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# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330,
# Boston, MA 02111-1307 USA
# This file is part of urlgrabber, a high-level cross-protocol url-grabber
# Copyright 2002-2004 Michael D. Stenner, Ryan Tomayko
"""A high-level cross-protocol url-grabber.
GENERAL ARGUMENTS (kwargs)
Where possible, the module-level default is indicated, and legal
values are provided.
copy_local = 0 [0|1]
ignored except for file:// urls, in which case it specifies
whether urlgrab should still make a copy of the file, or simply
point to the existing copy. The module level default for this
option is 0.
close_connection = 0 [0|1]
tells URLGrabber to close the connection after a file has been
transfered. This is ignored unless the download happens with the
http keepalive handler (keepalive=1). Otherwise, the connection
is left open for further use. The module level default for this
option is 0 (keepalive connections will not be closed).
keepalive = 1 [0|1]
specifies whether keepalive should be used for HTTP/1.1 servers
that support it. The module level default for this option is 1
(keepalive is enabled).
progress_obj = None
a class instance that supports the following methods:
po.start(filename, url, basename, length, text)
# length will be None if unknown
po.update(read) # read == bytes read so far
po.end()
text = None
specifies an alternativ text item in the beginning of the progress
bar line. If not given, the basename of the file is used.
throttle = 1.0
a number - if it's an int, it's the bytes/second throttle limit.
If it's a float, it is first multiplied by bandwidth. If throttle
== 0, throttling is disabled. If None, the module-level default
(which can be set on default_grabber.throttle) is used. See
BANDWIDTH THROTTLING for more information.
timeout = None
a positive float expressing the number of seconds to wait for socket
operations. If the value is None or 0.0, socket operations will block
forever. Setting this option causes urlgrabber to call the settimeout
method on the Socket object used for the request. See the Python
documentation on settimeout for more information.
http://www.python.org/doc/current/lib/socket-objects.html
bandwidth = 0
the nominal max bandwidth in bytes/second. If throttle is a float
and bandwidth == 0, throttling is disabled. If None, the
module-level default (which can be set on
default_grabber.bandwidth) is used. See BANDWIDTH THROTTLING for
more information.
range = None
a tuple of the form (first_byte, last_byte) describing a byte
range to retrieve. Either or both of the values may set to
None. If first_byte is None, byte offset 0 is assumed. If
last_byte is None, the last byte available is assumed. Note that
the range specification is python-like in that (0,10) will yeild
the first 10 bytes of the file.
If set to None, no range will be used.
reget = None [None|'simple'|'check_timestamp']
whether to attempt to reget a partially-downloaded file. Reget
only applies to .urlgrab and (obviously) only if there is a
partially downloaded file. Reget has two modes:
'simple' -- the local file will always be trusted. If there
are 100 bytes in the local file, then the download will always
begin 100 bytes into the requested file.
'check_timestamp' -- the timestamp of the server file will be
compared to the timestamp of the local file. ONLY if the
local file is newer than or the same age as the server file
will reget be used. If the server file is newer, or the
timestamp is not returned, the entire file will be fetched.
NOTE: urlgrabber can do very little to verify that the partial
file on disk is identical to the beginning of the remote file.
You may want to either employ a custom "checkfunc" or simply avoid
using reget in situations where corruption is a concern.
user_agent = 'urlgrabber/VERSION'
a string, usually of the form 'AGENT/VERSION' that is provided to
HTTP servers in the User-agent header. The module level default
for this option is "urlgrabber/VERSION".
http_headers = None
a tuple of 2-tuples, each containing a header and value. These
will be used for http and https requests only. For example, you
can do
http_headers = (('Pragma', 'no-cache'),)
ftp_headers = None
this is just like http_headers, but will be used for ftp requests.
proxies = None
a dictionary that maps protocol schemes to proxy hosts. For
example, to use a proxy server on host "foo" port 3128 for http
and https URLs:
proxies={ 'http' : 'http://foo:3128', 'https' : 'http://foo:3128' }
note that proxy authentication information may be provided using
normal URL constructs:
proxies={ 'http' : 'http://user:host@foo:3128' }
Lastly, if proxies is None, the default environment settings will
be used.
prefix = None
a url prefix that will be prepended to all requested urls. For
example:
g = URLGrabber(prefix='http://foo.com/mirror/')
g.urlgrab('some/file.txt')
## this will fetch 'http://foo.com/mirror/some/file.txt'
This option exists primarily to allow identical behavior to
MirrorGroup (and derived) instances. Note: a '/' will be inserted
if necessary, so you cannot specify a prefix that ends with a
partial file or directory name.
opener = None
Overrides the default urllib2.OpenerDirector provided to urllib2
when making requests. This option exists so that the urllib2
handler chain may be customized. Note that the range, reget,
proxy, and keepalive features require that custom handlers be
provided to urllib2 in order to function properly. If an opener
option is provided, no attempt is made by urlgrabber to ensure
chain integrity. You are responsible for ensuring that any
extension handlers are present if said features are required.
