Gabriel,
On Sun, 2014-06-29 at 12:37 -0700, Gabriel Gonzalez wrote:
> This is a simple "echo" server written using `pipes-wai`:
>
> {-# LANGUAGE OverloadedStrings #-}
>
> import Blaze.ByteString.Builder (fromByteString)
> import Pipes
> import qualified Pipes.Prelude as Pipes
> import Pipes.Wai
> import Network.Wai.Handler.Warp
> import Network.HTTP.Types (Status(..))
>
> main = run 8000 $ \request onResponse -> do
> let p = do
> producerRequestBody request >-> Pipes.map (Chunk .
> fromByteString)
> yield Flush
>
> onResponse (responseProducer (Status 200 "") [] p)
>
> `producerRequestBody` turns the incoming client's request into a
> `Producer`. Then you can do whatever you want with that `Producer`,
> like read in its contents, discard it, or (in the above example) stream
> it directly to the response.
>
> If you give a more specific example of what you want to do, I can give a
> more specific example.
Thanks for taking time looking into this. It looks like I might have
been somewhat unclear before.
Whilst your example above indeed turns a client request into a Producer
and turns a Producer into a response, this is all at another layer than
what I'm trying to accomplish.
Here's the difference: in your example, the 'run' function (as provided
by Warp) takes care of setting up a listening socket, accepting client
connections, forking threads,...
Whilst in my application, all this functionality is provided already,
all I'm left with are a ByteString Producer and ByteString Consumer
representing a client socket connection. Now a Request should be
read/parsed from the Producer, handled, and then a Response should be
yield'ed to the Consumer. All of this for this single client connection,
no need to accept connections, spawn threads,...
This could boil down to, e.g.
runHTTPInteraction :: Monad m => Pipe ByteString ByteString m r
runHTTPInteraction = do
req <- readRequest
let resp = ...
renderResponse resp
Then, when my client handler function is called with a `Producer
ByteString m r` and `Consumer ByteString m r`, I can use the above using
something like
-- Interact with a single client. This runs in its own thread etc.
myHandler :: Monad m => Producer ByteString IO () -> Consumer ByteString
IO () -> ()
myHandler prod cons =
runEffect $
{- for HTTP pipelining / connection re-use... -} forever $
prod >-> runHTTPInteractoin >-> cons
(or something along those lines, this is no real code so might not even
type-check).
Thanks,
Nicolas
>
> On 06/28/2014 02:20 PM, Nicolas Trangez wrote:
> > On Sat, 2014-06-28 at 14:12 -0700, Gabriel Gonzalez wrote:
> >> Have you tried the `pipes-wai` library?
> > I passed by it during my search, but its operations seem client-centric:
> > turning a `Request` into a `Producer ByteString m ()` (in order to
> > stream the data from that producer to some server?), or create a
> > `Response` out of a `Producer (Flush Builder) IO ()` (in order to stream
> > data from the producer to a client on some server?).
> >
> > I could be missing something very obvious, but I don't think that's what
> > I need.
> >
> > Thanks,
> >
> > Nicolas
> >
> >> On Jun 28, 2014 1:52 PM, "Nicolas Trangez" <[email protected]> wrote:
> >>
> >>> All,
> >>>
> >>> Has anyone ever written anything HTTP-server-like using Pipes? I looked
> >>> into Warp to check whether it could be integrated, but Warp seems to do
> >>> connection management, thread management, timeout handling, whatnot,
> >>> which is not what I need.
> >>>
> >>> I'm looking for something simpler: given a `Producer ByteString m r` and
> >>> a `Consumer ByteString m r`, read a `Request` from the producer, then do
> >>> some handling, and render a `Response` to the consumer.
> >>>
> >>> Are there any libraries I could look into, or is Warp easy to integrate
> >>> yet I'm failing to see how?
> >>>
> >>> Thanks,
> >>>
> >>> Nicolas
> >>>
> >>> --
> >>> You received this message because you are subscribed to the Google Groups
> >>> "Haskell Pipes" group.
> >>> To unsubscribe from this group and stop receiving emails from it, send an
> >>> email to [email protected].
> >>> To post to this group, send email to [email protected].
> >>>
> >
>
--
You received this message because you are subscribed to the Google Groups
"Haskell Pipes" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
