Class PoolUtils.ErodingKeyedObjectPool<K,​V>

  • All Implemented Interfaces:
    KeyedObjectPool<K,​V>
    Direct Known Subclasses:
    PoolUtils.ErodingPerKeyKeyedObjectPool
    Enclosing class:
    PoolUtils

    private static class PoolUtils.ErodingKeyedObjectPool<K,​V>
    extends java.lang.Object
    implements KeyedObjectPool<K,​V>
    Decorates a keyed object pool, adding "eroding" behavior. Based on the configured erosion factor, objects returning to the pool may be invalidated instead of being added to idle capacity.
    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      void addObject​(K key)
      Create an object using the factory or other implementation dependent mechanism, passivate it, and then place it in the idle object pool.
      V borrowObject​(K key)
      Obtains an instance from this pool for the specified key.
      void clear()
      Clears the pool, removing all pooled instances (optional operation).
      void clear​(K key)
      Clears the specified pool, removing all pooled instances corresponding to the given key (optional operation).
      void close()
      Close this pool, and free any resources associated with it.
      protected PoolUtils.ErodingFactor getErodingFactor​(K key)
      Returns the eroding factor for the given key
      protected KeyedObjectPool<K,​V> getKeyedPool()
      Returns the underlying pool
      int getNumActive()
      Returns the total number of instances current borrowed from this pool but not yet returned (optional operation).
      int getNumActive​(K key)
      Returns the number of instances currently borrowed from but not yet returned to the pool corresponding to the given key (optional operation).
      int getNumIdle()
      Returns the total number of instances currently idle in this pool (optional operation).
      int getNumIdle​(K key)
      Returns the number of instances corresponding to the given key currently idle in this pool (optional operation).
      void invalidateObject​(K key, V obj)
      Invalidates an object from the pool.
      protected int numIdle​(K key)
      Returns the total number of instances currently idle in this pool (optional operation).
      void returnObject​(K key, V obj)
      Returns obj to the pool, unless erosion is triggered, in which case obj is invalidated.
      void setFactory​(KeyedPoolableObjectFactory<K,​V> factory)
      Deprecated.
      to be removed in pool 2.0
      java.lang.String toString()
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • ErodingKeyedObjectPool

        public ErodingKeyedObjectPool​(KeyedObjectPool<K,​V> keyedPool,
                                      float factor)
        Create an ErodingObjectPool wrapping the given pool using the specified erosion factor.
        Parameters:
        keyedPool - underlying pool
        factor - erosion factor - determines the frequency of erosion events
        See Also:
        erodingFactor
      • ErodingKeyedObjectPool

        protected ErodingKeyedObjectPool​(KeyedObjectPool<K,​V> keyedPool,
                                         PoolUtils.ErodingFactor erodingFactor)
        Create an ErodingObjectPool wrapping the given pool using the specified erosion factor.
        Parameters:
        keyedPool - underlying pool - must not be null
        erodingFactor - erosion factor - determines the frequency of erosion events
        See Also:
        #factor
    • Method Detail

      • borrowObject

        public V borrowObject​(K key)
                       throws java.lang.Exception,
                              java.util.NoSuchElementException,
                              java.lang.IllegalStateException
        Obtains an instance from this pool for the specified key.

        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 object using returnObject, invalidateObject, or a related method as defined in an implementation or sub-interface, using a key that is equivalent to the one used to borrow the instance in the first place.

        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.

        Specified by:
        borrowObject in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key used to obtain the object
        Returns:
        an instance from this pool.
        Throws:
        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
      • returnObject

        public void returnObject​(K key,
                                 V obj)
                          throws java.lang.Exception
        Returns obj to the pool, unless erosion is triggered, in which case obj is invalidated. Erosion is triggered when there are idle instances in the pool associated with the given key and more than the configured erosion factor time has elapsed since the last returnObject activation.
        Specified by:
        returnObject in interface KeyedObjectPool<K,​V>
        Parameters:
        obj - object to return or invalidate
        key - key
        Throws:
        java.lang.Exception
        See Also:
        erodingFactor
      • numIdle

        protected int numIdle​(K key)
        Returns the total number of instances currently idle in this pool (optional operation). Returns a negative value if this information is not available.
        Parameters:
        key - ignored
        Returns:
        the total number of instances currently idle in this pool or a negative value if unsupported
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation
      • getErodingFactor

        protected PoolUtils.ErodingFactor getErodingFactor​(K key)
        Returns the eroding factor for the given key
        Parameters:
        key - key
        Returns:
        eroding factor for the given keyed pool
      • invalidateObject

        public void invalidateObject​(K key,
                                     V 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 using a key that is equivalent to the one used to borrow the Object in the first place.

