[squeak-dev] WebClient test fails in trunk

David T. Lewis lewis at mail.msen.com
Sun Jul 15 18:53:59 UTC 2012


Hi Andreas,

The changes should hopefully work with any image regardless of whether
the new socket code is present, and regardless of what flavor of VM and
SocketPlugin are running.

There should be no compatibity issues either for IPv4 or IPv6. The only
problem was that if the four-byte socket address is being represented by
a SocketAddress (subclass of ByteArray) rather than a ByteArray, then
converting it to a host name string with this does not work:

  String streamContents:[:s| anAddress
    do:[:b| s print: b] separatedBy:[s nextPut: $.]]

Aside from that, no real issues as far as I know (other than the trivial
undeclared CrLf issue).

A SocketAddress is a kind of ByteArray, but it represents an opaque 
reference to a data structure managed in the plugin. That data structure
does include the four-byte network address (for IPv4) but this should
not be directly referenced from the image.

For example, on my PC with a 64 bit VM, the local address 127.0.0.2
is represented by a SocketAddress that, if printed out byte-by-byte,
would look like this:

 '117.49.82.81.16.0.0.0.2.0.0.0.127.0.0.2.0.0.0.0.0.0.0.0'

This is an 8 byte pointer, followed by the 32 bit network address, followed
by some other stuff I don't remember. But the printString for this object
provides a more useful representation:

 '127.0.0.2(linux-jh8m),0(0)'

Thus for a network address represented in the traditional way, printing
it out as bytes separated by $. does the right thing, and for the same
address represented by a SocketAddress, the first portion of the printString
up to $( is suitable. I did not check to see if this works with an IPv6
address, but it's good enough to cover the cases in the WebClient tests. 

I am guessing that for logging purposes, you would want to use the complete
SocketAddress>>printString '127.0.0.2(linux-jh8m),0(0)' while for converting
a socket address to a host string you would want only the address portion
'127.0.0.2', so I put two separate methods in WebUtils for those two cases. 

Dave

On Sun, Jul 15, 2012 at 06:48:15PM +0200, Andreas Raab wrote:
> Hi David -
>  
>  Are these patches needed only for IPv6 or also to support IPv4? If the  
> latter, this would bother me greatly. I can understand why IPv6 may be  
> implemented in incompatible ways but I can't see why there should be an  
> incompatible interface to IPv4 addresses which have been used for  eternity 
> in Squeak. In particular given that (I believe) SocketAddress is a subclass 
> of ByteArray it strikes me as not particularly hard to have Sockets support 
> ByteArrays of length 4 as IPv4 socket addresses (and perhaps return 
> instances of SocketAddress with length 4 or so). In any case, I'm not 
> looking forward to seeing every last bit of networking code break - there 
> has to be a better way...
> 
>  Cheers,
>  ?? - Andreas
> 
>  
> >             
> > -------- Original-Nachricht --------
> > Datum: Sun, 15 Jul 2012 11:46:54 -0400
> > Von: "David T. Lewis" <lewis at mail.msen.com>
> > An: The general-purpose Squeak developers list 
> > <squeak-dev at lists.squeakfoundation.org>, andreas.raab at gmx.de
> > Betreff: Re: [squeak-dev] WebClient test fails in trunk
> > 
> >             On Wed, Jul 04, 2012 at 11:46:58PM +0200, Levente Uzonyi 
> > wrote:
> > > On Tue, 3 Jul 2012, Frank Shearar wrote:
> > > 
> > > >On 3 July 2012 17:42, Frank Shearar <frank.shearar at gmail.com> wrote:
> > > >>On 3 July 2012 17:38, Levente Uzonyi <leves at elte.hu> wrote:
> > > >>>On Tue, 3 Jul 2012, Frank Shearar wrote:
> > > >>>
> > > >>>>Hi,
> > > >>>>
> > > >>>>I took WebClient for a spin in a trunk image, and found a failing
> > > >>>>test: WebClientServerTest >> #testServerDestroy throws a
> > > >>>>"ConnectionClosed: Connection closed while waiting for data". That
> > > >>>>sounds familiar - I think this was introduced in a recent Network
> > > >>>>change.
> > > >>>>
> > > >>>>Still, it means WebClient needs fixing. I'll try fix it on my 
> > evening
> > > >>>>commute, but if anyone feels like racing me, I'll be happy!
> > > >>>
> > > >>>
> > > >>>Interesting, I had no issue with it on windows, except for some 
> > extension
> > > >>>methods trying to use the CrLf class variable in HTTPSocket (or some 
> > > >>>other
> > > >>>class), but that variable doesn't exist.
> > > >>
> > > >>Which reminds me of an important fact I should mention: I'm testing
> > > >>this on an Ubuntu Lynx box.
> > > 
> > > The VM also matters in this case. I tried it with an older CogVM which 
> > > doesn't have the new socket primitives.
> > 
> > I wanted to check that the recent network updates were not causing
> > problems for WebClient. I found that some updates to WebClient are
> > needed to account for the fact that network addresses are now being
> > represented as SocketAddress rather than ByteArray when running on
> > a VM that supports the new network primitives.
> > 
> > Attached is a change set that addresses all the issues that I could
> > find. I'm assuming that the testServerDestroy issue discussed above
> > has already been addressed, as I had no failures for that test.
> > 
> > From the preamble:
> > 
> >   Change Set:		WebClient-networkPatches-dtl
> >   Date:			15 July 2012
> >   Author:			David T Lewis
> >   
> >   These patches update WebClient to work with new network code in Squeak
> >   trunk (all tests green).
> >   
> >   Explanation: When using the new network code along with a VM that 
> > supports the
> >   IPV6 primitives, socket addresses are instances of SocketAddress rather 
> > than
> >   ByteArray. Conversion of a socket address to a string must be 
> > implemented
> >   differently for SocketAddress.
> >   
> >   Also use String crlf instead of undeclared CrLf in HTTPSocket 
> > class>>httpPostMultipart:args:accept:request:
> >   
> >   Note: Squeak automatically uses SocketAddress if the VM supports it at 
> > image
> >   start time. To force use of old style ByteArray addresses, evaluate
> >   NetNameResolver useOldNetwork: true.
> >   
> >   Follow up: The WebClient methods in HTTPSocket are marked as overrides 
> > (category
> >   *WebClient-HTTP-override) but are not overrides with respect to Squeak 
> > trunk.
> >   The override category prevents these methods from appearing in a change 
> > set
> >   fileout. Should these methods just be adopted in trunk?
> > 
> > Dave
> > 
> > 
>         


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