| 305 |
|
e = e.next; |
| 306 |
|
} |
| 307 |
|
|
| 308 |
< |
if (oldValue != null) { |
| 309 |
< |
V v = e.value; |
| 310 |
< |
if (v == null || !oldValue.equals(v)) |
| 311 |
< |
return false; |
| 312 |
< |
} |
| 308 |
> |
V v = e.value; |
| 309 |
> |
if (v == null || !oldValue.equals(v)) |
| 310 |
> |
return false; |
| 311 |
|
|
| 312 |
|
e.value = newValue; |
| 313 |
|
count = c; // write-volatile |
| 318 |
|
} |
| 319 |
|
} |
| 320 |
|
|
| 321 |
+ |
V replace(K key, int hash, V newValue) { |
| 322 |
+ |
lock(); |
| 323 |
+ |
try { |
| 324 |
+ |
int c = count; |
| 325 |
+ |
HashEntry[] tab = table; |
| 326 |
+ |
int index = hash & (tab.length - 1); |
| 327 |
+ |
HashEntry<K,V> first = (HashEntry<K,V>) tab[index]; |
| 328 |
+ |
HashEntry<K,V> e = first; |
| 329 |
+ |
for (;;) { |
| 330 |
+ |
if (e == null) |
| 331 |
+ |
return null; |
| 332 |
+ |
if (e.hash == hash && key.equals(e.key)) |
| 333 |
+ |
break; |
| 334 |
+ |
e = e.next; |
| 335 |
+ |
} |
| 336 |
+ |
|
| 337 |
+ |
V v = e.value; |
| 338 |
+ |
e.value = newValue; |
| 339 |
+ |
count = c; // write-volatile |
| 340 |
+ |
return v; |
| 341 |
+ |
|
| 342 |
+ |
} finally { |
| 343 |
+ |
unlock(); |
| 344 |
+ |
} |
| 345 |
+ |
} |
| 346 |
+ |
|
| 347 |
|
|
| 348 |
|
V put(K key, int hash, V value, boolean onlyIfAbsent) { |
| 349 |
|
lock(); |
| 877 |
|
} |
| 878 |
|
|
| 879 |
|
/** |
| 880 |
< |
* Replace entry for key only if key is currently mapped. |
| 880 |
> |
* Replace entry for key only if currently mapped to some value. |
| 881 |
|
* Acts as |
| 882 |
|
* <pre> |
| 883 |
|
* if ((map.containsKey(key)) { |
| 884 |
< |
* map.put(key, value); |
| 885 |
< |
* return true; |
| 862 |
< |
* } else return false; |
| 884 |
> |
* return map.put(key, value); |
| 885 |
> |
* } else return null; |
| 886 |
|
* </pre> |
| 887 |
|
* except that the action is performed atomically. |
| 888 |
|
* @param key key with which the specified value is associated. |
| 889 |
|
* @param value value to be associated with the specified key. |
| 890 |
< |
* @return true if the value was replaced |
| 890 |
> |
* @return previous value associated with specified key, or <tt>null</tt> |
| 891 |
> |
* if there was no mapping for key. |
| 892 |
|
* @throws NullPointerException if the specified key or value is |
| 893 |
|
* <tt>null</tt>. |
| 894 |
|
*/ |
| 895 |
< |
public boolean replace(K key, V value) { |
| 895 |
> |
public V replace(K key, V value) { |
| 896 |
|
if (value == null) |
| 897 |
|
throw new NullPointerException(); |
| 898 |
|
int hash = hash(key); |
| 899 |
< |
return segmentFor(hash).replace(key, hash, null, value); |
| 899 |
> |
return segmentFor(hash).replace(key, hash, value); |
| 900 |
|
} |
| 901 |
|
|
| 902 |
|
|