RETRY RELATED ARGUMENTS
retry = None
the number of times to retry the grab before bailing. If this is
zero, it will retry forever. This was intentional... really, it
was :). If this value is not supplied or is supplied but is None
retrying does not occur.
retrycodes = [-1,2,4,5,6,7]
a sequence of errorcodes (values of e.errno) for which it should
retry. See the doc on URLGrabError for more details on
this. retrycodes defaults to [-1,2,4,5,6,7] if not specified
explicitly.
checkfunc = None
a function to do additional checks. This defaults to None, which
means no additional checking. The function should simply return
on a successful check. It should raise URLGrabError on an
unsuccessful check. Raising of any other exception will be
considered immediate failure and no retries will occur.
If it raises URLGrabError, the error code will determine the retry
behavior. Negative error numbers are reserved for use by these
passed in functions, so you can use many negative numbers for
different types of failure. By default, -1 results in a retry,
but this can be customized with retrycodes.
If you simply pass in a function, it will be given exactly one
argument: a CallbackObject instance with the .url attribute
defined and either .filename (for urlgrab) or .data (for urlread).
For urlgrab, .filename is the name of the local file. For
urlread, .data is the actual string data. If you need other
arguments passed to the callback (program state of some sort), you
can do so like this:
checkfunc=(function, ('arg1', 2), {'kwarg': 3})
if the downloaded file has filename /tmp/stuff, then this will
result in this call (for urlgrab):
function(obj, 'arg1', 2, kwarg=3)
# obj.filename = '/tmp/stuff'
# obj.url = 'http://foo.com/stuff'
NOTE: both the "args" tuple and "kwargs" dict must be present if
you use this syntax, but either (or both) can be empty.
failure_callback = None
The callback that gets called during retries when an attempt to
fetch a file fails. The syntax for specifying the callback is
identical to checkfunc, except for the attributes defined in the
CallbackObject instance. In this case, it will have .exception
and .url defined. As you might suspect, .exception is the
exception that was raised.
The callback is present primarily to inform the calling program of
the failure, but if it raises an exception (including the one it's
passed) that exception will NOT be caught and will therefore cause
future retries to be aborted.
BANDWIDTH THROTTLING
urlgrabber supports throttling via two values: throttle and
bandwidth Between the two, you can either specify and absolute
throttle threshold or specify a theshold as a fraction of maximum
available bandwidth.
throttle is a number - if it's an int, it's the bytes/second
throttle limit. If it's a float, it is first multiplied by
bandwidth. If throttle == 0, throttling is disabled. If None, the
module-level default (which can be set with set_throttle) is used.
bandwidth is the nominal max bandwidth in bytes/second. If throttle
is a float and bandwidth == 0, throttling is disabled. If None, the
module-level default (which can be set with set_bandwidth) is used.
THROTTLING EXAMPLES:
Lets say you have a 100 Mbps connection. This is (about) 10^8 bits
per second, or 12,500,000 Bytes per second. You have a number of
throttling options:
*) set_bandwidth(12500000); set_throttle(0.5) # throttle is a float
This will limit urlgrab to use half of your available bandwidth.
*) set_throttle(6250000) # throttle is an int
This will also limit urlgrab to use half of your available
bandwidth, regardless of what bandwidth is set to.
*) set_throttle(6250000); set_throttle(1.0) # float
Use half your bandwidth
*) set_throttle(6250000); set_throttle(2.0) # float
Use up to 12,500,000 Bytes per second (your nominal max bandwidth)
*) set_throttle(6250000); set_throttle(0) # throttle = 0
Disable throttling - this is more efficient than a very large
throttle setting.
*) set_throttle(0); set_throttle(1.0) # throttle is float, bandwidth = 0
Disable throttling - this is the default when the module is loaded.
SUGGESTED AUTHOR IMPLEMENTATION (THROTTLING)
While this is flexible, it's not extremely obvious to the user. I
suggest you implement a float throttle as a percent to make the
distinction between absolute and relative throttling very explicit.
Also, you may want to convert the units to something more convenient
than bytes/second, such as kbps or kB/s, etc.
