12 |
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|
13 |
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/** |
14 |
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* A keyed table of adders, that may be useful in computing frequency |
15 |
< |
* counts and histograms, or may be used a form of multiset. A {@link |
16 |
< |
* LongAdder} is associated with each key. Keys are added to the table |
17 |
< |
* implicitly upon any attempt to update, or may be added explicitly |
18 |
< |
* using method {@link #install}. |
15 |
> |
* counts and histograms, or may be used as a form of multiset. A |
16 |
> |
* {@link LongAdder} is associated with each key. Keys are added to |
17 |
> |
* the table implicitly upon any attempt to update, or may be added |
18 |
> |
* explicitly using method {@link #install}. |
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* |
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* <p><em>jsr166e note: This class is targeted to be placed in |
21 |
< |
* java.util.concurrent.atomic<em> |
21 |
> |
* java.util.concurrent.atomic.</em> |
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* |
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+ |
* @since 1.8 |
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* @author Doug Lea |
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*/ |
26 |
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public class LongAdderTable<K> implements Serializable { |
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private final ConcurrentHashMapV8<K, LongAdder> map; |
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|
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static final class CreateAdder |
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< |
implements ConcurrentHashMapV8.MappingFunction<Object, LongAdder> { |
35 |
< |
public LongAdder map(Object unused) { return new LongAdder(); } |
34 |
> |
implements ConcurrentHashMapV8.Fun<Object, LongAdder> { |
35 |
> |
public LongAdder apply(Object unused) { return new LongAdder(); } |
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} |
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|
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private static final CreateAdder createAdder = new CreateAdder(); |
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* @return the adder associated with the key |
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*/ |
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public LongAdder install(K key) { |
56 |
< |
LongAdder a = map.get(key); |
56 |
< |
if (a == null) { |
57 |
< |
LongAdder r = new LongAdder(); |
58 |
< |
if ((a = map.putIfAbsent(key, r)) == null) |
59 |
< |
a = r; |
60 |
< |
} |
61 |
< |
return a; |
56 |
> |
return map.computeIfAbsent(key, createAdder); |
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} |
58 |
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|
59 |
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/** |
65 |
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* @param x the value to add |
66 |
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*/ |
67 |
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public void add(K key, long x) { |
68 |
< |
LongAdder a = map.get(key); |
74 |
< |
if (a == null) |
75 |
< |
a = map.computeIfAbsent(key, createAdder); |
76 |
< |
a.add(x); |
68 |
> |
map.computeIfAbsent(key, createAdder).add(x); |
69 |
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} |
70 |
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|
71 |
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/** |
127 |
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/** |
128 |
|
* Returns the sum totalled across all keys. |
129 |
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* |
130 |
< |
* @return the sum totalled across all keys. |
130 |
> |
* @return the sum totalled across all keys |
131 |
|
*/ |
132 |
|
public long sumAll() { |
133 |
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long sum = 0L; |
147 |
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/** |
148 |
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* Totals, then resets, the sums associated with all keys. |
149 |
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* |
150 |
< |
* @return the sum totalled across all keys. |
150 |
> |
* @return the sum totalled across all keys |
151 |
|
*/ |
152 |
|
public long sumThenResetAll() { |
153 |
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long sum = 0L; |