Brock Whitten sintaxi

ETags & If-None-Match headers: a dialogue

browser: can haz foo?

GET /foo HTTP/1.1

HTTP provides two ways for servers to control client-side caching of page components:

freshness may be based on a date or a token whose meaning is app-specific
whether or not the client needs to confirm the cached version is up-to-date with the server

This breaks down as follows:

Prerequisites:

One or more clients running a UNIX-like OS. Examples are given for Ubuntu 12.04 LTS, although all software components are available for other platforms as well (e.g. OS X). YMMV
A cheap Ubuntu 12.04 VPS with storage. I recommend Backupsy, they offer 250GB storage for $5/month. Ask Google for coupon codes.

Software components used:

A quick example Harp app that uses the correct title for your blog in the correct place.

The App

app/
  |- _harp.json
  |- _layout.ejs
  |- index.ejs
  |+ posts/
      |- _data.json

	var fs = require('fs');
	var lame = require('lame');
	var Speaker = require('speaker');

	fs.createReadStream(process.argv[2])
	.pipe(new lame.Decoder())
	.on('format', function (format) {
	this.pipe(new Speaker(format));
	});

	var express = require('express'),
	passport = require('passport'),
	LocalStrategy = require('passport-local').Strategy,
	connect = require('connect'),
	http = require('http'),
	path = require('path'),
	util = require('util'),
	fs = require('fs'),
	redis = require('redis'),
	cookie = require('cookie'),

	gifify() {
	if [[ -n "$1" ]]; then
	if [[ $2 == '--good' ]]; then
	ffmpeg -i $1 -r 10 -vcodec png out-static-%05d.png
	time convert -verbose +dither -layers Optimize -resize 600x600\> out-static*.png GIF:- \| gifsicle --colors 128 --delay=5 --loop --optimize=3 --multifile - > $1.gif
	rm out-static*.png
	else
	ffmpeg -i $1 -s 600x400 -pix_fmt rgb24 -r 10 -f gif - \| gifsicle --optimize=3 --delay=3 > $1.gif
	fi
	else

	var http = require('http');

	var timeInterval = 20; //ms
	var maxOutstandingRequests = 10;

	var successCount = 0;
	var outstandingRequests = 0;

	var options = {
	hostname: 'www.google.com'

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
	<title>Stripe Getting Started Form</title>

	<!-- The required Stripe lib -->
	<script type="text/javascript" src="https://js.stripe.com/v2/"></script>

	<!-- jQuery is used only for this example; it isn't required to use Stripe -->