by Integer.MAX_VALUE.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PoolBasedLimiter.Factory

Constructor Summary

Constructors

Constructor and Description
PoolBasedLimiter(int poolSize)

Method Summary

Modifier and Type	Method and Description
Closeable	acquirePermits(long permits) Acquire a given number of permits.
void	start() Start the Limiter.
void	stop() Stop the Limiter.

Methods inherited from class java.lang.Object

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

Constructor Detail

PoolBasedLimiter

public PoolBasedLimiter(int poolSize)

Method Detail

start

public void start()

Description copied from interface: Limiter

Start the Limiter. See Limiter.stop()

Specified by:

start in interface Limiter

acquirePermits

public Closeable acquirePermits(long permits)
                         throws InterruptedException

Description copied from interface: Limiter

Acquire a given number of permits.

Depending on the implementation, the caller of this method may be blocked. It is also up to the caller to decide how to deal with the return value.

Specified by:

acquirePermits in interface Limiter

Parameters:

permits - number of permits to get

Returns:

a Closeable instance if the requested permits have been successfully acquired, or null if otherwise; in the former case, calling Closeable.close() on the returned Closeable instance will release the acquired permits.

Throws:

InterruptedException - if the caller is interrupted while being blocked

stop

public void stop()

Description copied from interface: Limiter

Stop the Limiter. See Limiter.start()

Specified by:

stop in interface Limiter