4 |
|
* http://creativecommons.org/licenses/publicdomain |
5 |
|
*/ |
6 |
|
|
7 |
< |
package jsr166x; |
7 |
> |
package jsr166x; |
8 |
|
|
9 |
|
import java.util.*; |
10 |
|
import java.util.concurrent.*; |
11 |
|
|
12 |
|
/** |
13 |
< |
* A scalable concurrent {@link SortedSet} and (priority) {@link |
14 |
< |
* Queue} implementation based on a {@link ConcurrentSkipListMap}. |
15 |
< |
* This class maintains a set in ascending order, sorted according to |
16 |
< |
* the <i>natural order</i> for the element's class (see {@link |
17 |
< |
* Comparable}), or by the comparator provided at creation time, |
18 |
< |
* depending on which constructor is used.<p> |
13 |
> |
* A scalable concurrent {@link NavigableSet} implementation based on |
14 |
> |
* a {@link ConcurrentSkipListMap}. This class maintains a set in |
15 |
> |
* ascending order, sorted according to the <i>natural order</i> for |
16 |
> |
* the element's class (see {@link Comparable}), or by the comparator |
17 |
> |
* provided at creation time, depending on which constructor is |
18 |
> |
* used.<p> |
19 |
|
* |
20 |
|
* This implementation provides expected average <i>log(n)</i> time |
21 |
|
* cost for the <tt>contains</tt>, <tt>add</tt>, and <tt>remove</tt> |
24 |
|
* threads. Iterators are <i>weakly consistent</i>, returning elements |
25 |
|
* reflecting the state of the set at some point at or since the |
26 |
|
* creation of the iterator. They do <em>not</em> throw {@link |
27 |
< |
* ConcurrentModificationException}, and may procede concurrently with |
27 |
> |
* ConcurrentModificationException}, and may proceed concurrently with |
28 |
|
* other operations. |
29 |
|
* |
30 |
– |
* <p>This class provides extended <tt>SortedSet</tt> methods |
31 |
– |
* searching for closest matches. Methods <tt>lower</tt>, |
32 |
– |
* <tt>floor</tt>, <tt>ceiling</tt>, and <tt>higher</tt> return |
33 |
– |
* elements respectively less, less than or equal, greater than or |
34 |
– |
* equal, and greater than a given value, returning null if there is |
35 |
– |
* no such element. These methods are designed for locating, not |
36 |
– |
* traversing entries. To traverse, use iterators and/or |
37 |
– |
* <tt>subset</tt>. |
38 |
– |
* |
39 |
– |
* <p>The class additionally supports {@link Queue} methods such as |
40 |
– |
* <tt>poll</tt> that atomically returns and removes the first |
41 |
– |
* element, if one exists. Thus, this class can serve as a priority |
42 |
– |
* queue in which there are no duplicate elements. |
43 |
– |
* |
44 |
– |
* <p>The {@link ConcurrentSkipListSubSet} objects returned by methods |
45 |
– |
* <tt>subset</tt>, <tt>headSet</tt>, and <tt>tailSet</tt> support the |
46 |
– |
* same extended set of operations as this class, but operate on their |
47 |
– |
* designated subrange of elements. |
48 |
– |
* |
30 |
|
* <p>Beware that, unlike in most collections, the <tt>size</tt> |
31 |
< |
* method is <em>NOT</em> a constant-time operation. Because of the |
31 |
> |
* method is <em>not</em> a constant-time operation. Because of the |
32 |
|
* asynchronous nature of these sets, determining the current number |
33 |
< |
* of elements requires a traversal of the elements. |
33 |
> |
* of elements requires a traversal of the elements. Additionally, the |
34 |
> |
* bulk operations <tt>addAll</tt>, <tt>removeAll</tt>, |
35 |
> |
* <<tt>retainAll</tt>, and tt>containsAll</tt> are <em>not</em> |
36 |
> |
* guaranteed to be performed atomically. For example, an iterator |
37 |
> |
* operating concurrently with an <tt>addAll</tt> operation might view |
