Java AtomicValue类代码示例

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
@Override
public void updateMaxTimestamp(long previousMaxTimestamp, long newMaxTimestamp) throws IOException {

    if (newMaxTimestamp < 0) {
        LOG.error("Negative value received for maxTimestamp: {}", newMaxTimestamp);
        throw new IllegalArgumentException();
    }
    if (newMaxTimestamp <= previousMaxTimestamp) {
        LOG.error("maxTimestamp {} <= previousMaxTimesamp: {}", newMaxTimestamp, previousMaxTimestamp);
        throw new IllegalArgumentException();
    }
    AtomicValue<Long> compareAndSet;
    try {
        compareAndSet = timestamp.compareAndSet(previousMaxTimestamp, newMaxTimestamp);
    } catch (Exception e) {
        throw new IOException("Problem setting timestamp in ZK", e);
    }
    if (!compareAndSet.succeeded()) { // We have to explicitly check for success (See Curator doc)
        throw new IOException("GetAndSet operation for storing timestamp in ZK did not succeed "
                + compareAndSet.preValue() + " " + compareAndSet.postValue());
    }

}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * Return the shared counter.
 * @return
 * @throws Exception 
 */
private long getRequests() throws Exception {
	long contador = 0;
	AtomicValue<Long> value = this.zkw.getCounter().get();
	if (value.succeeded()) {
		contador = value.postValue();
	}
	else {
		contador = value.preValue();
	}
	return contador;
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
public static void main(String[] args) throws IOException, Exception {
	try (TestingServer server = new TestingServer()) {
		CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(), new ExponentialBackoffRetry(1000, 3));
		client.start();

		List<DistributedAtomicLong> examples = Lists.newArrayList();
		ExecutorService service = Executors.newFixedThreadPool(QTY);
		for (int i = 0; i < QTY; ++i) {
			final DistributedAtomicLong count = new DistributedAtomicLong(client, PATH, new RetryNTimes(10, 10));
			
			examples.add(count);
			Callable<Void> task = new Callable<Void>() {
				@Override
				public Void call() throws Exception {
					try {
						//Thread.sleep(rand.nextInt(1000));
						AtomicValue<Long> value = count.increment();
						//AtomicValue<Long> value = count.decrement();
						//AtomicValue<Long> value = count.add((long)rand.nextInt(20));
						System.out.println("succeed: " + value.succeeded());
						if (value.succeeded())
							System.out.println("Increment: from " + value.preValue() + " to " + value.postValue());
					} catch (Exception e) {
						e.printStackTrace();
					}

					return null;
				}
			};
			service.submit(task);
		}

		service.shutdown();
		service.awaitTermination(10, TimeUnit.MINUTES);
	}

}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * {@inheritDoc}
 */
@Override
public long nextId(final String namespace) {
    final String[] paths = calcPathIdAndPathLock(namespace);
    final String pathId = paths[0];
    final String pathLock = paths[1];

    RetryPolicy retryPolicyMutex = new BoundedExponentialBackoffRetry(10, 1000, 5);
    PromotedToLock promotedToLock = PromotedToLock.builder().retryPolicy(retryPolicyMutex)
            .lockPath(pathLock).build();
    RetryPolicy retryPolicyOptimistic = new RetryNTimes(3, 100);
    DistributedAtomicLong dal = new DistributedAtomicLong(curatorFramework, pathId,
            retryPolicyOptimistic, promotedToLock);
    semaphore.acquireUninterruptibly();
    try {
        AtomicValue<Long> value = dal.increment();
        if (value != null && value.succeeded()) {
            return value.postValue();
        }
        return -1;
    } catch (Exception e) {
        throw e instanceof IdException ? (IdException) e : new IdException(e);
    } finally {
        semaphore.release();
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * {@inheritDoc}
 */
@Override
public long currentId(final String namespace) {
    final String[] paths = calcPathIdAndPathLock(namespace);
    final String pathId = paths[0];
    final String pathLock = paths[1];

