com.telenav.cactus.tasks.TaskGroup Maven / Gradle / Ivy
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//
// © 2011-2022 Telenav, Inc.
//
// 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 com.telenav.cactus.tasks;
import com.mastfrog.function.throwing.ThrowingConsumer;
import com.mastfrog.function.throwing.ThrowingRunnable;
import com.mastfrog.function.throwing.ThrowingSupplier;
/**
* A group of tasks which should be run in the order tasks were added to it.
*
* @author Tim Boudreau
*/
public interface TaskGroup extends Task, Iterable
{
/**
* Add a task implementation.
*
* @param task A task
* @return this
*/
TaskGroup add(Task task);
@Override
default StringBuilder stringify(int depth, StringBuilder into)
{
if (isEmpty())
{
return into;
}
Task.super.stringify(depth, into);
for (Task child : this)
{
child.stringify(depth + 1, into);
}
return into;
}
/**
* Add a runnable to this set of tasks
*
* @param name A textual description of what the passed runnable will do,
* suitable for logging
* @param code The thing to run
* @return this
*/
default TaskGroup add(String name, ThrowingRunnable code)
{
return add(new TaskImpl(name, code));
}
/**
* Add some code to run to this set of tasks, which may return a
* ThrowingRunnable which should be used to roll back whatever
* the code did, in the event that a subsequent task throws an exception or
* error.
*
* In the event of rollback, the framework guarantees that the rollback code
* will run regardless of whether previously run rollback code
* threw an exception, unless the throwable thrown by a rollback or a
* task is neither an instance of java.lang.Exception nor
* java.lang.Error.
*
*
* @param name A textual description of what the passed code will do,
* suitable for logging
* @param code The thing to run, which (optionally) returns a
* ThrowingRunnable that can undo
* @return this
*/
default TaskGroup add(String name, ThrowingSupplier code)
{
return add(new RollbackTaskImpl(name, code));
}
/**
* Creates a new child task group attached to this group. Note: When logging
* or using toString() on a TaskGroup a group only
* appears in the string representation if it contains non-empty children.
*
* @param name The name for the group
* @return A new task group
*/
default TaskGroup group(String name)
{
TaskGroup result = new TaskGroupImpl(name);
add(result);
return result;
}
/**
* Creates a new child task group attached to this group and passes it to
* the passed consumer. Note: When logging or using toString()
* on a TaskGroup a group only appears in the string
* representation if it contains non-empty children.
*
* @param name The name for the group
* @param childConsumer A consumer which will add to the tasks
* @return this - the created group is accessible only via the consumer
*/
default TaskGroup group(String name,
ThrowingConsumer childConsumer)
{
TaskGroup child = group(name);
childConsumer.toNonThrowing().accept(child);
return this;
}
}