@Override
public Set<String> getArtifactIds(Integer limit) {
    Set<String> ids = new ConcurrentSkipListSet<>();
    try (Stream<String> stream = storageStore.allKeys()) {
        // exists can be costly ...
        if (limit != null) {
            stream.filter(this::exists)
                    .limit(limit)
                    .forEach(ids::add);
        } else {
            stream.filter(this::exists).forEach(ids::add);
        }
    }
    ids.remove(GLOBAL_RULES_ID);
    return ids;
}
 

public TableCacheImpl(CacheCleanupPolicy cleanupPolicy) {

    // As for full table cache only we need elements to be inserted in sorted
    // manner, so that list will be easy. For other we can go with Hash map.
    if (cleanupPolicy == CacheCleanupPolicy.NEVER) {
      cache = new ConcurrentSkipListMap<>();
    } else {
      cache = new ConcurrentHashMap<>();
    }
    epochEntries = new ConcurrentSkipListSet<>();
    // Created a singleThreadExecutor, so one cleanup will be running at a
    // time.
    ThreadFactory build = new ThreadFactoryBuilder().setDaemon(true)
        .setNameFormat("PartialTableCache Cleanup Thread - %d").build();
    executorService = Executors.newSingleThreadExecutor(build);
    this.cleanupPolicy = cleanupPolicy;
  }
 

/**
 * Subsets of subsets subdivide correctly
 */
public void testRecursiveSubSets() throws Exception {
    int setSize = expensiveTests ? 1000 : 100;
    Class cl = ConcurrentSkipListSet.class;

    NavigableSet<Integer> set = newSet(cl);
    BitSet bs = new BitSet(setSize);

    populate(set, setSize, bs);
    check(set,                 0, setSize - 1, true, bs);
    check(set.descendingSet(), 0, setSize - 1, false, bs);

    mutateSet(set, 0, setSize - 1, bs);
    check(set,                 0, setSize - 1, true, bs);
    check(set.descendingSet(), 0, setSize - 1, false, bs);

    bashSubSet(set.subSet(0, true, setSize, false),
               0, setSize - 1, true, bs);
}
 

void doRun() {
    checkTimes++;
    logger.debug("\n========================================================================= {}", checkTimes);
    dumpSegmentBuildJobCheckList();
    coordinator.getStreamMetadataStore().reportStat();
    List<SegmentJobBuildInfo> successJobs = traceEarliestSegmentBuildJob();

    for (SegmentJobBuildInfo successJob : successJobs) {
        ConcurrentSkipListSet<SegmentJobBuildInfo> submittedBuildJobs = segmentBuildJobCheckList
                .get(successJob.cubeName);
        logger.trace("Remove job {} from check list.", successJob.jobID);
        submittedBuildJobs.remove(successJob);
    }

    findSegmentReadyToBuild();

    if (checkTimes % 100 == 1) {
        logger.info("Force traverse all cubes periodically.");
        for (StreamingCubeInfo cubeInfo : coordinator.getEnableStreamingCubes()) {
            List<String> segmentList = checkSegmentBuildJobFromMetadata(cubeInfo.getCubeName());
            for (String segmentName : segmentList) {
                submitSegmentBuildJob(cubeInfo.getCubeName(), segmentName);
            }
        }
    }
}
 

/**
 * Attempts to create a new collection of the same known type. Will return null if collection type is unknown.
 *
 * @param col Collection.
 * @return New empty collection.
 */
public static <V> Collection<V> newKnownCollection(Object col) {
    Class<?> cls = col == null ? null : col.getClass();

    if (cls == HashSet.class)
        return U.newHashSet(((Collection)col).size());
    else if (cls == LinkedHashSet.class)
        return U.newLinkedHashSet(((Collection)col).size());
    else if (!wrapTrees() && cls == TreeSet.class)
        return new TreeSet<>(((TreeSet<Object>)col).comparator());
    else if (cls == ConcurrentSkipListSet.class)
        return new ConcurrentSkipListSet<>(((ConcurrentSkipListSet<Object>)col).comparator());
    else if (cls == ArrayList.class)
        return new ArrayList<>(((Collection)col).size());
    else if (cls == LinkedList.class)
        return new LinkedList<>();
    else if (cls == SINGLETON_LIST_CLS)
        return new MutableSingletonList<>();

    return null;
}
 

public void testSubSetContents2() {
    ConcurrentSkipListSet set = set5();
    SortedSet sm = set.subSet(two, three);
    assertEquals(1, sm.size());
    assertEquals(two, sm.first());
    assertEquals(two, sm.last());
    assertFalse(sm.contains(one));
    assertTrue(sm.contains(two));
    assertFalse(sm.contains(three));
    assertFalse(sm.contains(four));
    assertFalse(sm.contains(five));
    Iterator i = sm.iterator();
    Object k;
    k = (Integer)(i.next());
    assertEquals(two, k);
    assertFalse(i.hasNext());
    Iterator j = sm.iterator();
    j.next();
    j.remove();
    assertFalse(set.contains(two));
    assertEquals(4, set.size());
    assertEquals(0, sm.size());
    assertTrue(sm.isEmpty());
    assertFalse(sm.remove(three));
    assertEquals(4, set.size());
}
 

