Waffle is a fast, asynchronous, express-inspired web framework for Lua/Torch built on top of ASyNC.
Waffle's performance is impressive. On this test, given in examples/fib.lua, Waffle reaches over 20,000 requests/sec (2-4 x Node+express, 1/2 x multithreaded Go). With automatic caching enabled, Waffle can reach over 26,000 requests/sec, equaling single-threaded Go.
This project depends on htmlua for HTML templating.
> (sudo) luarocks install https://raw.githubusercontent.com/benglard/htmlua/master/htmlua-scm-1.rockspec
> (sudo) luarocks install https://raw.githubusercontent.com/benglard/waffle/master/waffle-scm-1.rockspec
local app = require('waffle')
app.get('/', function(req, res)
res.send('Hello World!')
end)
app.listen()app.get('/', function(req, res)
res.send('Getting...')
end)
app.post('/', function(req, res)
res.send('Posting...')
end)
app.put('/', function(req, res)
res.send('Putting...')
end)
app.delete('/', function(req, res)
res.send('Deleting...')
end)app.get('/user/(%d+)', function(req, res)
local userId = tonumber(req.params[1])
local users = {
[1] = 'Lua',
[2] = 'JavaScript',
[3] = 'Python'
}
res.send(string.format('Hello, %s', users[userId] or 'undefined'))
end)
app.get('/user/(%a+)', function(req, res)
local name = req.params[1]
res.send(string.format('Hello, %s', name))
end)There are two options for html rendering. The first involves writing actual html and using the string interp utility provided, ${variable-name}.
<html>
<head></head>
<body>
<h3>Welcome, ${name}</h3>
<p>Time: ${time}</p>
</body>
</html>app.get('/render/(%a+)', function(req, res)
res.render('./examples/template.html', {
name = req.params[1],
time = os.time()
})
end)The second, preferable, more powerful way involves writing htmlua scripts, either as separate template files, or inline in view functions.
-- luatemp.html
local base = extends 'examples/baseluatemp.html'
return block(base, 'content'){
h3 'Welcome, ${name}',
p 'Time: ${time}',
ul(each([[${users}]], li)),
img {
src = 'https://www.google.com/images/srpr/logo11w.png'
}
}-- htmlua.lua
-- Template
app.get('/', function(req, res)
res.htmlua('luatemp.html', {
name = 'waffle',
time = os.time(),
users = {'lua', 'python', 'javascript'}
})
end)
-- Inline
app.get('/i', function(req, res)
res.send(html {
head { title 'Title' },
body { p 'Hello World!' }
})
end)The htmlua page provides further documentation and examples.
app.get('/m', function(req, res)
res.send(html { body { form {
action = '/m',
method = 'POST',
enctype = 'multipart/form-data',
p { input {
type = 'text',
name = 'firstname',
placeholder = 'First Name'
}},
p { input {
type = 'text',
name = 'lastname',
placeholder = 'Last Name'
}},
p { input {
type = 'file',
name = 'file'
}},
p { input {
type = 'submit',
'Upload'
}}
}}})
end)
app.post('/m', function(req, res)
local name = string.format('%s %s', req.form.firstname, req.form.lastname)
local path = paths.add(os.getenv('HOME'), req.form.file.filename)
req.form.file:save{path=path}
res.send('Saved to ' .. path)
end)You can easily transform an uploaded image into a typical torch tensor like so:
app.post('/', function(req, res)
local img = req.form.file:toImage()
local m = img:mean()
res.send('Image mean: ' .. m)
end)To implement a websocket server, call app.ws with a url path and a function accepting a single table. You can then define checkorigin, onopen, onmessage, onpong, and onclose for that table, to control the server-side websocket connection.
