smartstream/ts/smartstream.classes.streamwrapper.ts
2023-11-03 21:36:10 +01:00

97 lines
2.2 KiB
TypeScript

import * as plugins from './smartstream.plugins.js';
// interfaces
import { Transform } from 'stream';
export interface IErrorFunction {
(err: Error): any;
}
export interface ICustomEventFunction {
(): any;
}
export interface ICustomEventObject {
eventName: string;
eventFunction: ICustomEventFunction;
}
/**
* class Smartstream handles
*/
export class StreamWrapper {
private streamArray: Array<plugins.stream.Duplex> = [];
private customEventObjectArray: ICustomEventObject[] = [];
private streamStartedDeferred = plugins.smartpromise.defer();
/**
* constructor
*/
constructor(streamArrayArg: any[]) {
this.streamArray = streamArrayArg;
}
/**
* make something with the stream itself
*/
streamStarted(): Promise<any> {
return this.streamStartedDeferred.promise;
}
/**
* attach listener to custom event
*/
onCustomEvent(eventNameArg: string, eventFunctionArg: ICustomEventFunction) {
this.customEventObjectArray.push({
eventName: eventNameArg,
eventFunction: eventFunctionArg,
});
}
/**
* run the stream
* @returns Promise
*/
run(): Promise<void> {
const done = plugins.smartpromise.defer<void>();
// clone Array
const streamExecutionArray: Array<plugins.stream.Duplex> = [];
for (const streamItem of this.streamArray) {
streamExecutionArray.push(streamItem);
}
// combine the stream
let finalStream = null;
let firstIteration: boolean = true;
for (const stream of streamExecutionArray) {
if (firstIteration === true) {
finalStream = stream;
}
stream.on('error', (err) => {
done.reject(err);
});
for (const customEventObject of this.customEventObjectArray) {
stream.on(customEventObject.eventName, customEventObject.eventFunction);
}
if (!firstIteration) {
finalStream = finalStream.pipe(stream);
}
firstIteration = false;
}
this.streamStartedDeferred.resolve();
finalStream.on('end', () => {
done.resolve();
});
finalStream.on('close', () => {
done.resolve();
});
finalStream.on('finish', () => {
done.resolve();
});
return done.promise;
}
}