overleaf/services/document-updater/app/js/ShareJsDB.js

/* eslint-disable
    camelcase,
    no-unused-vars,
*/
// TODO: This file was created by bulk-decaffeinate.
// Fix any style issues and re-enable lint.
/*
 * decaffeinate suggestions:
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
let ShareJsDB;
const Keys = require('./UpdateKeys');
const RedisManager = require("./RedisManager");
const Errors = require("./Errors");

module.exports = (ShareJsDB = class ShareJsDB {
	constructor(project_id, doc_id, lines, version) {
		this.project_id = project_id;
		this.doc_id = doc_id;
		this.lines = lines;
		this.version = version;
		this.appliedOps = {};
		// ShareJS calls this detacted from the instance, so we need
		// bind it to keep our context that can access @appliedOps
		this.writeOp = this._writeOp.bind(this);
	}
	
	getOps(doc_key, start, end, callback) {
		if (start === end) {
			return callback(null, []);
		}

		// In redis, lrange values are inclusive.
		if (end != null) {
			end--;
		} else {
			end = -1;
		}

		const [project_id, doc_id] = Array.from(Keys.splitProjectIdAndDocId(doc_key));
		return RedisManager.getPreviousDocOps(doc_id, start, end, callback);
	}
	
	_writeOp(doc_key, opData, callback) {
		if (this.appliedOps[doc_key] == null) { this.appliedOps[doc_key] = []; }
		this.appliedOps[doc_key].push(opData);
		return callback();
	}

	getSnapshot(doc_key, callback) {
		if (doc_key !== Keys.combineProjectIdAndDocId(this.project_id, this.doc_id)) {
			return callback(new Errors.NotFoundError(`unexpected doc_key ${doc_key}, expected ${Keys.combineProjectIdAndDocId(this.project_id, this.doc_id)}`));
		} else {
			return callback(null, {
				snapshot: this.lines.join("\n"),
				v: parseInt(this.version, 10),
				type: "text"
			});
		}
	}

	// To be able to remove a doc from the ShareJS memory
	// we need to called Model::delete, which calls this 
	// method on the database. However, we will handle removing
	// it from Redis ourselves
	delete(docName, dbMeta, callback) { return callback(); }
});