net.tascalate.concurrent.ExtraCancellationPromise Maven / Gradle / Ivy

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/**
 * Copyright 2015-2020 Valery Silaev (http://vsilaev.com)
 *
 * 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 net.tascalate.concurrent;

import java.util.concurrent.CompletionStage;
import java.util.function.Function;

import net.tascalate.concurrent.decorators.AbstractPromiseDecorator;

class ExtraCancellationPromise extends AbstractPromiseDecorator> {
    final Runnable code;
    
    ExtraCancellationPromise(Promise delegate, Runnable code) {
        super(delegate);
        this.code = code;
    }
    
    @Override
    public boolean cancel(boolean mayInterruptIfRunning) {
        if (super.cancel(mayInterruptIfRunning)) {
            code.run();
            return true;
        } else {
            return false;
        }
    }
    
    @Override
    protected  Promise wrap(CompletionStage original) {
        return (Promise)original;
    }
    
    @Override
    public Promise unwrap() {
        return new Unwrapped<>(delegate, code);
    }
    
    @Override
    public Promise raw() {
        return unwrap(Promise::raw);
    }
    
    Promise unwrap(Function, Promise> fn) {
        Promise unwrapped = fn.apply(delegate);
        if (unwrapped == delegate) {
            return this;
        } else {
            return new Unwrapped<>(unwrapped, code);
        }   
    } 
    
    static class Unwrapped extends ExtraCancellationPromise {
        Unwrapped(Promise delegate, Runnable code) {
            super(delegate, code);
        }
        
        @Override
        public Promise unwrap() {
            return unwrap(Promise::unwrap);
        }
    }
}