    RetryPolicy retryPolicyMutex = new BoundedExponentialBackoffRetry(10, 1000, 5);
    PromotedToLock promotedToLock = PromotedToLock.builder().retryPolicy(retryPolicyMutex)
            .lockPath(pathLock).build();
    RetryPolicy retryPolicyOptimistic = new RetryNTimes(3, 100);
    DistributedAtomicLong dal = new DistributedAtomicLong(curatorFramework, pathId,
            retryPolicyOptimistic, promotedToLock);
    try {
        AtomicValue<Long> value = dal.get();
        if (value != null && value.succeeded()) {
            return value.postValue();
        }
        throw new IdException("Operation was not successful!");
    } catch (Exception e) {
        throw e instanceof IdException ? (IdException) e : new IdException(e);
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * 获得ZK中的当前值,如果不存在，抛出异常
 * @param path
 * @return
 * @throws Exception
 */
private long currentValueFromZk (String path) throws Exception {
    if (isExists(path)) {
        DistributedAtomicLong count = new DistributedAtomicLong(client, path, new RetryNTimes(10, 1000));
        AtomicValue<Long> val = count.get();
        return val.postValue();
    } else {
        throw new RuntimeException("Path is not existed! Call nextValue firstly!");
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * 获得分布式自增变量
 * @param path
 * @return
 * @throws Exception
 */
public Long getIncrementValue(String path) throws Exception {
    DistributedAtomicLong atomicId = new DistributedAtomicLong(client, path, new RetryNTimes(32,1000));
    AtomicValue<Long> rc = atomicId.get();
    if (rc.succeeded()) {
        logger.debug("getIncrementValue({}) success! get: {}.", path, rc.postValue());
    } else {
        logger.warn("getIncrementValue({}) failed! get: {}.", path, rc.postValue());
    }
    return rc.postValue();
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * 自增并获得，自增后的变量
 * @param path
 * @return
 * @throws Exception
 */
public Long incrementAndGetValue(String path) throws Exception {
    DistributedAtomicLong atomicId = new DistributedAtomicLong(client, path, new RetryNTimes(32,1000));
    AtomicValue<Long> rc = atomicId.increment();
    if (rc.succeeded()) {
        logger.info("incrementAndGetValue({}) success! before: {}, after: {}.", path, rc.preValue(), rc.postValue());
    } else {
        logger.warn("incrementAndGetValue({}) failed! before: {}, after: {}.", path, rc.preValue(), rc.postValue());
    }
    return rc.postValue();
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
private static void addInSync(String path, long delta){
    try {
        ZKPaths.mkdirs(CURATOR_FRAMEWORK.getZookeeperClient().getZooKeeper(), path);
        COUNTERS.putIfAbsent(path, new DistributedAtomicLong(CURATOR_FRAMEWORK, path, RETRY_N_TIMES));
        DistributedAtomicLong counter = COUNTERS.get(path);
        AtomicValue<Long> returnValue = counter.add(delta);
        while (!returnValue.succeeded()) {
            returnValue = counter.add(delta);
        }
    }catch (Exception e){
        LOGGER.error("addInSync "+delta+" failed for "+path, e);
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
private static void subtract(String path, long delta){
    try {
        ZKPaths.mkdirs(CURATOR_FRAMEWORK.getZookeeperClient().getZooKeeper(), path);
        COUNTERS.putIfAbsent(path, new DistributedAtomicLong(CURATOR_FRAMEWORK, path, RETRY_N_TIMES));
        DistributedAtomicLong counter = COUNTERS.get(path);
        AtomicValue<Long> returnValue = counter.subtract(delta);
        while (!returnValue.succeeded()) {
            returnValue = counter.subtract(delta);
        }
    }catch (Exception e){
        LOGGER.error("subtract "+delta+" failed for "+path, e);
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
public String getNextExecutorId() {
  checkState(distributedGenerator != null, "never started!");
  try {
    AtomicValue<Integer> atomic = distributedGenerator.increment();
    Preconditions.checkState(atomic.succeeded(), "Atomic increment did not succeed");
    return convertUsingAlphabet(atomic.postValue());
  } catch (Throwable t) {
    throw Throwables.propagate(t);
  }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
@Override
public long getMaxTimestamp() throws IOException {

    AtomicValue<Long> atomicValue;
    try {
        atomicValue = timestamp.get();
    } catch (Exception e) {
        throw new IOException("Problem getting data from ZK", e);
    }
    if (!atomicValue.succeeded()) { // We have to explicitly check for success (See Curator doc)
        throw new IOException("Get operation to obtain timestamp from ZK did not succeed");
    }
    return atomicValue.postValue();

}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * Atomically increment and return resulting value.
 *
 * @return the resulting value
 * @throws IllegalStateException if increment fails
 */
public synchronized long next() {
    try {
        AtomicValue<Long> value = counter.increment();
        if (!value.succeeded()) {
            throw new IllegalStateException("Increment did not succeed");
        }
        return value.postValue();
    } catch (Exception e) {
        throw new IllegalStateException("Unable to get next value", e);
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
/**
 * Atomically decrement and return the resulting value.
 *
 * @return the resulting value
 * @throws IllegalStateException if decrement fails
 */
public synchronized long previous() {
    try {
        AtomicValue<Long> value = counter.subtract(1L);
        if (!value.succeeded()) {
            throw new IllegalStateException("Decrement did not succeed");
        }
        return value.postValue();
    } catch (Exception e) {
        throw new IllegalStateException("Unable to get previous value", e);
    }
}
 

import org.apache.curator.framework.recipes.atomic.AtomicValue; //导入依赖的package包/类
public long get() {
    try {
        AtomicValue<Long> value = counter.get();
        if (!value.succeeded()) {
            throw new RuntimeException("Get did not succeed");
        }
        return value.postValue();
    } catch (Exception e) {
        throw new RuntimeException("Unable to get value", e);
    }
}