parallel-es/src/common/parallel/stream/resolved-parallel-stream.ts

Simple parallelization for EcmaScript

import {IParallelStream} from "./parallel-stream";

/**
 * Parallel stream for a static, already resolved result.
 *
 * This stream has no sub results as the end result is already known. It can also never fail.
 */
export class ResolvedParallelStream<TSub, TOut> implements IParallelStream<TSub, TOut> {

    private promise: Promise<TOut>;

    /**
     * Creates a new stream that returns the given end result.
     * @param result the end result to return
     */
    constructor(result: TOut) {
        this.promise = Promise.resolve(result);
    }

    public subscribe(onNext: (subResult: TSub, taskIndex: number, valuesPerWorker: number) => void, onError?: (reason: any) => void, onComplete?: (result: TOut) => void): IParallelStream<TSub, TOut> {
        if (onComplete || onError) {
            this.promise.then(onComplete!, onError!);
        }

        return this;
    }

    public then<TResult1, TResult2>(onfulfilled: (value: TOut) => (PromiseLike<TResult1>|TResult1), onrejected: (reason: any) => (PromiseLike<TResult2>|TResult2)): Promise<TResult2|TResult1>;
    public then<TResult>(onfulfilled: (value: TOut) => (PromiseLike<TResult>|TResult), onrejected: (reason: any) => (PromiseLike<TResult>|TResult)): Promise<TResult>;
    public then<TResult>(onfulfilled: (value: TOut) => (PromiseLike<TResult>|TResult)): Promise<TResult>;
    public then<TResult>(onfulfilled?: (value: TOut) => (PromiseLike<TResult>|TResult), onrejected?: (reason: any) => (PromiseLike<TResult>|TResult)): Promise<TResult>;
    public then<TResult>(onfulfilled?: (value: TOut) => (PromiseLike<TResult>|TResult), onrejected?: (reason: any) => void): Promise<TResult>;
    public then(onfulfilled?: any, onrejected?: any): any {
        return this.promise.then(onfulfilled, onrejected);
    }

    public catch<TResult>(onrejected: (reason: any) => (PromiseLike<TResult>|TResult)): Promise<TResult|TOut>;
    public catch(onrejected: (reason: any) => (PromiseLike<TOut>|TOut)): Promise<TOut>;
    public catch(onrejected: any): any {
        return this.promise.catch(onrejected);
    }
}