"""
# $Id: grabber.py,v 1.39 2005/03/03 00:54:23 mstenner Exp $
import os
import os.path
import urlparse
import rfc822
import time
import string
import urllib
import urllib2
from stat import * # S_* and ST_*
try:
exec('from ' + (__name__.split('.'))[0] + ' import __version__')
except:
__version__ = '???'
auth_handler = urllib2.HTTPBasicAuthHandler( \
urllib2.HTTPPasswordMgrWithDefaultRealm())
DEBUG=0
try:
from i18n import _
except ImportError, msg:
def _(st): return st
try:
from httplib import HTTPException
except ImportError, msg:
HTTPException = None
try:
# This is a convenient way to make keepalive optional.
# Just rename the module so it can't be imported.
from keepalive import HTTPHandler
except ImportError, msg:
keepalive_handler = None
else:
keepalive_handler = HTTPHandler()
try:
# add in range support conditionally too
from urlgrabber.byterange import HTTPRangeHandler, FileRangeHandler, \
FTPRangeHandler, range_tuple_normalize, range_tuple_to_header, \
RangeError
except ImportError, msg:
range_handlers = ()
RangeError = None
have_range = 0
else:
range_handlers = (HTTPRangeHandler(), FileRangeHandler(), FTPRangeHandler())
have_range = 1
# check whether socket timeout support is available (Python >= 2.3)
import socket
try:
TimeoutError = socket.timeout
have_socket_timeout = True
except AttributeError:
TimeoutError = None
have_socket_timeout = False
class URLGrabError(IOError):
"""
URLGrabError error codes:
URLGrabber error codes (0 -- 255)
0 - everything looks good (you should never see this)
1 - malformed url
2 - local file doesn't exist
3 - request for non-file local file (dir, etc)
4 - IOError on fetch
5 - OSError on fetch
6 - no content length header when we expected one
7 - HTTPException
8 - Exceeded read limit (for urlread)
9 - Requested byte range not satisfiable.
10 - Byte range requested, but range support unavailable
11 - Illegal reget mode
12 - Socket timeout.
MirrorGroup error codes (256 -- 511)
256 - No more mirrors left to try
Custom (non-builtin) classes derived from MirrorGroup (512 -- 767)
[ this range reserved for application-specific error codes ]
Retry codes (< 0)
-1 - retry the download, unknown reason
Note: to test which group a code is in, you can simply do integer
division by 256: e.errno / 256
Negative codes are reserved for use by functions passed in to
retrygrab with checkfunc. The value -1 is built in as a generic
retry code and is already included in the retrycodes list.
Therefore, you can create a custom check function that simply
returns -1 and the fetch will be re-tried. For more customized
retries, you can use other negative number and include them in
retry-codes. This is nice for outputting useful messages about
what failed.
You can use these error codes like so:
try: urlgrab(url)
except URLGrabError, e:
if e.errno == 3: ...
# or
print e.strerror
# or simply
print e #### print '[Errno %i] %s' % (e.errno, e.strerror)
"""
pass
class CallbackObject:
"""Container for returned callback data.
This is currently a dummy class into which urlgrabber can stuff
information for passing to callbacks. This way, the prototype for
all callbacks is the same, regardless of the data that will be
passed back. Any function that accepts a callback function as an
argument SHOULD document what it will define in this object.
It is possible that this class will have some greater
functionality in the future.
"""
pass
def close_all():
"""close any open keepalive connections"""
if keepalive_handler: keepalive_handler.close_all()
def urlgrab(url, filename=None, **kwargs):
"""grab the file at <url> and make a local copy at <filename>
If filename is none, the basename of the url is used.
urlgrab returns the filename of the local file, which may be different
from the passed-in filename if the copy_local kwarg == 0.
See module documentation for a description of possible kwargs.
"""
return default_grabber.urlgrab(url, filename, **kwargs)
def urlopen(url, **kwargs):
"""open the url and return a file object
If a progress object or throttle specifications exist, then
a special file object will be returned that supports them.
The file object can be treated like any other file object.
See module documentation for a description of possible kwargs.
"""
return default_grabber.urlopen(url, **kwargs)
def urlread(url, limit=None, **kwargs):
"""read the url into a string, up to 'limit' bytes
If the limit is exceeded, an exception will be thrown. Note that urlread
is NOT intended to be used as a way of saying "I want the first N bytes"
but rather 'read the whole file into memory, but don't use too much'
See module documentation for a description of possible kwargs.
