Moonslice is a collection of interfaces and lua libraries.

It's a mix of the code and technology from the luvit project mixed with some new experimental APIs that are designed to make it more lua friendly and easier to code.

Two external dependencies are luv and lhttp_parser. The first is a new set of lua - libuv bindings designed to be standalone, minimal and fast. The latter is the http_parser bindings used in luvit, but packaged as a standalone project.

Included in this directory is a Makefile that pulls in the gitsubmodules and builds the two libraries. The respective libraries that use them have symlinks in place already.

Continuable

This is a collection of libraries that implement the continuable interface.

In short, the continuable interface is like node.js style callbacks except the function that accepts the callback is returned from the initial function call as a continuable closure.

fs.readFile("/path/to/file.txt")(function (err, contents)
  ...
end)

Continuable.stream

This library contains the stream implementation. It's a simple queue where writes to one end come out in reads to the other end. Built-in is backpressure and controlled buffering via low-water and high-water marks for full proper flow-control.

The streams have only .read() and .write() continuable style functions. They are mobile and can be moved around at will as seen in this example for creating a duplex pipe with a stream at each end.

local function newPipe()
  -- Create two streams
  local a, b = newStream(), newStream()
  -- Cross their write functions
  a.write, b.write = b.write, a.write
  -- Return them as two duplex streams that are the two ends of the pipe
  return a, b
end

Web

This library is a new web interface. Web consumes a raw http stream (usually over TCP, but any stream will do) and a web app. It parses HTTP requests on the stream and calls the app function. When the app function responds, it writes the corresponding HTTP data to the socket.

local function app(req, res)
  res(200, {
    ["Content-Type"] = "text/plain"
  }, "Hello World\n")
end

Web.autoheaders

This middleware wraps around any web app and adds in all sorts of useful spec adherence. It does useful things like auto Content-Length header. Also it can do chunked encoding on the body stream if it's unable to calculate the length.

-- Just wrap your app in autoheaders to get a new app
app = autoheaders(app)

Web.log

A very simple middleware to log HTTP requests.

-- Just wrap your app in autoheaders to get a new app
app = log(app)

Web.websocket

TODO: Finish implementing this API

A sample websocket implementation to prove that web is capable of handling HTTP upgrades.

local app = function (req, res)
  if not req.upgrade then
    res(400, {}, "Websocket only\n")
  end
  local socket = websocket.upgrade(req)
  repeat
    local message, head = await(socket.read())
    p({
      message=message,
      opcode=head.opcode
    })
    socket.write("Hello " .. message)()
  until not message
end

Web.gzip

TODO: Implement this

A middleware to gzip body streams. This is just an example of how this would be done. I think I'll implement it using FFI calls to zlib.