38 |
> |
* only some of the added elements. |
39 |
|
* |
40 |
|
* <p>This class and its iterators implement all of the |
41 |
|
* <em>optional</em> methods of the {@link Set} and {@link Iterator} |
42 |
|
* interfaces. Like most other concurrent collection implementations, |
43 |
|
* this class does not permit the use of <tt>null</tt> elements. |
44 |
< |
* because null arguments and return values cannot be reliably |
44 |
> |
* because <tt>null</tt> arguments and return values cannot be reliably |
45 |
|
* distinguished from the absence of elements. |
46 |
|
* |
47 |
|
* @author Doug Lea |
49 |
|
*/ |
50 |
|
public class ConcurrentSkipListSet<E> |
51 |
|
extends AbstractSet<E> |
52 |
< |
implements SortedSet<E>, Queue<E>, Cloneable, java.io.Serializable { |
52 |
> |
implements NavigableSet<E>, Cloneable, java.io.Serializable { |
53 |
|
|
54 |
|
private static final long serialVersionUID = -2479143111061671589L; |
55 |
|
|
60 |
|
* fields of underlying map, but enables this field to be declared |
61 |
|
* final, which is necessary for thread safety. |
62 |
|
*/ |
63 |
< |
private final ConcurrentSkipListMap<E,Object> m; |
63 |
> |
private final ConcurrentSkipListMap<E,Object> m; |
64 |
|
|
65 |
|
/** |
66 |
|
* Constructs a new, empty set, sorted according to the elements' natural |
67 |
< |
* order. |
67 |
> |
* order. |
68 |
|
*/ |
69 |
|
public ConcurrentSkipListSet() { |
70 |
|
m = new ConcurrentSkipListMap<E,Object>(); |
72 |
|
|
73 |
|
/** |
74 |
|
* Constructs a new, empty set, sorted according to the specified |
75 |
< |
* comparator. |
75 |
> |
* comparator. |
76 |
|
* |
77 |
|
* @param c the comparator that will be used to sort this set. A |
78 |
|
* <tt>null</tt> value indicates that the elements' <i>natural |
90 |
|
* |
91 |
|
* @throws ClassCastException if the elements in the specified |
92 |
|
* collection are not comparable, or are not mutually comparable. |
93 |
< |
* @throws NullPointerException if the specified collection is null. |
93 |
> |
* @throws NullPointerException if the specified collection is |
94 |
> |
* <tt>null</tt>. |
95 |
|
*/ |
96 |
|
public ConcurrentSkipListSet(Collection<? extends E> c) { |
97 |
|
m = new ConcurrentSkipListMap<E,Object>(); |
103 |
|
* sorted set, sorted according to the same ordering. |
104 |
|
* |
105 |
|
* @param s sorted set whose elements will comprise the new set. |
106 |
< |
* @throws NullPointerException if the specified sorted set is null. |
106 |
> |
* @throws NullPointerException if the specified sorted set is |
107 |
> |
* <tt>null</tt>. |
108 |
|
*/ |
109 |
|
public ConcurrentSkipListSet(SortedSet<E> s) { |
110 |
|
m = new ConcurrentSkipListMap<E,Object>(s.comparator()); |
119 |
|
*/ |
120 |
|
public Object clone() { |
121 |
|
ConcurrentSkipListSet<E> clone = null; |
122 |
< |
try { |
123 |
< |
clone = (ConcurrentSkipListSet<E>) super.clone(); |
124 |
< |
} catch (CloneNotSupportedException e) { |
125 |
< |
throw new InternalError(); |
126 |
< |
} |
122 |
> |
try { |
123 |
> |
clone = (ConcurrentSkipListSet<E>) super.clone(); |
124 |
> |
} catch (CloneNotSupportedException e) { |
125 |
> |
throw new InternalError(); |
126 |
> |
} |
127 |
|
|
128 |
|
clone.m.initialize(); |
129 |
|
clone.addAll(this); |
149 |
|
* @return the number of elements in this set. |
150 |
|
*/ |
151 |
|
public int size() { |
152 |
< |
return m.size(); |
152 |
> |
return m.size(); |
153 |
|
} |
154 |
|
|
155 |
|
/** |
157 |
|
* @return <tt>true</tt> if this set contains no elements. |
158 |
|
*/ |
159 |
|
public boolean isEmpty() { |
160 |
< |
return m.isEmpty(); |
