hrj hrj

Navigating to Wikipedia home page was causing a massive slowdown of the browser. After analysis the problem turned out to be due to a long chain of causes.

A] Whenever mouse is hovered on an element, the element and its descendants are invalidated.

This is a known and important issue, but will take time to fix. Issue #89. See Update below.

B] Invalidation causes re-layouting of the whole DOM tree

As a consequence of A, every mouse move causes the body element to be invalidated, and also its descendants. By itself, this is correct behaviour. (Not really, see update below).

C] Re-layouting of inline-blocks was causing new instances of RInlineBlock to be created.

This is bad but by itself it is not terribly inefficient. However, it causes more trouble...

TL;DR

When you are in a shell in Linux, you may be led to believe you are in directory xyz but might actually be in directory pqr.

Demonstration

In a terminal,

	package properties

	import org.eclipse.xtend.lib.macro.AbstractClassProcessor
	import org.eclipse.xtend.lib.macro.Active
	import org.eclipse.xtend.lib.macro.TransformationContext
	import org.eclipse.xtend.lib.macro.declaration.MutableClassDeclaration

	import static extension properties.ASTExtensions.*

	/**

	import java.util.Arrays

	object Util {
	import concurrent._
	import ExecutionContext.Implicits.global
	def par(f1 : => Unit, f2 : => Unit) {
	val fut1 = future { f1 }
	val fut2 = future { f2 }
	Await.ready(fut1.zip(fut2), duration.Duration.Inf)
	}

	import bpy
	import mathutils

	C = bpy.context

	def insertKeyFrames(obj, curve):
	points = curve.data.splines[0].points
	duration = curve.data.path_duration
	N = len(points)
	framesPerPoint = duration / (N-1)

	#!/bin/bash

	# Call with a percentage value from 0 to 100
	# 0 means only red and green, 50 means half of blue is shown through
	# if you don't give any arguments the calibration is cleared

	if [[ -z "$1" ]]; then
	echo Clearing all calibrations
	xcalib -clear
	else

	## call sha1sum and check whether the hash matches
	## Syntax: sha1check <hash> <filename>
	## Just copy paste the follow line into ~/.zshrc or ~/.bashrc

	function sha1check() { echo $1 $2 \| sha1sum -c; }

	var count = 0
	var totalTime = 0L

	fun test() {
	val start = System.currentTimeMillis()

	val x = (1L..5000000L) map {it * 40} reduce {a,b -> (a*b)%19 + 1}

	val end = System.currentTimeMillis()

	import net.iryndin.jdbf.reader.*
	import net.iryndin.jdbf.core.*

	val fis = java.io.FileInputStream(args[0])
	val reader = DbfReader(fis)

	val md = reader.getMetadata()

	val fields = md.getFields()

	#!/usr/bin/python

	import SocketServer
	import BaseHTTPServer
	import SimpleHTTPServer

	class ThreadingSimpleServer(SocketServer.ThreadingMixIn,
	BaseHTTPServer.HTTPServer):
	pass