@openhps/core/dist/esm5/nodes/shapes/BufferNode.js

Open Hybrid Positioning System - Core component

import { DataFrame } from '../../data/DataFrame';
import { Node } from '../../Node';
/**
 * @category Flow shape
 */
export class BufferNode extends Node {
  constructor(options) {
    super(options);
    this.on('pull', this.onPull.bind(this));
    this.on('push', this.onPush.bind(this));
    this.on('build', this._initService.bind(this));
  }
  _initService() {
    return new Promise(resolve => {
      if (!this.service) {
        this.service = this.model.findDataService(this.options.service || DataFrame);
      }
      resolve();
    });
  }
  onPull(options) {
    return new Promise((resolve, reject) => {
      this.shift().then(frame => {
        if (frame) {
          this.outlets.forEach(outlet => outlet.push(frame, options));
        }
        resolve();
      }).catch(reject);
    });
  }
  onPush(frame) {
    return new Promise((resolve, reject) => {
      this.service.insertFrame(frame).then(() => {
        resolve();
      }).catch(reject);
    });
  }
  next() {
    return new Promise((resolve, reject) => {
      this.service.findOne({}, {
        sort: [['createdTimestamp', 1]]
      }).then(resolve).catch(reject);
    });
  }
  shift() {
    return new Promise((resolve, reject) => {
      let result;
      this.next().then(frame => {
        if (frame) {
          result = frame;
          return this.service.delete(frame.uid);
        } else {
          resolve(undefined);
        }
      }).then(() => resolve(result)).catch(reject);
    });
  }
}