Package org.glassfish.hk2.utilities.general.internal

Class WeakHashClockImpl<K,​V>

  • All Implemented Interfaces:
    WeakHashClock<K,​V>
    public class WeakHashClockImpl<K,​V>
extends java.lang.Object
implements WeakHashClock<K,​V>
    Implementation of WeakHashClock as needed by the CAR algorithm

    • Field Detail

      • isWeak

        private final boolean isWeak

      • byKeyNotWeak

        private final java.util.concurrent.ConcurrentHashMap<K,​DoubleNode<K,​V>> byKeyNotWeak

      • byKey

        private final java.util.WeakHashMap<K,​DoubleNode<K,​V>> byKey

      • myQueue

        private final java.lang.ref.ReferenceQueue<? super K> myQueue

    • Constructor Detail

      • WeakHashClockImpl

        public WeakHashClockImpl​(boolean isWeak)

    • Method Detail

      • addBeforeDot

        private DoubleNode<K,​V> addBeforeDot​(K key,
                                           V value)

      • removeFromDLL

        private void removeFromDLL​(DoubleNode<K,​V> removeMe)

      • put

        public void put​(K key,
                V value)
        Description copied from interface: WeakHashClock
        Adds the given pair to the clock. It will be placed at the current tail of the clock
        Specified by:
        put in interface WeakHashClock<K,​V>
        Parameters:
        key - Must not be null
        value - May not be null

      • get

        public V get​(K key)
        Description copied from interface: WeakHashClock
        Gets the given key, returning null if not found
        Specified by:
        get in interface WeakHashClock<K,​V>
        Parameters:
        key - The key to search for, may not be null
        Returns:
        The value found, or null if not found

      • remove

        public V remove​(K key)
        Description copied from interface: WeakHashClock
        Removes the given key from the clock, if found
        Specified by:
        remove in interface WeakHashClock<K,​V>
        Parameters:
        key - The key to remove, may not be null
        Returns:
        The value removed if found, or null if not found

      • releaseMatching

        public void releaseMatching​(CacheKeyFilter<K> filter)
        Description copied from interface: WeakHashClock
        Releases all key/value pairs that match the filter
        Specified by:
        releaseMatching in interface WeakHashClock<K,​V>
        Parameters:
        filter - A non-null filter that can be used to delete every key/value pair that matches the filter

      • size

        public int size()
        Description copied from interface: WeakHashClock
        Returns the number of elements currently in the clock. References that have gone away because they were weakly referenced will not be counted in the size
        Specified by:
        size in interface WeakHashClock<K,​V>
        Returns:
        The number of entries currently in the clock

      • moveDotNoWeak

        private DoubleNode<K,​V> moveDotNoWeak()

      • next

        public java.util.Map.Entry<K,​V> next()
        Description copied from interface: WeakHashClock
        Returns the next key/value pair in the clock, or null if the clock has no members. This will advance the head and tail of the clock to the next element. If the WeakReference for the returned element is null then this element will also have been removed from the clock by this operation
        Specified by:
        next in interface WeakHashClock<K,​V>
        Returns:
        The next key/value pair in the

      • clear

        public void clear()
        Description copied from interface: WeakHashClock
        Sets the clock size back to zero, no entries
        Specified by:
        clear in interface WeakHashClock<K,​V>

      • clearStaleReferences

        public void clearStaleReferences()
        Description copied from interface: WeakHashClock
        Causes stale references to be cleared from the data structures. Since this is a weak clock the references can go away at any time, which happens whenever any operation has been performed. However, it may be the case that no operation will be performed for a while and so this method is provided to have a no-op operation to call in order to clear out any stale references
        Specified by:
        clearStaleReferences in interface WeakHashClock<K,​V>

      • removeStale

        private void removeStale()

      • hasWeakKeys

        public boolean hasWeakKeys()
        Description copied from interface: WeakHashClock
        Tells if this WeakHashClock has Weak keys
        Specified by:
        hasWeakKeys in interface WeakHashClock<K,​V>
        Returns:
        true if this map has weak keys, true otherwise

      • toString

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