"""
return default_grabber.urlread(url, limit, **kwargs)
class URLGrabberOptions:
"""Class to ease kwargs handling."""
def __init__(self, delegate=None, **kwargs):
"""Initialize URLGrabberOptions object.
Set default values for all options and then update options specified
in kwargs.
"""
self.delegate = delegate
if delegate is None:
self._set_defaults()
self._set_attributes(**kwargs)
def __getattr__(self, name):
if self.delegate and hasattr(self.delegate, name):
return getattr(self.delegate, name)
raise AttributeError, name
def raw_throttle(self):
"""Calculate raw throttle value from throttle and bandwidth
values.
"""
if self.throttle <= 0:
return 0
elif type(self.throttle) == type(0):
return float(self.throttle)
else: # throttle is a float
return self.bandwidth * self.throttle
def derive(self, **kwargs):
"""Create a derived URLGrabberOptions instance.
This method creates a new instance and overrides the
options specified in kwargs.
"""
return URLGrabberOptions(delegate=self, **kwargs)
def _set_attributes(self, **kwargs):
"""Update object attributes with those provided in kwargs."""
self.__dict__.update(kwargs)
if have_range and kwargs.has_key('range'):
# normalize the supplied range value
self.range = range_tuple_normalize(self.range)
if not self.reget in [None, 'simple', 'check_timestamp']:
raise URLGrabError(11, _('Illegal reget mode: %s') \
% (self.reget, ))
def _set_defaults(self):
"""Set all options to their default values.
When adding new options, make sure a default is
provided here.
"""
self.progress_obj = None
self.throttle = 1.0
self.bandwidth = 0
self.retry = None
self.retrycodes = [-1,2,4,5,6,7]
self.checkfunc = None
self.copy_local = 0
self.close_connection = 0
self.range = None
self.user_agent = 'urlgrabber/%s' % __version__
self.keepalive = 1
self.proxies = None
self.reget = None
self.failure_callback = None
self.prefix = None
self.opener = None
self.cache_openers = True
self.timeout = None
self.text = None
self.http_headers = None
self.ftp_headers = None
class URLGrabber:
"""Provides easy opening of URLs with a variety of options.
All options are specified as kwargs. Options may be specified when
the class is created and may be overridden on a per request basis.
New objects inherit default values from default_grabber.
"""
def __init__(self, **kwargs):
self.opts = URLGrabberOptions(**kwargs)
def _retry(self, opts, func, *args):
tries = 0
while 1:
tries = tries + 1
try:
return apply(func, (opts,) + args, {})
except URLGrabError, e:
if DEBUG: print 'EXCEPTION: %s' % e
if (opts.retry is None) \
or (tries == opts.retry) \
or (e.errno not in opts.retrycodes): raise
if opts.failure_callback:
cb_func, cb_args, cb_kwargs = \
self._make_callback(opts.failure_callback)
# this is a little icky - for now, the first element
# of args is the url. we might consider a way to tidy
# that up, though
obj = CallbackObject()
obj.exception = e
obj.url = args[0]
cb_func(obj, *cb_args, **cb_kwargs)
def urlopen(self, url, **kwargs):
"""open the url and return a file object
If a progress object or throttle value specified when this
object was created, then a special file object will be
returned that supports them. The file object can be treated
like any other file object.
"""
opts = self.opts.derive(**kwargs)
(url,parts) = self._parse_url(url)
def retryfunc(opts, url):
return URLGrabberFileObject(url, filename=None, opts=opts)
return self._retry(opts, retryfunc, url)
def urlgrab(self, url, filename=None, **kwargs):
"""grab the file at <url> and make a local copy at <filename>
If filename is none, the basename of the url is used.
urlgrab returns the filename of the local file, which may be
different from the passed-in filename if copy_local == 0.