160 |
> |
return m.isEmpty(); |
161 |
|
} |
162 |
|
|
163 |
|
/** |
167 |
|
* @return <tt>true</tt> if this set contains the specified element. |
168 |
|
* |
169 |
|
* @throws ClassCastException if the specified object cannot be compared |
170 |
< |
* with the elements currently in the set. |
170 |
> |
* with the elements currently in the set. |
171 |
|
* @throws NullPointerException if o is <tt>null</tt>. |
172 |
|
*/ |
173 |
|
public boolean contains(Object o) { |
174 |
< |
return m.containsKey(o); |
174 |
> |
return m.containsKey(o); |
175 |
|
} |
176 |
|
|
177 |
|
/** |
182 |
|
* element. |
183 |
|
* |
184 |
|
* @throws ClassCastException if the specified object cannot be compared |
185 |
< |
* with the elements currently in the set. |
185 |
> |
* with the elements currently in the set. |
186 |
|
* @throws NullPointerException if o is <tt>null</tt>. |
187 |
|
*/ |
188 |
|
public boolean add(E o) { |
189 |
< |
return m.putIfAbsent(o, Boolean.TRUE) == null; |
189 |
> |
return m.putIfAbsent(o, Boolean.TRUE) == null; |
190 |
|
} |
191 |
|
|
192 |
|
/** |
196 |
|
* @return <tt>true</tt> if the set contained the specified element. |
197 |
|
* |
198 |
|
* @throws ClassCastException if the specified object cannot be compared |
199 |
< |
* with the elements currently in the set. |
199 |
> |
* with the elements currently in the set. |
200 |
|
* @throws NullPointerException if o is <tt>null</tt>. |
201 |
|
*/ |
202 |
|
public boolean remove(Object o) { |
203 |
< |
return m.removep(o); |
203 |
> |
return m.removep(o); |
204 |
|
} |
205 |
|
|
206 |
|
/** |
207 |
|
* Removes all of the elements from this set. |
208 |
|
*/ |
209 |
|
public void clear() { |
210 |
< |
m.clear(); |
210 |
> |
m.clear(); |
211 |
|
} |
212 |
|
|
213 |
|
/** |
217 |
|
* @return an iterator over the elements in this set. |
218 |
|
*/ |
219 |
|
public Iterator<E> iterator() { |
220 |
< |
return m.keyIterator(); |
220 |
> |
return m.keyIterator(); |
221 |
|
} |
234 |
– |
|
235 |
– |
/* ---------------- Queue operations -------------- */ |
222 |
|
|
223 |
|
/** |
224 |
< |
* Adds the specified element, or fails if this element is already |
225 |
< |
* present. |
240 |
< |
* @param o the element to insert. |
241 |
< |
* @return <tt>true</tt> if it was possible to add the element, |
242 |
< |
* else <tt>false</tt> |
243 |
< |
*/ |
244 |
< |
public boolean offer(E o) { |
245 |
< |
return add(o); |
246 |
< |
} |
247 |
< |
|
248 |
< |
/** |
249 |
< |
* Retrieves and removes the first (lowest) element. |
224 |
> |
* Returns an iterator over the elements in this set. The elements |
225 |
> |
* are returned in descending order. |
226 |
|
* |
227 |
< |
* @return the least element, or <tt>null</tt> if empty. |
227 |
> |
* @return an iterator over the elements in this set. |
228 |
|
*/ |
229 |
< |
public E poll() { |
230 |
< |
return m.removeFirstKey(); |
229 |
> |
public Iterator<E> descendingIterator() { |
230 |
> |
return m.descendingKeyIterator(); |
231 |
|
} |
232 |
|
|
233 |
< |
/** |
258 |
< |
* Retrieves and removes the first (lowest) element. This method |
259 |
< |
* differs from the <tt>poll</tt> method in that it throws an |
260 |
< |
* exception if empty. |
261 |
< |
* |
262 |
< |
* @return the first (lowest) element. |
263 |
< |
* @throws NoSuchElementException if empty. |
264 |
< |
*/ |
265 |
< |
public E remove() { |
266 |
< |
E x = m.removeFirstKey(); |
267 |
< |
if (x == null) |
268 |
< |
throw new NoSuchElementException(); |
269 |
< |
return x; |
270 |
< |
} |
233 |
> |
/* ---------------- AbstractSet Overrides -------------- */ |
