Java Code Examples for org.apache.zookeeper.data.Stat#getCversion()

private int getCurrentChildVersion(String path) {
  Stat stat = null;

  try {
    stat = curator.checkExists().forPath(path);
  } catch (Exception e) {
    LOG.error("While checking stat for {}", path, e);
    return -1;
  }

  if (stat != null) {
    return stat.getCversion();
  }

  return -1;
}
 

@Override
@SuppressWarnings("unchecked")
public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat) {
    CompletableFuture<Versioned<List<String>>> result = ((CompletableFuture<Versioned<List<String>>>) ctx);
    if (KeeperException.Code.OK.intValue() == rc) {
        /** cversion: the number of changes to the children of this znode **/
        LongVersion zkVersion = new LongVersion(stat.getCversion());
        result.complete(new Versioned(children, zkVersion));
    } else if (KeeperException.Code.NONODE.intValue() == rc) {
        result.completeExceptionally(new LogNotFoundException("Log " + path + " not found"));
    } else {
        result.completeExceptionally(new ZKException("Failed to get log segments from " + path,
                KeeperException.Code.get(rc)));
    }
}
 

@VisibleForTesting
protected int getHFileRefsZNodeCversion() throws ReplicationException {
  Stat stat = new Stat();
  try {
    ZKUtil.getDataNoWatch(zookeeper, hfileRefsZNode, stat);
  } catch (KeeperException e) {
    throw new ReplicationException("Failed to get stat of replication hfile references node.", e);
  }
  return stat.getCversion();
}
 

private void checkChildrenChanged(String fromPath, Stat oldStat, Stat newStat)
{
    if ( (state.get() != State.STARTED) || !recursive )
    {
        return;
    }

    if ( (oldStat != null) && (oldStat.getCversion() == newStat.getCversion()) )
    {
        return; // children haven't changed
    }

    try
    {
        BackgroundCallback callback = (__, event) -> {
            if ( event.getResultCode() == OK.intValue() )
            {
                event.getChildren().forEach(child -> nodeChanged(ZKPaths.makePath(fromPath, child)));
            }
            else if ( event.getResultCode() == NONODE.intValue() )
            {
                removeStorage(event.getPath());
            }
            else
            {
                handleException(event);
            }
            outstandingOps.decrement();
        };

        outstandingOps.increment();
        client.getChildren().inBackground(callback).forPath(fromPath);
    }
    catch ( Exception e )
    {
        handleException(e);
    }
}
 

/**
 * Gets all available state handles from ZooKeeper and locks the respective state nodes.
 *
 * <p>If there is a concurrent modification, the operation is retried until it succeeds.
 *
 * @return All state handles from ZooKeeper.
 * @throws Exception If a ZooKeeper or state handle operation fails
 */
@SuppressWarnings("unchecked")
public List<Tuple2<RetrievableStateHandle<T>, String>> getAllAndLock() throws Exception {
	final List<Tuple2<RetrievableStateHandle<T>, String>> stateHandles = new ArrayList<>();

	boolean success = false;

	retry:
	while (!success) {
		stateHandles.clear();

		Stat stat = client.checkExists().forPath("/");
		if (stat == null) {
			break; // Node does not exist, done.
		} else {
			// Initial cVersion (number of changes to the children of this node)
			int initialCVersion = stat.getCversion();

			List<String> children = client.getChildren().forPath("/");

			for (String path : children) {
				path = "/" + path;

				try {
					final RetrievableStateHandle<T> stateHandle = getAndLock(path);
					stateHandles.add(new Tuple2<>(stateHandle, path));
				} catch (KeeperException.NoNodeException ignored) {
					// Concurrent deletion, retry
					continue retry;
				} catch (IOException ioException) {
					LOG.warn("Could not get all ZooKeeper children. Node {} contained " +
						"corrupted data. Ignoring this node.", path, ioException);
				}
			}

			int finalCVersion = client.checkExists().forPath("/").getCversion();

			// Check for concurrent modifications
			success = initialCVersion == finalCVersion;
		}
	}

	return stateHandles;
}
 

/**
 * Gets all available state handles from ZooKeeper and locks the respective state nodes.
 *
 * <p>If there is a concurrent modification, the operation is retried until it succeeds.
 *
 * @return All state handles from ZooKeeper.
 * @throws Exception If a ZooKeeper or state handle operation fails
 */
@SuppressWarnings("unchecked")
public List<Tuple2<RetrievableStateHandle<T>, String>> getAllAndLock() throws Exception {
	final List<Tuple2<RetrievableStateHandle<T>, String>> stateHandles = new ArrayList<>();

	boolean success = false;

	retry:
	while (!success) {
		stateHandles.clear();

		Stat stat = client.checkExists().forPath("/");
		if (stat == null) {
			break; // Node does not exist, done.
		} else {
			// Initial cVersion (number of changes to the children of this node)
			int initialCVersion = stat.getCversion();

			List<String> children = client.getChildren().forPath("/");

			for (String path : children) {
				path = "/" + path;

				try {
					final RetrievableStateHandle<T> stateHandle = getAndLock(path);
					stateHandles.add(new Tuple2<>(stateHandle, path));
				} catch (KeeperException.NoNodeException ignored) {
					// Concurrent deletion, retry
					continue retry;
				} catch (IOException ioException) {
					LOG.warn("Could not get all ZooKeeper children. Node {} contained " +
						"corrupted data. Ignoring this node.", path, ioException);
				}
			}

			int finalCVersion = client.checkExists().forPath("/").getCversion();

			// Check for concurrent modifications
			success = initialCVersion == finalCVersion;
		}
	}

	return stateHandles;
}
 

@VisibleForTesting
protected int getQueuesZNodeCversion() throws KeeperException {
  Stat stat = new Stat();
  ZKUtil.getDataNoWatch(this.zookeeper, this.queuesZNode, stat);
  return stat.getCversion();
}