/**
 * headSet returns set with keys in requested range
 */
public void testHeadSetContents() {
    ConcurrentSkipListSet set = set5();
    SortedSet sm = set.headSet(four);
    assertTrue(sm.contains(one));
    assertTrue(sm.contains(two));
    assertTrue(sm.contains(three));
    assertFalse(sm.contains(four));
    assertFalse(sm.contains(five));
    Iterator i = sm.iterator();
    Object k;
    k = (Integer)(i.next());
    assertEquals(one, k);
    k = (Integer)(i.next());
    assertEquals(two, k);
    k = (Integer)(i.next());
    assertEquals(three, k);
    assertFalse(i.hasNext());
    sm.clear();
    assertTrue(sm.isEmpty());
    assertEquals(2, set.size());
    assertEquals(four, set.first());
}
 

@Override
protected ConcurrentSkipListSet<MeanShiftSeed> compute() {
	if(high - low <= 1) { // generally should equal one...
		return reduce(chunks.get(low));
		
	} else {
		int mid = this.low + (this.high - this.low) / 2;
		ParallelSeedExecutor left  = new ParallelSeedExecutor(this, low, mid);
		ParallelSeedExecutor right  = new ParallelSeedExecutor(this, mid, high);
		
           left.fork();
           right.compute();
           left.join();
           
           return computedSeeds;
	}
}
 

@Override
public void delete(RegionInfo regionInfo) {
    Set<RegionInfo> infoSet = GaeCollectionUtils.getAndCreateIfNeed(
            regionInfo.getUnitId(),
            unitRegionMap,
            () -> new ConcurrentSkipListSet<>()
    );

    infoSet.remove(regionInfo);
}
 

@Before
public void initialize() throws Exception {
    testingServer = new TestingServer();
    testingServer.start();
    incrSequenceZKHandler = new IncrSequenceZKHandler[MAX_CONNECTION];
    results = new ConcurrentSkipListSet();
}
 

@Test
public void testLambda() {
    Map<String, Set<Long>> map = new HashMap<>();
    Set<Long> set = getOrCreate("key", map, ConcurrentSkipListSet::new);
    set.add(666L);
    log.debug("now the map is {}", map);

    //result:
    //09:59:34.002 [main] DEBUG top.ezttf.ad.withoutspring.Jdk8Test - now the map is {key=[666]}

    set = getOrCreate("key", map, ConcurrentSkipListSet::new);
    set.add(777L);
    log.debug("now the map is {}", map);
}
 

@Override
public void register() throws Exception {
    applications.compute(getApplication().getAppName(), (k, v) -> {
        Set<Application> container = Optional.ofNullable(v)
            .orElse(new ConcurrentSkipListSet<>());
        container.add(getApplication());
        return container;
    });
}
 

@Override
public void publish(StagingTableId stagingTableId, TableId tableId) {
  stagingTableIds.remove(formatTableIdKey(tableId));

  final DatasetId datasetId = datasetIdOf(tableId);
  publishedTables.computeIfAbsent(datasetId, k -> new ConcurrentSkipListSet<>())
      .add(tableId.getTable());
}
 

public void recycle() {
    if (queries.size() > MAX_RECORDS) {
        SortedSet<SqlLast> queries2 = new ConcurrentSkipListSet<>();
        List<SqlLast> keyList = new ArrayList<>(queries);
        int i = 0;
        for (SqlLast key : keyList) {
            if (i == MAX_RECORDS) {
                break;
            }
            queries2.add(key);
            i++;
        }
        queries = queries2;
    }
}
 

/**
 * ceiling returns next element
 */
public void testCeiling() {
    ConcurrentSkipListSet q = set5();
    Object e1 = q.ceiling(three);
    assertEquals(three, e1);

    Object e2 = q.ceiling(zero);
    assertEquals(one, e2);

    Object e3 = q.ceiling(five);
    assertEquals(five, e3);