234 |
|
|
235 |
|
/** |
236 |
< |
* Retrieves, but does not remove, the first (lowest) element, |
237 |
< |
* returning <tt>null</tt> if empty. |
238 |
< |
* |
239 |
< |
* @return the first (lowest) element, or <tt>null</tt> if empty. |
240 |
< |
*/ |
241 |
< |
public E peek() { |
242 |
< |
return m.lowestKey(); |
236 |
> |
* Compares the specified object with this set for equality. Returns |
237 |
> |
* <tt>true</tt> if the specified object is also a set, the two sets |
238 |
> |
* have the same size, and every member of the specified set is |
239 |
> |
* contained in this set (or equivalently, every member of this set is |
240 |
> |
* contained in the specified set). This definition ensures that the |
241 |
> |
* equals method works properly across different implementations of the |
242 |
> |
* set interface. |
243 |
> |
* |
244 |
> |
* @param o Object to be compared for equality with this set. |
245 |
> |
* @return <tt>true</tt> if the specified Object is equal to this set. |
246 |
> |
*/ |
247 |
> |
public boolean equals(Object o) { |
248 |
> |
// Override AbstractSet version to avoid calling size() |
249 |
> |
if (o == this) |
250 |
> |
return true; |
251 |
> |
if (!(o instanceof Set)) |
252 |
> |
return false; |
253 |
> |
Collection c = (Collection) o; |
254 |
> |
try { |
255 |
> |
return containsAll(c) && c.containsAll(this); |
256 |
> |
} catch(ClassCastException unused) { |
257 |
> |
return false; |
258 |
> |
} catch(NullPointerException unused) { |
259 |
> |
return false; |
260 |
> |
} |
261 |
|
} |
262 |
|
|
263 |
|
/** |
264 |
< |
* Retrieves, but does not remove, the first (lowest) element. |
265 |
< |
* This method differs from the <tt>peek</tt> method only in that |
266 |
< |
* it throws an exception if empty. |
267 |
< |
* |
268 |
< |
* @return the first (lowest) element. |
269 |
< |
* @throws NoSuchElementException if empty. |
270 |
< |
*/ |
271 |
< |
public E element() { |
272 |
< |
return m.firstKey(); |
273 |
< |
} |
264 |
> |
* Removes from this set all of its elements that are contained in |
265 |
> |
* the specified collection. If the specified collection is also |
266 |
> |
* a set, this operation effectively modifies this set so that its |
267 |
> |
* value is the <i>asymmetric set difference</i> of the two sets. |
268 |
> |
* |
269 |
> |
* @param c collection that defines which elements will be removed from |
270 |
> |
* this set. |
271 |
> |
* @return <tt>true</tt> if this set changed as a result of the call. |
272 |
> |
* |
273 |
> |
* @throws ClassCastException if the types of one or more elements in this |
274 |
> |
* set are incompatible with the specified collection |
275 |
> |
* @throws NullPointerException if the specified collection, or any |
276 |
> |
* of its elements are <tt>null</tt>. |
277 |
> |
*/ |
278 |
> |
public boolean removeAll(Collection<?> c) { |
279 |
> |
// Override AbstractSet version to avoid unnecessary call to size() |
280 |
> |
boolean modified = false; |
281 |
> |
for (Iterator<?> i = c.iterator(); i.hasNext(); ) |
282 |
> |
if (remove(i.next())) |
283 |
> |
modified = true; |
284 |
> |
return modified; |
285 |
> |
} |
286 |
|
|
287 |
|
/* ---------------- Relational operations -------------- */ |
288 |
|
|
289 |
|
/** |
290 |
|
* Returns an element greater than or equal to the given element, or |
291 |
< |
* null if there is no such element. |
292 |
< |
* |
291 |
> |
* <tt>null</tt> if there is no such element. |
292 |
> |
* |
293 |
|
* @param o the value to match |
294 |
< |
* @return an element greater than or equal to given element, or null |
295 |
