org.jboss.elemento.flow.RepeatTask Maven / Gradle / Ivy
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/*
* Copyright 2023 Red Hat
*
* 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
*
* https://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.jboss.elemento.flow;
import java.util.List;
import java.util.function.Predicate;
import elemental2.promise.Promise;
import static org.jboss.elemento.flow.Flow.repeat;
/**
* A task implementation that executes a {@linkplain Task task} as long as certain conditions are met.
*
* This implementation makes it easy to nest the execution of {@linkplain Task asynchronous tasks} inside a call to
* {@link Flow#parallel(FlowContext, List)}, {@link Flow#sequential(FlowContext, List)} or
* {@link Flow#repeat(FlowContext, Task)}.
*
* @param the type of the {@linkplain FlowContext context} shared between tasks
*/
public class RepeatTask implements Task {
private final C context;
private final Task task;
private final Predicate predicate;
private final boolean failFast;
private final long interval;
private final long timeout;
private final int iterations;
/**
* Creates a new task that executes the given {@linkplain Task tasks} as long as the given {@linkplain Predicate predicate}
* evaluates to {@code true}.
*
* The task re-uses the {@linkplain FlowContext context} from the outer call to {@link Flow#parallel(FlowContext, List)},
* {@link Flow#sequential(FlowContext, List)} or {@link Flow#repeat(FlowContext, Task)}.
*
* @param task the task to execute while the predicate evaluates to {@code true}
* @param predicate the predicate used to decide whether to continue or break the loop
* @param failFast whether the execution of the list should fail fast or fail last
* @param interval the interval between the iterations
* @param timeout the timeout for the while loop
*/
public RepeatTask(Task task, Predicate predicate,
boolean failFast, long interval, long timeout) {
this(null, task, predicate, failFast, interval, timeout, Repeat.DEFAULT_ITERATIONS);
}
/**
* Creates a new task that executes the given {@linkplain Task tasks} as long as the given {@linkplain Predicate predicate}
* evaluates to {@code true}.
*
* The task re-uses the {@linkplain FlowContext context} from the outer call to {@link Flow#parallel(FlowContext, List)},
* {@link Flow#sequential(FlowContext, List)} or {@link Flow#repeat(FlowContext, Task)}.
*
* @param task the task to execute while the predicate evaluates to {@code true}
* @param predicate the predicate used to decide whether to continue or break the loop
* @param failFast whether the execution of the list should fail fast or fail last
* @param interval the interval between the iterations
* @param timeout the timeout for the while loop
* @param iterations the maximal iterations the loop
*/
public RepeatTask(Task task, Predicate predicate,
boolean failFast, long interval, long timeout, int iterations) {
this(null, task, predicate, failFast, interval, timeout, iterations);
}
/**
* Creates a new task that executes the given {@linkplain Task tasks} as long as the given {@linkplain Predicate predicate}
* evaluates to {@code true}.
*
* The task uses the given {@linkplain FlowContext context} for the execution of the {@linkplain Task task}.
*
* @param context the context shared between the iterations
* @param task the task to execute while the predicate evaluates to {@code true}
* @param predicate the predicate used to decide whether to continue or break the loop
* @param failFast whether the execution of the list should fail fast or fail last
* @param interval the interval between the iterations
* @param timeout the timeout for the while loop
* @param iterations the maximal iterations the loop
*/
public RepeatTask(C context, Task task, Predicate predicate,
boolean failFast, long interval, long timeout) {
this(context, task, predicate, failFast, interval, timeout, Repeat.DEFAULT_ITERATIONS);
}
/**
* Creates a new task that executes the given {@linkplain Task tasks} as long as the given {@linkplain Predicate predicate}
* evaluates to {@code true}.
*
* The task uses the given {@linkplain FlowContext context} for the execution of the {@linkplain Task task}.
*
* @param context the context shared between the iterations
* @param task the task to execute while the predicate evaluates to {@code true}
* @param predicate the predicate used to decide whether to continue or break the loop
* @param failFast whether the execution of the list should fail fast or fail last
* @param interval the interval between the iterations
* @param timeout the timeout for the while loop
* @param iterations the maximal iterations the loop
*/
public RepeatTask(C context, Task task, Predicate predicate,
boolean failFast, long interval, long timeout, int iterations) {
this.context = context;
this.task = task;
this.predicate = predicate;
this.interval = interval;
this.timeout = timeout;
this.failFast = failFast;
this.iterations = iterations;
}
@Override
public Promise apply(C context) {
C contextToUse = this.context != null ? this.context : context;
return repeat(contextToUse, task)
.while_(predicate)
.failFast(failFast)
.interval(interval)
.timeout(timeout)
.iterations(iterations)
.promise();
}
}