        This method should be used when an object that has been borrowed is determined (due to an exception or other problem) to be invalid.

        Specified by:
        invalidateObject in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key used to obtain the object
        obj - a borrowed instance to be returned.
      • addObject

        public void addObject​(K key)
                       throws java.lang.Exception,
                              java.lang.IllegalStateException,
                              java.lang.UnsupportedOperationException
        Create an object using the 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).
        Specified by:
        addObject in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key a new instance should be added to
        Throws:
        java.lang.Exception - when KeyedPoolableObjectFactory.makeObject(K) fails.
        java.lang.IllegalStateException - after KeyedObjectPool.close() has been called on this pool.
        java.lang.UnsupportedOperationException - when this pool cannot add new idle objects.
      • getNumIdle

        public int getNumIdle()
                       throws java.lang.UnsupportedOperationException
        Returns the total number of instances currently idle in this pool (optional operation). Returns a negative value if this information is not available.
        Specified by:
        getNumIdle in interface KeyedObjectPool<K,​V>
        Returns:
        the total number of instances currently idle in this pool or a negative value if unsupported
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation
      • getNumIdle

        public int getNumIdle​(K key)
                       throws java.lang.UnsupportedOperationException
        Returns the number of instances corresponding to the given key currently idle in this pool (optional operation). Returns a negative value if this information is not available.
        Specified by:
        getNumIdle in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key to query
        Returns:
        the number of instances corresponding to the given key currently idle in this pool or a negative value if unsupported
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation
      • getNumActive

        public int getNumActive()
                         throws java.lang.UnsupportedOperationException
        Returns the total number of instances current borrowed from this pool but not yet returned (optional operation). Returns a negative value if this information is not available.
        Specified by:
        getNumActive in interface KeyedObjectPool<K,​V>
        Returns:
        the total number of instances currently borrowed from this pool or a negative value if unsupported
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation
      • getNumActive

        public int getNumActive​(K key)
                         throws java.lang.UnsupportedOperationException
        Returns the number of instances currently borrowed from but not yet returned to the pool corresponding to the given key (optional operation). Returns a negative value if this information is not available.
        Specified by:
        getNumActive in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key to query
        Returns:
        the number of instances corresponding to the given key currently borrowed in this pool or a negative value if unsupported
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation
      • clear

        public void clear()
                   throws java.lang.Exception,
                          java.lang.UnsupportedOperationException
        Clears the pool, removing all pooled instances (optional operation). Throws UnsupportedOperationException if the pool cannot be cleared.
        Specified by:
        clear in interface KeyedObjectPool<K,​V>
        Throws:
        java.lang.UnsupportedOperationException - when this implementation doesn't support the operation
        java.lang.Exception
      • clear

        public void clear​(K key)
                   throws java.lang.Exception,
                          java.lang.UnsupportedOperationException
        Clears the specified pool, removing all pooled instances corresponding to the given key (optional operation). Throws UnsupportedOperationException if the pool cannot be cleared.
        Specified by:
        clear in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key to clear
        Throws:
        java.lang.UnsupportedOperationException - when this implementation doesn't support the operation
        java.lang.Exception
      • close

        public void close()
        Close this pool, and free any resources associated with it.

        Calling addObject or borrowObject after invoking this method on a pool will cause them to throw an IllegalStateException.

        Specified by:
        close in interface KeyedObjectPool<K,​V>
      • setFactory

        @Deprecated
        public void setFactory​(KeyedPoolableObjectFactory<K,​V> factory)
                        throws java.lang.IllegalStateException,
                               java.lang.UnsupportedOperationException
        Deprecated.
        to be removed in pool 2.0
        Sets the factory the 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.
        Specified by:
        setFactory in interface KeyedObjectPool<K,​V>
        Parameters:
        factory - the KeyedPoolableObjectFactory used to create new instances.
        Throws:
        java.lang.IllegalStateException - when the factory cannot be set at this time
        java.lang.UnsupportedOperationException - when this implementation doesn't support the operation
      • getKeyedPool

        protected KeyedObjectPool<K,​V> getKeyedPool()
        Returns the underlying pool
        Returns:
        the keyed pool that this ErodingKeyedObjectPool wraps
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object