"""
opts = self.opts.derive(**kwargs)
(url, parts) = self._parse_url(url)
(scheme, host, path, parm, query, frag) = parts
if filename is None:
if scheme in [ 'http', 'https' ]:
filename = os.path.basename( urllib.unquote(path) )
else:
filename = os.path.basename( path )
if scheme == 'file' and not opts.copy_local:
# just return the name of the local file - don't make a
# copy currently
if not os.path.exists(path):
raise URLGrabError(2,
_('Local file does not exist: %s') % (path, ))
elif not os.path.isfile(path):
raise URLGrabError(3,
_('Not a normal file: %s') % (path, ))
elif not opts.range:
return path
def retryfunc(opts, url, filename):
fo = URLGrabberFileObject(url, filename, opts)
try:
fo._do_grab()
if not opts.checkfunc is None:
cb_func, cb_args, cb_kwargs = \
self._make_callback(opts.checkfunc)
obj = CallbackObject()
obj.filename = filename
obj.url = url
apply(cb_func, (obj, )+cb_args, cb_kwargs)
finally:
fo.close()
return filename
return self._retry(opts, retryfunc, url, filename)
def urlread(self, url, limit=None, **kwargs):
"""read the url into a string, up to 'limit' bytes
If the limit is exceeded, an exception will be thrown. Note
that urlread is NOT intended to be used as a way of saying
"I want the first N bytes" but rather 'read the whole file
into memory, but don't use too much'
"""
opts = self.opts.derive(**kwargs)
(url, parts) = self._parse_url(url)
if limit is not None:
limit = limit + 1
def retryfunc(opts, url, limit):
fo = URLGrabberFileObject(url, filename=None, opts=opts)
s = ''
try:
# this is an unfortunate thing. Some file-like objects
# have a default "limit" of None, while the built-in (real)
# file objects have -1. They each break the other, so for
# now, we just force the default if necessary.
if limit is None: s = fo.read()
else: s = fo.read(limit)
if not opts.checkfunc is None:
cb_func, cb_args, cb_kwargs = \
self._make_callback(opts.checkfunc)
obj = CallbackObject()
obj.data = s
obj.url = url
apply(cb_func, (obj, )+cb_args, cb_kwargs)
finally:
fo.close()
return s
s = self._retry(opts, retryfunc, url, limit)
if limit and len(s) > limit:
raise URLGrabError(8,
_('Exceeded limit (%i): %s') % (limit, url))
return s
def _parse_url(self,url):
"""break up the url into its component parts
This function disassembles a url and
1) "normalizes" it, tidying it up a bit
2) does any authentication stuff it needs to do
it returns the (cleaned) url and a tuple of component parts
"""
if self.opts.prefix:
p = self.opts.prefix
if p[-1] == '/' or url[0] == '/': url = p + url
else: url = p + '/' + url
(scheme, host, path, parm, query, frag) = \
urlparse.urlparse(url)
if not scheme:
if not url[0] == '/': url = os.path.abspath(url)
url = 'file:' + url
(scheme, host, path, parm, query, frag) = \
urlparse.urlparse(url)
path = os.path.normpath(path)
if scheme in ['http', 'https']: path = urllib.quote(path)
if '@' in host and auth_handler and scheme in ['http', 'https']:
try:
user_pass, host = host.split('@', 1)
if ':' in user_pass: user, password = user_pass.split(':', 1)
except ValueError, e:
raise URLGrabError(1, _('Bad URL: %s') % url)
if DEBUG: print 'adding HTTP auth: %s, %s' % (user, password)
auth_handler.add_password(None, host, user, password)
parts = (scheme, host, path, parm, query, frag)
url = urlparse.urlunparse(parts)
return url, parts
def _make_callback(self, callback_obj):
if callable(callback_obj):
return callback_obj, (), {}
else:
return callback_obj
# create the default URLGrabber used by urlXXX functions.
# NOTE: actual defaults are set in URLGrabberOptions
default_grabber = URLGrabber()
class URLGrabberFileObject:
"""This is a file-object wrapper that supports progress objects
and throttling.
This exists to solve the following problem: lets say you want to
drop-in replace a normal open with urlopen. You want to use a
progress meter and/or throttling, but how do you do that without
rewriting your code? Answer: urlopen will return a wrapped file
object that does the progress meter and-or throttling internally.
"""
def __init__(self, url, filename, opts):
self.url = url
self.filename = filename
self.opts = opts
self.fo = None
self._rbuf = ''
self._rbufsize = 1024*8
self._ttime = time.time()
self._tsize = 0
self._amount_read = 0
self._opener = None
self._do_open()
def __getattr__(self, name):
"""This effectively allows us to wrap at the instance level.