Benchmarking websockets is tricky, but on first attempts, waffle seems competitive with similar node libraries.
local app = require('waffle')
local js = [[
var ws = new WebSocket("ws://127.0.0.1:8080/ws/");
function print() { console.log(ws.readyState); }
ws.onopen = function() {
console.log("opened");
print();
ws.send("Hello");
}
ws.onmessage = function(msg) {
console.log(msg);
setTimeout(function() { ws.close(); }, 1000);
}
ws.onclose = function(event) {
console.log(event);
console.log("closed");
print();
}
]]
app.get('/', function(req, res)
res.send(html { body {
p 'Hello, World',
script { type='text/javascript', js }
}})
end)
app.ws('/ws', function(ws)
ws.checkorigin = function(origin) return origin == 'http://127.0.0.1:8080' end
ws.onopen = function(req) print('/ws/opened') end
ws.onmessage = function(data)
print(data)
ws:write('World')
ws:ping('test')
end
ws.onpong = function(data) print(data) end
ws.onclose = function(req) print('/ws/closed') end
end)You can broadcast a message to all open websockets on a url like this:
ws:broadcast('message')or like this:
app.ws.broadcast(req.url.path, 'message')app.get('/search', function(req, res)
local search = req.url.args.q
res.redirect('https://www.google.com/search?q=' .. search)
end)local app = require('waffle')
app.set('public', '.')
app.listen()app.error(404, function(description, req, res)
local url = string.format('%s%s', req.headers.host, req.url.path)
res.status(404).send('No page found at ' .. url)
end)
app.error(500, function(description, req, res)
if app.debug then
res.status(500).send(description)
else
res.status(500).send('500 Error')
end
end)app.get('/cookie', function(req, res)
local c = req.cookies.counter or -1
res.cookie('counter', tonumber(c) + 1)
res.send('#' .. c)
end)Waffle has both in-memory and redis sessions using redis-async.
local app = require('../waffle').CmdLine()
app.get('/', function(req, res)
if app.session.type == 'memory' then
local n = app.session.n or 0
res.send('#' .. n)
if n > 19 then app.session.n = nil
else app.session.n = n + 1 end
else
app.session:get('n', function(n)
res.send('#' .. n)
if n > 19 then app.session:delete('n')
else app.session.n = n + 1 end
end, 0)
end
end)
app.listen()app.get('/', function(req, res)
res.json{test=true}
end)-- Add a name parameter, e.g. 'test'
app.get('/test', function(req, res) res.send('Hello World!') end, 'test')
-- Retreive url corresponding to route named 'test'
local url = app.urlfor('test')Modules let you group routes together by url and name (really by function)
app.module('/', 'home') -- Home Routes
.get('', function(req, res) res.send 'Home' end, 'index')
.get('test', function(req, res) res.send 'Test' end, 'test')
app.module('/auth', 'auth') -- Authentication Routes
.get('', function(req, res) res.redirect(app.urlfor('auth.login'))
end, 'index')
.get('/login', function(req, res) res.send 'Login' end, 'login')
.get('/signup', function(req, res) res.send 'Signup' end, 'signup')Allows you to write every currently possible waffle application property as a command line option, and have it handled seamlessly.
local app = require('waffle').CmdLine()> th examples/cmdline.lua --debug --print --port 3000 --templates examples/
app = require('waffle')
a = 1
b = 2
c = 3
app.repl()
app.listen()th> async = require 'async'
[0.0133s]
th> async.repl.connect({host='127.0.0.1', port=8081})
[0.0005s]
th> async.go()
127.0.0.1:8081> a
1
127.0.0.1:8081> b
2
127.0.0.1:8081> c
3
127.0.0.1:8081> app
{ ... }
127.0.0.1:8081> _G
{ ... }The wafflemaker executable can be used:
- to create project directories in MVC style, like so:
wafflemaker --create name_of_project
- to serve static files akin to running
python -m SimpleHTTPServer, but with much, much, much better performance (almost 20x requests/sec).
cd folder/i/want/to/serve
wafflemaker --serve
When autocache is set to true, waffle will automatically store the response body, headers, and status code, and reuse them when a request is sent to the same http method/url. So, for instance, when a request is sent to GET/10 in the example below, it will only have to compute fib(10) once. Note that app.urlCache is set by default to cache the data of the last 20 method/url requests.
local app = require('../waffle') {
debug = true,
autocache = true
}
fib = function(n)
if n == 0 then return 0
elseif n == 1 then return 1
else return fib(n-1) + fib(n-2)
end
end
app.get('/(%d+)', function(req, res)
local n = req.params[1]
local result = fib(tonumber(n))
res.header('Content-Type', 'text/html')
res.send('ASyNC + Waffle<hr> fib(' .. n .. '): ' .. result)
end)
app.listen()- Named URL route parameters
- Automatic caching of static files
- Secure cookies & cookie based sessions
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