Package com.pnfsoftware.jeb.util.collect
Class WeakIdentityHashMap<K,V>
java.lang.Object
com.pnfsoftware.jeb.util.collect.WeakIdentityHashMap<K,V>
A pseudo map where keys are compared using identity comparison (like
IdentityHashMap
) but
where the presence of an object as a key in the map does not prevent it being garbage collected
(like WeakHashMap
). This class does not implement the Map
interface because it is
difficult to ensure correct semantics for iterators over the entrySet(). This map does not
support null keys.
Because we do not implement Map, we do not copy the questionable interface where you can call get(k) or remove(k) for any type of k, which of course can only have an effect if k is of type K.
Implementation note: The approach is to wrap each key in a WeakReference and use the wrapped value as a key in an ordinary HashMap. The WeakReference has to be a subclass IdentityWeakReference (IWR) where two IWRs are equal if they refer to the same object. This enables us to find the entry again.
Forked from https://android.googlesource.com/platform/libcore/+/42cdd0bf7251074df8bf6dfa7f5d62a01c0a1ef6/ojluni/src/main/java/com/sun/jmx/mbeanserver/WeakIdentityHashMap.java
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Constructor Summary
ConstructorsConstructorDescriptionWeakIdentityHashMap
(int initialCapacity) WeakIdentityHashMap
(int initialCapacity, float loadFactor) -
Method Summary
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Constructor Details
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WeakIdentityHashMap
public WeakIdentityHashMap(int initialCapacity, float loadFactor) -
WeakIdentityHashMap
public WeakIdentityHashMap(int initialCapacity) -
WeakIdentityHashMap
public WeakIdentityHashMap()
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Method Details