Any attribute not found in _this_ object will be searched for
in self.fo. This includes methods."""
if hasattr(self.fo, name):
return getattr(self.fo, name)
raise AttributeError, name
def _get_opener(self):
"""Build a urllib2 OpenerDirector based on request options."""
if self.opts.opener:
return self.opts.opener
elif self._opener is None:
handlers = []
need_keepalive_handler = (keepalive_handler and self.opts.keepalive)
need_range_handler = (range_handlers and \
(self.opts.range or self.opts.reget))
# if you specify a ProxyHandler when creating the opener
# it _must_ come before all other handlers in the list or urllib2
# chokes.
if self.opts.proxies:
handlers.append( CachedProxyHandler(self.opts.proxies) )
# -------------------------------------------------------
# OK, these next few lines are a serious kludge to get
# around what I think is a bug in python 2.2's
# urllib2. The basic idea is that default handlers
# get applied first. If you override one (like a
# proxy handler), then the default gets pulled, but
# the replacement goes on the end. In the case of
# proxies, this means the normal handler picks it up
# first and the proxy isn't used. Now, this probably
# only happened with ftp or non-keepalive http, so not
# many folks saw it. The simple approach to fixing it
# is just to make sure you override the other
# conflicting defaults as well. I would LOVE to see
# these go way or be dealt with more elegantly. The
# problem isn't there after 2.2. -MDS 2005/02/24
if not need_keepalive_handler:
handlers.append( urllib2.HTTPHandler() )
if not need_range_handler:
handlers.append( urllib2.FTPHandler() )
# -------------------------------------------------------
if need_keepalive_handler:
handlers.append( keepalive_handler )
if need_range_handler:
handlers.extend( range_handlers )
handlers.append( auth_handler )
if self.opts.cache_openers:
self._opener = CachedOpenerDirector(*handlers)
else:
self._opener = urllib2.build_opener(*handlers)
# OK, I don't like to do this, but otherwise, we end up with
# TWO user-agent headers.
self._opener.addheaders = []
return self._opener
def _do_open(self):
opener = self._get_opener()
req = urllib2.Request(self.url) # build request object
self._add_headers(req) # add misc headers that we need
self._build_range(req) # take care of reget and byterange stuff
fo, hdr = self._make_request(req, opener)
if self.reget_time and self.opts.reget == 'check_timestamp':
# do this if we have a local file with known timestamp AND
# we're in check_timestamp reget mode.
fetch_again = 0
try:
modified_tuple = hdr.getdate_tz('last-modified')
modified_stamp = rfc822.mktime_tz(modified_tuple)
if modified_stamp > self.reget_time: fetch_again = 1
except (TypeError,):
fetch_again = 1
if fetch_again:
# the server version is newer than the (incomplete) local
# version, so we should abandon the version we're getting
# and fetch the whole thing again.
fo.close()
self.opts.reget = None
del req.headers['Range']
self._build_range(req)
fo, hdr = self._make_request(req, opener)
(scheme, host, path, parm, query, frag) = urlparse.urlparse(self.url)
if not (self.opts.progress_obj or self.opts.raw_throttle() \
or self.opts.timeout):
# if we're not using the progress_obj, throttling, or timeout
# we can get a performance boost by going directly to
# the underlying fileobject for reads.
self.read = fo.read
if hasattr(fo, 'readline'):
self.readline = fo.readline
elif self.opts.progress_obj:
try: length = int(hdr['Content-Length'])
except: length = None
self.opts.progress_obj.start(str(self.filename), self.url,
os.path.basename(path),
length,
text=self.opts.text)
self.opts.progress_obj.update(0)
(self.fo, self.hdr) = (fo, hdr)
def _add_headers(self, req):
if self.opts.user_agent:
req.add_header('User-agent', self.opts.user_agent)
try: req_type = req.get_type()
except ValueError: req_type = None
if self.opts.http_headers and req_type in ('http', 'https'):
for h, v in self.opts.http_headers:
req.add_header(h, v)
if self.opts.ftp_headers and req_type == 'ftp':
for h, v in self.opts.ftp_headers:
req.add_header(h, v)
def _build_range(self, req):
self.reget_time = None
self.append = 0
reget_length = 0
rt = None
if have_range and self.opts.reget and type(self.filename) == type(''):
# we have reget turned on and we're dumping to a file
try:
s = os.stat(self.filename)
except OSError:
pass
else:
self.reget_time = s[ST_MTIME]
reget_length = s[ST_SIZE]
rt = reget_length, ''
self.append = 1
if self.opts.range:
if not have_range:
raise URLGrabError(10, _('Byte range requested but range '\
'support unavailable'))
rt = self.opts.range
if rt[0]: rt = (rt[0] + reget_length, rt[1])
if rt:
header = range_tuple_to_header(rt)
if header: req.add_header('Range', header)
def _make_request(self, req, opener):
try:
if have_socket_timeout and self.opts.timeout:
old_to = socket.getdefaulttimeout()
socket.setdefaulttimeout(self.opts.timeout)
try:
fo = opener.open(req)
finally:
socket.setdefaulttimeout(old_to)
else:
fo = opener.open(req)
hdr = fo.info()
except ValueError, e:
raise URLGrabError(1, _('Bad URL: %s') % (e, ))
except RangeError, e:
raise URLGrabError(9, _('%s') % (e, ))
except IOError, e:
if hasattr(e, 'reason') and have_socket_timeout and \
isinstance(e.reason, TimeoutError):
raise URLGrabError(12, _('Timeout: %s') % (e, ))
else:
raise URLGrabError(4, _('IOError: %s') % (e, ))
except OSError, e:
raise URLGrabError(5, _('OSError: %s') % (e, ))
except HTTPException, e:
raise URLGrabError(7, _('HTTP Error (%s): %s') % \
(e.__class__.__name__, e))
else:
return (fo, hdr)
def _do_grab(self):
"""dump the file to self.filename."""
