private static class PoolUtils.ErodingObjectPool<T> extends java.lang.Object implements ObjectPool<T>
erosion factor
, objects returning to the pool
may be invalidated instead of being added to idle capacity.Modifier and Type | Field and Description |
---|---|
private PoolUtils.ErodingFactor |
factor
Erosion factor
|
private ObjectPool<T> |
pool
Underlying object pool
|
Constructor and Description |
---|
ErodingObjectPool(ObjectPool<T> pool,
float factor)
Create an ErodingObjectPool wrapping the given pool using the specified erosion factor.
|
Modifier and Type | Method and Description |
---|---|
void |
addObject()
Create an object using the
factory or other
implementation dependent mechanism, passivate it, and then place it in the idle object pool. |
T |
borrowObject()
Obtains an instance from this pool.
|
void |
clear()
Clears any objects sitting idle in the pool, releasing any
associated resources (optional operation).
|
void |
close()
Close this pool, and free any resources associated with it.
|
int |
getNumActive()
Return the number of instances
currently borrowed from this pool
(optional operation).
|
int |
getNumIdle()
Return the number of instances
currently idle in this pool (optional operation).
|
void |
invalidateObject(T obj)
Invalidates an object from the pool.
|
void |
returnObject(T obj)
Returns obj to the pool, unless erosion is triggered, in which
case obj is invalidated.
|
void |
setFactory(PoolableObjectFactory<T> factory)
Deprecated.
to be removed in pool 2.0
|
java.lang.String |
toString() |
private final ObjectPool<T> pool
private final PoolUtils.ErodingFactor factor
public ErodingObjectPool(ObjectPool<T> pool, float factor)
pool
- underlying poolfactor
- erosion factor - determines the frequency of erosion eventsfactor
public T borrowObject() throws java.lang.Exception, java.util.NoSuchElementException, java.lang.IllegalStateException
Instances returned from this method will have been either newly created with
makeObject
or will be a previously idle object and
have been activated with activateObject
and
then validated with validateObject
.
By contract, clients must return the borrowed instance using
returnObject
, invalidateObject
, or a related method
as defined in an implementation or sub-interface.
The behaviour of this method when the pool has been exhausted
is not strictly specified (although it may be specified by implementations).
Older versions of this method would return null
to indicate exhaustion,
newer versions are encouraged to throw a NoSuchElementException
.
borrowObject
in interface ObjectPool<T>
java.lang.IllegalStateException
- after close
has been called on this pool.java.lang.Exception
- when makeObject
throws an exception.java.util.NoSuchElementException
- when the pool is exhausted and cannot or will not return another instance.public void returnObject(T obj)
erosion factor
-determined time has elapsed
since the last returnObject activation.returnObject
in interface ObjectPool<T>
obj
- object to return or invalidatefactor
public void invalidateObject(T obj)
Invalidates an object from the pool.
By contract, obj
must have been obtained
using borrowObject
or a related method as defined in
an implementation or sub-interface.
This method should be used when an object that has been borrowed is determined (due to an exception or other problem) to be invalid.
invalidateObject
in interface ObjectPool<T>
obj
- a borrowed
instance to be disposed.public void addObject() throws java.lang.Exception, java.lang.IllegalStateException, java.lang.UnsupportedOperationException
factory
or other
implementation dependent mechanism, passivate it, and then place it in the idle object pool.
addObject
is useful for "pre-loading" a pool with idle objects.
(Optional operation).addObject
in interface ObjectPool<T>
java.lang.Exception
- when PoolableObjectFactory.makeObject()
fails.java.lang.IllegalStateException
- after ObjectPool.close()
has been called on this pool.java.lang.UnsupportedOperationException
- when this pool cannot add new idle objects.public int getNumIdle() throws java.lang.UnsupportedOperationException
borrowed
without creating any new instances.
Returns a negative value if this information is not available.getNumIdle
in interface ObjectPool<T>
java.lang.UnsupportedOperationException
- deprecated: if this implementation does not support the operationpublic int getNumActive() throws java.lang.UnsupportedOperationException
getNumActive
in interface ObjectPool<T>
java.lang.UnsupportedOperationException
- deprecated: if this implementation does not support the operationpublic void clear() throws java.lang.Exception, java.lang.UnsupportedOperationException
destroyed
.clear
in interface ObjectPool<T>
java.lang.UnsupportedOperationException
- if this implementation does not support the operationjava.lang.Exception
public void close()
Calling ObjectPool.addObject()
or ObjectPool.borrowObject()
after invoking
this method on a pool will cause them to throw an
IllegalStateException
.
close
in interface ObjectPool<T>
@Deprecated public void setFactory(PoolableObjectFactory<T> factory) throws java.lang.IllegalStateException, java.lang.UnsupportedOperationException
factory
this pool uses
to create new instances (optional operation). Trying to change
the factory
after a pool has been used will frequently
throw an UnsupportedOperationException
. It is up to the pool
implementation to determine when it is acceptable to call this method.setFactory
in interface ObjectPool<T>
factory
- the PoolableObjectFactory
used to create new instances.java.lang.IllegalStateException
- when the factory cannot be set at this timejava.lang.UnsupportedOperationException
- if this implementation does not support the operationpublic java.lang.String toString()
toString
in class java.lang.Object