[Python-Dev] Adding socket timeout to urllib2

[Facundo Batista]

I studied which modifications I need to make into urllib2 to support a
socket timeout.

- I'll modify urlopen for it to accept a socket_timeout parameter,
default to None
- Request will also accept a socket_timeout parameter, default to None.
It will keep it in a socket_timeout attribute, so it could be
added/modified from outside.
- OpenerDirector's 'open' method will accept socket_timeout, and build
the Request object with it

So, when it gets into the Handlers, how it'll be used? I checked the
Handlers, and here is a resume of their 'open' or 'open'-like methods:

- AbstractHTTPHandler: receives a class, and uses its .request and
.getresponse methods
- HTTPHandler: just calls AbstractHTTPHandler.do_open with
httplib.HTTPConnection
- HTTPSHandler: just calls AbstractHTTPHandler.do_open with
httplib.HTTPSConnection
- UnknownHandler: raises an Error
- FileHandler: opens a file in a local host
- FTPHandler: uses sockets in ftplib.FTP().connect, .login, .cwd, and
.ntransfercmd, all through urllib's ftwrapper object
- CacheFTPHandler: instantiates ftpwrapper object; does not uses it
directly, though.
- GopherHandler: is deprecated...

So, these are the necessary further modifications in urllib2 beyond
those detailed at the beggining of the mail:

- Modify AbstractHTTPHandler to pass the socket_timeout parameter to
the received class' methods.
- Modify FTPHandler to pass the socket_timeout to ftpwrapper class.
- Modify CacheFTPHandler the same way that FTPHandler
  
Beyond that, I'll also need to:

- Modify urllib.ftpwrapper to accept a socket_timeout parameter and
pass it to ftplib.FTP object.
- Add support to socket_timeout to ftplib's FTP object
- Add support to socket_timeout to httplib's HTTPConnection and
HTTPSConnection objects

So, I think that in the name of clarity, I shall first modify ftplib
and httplib, add socket_timeout where is necessary, and then add
support to that in the more general urllib2.

What do you think? Comments are very appreciated.

Thank you very much!

-- 
.   Facundo
.
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