if self.append: new_fo = open(self.filename, 'ab')
else: new_fo = open(self.filename, 'wb')
bs = 1024*8
size = 0
block = self.read(bs)
size = size + len(block)
while block:
new_fo.write(block)
block = self.read(bs)
size = size + len(block)
new_fo.close()
try:
modified_tuple = self.hdr.getdate_tz('last-modified')
modified_stamp = rfc822.mktime_tz(modified_tuple)
os.utime(self.filename, (modified_stamp, modified_stamp))
except (TypeError,), e: pass
return size
def _fill_buffer(self, amt=None):
"""fill the buffer to contain at least 'amt' bytes by reading
from the underlying file object. If amt is None, then it will
read until it gets nothing more. It updates the progress meter
and throttles after every self._rbufsize bytes."""
# the _rbuf test is only in this first 'if' for speed. It's not
# logically necessary
if self._rbuf and not amt is None:
L = len(self._rbuf)
if amt > L:
amt = amt - L
else:
return
# if we've made it here, then we don't have enough in the buffer
# and we need to read more.
buf = [self._rbuf]
bufsize = len(self._rbuf)
while amt is None or amt:
# first, delay if necessary for throttling reasons
if self.opts.raw_throttle():
diff = self._tsize/self.opts.raw_throttle() - \
(time.time() - self._ttime)
if diff > 0: time.sleep(diff)
self._ttime = time.time()
# now read some data, up to self._rbufsize
if amt is None: readamount = self._rbufsize
else: readamount = min(amt, self._rbufsize)
try:
new = self.fo.read(readamount)
except socket.error, e:
raise URLGrabError(4, _('Socket Error: %s') % (e, ))
except TimeoutError, e:
raise URLGrabError(12, _('Timeout: %s') % (e, ))
newsize = len(new)
if not newsize: break # no more to read
if amt: amt = amt - newsize
buf.append(new)
bufsize = bufsize + newsize
self._tsize = newsize
self._amount_read = self._amount_read + newsize
if self.opts.progress_obj:
self.opts.progress_obj.update(self._amount_read)
self._rbuf = string.join(buf, '')
return
def read(self, amt=None):
self._fill_buffer(amt)
if amt is None:
s, self._rbuf = self._rbuf, ''
else:
s, self._rbuf = self._rbuf[:amt], self._rbuf[amt:]
return s
def readline(self, limit=-1):
i = string.find(self._rbuf, '\n')
while i < 0 and not (0 < limit <= len(self._rbuf)):
L = len(self._rbuf)
self._fill_buffer(L + self._rbufsize)
if not len(self._rbuf) > L: break
i = string.find(self._rbuf, '\n', L)
if i < 0: i = len(self._rbuf)
else: i = i+1
if 0 <= limit < len(self._rbuf): i = limit
s, self._rbuf = self._rbuf[:i], self._rbuf[i:]
return s
def close(self):
if self.opts.progress_obj:
self.opts.progress_obj.end(self._amount_read)
self.fo.close()
if self.opts.close_connection:
try: self.fo.close_connection()
except: pass
_handler_cache = []
def CachedOpenerDirector(*handlers):
for (cached_handlers, opener) in _handler_cache:
if cached_handlers == handlers:
for handler in opener.handlers:
handler.add_parent(opener)
return opener
opener = urllib2.build_opener(*handlers)
_handler_cache.append( (handlers, opener) )
return opener
_proxy_cache = []
def CachedProxyHandler(proxies):
for (pdict, handler) in _proxy_cache:
if pdict == proxies:
break
else:
handler = urllib2.ProxyHandler(proxies)
_proxy_cache.append( (proxies, handler) )
return handler
#####################################################################
# DEPRECATED FUNCTIONS
def set_throttle(new_throttle):
"""Deprecated. Use: default_grabber.throttle = new_throttle"""
default_grabber.throttle = new_throttle
def set_bandwidth(new_bandwidth):
"""Deprecated. Use: default_grabber.bandwidth = new_bandwidth"""
default_grabber.bandwidth = new_bandwidth
def set_progress_obj(new_progress_obj):
