com.google.common.util.concurrent.CollectionFuture Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of wildfly-client-all

This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

There is a newer version: 35.0.0.Final

Show newest version

/*
 * Copyright (C) 2006 The Guava Authors
 *
 * Licensed 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 com.google.common.util.concurrent;

import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.Lists.newArrayListWithCapacity;
import static java.util.Collections.unmodifiableList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Optional;
import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import java.util.List;
import org.checkerframework.checker.nullness.compatqual.NullableDecl;

/** Aggregate future that collects (stores) results of each future. */
@GwtCompatible(emulated = true)
abstract class CollectionFuture extends AggregateFuture {

  abstract class CollectionFutureRunningState extends RunningState {
    private List> values;

    CollectionFutureRunningState(
        ImmutableCollection> futures,
        boolean allMustSucceed) {
      super(futures, allMustSucceed, true);

      this.values =
          futures.isEmpty()
              ? ImmutableList.>of()
              : Lists.>newArrayListWithCapacity(futures.size());

      // Populate the results list with null initially.
      for (int i = 0; i < futures.size(); ++i) {
        values.add(null);
      }
    }

    @Override
    final void collectOneValue(boolean allMustSucceed, int index, @NullableDecl V returnValue) {
      List> localValues = values;

      if (localValues != null) {
        localValues.set(index, Optional.fromNullable(returnValue));
      } else {
        // Some other future failed or has been cancelled, causing this one to also be cancelled or
        // have an exception set. This should only happen if allMustSucceed is true or if the output
        // itself has been cancelled.
        checkState(
            allMustSucceed || isCancelled(), "Future was done before all dependencies completed");
      }
    }

    @Override
    final void handleAllCompleted() {
      List> localValues = values;
      if (localValues != null) {
        set(combine(localValues));
      } else {
        checkState(isDone());
      }
    }

    @Override
    void releaseResourcesAfterFailure() {
      super.releaseResourcesAfterFailure();
      this.values = null;
    }

    abstract C combine(List> values);
  }

  /** Used for {@link Futures#allAsList} and {@link Futures#successfulAsList}. */
  static final class ListFuture extends CollectionFuture> {
    ListFuture(
        ImmutableCollection> futures,
        boolean allMustSucceed) {
      init(new ListFutureRunningState(futures, allMustSucceed));
    }

    private final class ListFutureRunningState extends CollectionFutureRunningState {
      ListFutureRunningState(
          ImmutableCollection> futures,
          boolean allMustSucceed) {
        super(futures, allMustSucceed);
      }

      @Override
      public List combine(List> values) {
        List result = newArrayListWithCapacity(values.size());
        for (Optional element : values) {
          result.add(element != null ? element.orNull() : null);
        }
        return unmodifiableList(result);
      }
    }
  }
}