[mod_python] Sessions performance and some numbers

Hi,

Your code seems perfect to me. We could indeed add an extra hash to
the directory name so that all sessions do not end in the same
directory ; but I guess this is not needed on modern FS like ReiserFS
or WinFS.

Also, the unlink call in do_delete needs an "os." to be correct...

If everybody is OK I could integrate your class into the Session.py
module, so that it becomes a standard session implementation in the
next release. Grisha, Graham, what do you think ?

Just as a note, the DbmSession relies on the anydbm module ; maybe the
crappy performance were due to the fact that anydbm reverted to a
crappy implementation, not the fastest (?) Berkeley-DB based one.

Regards,

Nicolas

On Apr 7, 2005 5:01 PM, dharana <dharana at dharana.net> wrote:
> 
> 
> Graham Dumpleton wrote:
> >
> > On 07/04/2005, at 8:08 PM, dharana wrote:
> >
> >> If you want I can send my modified Session.py with the new FileSession
> >> class for review.
> >
> >
> > There probably shouldn't have been a need for you to copy/modify the actual
> > Session.py file which came with mod_python as your derived version could
> > live quite happily in its own module and simply used the installed Session
> > module.
> >
> 
> I presumptuously thought that it could fit into the official mod_python
> package due to it's high performance when compared to DbmSession.
> 
>  >
> > Anyway, by all means post your code as sure it will be of interest to
> > someone, if not now then maybe in the future. If there are any problems
> > in what you have done, someone is also bound to point it out.
> >
> 
> Here it goes. Please point out any obvious problem. Apart from being new
> to mod_python I'm also new to Python in general. For example, I don't
> think the exception handling I've put is completely correct.
> 
> In anticipation for any possible attachment problems i pasted it
> directly. (I have read PEP 0008 and the 4 spaces indentation level
> recommendation but I'm in a hurry right now, sorry.)
> 
> --- FileSession.py -----------------------------------------------------
> import cPickle
> import tempfile
> 
> from mod_python import Session
> 
> tempdir = tempfile.gettempdir()
> 
> class FileSession(Session.BaseSession):
> 
>    def __init__(self, req, sid=0, secret=None, timeout=0, lock=1):
> 
>      Session.BaseSession.__init__(self, req, sid=sid, secret=secret,
>                           timeout=timeout, lock=lock)
> 
>    def do_cleanup(self):
>      import os
> 
>      # is there any faster way of doing this?
>      for f in os.listdir(tempdir):
>        if f.find('mp_sess_', 0, 11) == -1:
>          continue
> 
>        fp = file('%s%s' % (tempdir, f))
>        dict = cPickle.load(fp)
>        fp.close()
> 
>        if (time() - dict['_accessed']) > dict['_timeout']:
>          os.unlink('%s%s' % (tempdir, f))
> 
>    def do_load(self):
>      try:
>      # again, is there a more pythonic way of doing this check?
>        fp = file('%s/mp_sess_%s' % (tempdir, self._sid))
>      except Exception:
>        return None
>      else:
>        try:
>          data = cPickle.load(fp)
>          fp.close()
>          return data
> 
>        except Exception:
>          fp.close()
>          pass
> 
>    def do_save(self, dict):
>      fp = file('%s/mp_sess_%s' % (tempdir, self._sid), 'w+')
>      cPickle.dump(dict, fp)
>      fp.close()
> 
>    def do_delete(self):
>      try:
>        unlink('%s/mp_sess_%s' % (tempdir, self._sid))
>      except Exception:
>        pass
> ------------------------------------------------------------------------
> 
> --
> Juan Alonso
> http://gamersmafia.com | http://laflecha.net
> 
> 
> import cPickle
> import tempfile
> 
> from mod_python import Session
> 
> tempdir = tempfile.gettempdir()
> 
> class FileSession(Session.BaseSession):
> 
>   def __init__(self, req, sid=0, secret=None, timeout=0, lock=1):
> 
>     Session.BaseSession.__init__(self, req, sid=sid, secret=secret,
>                          timeout=timeout, lock=lock)
> 
>   def do_cleanup(self):
>     import os
> 
>     # is there any faster way of doing this?
>     for f in os.listdir(tempdir):
>       if f.find('mp_sess_', 0, 11) == -1:
>         continue
> 
>       fp = file('%s%s' % (tempdir, f))
>       dict = cPickle.load(fp)
>       fp.close()
> 
>       if (time() - dict['_accessed']) > dict['_timeout']:
>         os.unlink('%s%s' % (tempdir, f))
> 
>   def do_load(self):
>     try:
>     # again, is there a more pythonic way of doing this check?
>       fp = file('%s/mp_sess_%s' % (tempdir, self._sid))
>     except Exception:
>       return None
>     else:
>       try:
>         data = cPickle.load(fp)
>         fp.close()
>         return data
> 
>       except Exception:
>         fp.close()
>         pass
> 
>   def do_save(self, dict):
>     fp = file('%s/mp_sess_%s' % (tempdir, self._sid), 'w+')
>     cPickle.dump(dict, fp)
>     fp.close()
> 
>   def do_delete(self):
>     try:
>       unlink('%s/mp_sess_%s' % (tempdir, self._sid))
>     except Exception:
>       pass
> 
> 
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