Examples with BackgroundCallback org.apache.curator.framework.api.BackgroundCallback used on opensource projects

Example 1 with BackgroundCallback

use of org.apache.curator.framework.api.BackgroundCallback in project heron by twitter.

the class CuratorStateManager method getNodeData.

@Override
protected <M extends Message> ListenableFuture<M> getNodeData(WatchCallback watcher, String path, final Message.Builder builder) {
    final SettableFuture<M> future = SettableFuture.create();
    Watcher wc = ZkWatcherCallback.makeZkWatcher(watcher);
    BackgroundCallback cb = new BackgroundCallback() {

        @Override
        // we don't know what M is until runtime
        @SuppressWarnings("unchecked")
        public void processResult(CuratorFramework aClient, CuratorEvent event) throws Exception {
            byte[] data;
            if (event != null & (data = event.getData()) != null) {
                builder.mergeFrom(data);
                future.set((M) builder.build());
            } else {
                future.setException(new RuntimeException("Failed to fetch data from path: " + event.getPath()));
            }
        }
    };
    try {
        client.getData().usingWatcher(wc).inBackground(cb).forPath(path);
    // Suppress it since forPath() throws Exception
    // SUPPRESS CHECKSTYLE IllegalCatch
    } catch (Exception e) {
        future.setException(new RuntimeException("Could not getNodeData", e));
    }
    return future;
}

Example 2 with BackgroundCallback

use of org.apache.curator.framework.api.BackgroundCallback in project flink by apache.

the class ZooKeeperStateHandleStoreITCase method testRemoveWithCallback.

/**
	 * Tests that state handles are correctly removed with a callback.
	 */
@Test
public void testRemoveWithCallback() throws Exception {
    // Setup
    LongStateStorage stateHandleProvider = new LongStateStorage();
    ZooKeeperStateHandleStore<Long> store = new ZooKeeperStateHandleStore<>(ZooKeeper.getClient(), stateHandleProvider, Executors.directExecutor());
    // Config
    final String pathInZooKeeper = "/testRemoveWithCallback";
    final Long state = 27255442L;
    store.add(pathInZooKeeper, state);
    final CountDownLatch sync = new CountDownLatch(1);
    BackgroundCallback callback = mock(BackgroundCallback.class);
    doAnswer(new Answer<Void>() {

        @Override
        public Void answer(InvocationOnMock invocation) throws Throwable {
            sync.countDown();
            return null;
        }
    }).when(callback).processResult(eq(ZooKeeper.getClient()), any(CuratorEvent.class));
    // Test
    store.remove(pathInZooKeeper, callback);
    // Verify discarded and callback called
    assertEquals(0, ZooKeeper.getClient().getChildren().forPath("/").size());
    sync.await();
    verify(callback, times(1)).processResult(eq(ZooKeeper.getClient()), any(CuratorEvent.class));
}

Example 3 with BackgroundCallback

use of org.apache.curator.framework.api.BackgroundCallback in project pravega by pravega.

the class ZKStoreHelper method createZNodeIfNotExist.

CompletableFuture<Void> createZNodeIfNotExist(final String path, final boolean createParent) {
    final CompletableFuture<Void> result = new CompletableFuture<>();
    try {
        CreateBuilder createBuilder = client.create();
        BackgroundCallback callback = callback(x -> result.complete(null), e -> {
            if (e instanceof StoreException.DataExistsException) {
                result.complete(null);
            } else {
                result.completeExceptionally(e);
            }
        }, path);
        if (createParent) {
            createBuilder.creatingParentsIfNeeded().inBackground(callback, executor).forPath(path);
        } else {
            createBuilder.inBackground(callback, executor).forPath(path);
        }
    } catch (Exception e) {
        result.completeExceptionally(StoreException.create(StoreException.Type.UNKNOWN, e, path));
    }
    return result;
}

Example 4 with BackgroundCallback

use of org.apache.curator.framework.api.BackgroundCallback in project pravega by pravega.

the class ZKStoreHelper method createEphemeralZNode.

CompletableFuture<Boolean> createEphemeralZNode(final String path, byte[] data) {
    final CompletableFuture<Boolean> result = new CompletableFuture<>();
    try {
        CreateBuilder createBuilder = client.create();
        BackgroundCallback callback = callback(x -> result.complete(true), e -> {
            if (e instanceof StoreException.DataExistsException) {
                result.complete(false);
            } else {
                result.completeExceptionally(e);
            }
        }, path);
        createBuilder.creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL).inBackground(callback, executor).forPath(path, data);
    } catch (Exception e) {
        result.completeExceptionally(StoreException.create(StoreException.Type.UNKNOWN, e, path));
    }
    return result;
}

Example 5 with BackgroundCallback

use of org.apache.curator.framework.api.BackgroundCallback in project weicoder by wdcode.

the class ZookeeperClient method getDataAsync.

/**
 * 异步获取ZK节点数据，同时自动重新注册Watcher.
 * @param path 路径
 * @param callback 回调
 */
public static void getDataAsync(final String path, final Callback callback) {
    // 异步读取数据回调
    final BackgroundCallback background = (CuratorFramework client, CuratorEvent event) -> {
        try {
            callback.callBack(event.getData());
        } catch (Exception e) {
            Logs.error(e);
        }
    };
    // 每次接收ZK事件都要重新注册Watcher，然后才异步读数据
    final Watcher watcher = new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            if (event.getType() == Event.EventType.NodeDataChanged) {
                try {
                    curatorFramework.getData().usingWatcher(this).inBackground(background).forPath(path);
                } catch (Exception e) {
                    Logs.error(e);
                }
            }
        }
    };
    // 这里首次注册Watcher并异步读数据
    try {
        curatorFramework.getData().usingWatcher(watcher).inBackground(background).forPath(path);
    } catch (Exception e) {
        Logs.error(e);
    }
}