Jin Yao uptonking

V8

V8 is Google’s open source high-performance JavaScript and WebAssembly engine, written in C++. It is used in Chrome and in Node.js, among others. It implements ECMAScript and WebAssembly, and runs on Windows 7 or later, macOS 10.12+, and Linux systems that use x64, IA-32, ARM, or MIPS processors. V8 can run standalone, or can be embedded into any C++ application.

SpiderMonkey

SpiderMonkey is Mozilla’s JavaScript and WebAssembly Engine, used in Firefox, Servo and various other projects. It is written in C++, Rust and JavaScript. You can embed it into C++ and Rust projects, and it can be run as a stand-alone shell. It can also be [compiled](https://bytecodealliance.org/articles/making-javascript-run-fast-on

So you want to write a sync system for a web app with offline and realtime support? Good luck. You might find the following resources useful.

Overview articles

Database in a browser, a spec (Stepan Parunashvili)

What problem are we trying to solve with a sync system?
The web of tomorrow (Nikita Prokopov)

So this is kind of a multi stage plugin system. Let me explain:

Plugins get sent to the makeUseTable constructor, which then type the available options usable on useTable.

const useTable = makeUseTable({
  plugins: [myPlugin],
})

function App() {

This gist lists challenges you run into when building offline-first applications based on IndexedDB, including open-source libraries like Firebase, pouchdb and AWS amplify (more).

Note that some of the following issues affect only Safari. Out of the major browsers, Chrome's IndexedDB implementation is the best.

Backing file on disk (WAL file) keeps growing (Safari)

When this bug occurs, every time you use the indexeddb, the WAL file grows. Garbage collection doesn't seem to be working, so after a while, you end up with gigabytes of data.

	export class Cache<T extends object, K> {
	items = new WeakMap<T, K>()

	get<P extends T>(item: P, cb: (item: P) => K) {
	if (!this.items.has(item)) {
	this.items.set(item, cb(item))
	}
	return this.items.get(item)!
	}

	import React, { useCallback, FunctionComponent } from 'react'
	import { useField } from 'payload/components/forms'
	import { Field } from 'payload/types'
	import Editor from 'rich-markdown-editor'

	// Make sure to never re-render the editor, since it tracks the value on its own.
	const MemorizedEditor = React.memo(Editor, (prev, next) => prev.id === next.id)

	type FieldWithPath = Field & { path?: string }

	// Consistent version of `useMutableSource`, Inspired by https://github.com/pmndrs/valtio/blob/master/src/useMutableSource.ts
	import { useEffect, useRef, useState } from 'react';

	const TARGET = Symbol('target');
	const GET_VERSION = Symbol('getVersion');

	export type Source<TargetType extends any, VersionType extends any> = {
	[TARGET]: TargetType;
	[GET_VERSION]: (target: TargetType) => VersionType;
	};

	import json1 from 'ot-json1'

	const integerRegEx = /^\d+$/
	function isInteger (v) {
	return Boolean(v.match(integerRegEx))
	}

	export function patchAtomToOpAtom (patchOp) {
	const { path, op, value } = patchOp
	const pathArray = path.split('/').slice(1).map(pathItem => {

	import * as Y from 'yjs'
	import * as mutex from 'lib0/mutex.js'
	import { Observable } from 'lib0/observable.js'
	import PouchDB from 'pouchdb';


	// This is the name of the top level Y.Map that is used to construct the main pouchDB
	// JSON document.
	const topDataYMapName = 'data';

	import * as React from "react";
	import { useMousePosition } from "~/hooks/useMousePosition";

	/** Component to cover the area between the mouse cursor and the sub-menu, to allow moving cursor to lower parts of sub-menu without the sub-menu disappearing. */
	export function MouseSafeArea(props: { parentRef: React.RefObject<HTMLDivElement> }) {
	const { x = 0, y = 0, height: h = 0, width: w = 0 } = props.parentRef.current?.getBoundingClientRect() \|\| {};
	const [mouseX, mouseY] = useMousePosition();
	const positions = { x, y, h, w, mouseX, mouseY };
	return (
	<div

Jin Yao uptonking

Overview articles

Backing file on disk (WAL file) keeps growing (Safari)

Random exceptions when working with a large number of indexeddb databases (Safari)