    Object e4 = q.ceiling(six);
    assertNull(e4);
}
 

QueueElement _poll(String ppoolId) {
    logger.trace("_poll({})", ppoolId);
    ConcurrentSkipListSet<QueueElement> queue = _findQueue(ppoolId);
    QueueElement qe = queue.pollFirst();
    if (qe != null) {
        logger.debug("dequeued for ppoolId={}: wfId={}", ppoolId, qe.wfId);
    }
    return qe;
}
 

public void addSegmentBuildJob(SegmentJobBuildInfo segmentBuildJob) {
    ConcurrentSkipListSet<SegmentJobBuildInfo> buildInfos = segmentBuildJobMap.get(segmentBuildJob.cubeName);
    if (buildInfos == null) {
        buildInfos = new ConcurrentSkipListSet<>();
        ConcurrentSkipListSet<SegmentJobBuildInfo> previousValue = segmentBuildJobMap
                .putIfAbsent(segmentBuildJob.cubeName, buildInfos);
        if (previousValue != null) {
            buildInfos = previousValue;
        }
    }
    buildInfos.add(segmentBuildJob);
}
 

/**
 * Constructs new transition.
 *
 * @param frameRate frames which should be processed per second for this transition
 */
public AbstractTransition ( final FrameRate frameRate )
{
    super ();
    this.state = TransitionState.constructed;
    this.listeners = new ConcurrentSkipListSet<TransitionListener<V>> ( new TransitionListenerComparator<V> () );
    setFrameRate ( frameRate != null ? frameRate : DEFAULT_FRAME_RATE );
    setEventHandler ( null );
    setOptimizeEvents ( true );
}
 

void dumpSegmentBuildJobCheckList() {
    if (!logger.isTraceEnabled())
        return;
    StringBuilder sb = new StringBuilder("Dump JobCheckList:\t");
    for (Map.Entry<String, ConcurrentSkipListSet<SegmentJobBuildInfo>> cube : segmentBuildJobCheckList.entrySet()) {
        sb.append(cube.getKey()).append(":").append(cube.getValue());
    }
    if (logger.isTraceEnabled()) {
        logger.trace(sb.toString());
    }
}
 

public ReactorRabbitMQChannelPool(Mono<Connection> connectionMono, int poolSize) {
    this.connectionMono = connectionMono;
    ChannelFactory channelFactory = new ChannelFactory(connectionMono);

    GenericObjectPoolConfig<Channel> config = new GenericObjectPoolConfig<>();
    config.setMaxTotal(poolSize);
    this.pool = new GenericObjectPool<>(channelFactory, config);
    this.borrowedChannels = new ConcurrentSkipListSet<>(Comparator.comparingInt(System::identityHashCode));
}
 

public void add(String value, DecoratedKey key)
{
    ConcurrentSkipListSet<DecoratedKey> keys = get(value);
    if (keys == null)
    {
        ConcurrentSkipListSet<DecoratedKey> newKeys = new ConcurrentSkipListSet<>(DecoratedKey.comparator);
        keys = putIfAbsent(value, newKeys);
        if (keys == null)
            keys = newKeys;
    }

    keys.add(key);
}
 

/**
 * Returns the first (eldest) value of this LRU cache.
 *
 * @return first (eldest) value of this LRU cache
 */
public synchronized T getFirstValue() {
    // Get all keys sorted
    SortedSet<Integer> keys =
        new ConcurrentSkipListSet<Integer>(this.keySet());

    // Return the value that corresponds to the first key
    return this.get(keys.first());
}
 

/**
 * pollLast succeeds unless empty
 */
public void testPollLast() {
    ConcurrentSkipListSet q = populatedSet(SIZE);
    for (int i = SIZE - 1; i >= 0; --i) {
        assertEquals(i, q.pollLast());
    }
    assertNull(q.pollFirst());
}
 

/**
 * Constructs new {@link TimedAnimationPipeline}.
 */
public TimedAnimationPipeline ()
{
    // Concurrent transitions set
    transitions = new ConcurrentSkipListSet<Transition> ();

    // Active transitions animator
    animator = new Thread ( TimedAnimationPipeline.this );
    animator.setName ( ReflectUtils.getClassName ( TimedAnimationPipeline.this.getClass () ) );
    animator.setDaemon ( true );
    animator.start ();
}
 

@Test(timeout = 10000)
public void testThreadIDCollision() throws InterruptedException {
    CountDownLatch threadsStart = new CountDownLatch(1);
    CountDownLatch threadsFinished = new CountDownLatch(ThreadIndexCalculator.MAX_THREADS);

    ThreadIndexCalculator indexCalculator = ThreadIndexCalculator.newInstance();
    ConcurrentSkipListSet<Integer> uniqueIndices = new ConcurrentSkipListSet<>();