< |
* if there is no such element. |
294 |
> |
* @return an element greater than or equal to given element, or |
295 |
> |
* <tt>null</tt> if there is no such element. |
296 |
|
* @throws ClassCastException if o cannot be compared with the elements |
297 |
|
* currently in the set. |
298 |
|
* @throws NullPointerException if o is <tt>null</tt> |
302 |
|
} |
303 |
|
|
304 |
|
/** |
305 |
< |
* Returns an element strictly less than the given element, or null if |
306 |
< |
* there is no such element. |
307 |
< |
* |
305 |
> |
* Returns an element strictly less than the given element, or |
306 |
> |
* <tt>null</tt> if there is no such element. |
307 |
> |
* |
308 |
|
* @param o the value to match |
309 |
|
* @return the greatest element less than the given element, or |
310 |
< |
* null if there is no such element. |
310 |
> |
* <tt>null</tt> if there is no such element. |
311 |
|
* @throws ClassCastException if o cannot be compared with the elements |
312 |
|
* currently in the set. |
313 |
|
* @throws NullPointerException if o is <tt>null</tt>. |
317 |
|
} |
318 |
|
|
319 |
|
/** |
320 |
< |
* Returns an element less than or equal to the given element, or null |
321 |
< |
* if there is no such element. |
322 |
< |
* |
320 |
> |
* Returns an element less than or equal to the given element, or |
321 |
> |
* <tt>null</tt> if there is no such element. |
322 |
> |
* |
323 |
|
* @param o the value to match |
324 |
|
* @return the greatest element less than or equal to given |
325 |
< |
* element, or null if there is no such element. |
325 |
> |
* element, or <tt>null</tt> if there is no such element. |
326 |
|
* @throws ClassCastException if o cannot be compared with the elements |
327 |
|
* currently in the set. |
328 |
|
* @throws NullPointerException if o is <tt>null</tt>. |
332 |
|
} |
333 |
|
|
334 |
|
/** |
335 |
< |
* Returns an element strictly greater than the given element, or null |
336 |
< |
* if there is no such element. |
337 |
< |
* |
335 |
> |
* Returns an element strictly greater than the given element, or |
336 |
> |
* <tt>null</tt> if there is no such element. |
337 |
> |
* |
338 |
|
* @param o the value to match |
339 |
|
* @return the least element greater than the given element, or |
340 |
< |
* null if there is no such element. |
340 |
> |
* <tt>null</tt> if there is no such element. |
341 |
|
* @throws ClassCastException if o cannot be compared with the elements |
342 |
|
* currently in the set. |
343 |
|
* @throws NullPointerException if o is <tt>null</tt>. |
346 |
|
return m.higherKey(o); |
347 |
|
} |
348 |
|
|
349 |
+ |
/** |
350 |
+ |
* Retrieves and removes the first (lowest) element. |
351 |
+ |
* |
352 |
+ |
* @return the least element, or <tt>null</tt> if empty. |
353 |
+ |
*/ |
354 |
+ |
public E pollFirst() { |
355 |
+ |
return m.pollFirstKey(); |
356 |
+ |
} |
357 |
+ |
|
358 |
+ |
/** |
359 |
+ |
* Retrieves and removes the last (highest) element. |
360 |
+ |
* |
361 |
+ |
* @return the last element, or <tt>null</tt> if empty. |
362 |
+ |
*/ |
363 |
+ |
public E pollLast() { |
364 |
+ |
return m.pollLastKey(); |
365 |
+ |
} |
366 |
+ |
|
367 |
+ |
|
368 |
|
/* ---------------- SortedSet operations -------------- */ |
369 |
|
|
370 |
|
|
399 |
|
return m.lastKey(); |
400 |
|
} |
401 |
|
|
402 |
+ |
|
403 |
+ |
|
404 |
|
/** |
405 |
|
* Returns a view of the portion of this set whose elements range from |
406 |
|
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, exclusive. (If |
407 |
|
* <tt>fromElement</tt> and <tt>toElement</tt> are equal, the returned |
408 |
|
