ReferenceCounter
extends Object| java.lang.Object | |
| ↳ | com.pnfsoftware.jeb.util.collect.ReferenceCounter<K> |
Class Overview
A simple, thread-safe object reference counter. A counter can be associated to any object of the
provided K type.
Note that this utility class has nothing to do with Garbage Collection reference counting.
Summary
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ReferenceCounter()
Create a new reference counter.
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| Public Methods | |||||||||||
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| synchronized void |
clear()
Reset the reference counter.
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| synchronized Map<K, Integer> | copyToMap() | ||||||||||
| synchronized int |
dec(K key)
Unrecord an object, ie decrement its reference counter by one.
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| synchronized String |
formatAllReferences()
Format all references in descending order.
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| synchronized String |
formatTopReferences(int top)
Format the top references (= descending order) counted referenced by the counter.
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| synchronized int |
get(K key)
Get the reference counter for an object.
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| synchronized Map<K, Integer> |
getAsMap()
Get a read-only map of (referenced object -> count).
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| synchronized int |
getCount()
Get the total count for all the references actively counted by this counter.
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| synchronized boolean |
has(K key)
Check if an object is currently referenced, ie its reference counter is greater or equal than
zero.
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| synchronized int |
inc(K key)
Record an object, ie increment its reference counter.
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| synchronized boolean |
isEmpty()
Determine whether there are references actively tracked by this counter.
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| synchronized Set<K> | keys() | ||||||||||
| synchronized void | load(Collection<? extends K> coll) | ||||||||||
| synchronized boolean |
remove(K key)
Remove an object from tracking.
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| synchronized int |
size()
Get the number of references actively counted by this counter.
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| synchronized String | toString() | ||||||||||
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[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Object
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Public Constructors
public ReferenceCounter ()
Create a new reference counter.
Public Methods
public synchronized void clear ()
Reset the reference counter.
public synchronized Map<K, Integer> copyToMap ()
public synchronized int dec (K key)
Unrecord an object, ie decrement its reference counter by one. If the object is currently untracked, an exception will be raised.
Parameters
| key | object |
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Returns
- the updated counter for this object
Throws
| IllegalArgumentException | if the object is not present |
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public synchronized String formatAllReferences ()
Format all references in descending order.
Returns
- a string
public synchronized String formatTopReferences (int top)
Format the top references (= descending order) counted referenced by the counter.
Parameters
| top | the number of top references to format; a negative number means to format all references |
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Returns
- a string
public synchronized int get (K key)
Get the reference counter for an object.
Parameters
| key | object |
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Returns
- the counter; 0 if the object is currently not tracked
public synchronized Map<K, Integer> getAsMap ()
Get a read-only map of (referenced object -> count). To be used in a "this counter"-synchronized block.
public synchronized int getCount ()
Get the total count for all the references actively counted by this counter.
public synchronized boolean has (K key)
Check if an object is currently referenced, ie its reference counter is greater or equal than zero.
Parameters
| key | object |
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Returns
- true if the object is referenced
public synchronized int inc (K key)
Record an object, ie increment its reference counter. Will raise an IllegalStateException if the counter exceeds the capacity of a signed integer.
Parameters
| key | object |
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Returns
- the updated counter for this object
public synchronized boolean isEmpty ()
Determine whether there are references actively tracked by this counter.
public synchronized Set<K> keys ()
public synchronized void load (Collection<? extends K> coll)
public synchronized boolean remove (K key)
Remove an object from tracking. This method is equivalent to decrementing the object counter until zero.
Parameters
| key | object |
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Returns
- true if the object was actually referenced (ie its counter was >= 1), false if it was not
public synchronized int size ()
Get the number of references actively counted by this counter.