# CancellableCompositeTask.java

    /*
    ** Module   : CancellableCompositeTask.java
    ** Abstract : Cancellable composite FutureTask.
    **
    ** Copyright (c) 2025, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ---------------------------------Description----------------------------------
    ** 001 GBB 20250122 Created initial version.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
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    */

    package com.goldencode.p2j.util.appserver;

    import java.util.*;
    import java.util.concurrent.*;
    import java.util.concurrent.atomic.*;

    /** Cancellable composite FutureTask */
    class CancellableCompositeTask<V>
    extends FutureTask<V>
    {
       /** Generator for unique ids for the tasks. */
       private static final AtomicInteger taskIdGenerator = new AtomicInteger(1);

       /** The callable to be executed. */
       private final CancellableCallable<V> callable;

       /** The task ID. */
       private final int taskId;

       /** The request ID. */
       private final Integer requestId;

       /** The type of the task. */
       private final MultiSessionTaskType type;

       /**
        * Package-private constructor.
        *
        * @param    callable
        *           The callable to be executed.
        * @param    type
        *           The type of the callable.
        */
       CancellableCompositeTask(CancellableCallable<V> callable, MultiSessionTaskType type)
       {
          this(callable, type, null);
       }

       /**
        * Package-private constructor.
        *
        * @param    callable
        *           The callable to be executed.
        * @param    type
        *           The type of the callable.
        * @param    requestId
        *           The request ID.
        */
       CancellableCompositeTask(CancellableCallable<V> callable, MultiSessionTaskType type, Integer requestId)
       {
          super(callable);
          this.callable = callable;
          this.taskId = taskIdGenerator.getAndIncrement();
          this.requestId = requestId;
          this.type = type;
       }

       /**
        * If not already completed, completes this CompletableFuture with a {@link CancellationException}.
        *
        * @param    mayInterruptIfRunning
        *           Flag to interrupt to thread.
        *
        * @return   {@code true} if this task is now cancelled
        */
       @Override
       public boolean cancel(boolean mayInterruptIfRunning)
       {
          callable.cancel(CancelCause.REQUEST_TIMEOUT);
          return super.cancel(mayInterruptIfRunning);
       }

       /**
        * If not already completed, completes this CompletableFuture with a {@link CancellationException}.
        *
        * @param    mayInterruptIfRunning
        *           Flag to interrupt to thread.
        * @param    cancelCause
        *           The cause for the cancel.
        *
        * @return   {@code true} if this task is now cancelled
        */
       public boolean cancel(boolean mayInterruptIfRunning, CancelCause cancelCause)
       {
          callable.cancel(cancelCause);
          return super.cancel(mayInterruptIfRunning);
       }

       /**
        * Checks if the argument object represents the same task, identified by the taskId.
        *
        * @param    o
        *           The object to compare to.
        *
        * @return   <code>true</code> if it's the same instance or taskId is the same.
        *           <code>false</code> otherwise.
        */
       @Override
       public boolean equals(Object o)
       {
          if (this == o)
          {
             return true;
          }
          if (o == null || getClass() != o.getClass())
          {
             return false;
          }
          CancellableCompositeTask<?> that = (CancellableCompositeTask<?>) o;
          return taskId == that.taskId;
       }

       /**
        * Returns the hash of the fields uniquely identifying the object.
        *
        * @return   See above.
        */
       @Override
       public int hashCode()
       {
          return Objects.hash(taskId);
       }

       /**
        * Returns the string representation.
        *
        * @return   See above.
        */
       @Override
       public String toString()
       {
          return "CancellableCompositeTask{" +
             "taskId=" + taskId +
             ", requestId=" + requestId +
             ", type=" + type +
             '}';
       }

       /**
        * Interrupts the executor thread where the MSA task is running.
        */
       public void sendStop()
       {
          sendStop(CancelCause.SEND_STOP);
       }

       /**
        * Interrupts the executor thread where the MSA task is running.
        *
        * @param    cancelCause
        *           The cause for the cancel.
        */
       public void sendStop(CancelCause cancelCause)
       {
          callable.sendStop(cancelCause);
       }

       /**
        * Getter for {@link #taskId}
        *
        * @return   See above.
        */
       int getTaskId()
       {
          return taskId;
       }

       /**
        * Getter for {@link #type}
        *
        * @return   See above.
        */
       MultiSessionTaskType getType()
       {
          return type;
       }

       /**
        * Returns a thread-safe flag indicating if the MSA task is running.
        *
        * @return   See above.
        */
       AtomicBoolean getRunningSupplier()
       {
          return callable.getIsRunningSupplier();
       }

       /**
        * Returns the cause of the cancel, <code>null</code> when the callable is not cancelled.
        *
        * @return   See above.
        */
       CancelCause getCancelCause()
       {
          return callable.getCancelCause();
       }
    }