* sorted set is empty.) The returned sorted set is backed by this set, |
409 |
|
* so changes in the returned sorted set are reflected in this set, and |
410 |
< |
* vice-versa. |
410 |
> |
* vice-versa. |
411 |
|
* @param fromElement low endpoint (inclusive) of the subSet. |
412 |
|
* @param toElement high endpoint (exclusive) of the subSet. |
413 |
|
* @return a view of the portion of this set whose elements range from |
414 |
< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
415 |
< |
* exclusive. |
414 |
> |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
415 |
> |
* exclusive. |
416 |
|
* @throws ClassCastException if <tt>fromElement</tt> and |
417 |
|
* <tt>toElement</tt> cannot be compared to one another using |
418 |
|
* this set's comparator (or, if the set has no comparator, |
420 |
|
* @throws IllegalArgumentException if <tt>fromElement</tt> is |
421 |
|
* greater than <tt>toElement</tt>. |
422 |
|
* @throws NullPointerException if <tt>fromElement</tt> or |
423 |
< |
* <tt>toElement</tt> is <tt>null</tt>. |
423 |
> |
* <tt>toElement</tt> is <tt>null</tt>. |
424 |
|
*/ |
425 |
< |
public ConcurrentSkipListSubSet<E> subSet(E fromElement, E toElement) { |
426 |
< |
return new ConcurrentSkipListSubSet<E>(m, fromElement, toElement); |
425 |
> |
public NavigableSet<E> subSet(E fromElement, E toElement) { |
426 |
> |
return new ConcurrentSkipListSubSet<E>(m, fromElement, toElement); |
427 |
|
} |
428 |
|
|
429 |
|
/** |
430 |
|
* Returns a view of the portion of this set whose elements are strictly |
431 |
|
* less than <tt>toElement</tt>. The returned sorted set is backed by |
432 |
|
* this set, so changes in the returned sorted set are reflected in this |
433 |
< |
* set, and vice-versa. |
433 |
> |
* set, and vice-versa. |
434 |
|
* @param toElement high endpoint (exclusive) of the headSet. |
435 |
|
* @return a view of the portion of this set whose elements are strictly |
436 |
< |
* less than toElement. |
436 |
> |
* less than toElement. |
437 |
|
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
438 |
|
* with this set's comparator (or, if the set has no comparator, |
439 |
|
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
440 |
|
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt>. |
441 |
|
*/ |
442 |
< |
public ConcurrentSkipListSubSet<E> headSet(E toElement) { |
443 |
< |
return new ConcurrentSkipListSubSet<E>(m, null, toElement); |
442 |
> |
public NavigableSet<E> headSet(E toElement) { |
443 |
> |
return new ConcurrentSkipListSubSet<E>(m, null, toElement); |
444 |
|
} |
445 |
|
|
446 |
|
|
458 |
|
* <tt>Comparable</tt>). |
459 |
|
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt>. |
460 |
|
*/ |
461 |
< |
public ConcurrentSkipListSubSet<E> tailSet(E fromElement) { |
462 |
< |
return new ConcurrentSkipListSubSet<E>(m, fromElement, null); |
461 |
> |
public NavigableSet<E> tailSet(E fromElement) { |
462 |
> |
return new ConcurrentSkipListSubSet<E>(m, fromElement, null); |
463 |
> |
} |
464 |
> |
|
465 |
> |
/** |
466 |
> |
* Subsets returned by {@link ConcurrentSkipListSet} subset operations |
467 |
> |
* represent a subrange of elements of their underlying |
468 |
> |
* sets. Instances of this class support all methods of their |
469 |
> |
* underlying sets, differing in that elements outside their range are |
470 |
> |
* ignored, and attempts to add elements outside their ranges result |
471 |
> |
* in {@link IllegalArgumentException}. Instances of this class are |
472 |
> |
* constructed only using the <tt>subSet</tt>, <tt>headSet</tt>, and |
473 |
> |