"""Deprecated. Use: default_grabber.progress_obj = new_progress_obj"""
default_grabber.progress_obj = new_progress_obj
def set_user_agent(new_user_agent):
"""Deprecated. Use: default_grabber.user_agent = new_user_agent"""
default_grabber.user_agent = new_user_agent
def retrygrab(url, filename=None, copy_local=0, close_connection=0,
progress_obj=None, throttle=None, bandwidth=None,
numtries=3, retrycodes=[-1,2,4,5,6,7], checkfunc=None):
"""Deprecated. Use: urlgrab() with the retry arg instead"""
kwargs = {'copy_local' : copy_local,
'close_connection' : close_connection,
'progress_obj' : progress_obj,
'throttle' : throttle,
'bandwidth' : bandwidth,
'retry' : numtries,
'retrycodes' : retrycodes,
'checkfunc' : checkfunc
}
return urlgrab(url, filename, **kwargs)
#####################################################################
# TESTING
def _main_test():
import sys
try: url, filename = sys.argv[1:3]
except ValueError:
print 'usage:', sys.argv[0], \
'<url> <filename> [copy_local=0|1] [close_connection=0|1]'
sys.exit()
kwargs = {}
for a in sys.argv[3:]:
k, v = string.split(a, '=', 1)
kwargs[k] = int(v)
set_throttle(1.0)
set_bandwidth(32 * 1024)
print "throttle: %s, throttle bandwidth: %s B/s" % (default_grabber.throttle,
default_grabber.bandwidth)
try: from progress import text_progress_meter
except ImportError, e: pass
else: kwargs['progress_obj'] = text_progress_meter()
try: name = apply(urlgrab, (url, filename), kwargs)
except URLGrabError, e: print e
else: print 'LOCAL FILE:', name
def _retry_test():
import sys
try: url, filename = sys.argv[1:3]
except ValueError:
print 'usage:', sys.argv[0], \
'<url> <filename> [copy_local=0|1] [close_connection=0|1]'
sys.exit()
kwargs = {}
for a in sys.argv[3:]:
k, v = string.split(a, '=', 1)
kwargs[k] = int(v)
try: from progress import text_progress_meter
except ImportError, e: pass
else: kwargs['progress_obj'] = text_progress_meter()
global DEBUG
#DEBUG = 1
def cfunc(filename, hello, there='foo'):
print hello, there
import random
rnum = random.random()
if rnum < .5:
print 'forcing retry'
raise URLGrabError(-1, 'forcing retry')
if rnum < .75:
print 'forcing failure'
raise URLGrabError(-2, 'forcing immediate failure')
print 'success'
return
close_all()
kwargs['checkfunc'] = (cfunc, ('hello',), {'there':'there'})
try: name = apply(retrygrab, (url, filename), kwargs)
except URLGrabError, e: print e
else: print 'LOCAL FILE:', name
def _file_object_test(filename=None):
import random, cStringIO, sys
if filename is None:
filename = __file__
print 'using file "%s" for comparisons' % filename
fo = open(filename)
s_input = fo.read()
fo.close()
for testfunc in [_test_file_object_smallread,
_test_file_object_readall,
_test_file_object_readline,
_test_file_object_readlines]:
fo_input = cStringIO.StringIO(s_input)
fo_output = cStringIO.StringIO()
wrapper = URLGrabberFileObject(fo_input, None, 0)
print 'testing %-30s ' % testfunc.__name__,
testfunc(wrapper, fo_output)
s_output = fo_output.getvalue()
if s_output == s_input: print 'passed'
else: print 'FAILED'
def _test_file_object_smallread(wrapper, fo_output):
while 1:
s = wrapper.read(23)
fo_output.write(s)
if not s: return
def _test_file_object_readall(wrapper, fo_output):
s = wrapper.read()
fo_output.write(s)
def _test_file_object_readline(wrapper, fo_output):
while 1:
s = wrapper.readline()
fo_output.write(s)
if not s: return
def _test_file_object_readlines(wrapper, fo_output):
li = wrapper.readlines()
fo_output.write(string.join(li, ''))
if __name__ == '__main__':
_main_test()
_retry_test()
_file_object_test('test')
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