curator-master/curator-x-async/src/main/java/org/apache/curator/x/async/details/BackgroundProcs.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.curator.x.async.details;

import java.util.List;
import java.util.concurrent.Callable;
import java.util.function.Function;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.framework.api.transaction.CuratorTransactionResult;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;

class BackgroundProcs {
    static final BackgroundProc<String> nameProc = makeProc(CuratorEvent::getName);
    static final BackgroundProc<String> pathProc = makeProc(CuratorEvent::getPath);
    static final BackgroundProc<Void> ignoredProc = makeProc(e -> null);
    static final BackgroundProc<byte[]> dataProc = makeProc(CuratorEvent::getData);
    static final BackgroundProc<Stat> statProc = makeProc(CuratorEvent::getStat);
    static final BackgroundProc<Stat> safeStatProc = (event, future) -> {
        if ((event.getResultCode() == 0) || (event.getResultCode() == KeeperException.Code.NONODE.intValue())) {
            future.complete(event.getStat());
        } else {
            future.completeExceptionally(
                    KeeperException.create(KeeperException.Code.get(event.getResultCode()), event.getPath()));
        }
        return null;
    };
    static final BackgroundProc<List<String>> childrenProc = makeProc(CuratorEvent::getChildren);
    static final BackgroundProc<List<ACL>> aclProc = makeProc(CuratorEvent::getACLList);
    static final BackgroundProc<List<CuratorTransactionResult>> opResultsProc = makeProc(CuratorEvent::getOpResults);

    static <T> BackgroundProc<T> makeProc(Function<CuratorEvent, T> proc) {
        return (event, future) -> {
            if (event.getResultCode() == 0) {
                future.complete(proc.apply(event));
            } else {
                future.completeExceptionally(
                        KeeperException.create(KeeperException.Code.get(event.getResultCode()), event.getPath()));
            }
            return null;
        };
    }

    static <T> InternalCallback<T> safeCall(InternalCallback<T> callback, Callable<?> proc) {
        try {
            proc.call();
        } catch (Exception e) {
            callback.toCompletableFuture().completeExceptionally(e);
        }
        return callback;
    }

    BackgroundProcs() {}
}
