[mod_python] apache API and mod_python <-> protocol module integration

alright i just added the patch to my build directory.. and it wouldn't
compile.  OKAY.  what is the freakin point of maintaining an accurate
build archive if the freakin thing gets attacked by gremlins??

okay so i tossed the original build (which without a doubt has not been
changed by any legitimate or accidental work of my own on a machine that
isn't accessable from remote), untarred the same archive, patched,
rebuilt,
no problem... damn gremlins

BUT

i'm still getting the same error with the actual connection test...

any ideas?

[Tue Jul 15 17:56:44 2003] [error] python_connection:
ConnectionDispatch() returned nothing.


> -----Original Message-----
> From: mod_python-bounces at modpython.org 
> [mailto:mod_python-bounces at modpython.org] On Behalf Of 
> Gregory (Grisha) Trubetskoy
> Sent: Wednesday, July 16, 2003 8:47 PM
> To: Dustin Mitchell
> Cc: mod_python at modpython.org
> Subject: Re: [mod_python] apache API and mod_python <-> 
> protocol module integration
> 
> 
> 
> Well, after some looking, apparently the APR does work this 
> way, it's just
> that the way the connection handler was coded probably 
> because I didn't
> understand APR well enough at the time I made it loop until specified
> length of bytes was read (I started out with replicating 
> req.read(), which
> knows how much data there is to read).
> 
> I attached a patch to the connobject.c that changes its 
> behaviour so that
> read(len) will read at most len bytes, and will only block if 
> no data is
> available. And len is an optional argument.
> 
> Here is a connection handler code that does the exact same 
> thing you had
> below. (note that print writes to stdout, which is visible if you run
> httpd with -X (stay in foreground) option:
> 
> from mod_python import apache
> 
> def connectionhandler(conn):
> 
>     print "Connect from '%s'" % `conn.remote_addr`
> 
>     while 1:
>         data = conn.read()
>         if not data: break
>         print " Received: %s" % `data`
> 
>     print "Connection closed from '%s'" % `conn.remote_addr`
> 
>     return apache.OK
> 
> And here's the result:
> 
> $ ./bin/httpd -X
> Connect from '('0.0.0.0', 3513)'
>  Received: 'Hello\r\n'
>  Received: 'World\r\n'
> Connection closed from '('0.0.0.0', 3513)'
> 
> If I do 'for i in "Hello World"' thing, I get this:
> 
> Connect from '('0.0.0.0', 3524)'
>  Received: 'Hello World'
> Connection closed from '('0.0.0.0', 3524)'
> 
> Grisha
> 
> On Wed, 16 Jul 2003, Dustin Mitchell wrote:
> 
> > On Wed, Jul 16, 2003 at 01:59:58PM -0400, Gregory (Grisha) 
> Trubetskoy wrote:
> > > This is not a problem of mod_python or Apache, this is 
> the way sockets
> > > work. If your protocol is such that you know ahead of 
> time how much to
> > > read (e.g. HTTP), then you can request this much data in one read.
> > > Otherwise, you must read in smallest unit sizes of your 
> protocol, which
> > > (I'm guessing) is 1 byte in case of Z39.50.
> >
> > This is not strictly true, as long as you're OK with 
> possibly getting a
> > bit of *extra* data beyond a particular PDU (a little bit 
> of buffering
> > can take care of that).  Apache has to do this to read the 
> HTTP header,
> > which is not of a fixed length.
> >
> > The socket blocking read interface is structured such that 
> it will block
> > when *no* data is available, and will return *up to* the quantity
> > specified in the recv() call if it is available.  However, if some
> > smaller amount of data is available, that data will be returned
> > immediately.
> >
> > To demonstrate, I hacked this together:
> >
> > from socket import *
> > s = socket(AF_INET, SOCK_STREAM)
> > s.bind(("", 9900))
> > s.listen(5)
> > while 1:
> >   ss, sa = s.accept()
> >   print "Connect from '%s'" % (sa,)
> >   while 1:
> >     data = ss.recv(100)
> >     if not data: break
> >     print " Received: %s" % `data`
> >   print "Connection closed from '%s'" % (sa,)
> >
> > Then connected with telnet and typed "Hello" and "World" on separate
> > lines.  Telnet, by default, buffers lines of input until a 
> newline, but
> > you will note that in the two returns from ss.recv(), 
> neither contained
> > 100 bytes of data:
> >
> > Connect from '('127.0.0.1', 56260)'
> >  Received: 'Hello\r\n'
> >  Received: 'World\r\n'
> > Connection closed from '('127.0.0.1', 56260)'
> >
> > Further, a loop such as:
> >   for i in 'hello world': s.send(i)
> > will produce output like this:
> >
> > Connect from '('127.0.0.1', 56277)'
> >  Received: 'h'
> >  Received: 'ello world'
> > Connection closed from '('127.0.0.1', 56277)'
> >
> > Either the client or the server's socket implementation is 
> buffering the
> > characters because they're appearing so quickly, which cuts 
> down on the
> > number of recv() calls which must be made.
> >
> > I can't speak for the Apache sockets API, or the Python interface
> > thereto, but sockets themselves *do* support this interface 
> (they'd be
> > pretty useless if they didn't!).  I highly recommend W. Richard
> > Stevens' TCP/IP Illustrated for an in-depth and very readable
> > discussion of this and many other crucial implementation details of
> > TCP/IP.
> >
> > Dustin
> >
> > --
> >
> >   Dustin Mitchell
> >   dustin at ywlcs.org/djmitche at alumni.uchicago.edu
> >   http://people.cs.uchicago.edu/~dustin/
> > _______________________________________________
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> >
>