[Haskell-beginners] Warp and Yesod benchmark puzzle
lbolla at gmail.com
Sat Sep 1 16:55:38 CEST 2012
On Sat, Sep 01, 2012 at 11:20:06AM -0300, Felipe Almeida Lessa wrote:
> On Sat, Sep 1, 2012 at 6:33 AM, Krzysztof Skrzętnicki <gtener at gmail.com> wrote:
> > makeSessionBackend calls "getKey" from clientsession:
> > http://hackage.haskell.org/packages/archive/clientsession/0.8.0/doc/html/src/Web-ClientSession.html#getKey
> > Looking at that function no wonder it is a bottleneck:
> > -- | Get a key from the given text file.
> > --
> > -- If the file does not exist or is corrupted a random key will
> > -- be generated and stored in that file.
> > getKey :: FilePath -- ^ File name where key is stored.
> > -> IO Key -- ^ The actual key.
> > getKey keyFile = do
> > exists <- doesFileExist keyFile
> > if exists
> > then S.readFile keyFile >>= either (const newKey) return . initKey
> > else newKey
> > where
> > newKey = do
> > (bs, key') <- randomKey
> > S.writeFile keyFile bs
> > return key'
> > Plenty of syscalls, reading and parsing the same file over and over again.
> > Perhaps the default should be to store the key within the foundation
> > datatype at startup?
> Unfortunately it's not so simple: makeSessionBackend is called just
> once by 'toWaiAppPlain', which is in turn called just once when your
> application starts.
> Cheers, =)
I wonder if the problem is rather the `decrypt`ion of the _SESSION cookie at
each request, in which case the bottleneck is the encryption library (AES?).
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