* <tt>tailSet</tt> methods of their underlying sets. |
474 |
> |
* |
475 |
> |
*/ |
476 |
> |
static class ConcurrentSkipListSubSet<E> |
477 |
> |
extends AbstractSet<E> |
478 |
> |
implements NavigableSet<E>, java.io.Serializable { |
479 |
> |
|
480 |
> |
private static final long serialVersionUID = -7647078645896651609L; |
481 |
> |
|
482 |
> |
/** The underlying submap */ |
483 |
> |
private final ConcurrentSkipListMap.ConcurrentSkipListSubMap<E,Object> s; |
484 |
> |
|
485 |
> |
/** |
486 |
> |
* Creates a new submap. |
487 |
> |
* @param fromElement inclusive least value, or <tt>null</tt> if from start |
488 |
> |
* @param toElement exclusive upper bound or <tt>null</tt> if to end |
489 |
> |
* @throws IllegalArgumentException if fromElement and toElement |
490 |
> |
* nonnull and fromElement greater than toElement |
491 |
> |
*/ |
492 |
> |
ConcurrentSkipListSubSet(ConcurrentSkipListMap<E,Object> map, |
493 |
> |
E fromElement, E toElement) { |
494 |
> |
s = new ConcurrentSkipListMap.ConcurrentSkipListSubMap<E,Object> |
495 |
> |
(map, fromElement, toElement); |
496 |
> |
} |
497 |
> |
|
498 |
> |
// subsubset construction |
499 |
> |
|
500 |
> |
public NavigableSet<E> subSet(E fromElement, E toElement) { |
501 |
> |
if (!s.inOpenRange(fromElement) || !s.inOpenRange(toElement)) |
502 |
> |
throw new IllegalArgumentException("element out of range"); |
503 |
> |
return new ConcurrentSkipListSubSet<E>(s.getMap(), |
504 |
> |
fromElement, toElement); |
505 |
> |
} |
506 |
> |
|
507 |
> |
public NavigableSet<E> headSet(E toElement) { |
508 |
> |
E least = s.getLeast(); |
509 |
> |
if (!s.inOpenRange(toElement)) |
510 |
> |
throw new IllegalArgumentException("element out of range"); |
511 |
> |
return new ConcurrentSkipListSubSet<E>(s.getMap(), |
512 |
> |
least, toElement); |
513 |
> |
} |
514 |
> |
|
515 |
> |
public NavigableSet<E> tailSet(E fromElement) { |
516 |
> |
E fence = s.getFence(); |
517 |
> |
if (!s.inOpenRange(fromElement)) |
518 |
> |
throw new IllegalArgumentException("element out of range"); |
519 |
> |
return new ConcurrentSkipListSubSet<E>(s.getMap(), |
520 |
> |
fromElement, fence); |
521 |
> |
} |
522 |
> |
|
523 |
> |
// relays to submap methods |
524 |
> |
|
525 |
> |
public int size() { return s.size(); } |
526 |
> |
public boolean isEmpty() { return s.isEmpty(); } |
527 |
> |
public boolean contains(Object o) { return s.containsKey(o); } |
528 |
> |
public void clear() { s.clear(); } |
529 |
> |
public E first() { return s.firstKey(); } |
530 |
> |
public E last() { return s.lastKey(); } |
531 |
> |
public E ceiling(E o) { return s.ceilingKey(o); } |
532 |
> |
public E lower(E o) { return s.lowerKey(o); } |
533 |
> |
public E floor(E o) { return s.floorKey(o); } |
534 |
> |
public E higher(E o) { return s.higherKey(o); } |
535 |
> |
public boolean remove(Object o) { return s.remove(o)==Boolean.TRUE; } |
536 |
> |
public boolean add(E o) { return s.put(o, Boolean.TRUE)==null; } |
537 |
> |
public Comparator<? super E> comparator() { return s.comparator(); } |
538 |
> |
public Iterator<E> iterator() { return s.keySet().iterator(); } |
539 |
> |
public Iterator<E> descendingIterator() { |
540 |
> |
return s.descendingKeySet().iterator(); |
541 |
> |
} |
542 |
> |
public E pollFirst() { |
543 |
> |
Map.Entry<E,?> e = s.pollFirstEntry(); |
544 |
> |
return (e == null)? null : e.getKey(); |
545 |
> |
} |
546 |
> |
public E pollLast() { |
547 |
> |
Map.Entry<E,?> e = s.pollLastEntry(); |
548 |
> |
return (e == null)? null : e.getKey(); |
549 |
> |
} |
550 |
> |
|
551 |
|
} |
552 |
< |
} |
552 |
> |
} |