PATCH: httplib.py (was Re: Timing out URLs)
Aahz Maruch
aahz at netcom.com
Fri May 26 09:25:46 EDT 2000
Okay, here's the patch for the 1.5.2 httplib.py that allows a timeout to
be set. The default timeout is sixty seconds; you have to pass a
timeout of 0 to get no timeout.
WARNING: I have heard that Linux gives an AttributeError for
socket.SO_RCVTIMEO; while the try/except means it won't crash, you also
won't get the expected timeout, either. Any assistance in clearing this
up would be appreciated; I've been too busy.
"""HTTP client class
See the following URL for a description of the HTTP/1.0 protocol:
http://www.w3.org/hypertext/WWW/Protocols/
(I actually implemented it from a much earlier draft.)
Example:
>>> from httplib import HTTP
>>> h = HTTP('www.python.org')
>>> h.putrequest('GET', '/index.html')
>>> h.putheader('Accept', 'text/html')
>>> h.putheader('Accept', 'text/plain')
>>> h.endheaders()
>>> errcode, errmsg, headers = h.getreply()
>>> if errcode == 200:
... f = h.getfile()
... print f.read() # Print the raw HTML
...
<HEAD>
<TITLE>Python Language Home Page</TITLE>
[...many more lines...]
>>>
Note that an HTTP object is used for a single request -- to issue a
second request to the same server, you create a new HTTP object.
(This is in accordance with the protocol, which uses a new TCP
connection for each request.)
"""
import socket
import string
import mimetools
HTTP_VERSION = 'HTTP/1.0'
HTTP_PORT = 80
SOCKET_TIMEOUT = 60 * 1000 # Sixty seconds
class HTTP:
"""This class manages a connection to an HTTP server."""
def __init__(self, host = '', port = 0, timeout = None):
"""Initialize a new instance.
If specified, `host' is the name of the remote host to which
to connect. If specified, `port' specifies the port to which
to connect. By default, httplib.HTTP_PORT is used. If specified,
timeout is the socket timeout in milliseconds. By default,
httplib.SOCKET_TIMEOUT is used. If timeout == 0, then no timeout
is used.
"""
self.debuglevel = 0
self.file = None
if host: self.connect(host, port, timeout)
def set_debuglevel(self, debuglevel):
"""Set the debug output level.
A non-false value results in debug messages for connection and
for all messages sent to and received from the server.
"""
self.debuglevel = debuglevel
def connect(self, host, port = 0, timeout = None):
"""Connect to a host on a given port with timeout in milliseconds.
No timeout if timeout == 0.
Note: This method is automatically invoked by __init__,
if a host is specified during instantiation.
"""
if not port:
i = string.find(host, ':')
if i >= 0:
host, port = host[:i], host[i+1:]
try: port = string.atoi(port)
except string.atoi_error:
raise socket.error, "nonnumeric port"
if not port: port = HTTP_PORT
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Use try/except to catch platforms where socket options unavailable
if timeout is None:
try:
self.sock.setsockopt(socket.SOL_SOCKET,
socket.SO_RCVTIMEO, SOCKET_TIMEOUT)
except:
pass
elif timeout > 0:
try:
self.sock.setsockopt(socket.SOL_SOCKET,
socket.SO_RCVTIMEO, timeout)
except:
pass
if self.debuglevel > 0: print 'connect:', (host, port)
self.sock.connect(host, port)
def send(self, str):
"""Send `str' to the server."""
if self.debuglevel > 0: print 'send:', `str`
self.sock.send(str)
def putrequest(self, request, selector):
"""Send a request to the server.
`request' specifies an HTTP request method, e.g. 'GET'.
`selector' specifies the object being requested, e.g.
'/index.html'.
"""
if not selector: selector = '/'
str = '%s %s %s\r\n' % (request, selector, HTTP_VERSION)
self.send(str)
def putheader(self, header, *args):
"""Send a request header line to the server.
For example: h.putheader('Accept', 'text/html')
"""
str = '%s: %s\r\n' % (header, string.joinfields(args,'\r\n\t'))
self.send(str)
def endheaders(self):
"""Indicate that the last header line has been sent to the server."""
self.send('\r\n')
def getreply(self):
"""Get a reply from the server.
Returns a tuple consisting of:
- server response code (e.g. '200' if all goes well)
- server response string corresponding to response code
- any RFC822 headers in the response from the server
"""
self.file = self.sock.makefile('rb')
line = self.file.readline()
if self.debuglevel > 0: print 'reply:', `line`
try:
[ver, code, msg] = string.split(line, None, 2)
except ValueError:
try:
[ver, code] = string.split(line, None, 1)
msg = ""
except ValueError:
self.headers = None
return -1, line, self.headers
if ver[:5] != 'HTTP/':
self.headers = None
return -1, line, self.headers
errcode = string.atoi(code)
errmsg = string.strip(msg)
self.headers = mimetools.Message(self.file, 0)
return errcode, errmsg, self.headers
def getfile(self):
"""Get a file object from which to receive data from the HTTP server.
NOTE: This method must not be invoked until getreplies
has been invoked.
"""
return self.file
def close(self):
"""Close the connection to the HTTP server."""
if self.file:
self.file.close()
self.file = None
if self.sock:
self.sock.close()
self.sock = None
def test():
"""Test this module.
The test consists of retrieving and displaying the Python
home page, along with the error code and error string returned
by the www.python.org server.
"""
import sys
import getopt
opts, args = getopt.getopt(sys.argv[1:], 'd')
dl = 0
for o, a in opts:
if o == '-d': dl = dl + 1
host = 'www.python.org'
selector = '/'
if args[0:]: host = args[0]
if args[1:]: selector = args[1]
h = HTTP()
h.set_debuglevel(dl)
h.connect(host)
h.putrequest('GET', selector)
h.endheaders()
errcode, errmsg, headers = h.getreply()
print 'errcode =', errcode
print 'errmsg =', errmsg
print
if headers:
for header in headers.headers: print string.strip(header)
print
print h.getfile().read()
if __name__ == '__main__':
test()
--
--- Aahz (Copyright 2000 by aahz at netcom.com)
Androgynous poly kinky vanilla queer het <*> http://www.rahul.net/aahz/
Hugs and backrubs -- I break Rule 6
"Yes, but would you kick any of them out of bed?"
"That depends: do we have to do anything with them in the bed, or
are they just in the bed?" -- AM/SJM
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