    List<Thread> threads = new ArrayList<>(ThreadIndexCalculator.MAX_THREADS);

    while (threads.size() < ThreadIndexCalculator.MAX_THREADS) {

        Thread thread = new Thread(() -> {
            try {
                threadsStart.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            int index = indexCalculator.getIndex();
            uniqueIndices.add(index);
            threadsFinished.countDown();
        });
        if (thread.getId() % ThreadIndexCalculator.MAX_THREADS == 0) {
            threads.add(thread);
            thread.start();
        }
    }

    threadsStart.countDown();
    threadsFinished.await();
    Assert.assertEquals(ThreadIndexCalculator.MAX_THREADS, uniqueIndices.size());
}
 

/**
 * addAll(null) throws NPE
 */
public void testAddAll1() {
    ConcurrentSkipListSet q = new ConcurrentSkipListSet();
    try {
        q.addAll(null);
        shouldThrow();
    } catch (NullPointerException success) {}
}
 

/**
 * removeAll(c) removes only those elements of c and reports true if changed
 */
public void testRemoveAll() {
    for (int i = 1; i < SIZE; ++i) {
        ConcurrentSkipListSet q = populatedSet(SIZE);
        ConcurrentSkipListSet p = populatedSet(i);
        assertTrue(q.removeAll(p));
        assertEquals(SIZE - i, q.size());
        for (int j = 0; j < i; ++j) {
            Integer x = (Integer)(p.pollFirst());
            assertFalse(q.contains(x));
        }
    }
}
 

private synchronized void recordVote(final long messagePosition, final SignedMessage bftMessage,
		final int voterId) {
	// Get the map for this position
	this.votes.putIfAbsent(messagePosition, new ConcurrentHashMap<SignedMessage, Set<Integer>>());
	final ConcurrentMap<SignedMessage, Set<Integer>> positionVotes = this.votes.get(messagePosition);

	// Get the set of votes for this message
	positionVotes.putIfAbsent(bftMessage, new ConcurrentSkipListSet<>());
	final Set<Integer> messageVotes = positionVotes.get(bftMessage);
	messageVotes.add(voterId);

	// Check if Opt-BFT quorum has been met
	if (messageVotes.size() == this.optQuorum) {
		// System.err.println("QUORUM MET, added " + (optChain.size() + 1) + "th message
		// to Opt-BFT Chain: " /*+ bftMessage*/);
		synchronized (this.optChain) {

			System.out.println("Certified message #" + (messagePosition + 1) + " is available.");
			if (this.optChain.putIfAbsent(messagePosition + 1, bftMessage) == null) {

				// Increment contiguousOptMessages if we are contiguous
				while (this.optChain.containsKey(new Long(contiguousOptMessages.get() + 1))) {
					contiguousOptMessages.incrementAndGet();
				}

				final String msgFileName = String.format("%08d", messagePosition + 1) + ".msg";
				final File messageFile = new File(this.certifiedMessageFolder, msgFileName);
				try {
					AtomicFileOperations.atomicWriteSignedMessage(messageFile, bftMessage);
				} catch (IOException e) {
					e.printStackTrace();
					System.exit(-1);
				}
				this.notifyAll();
			}
		}
	}
}
 

/**
 * Set contains all elements of collection used to initialize
 */
public void testConstructor6() {
    Integer[] ints = new Integer[SIZE];
    for (int i = 0; i < SIZE; ++i)
        ints[i] = new Integer(i);
    ConcurrentSkipListSet q = new ConcurrentSkipListSet(Arrays.asList(ints));
    for (int i = 0; i < SIZE; ++i)
        assertEquals(ints[i], q.pollFirst());
}
 

/**
 * 判定相似度的方式：Jaccard相似性系数
 * @param words1 词列表1
 * @param words2 词列表2
 * @return 相似度分值
 */
@Override
protected double getSimilarityImpl(List<Word> words1, List<Word> words2) {
    if (words1.isEmpty() && words2.isEmpty()) {
        return 1.0;
    }
    //HashSet的contains性能要大于ArrayList的contains
    Set<Word> words2Set = new HashSet<>();
    words2Set.addAll(words2);
    //求交集
    Set<String> intersectionSet = new ConcurrentSkipListSet<>();
    words1.parallelStream().forEach(word -> {
        if (words2Set.contains(word)) {
            intersectionSet.add(word.getName());
        }
    });
    //交集的大小
    int intersectionSize = intersectionSet.size();
    //求并集
    Set<String> unionSet = new HashSet<>();
    words1.forEach(word -> unionSet.add(word.getName()));
    words2.forEach(word -> unionSet.add(word.getName()));
    //并集的大小
    int unionSize = unionSet.size();
    //相似度分值
    double score = intersectionSize / (double) unionSize;
    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("交集的大小：" + intersectionSize);
        LOGGER.debug("并集的大小：" + unionSize);
        LOGGER.debug("相似度分值=" + intersectionSize + "/(double)" + unionSize + "=" + score);
    }
    return score;
}