示例#1
0
 def _on_connect(self):
     self._remove_timeout()
     if self.request.request_timeout:
         self._timeout = self.io_loop.add_timeout(
             self.start_time + self.request.request_timeout,
             stack_context.wrap(self._on_timeout))
     if (self.request.method not in self._SUPPORTED_METHODS and
             not self.request.allow_nonstandard_methods):
         raise KeyError("unknown method %s" % self.request.method)
     for key in ('network_interface',
                 'proxy_host', 'proxy_port',
                 'proxy_username', 'proxy_password'):
         if getattr(self.request, key, None):
             raise NotImplementedError('%s not supported' % key)
     if "Connection" not in self.request.headers:
         self.request.headers["Connection"] = "close"
     if "Host" not in self.request.headers:
         if '@' in self.parsed.netloc:
             self.request.headers["Host"] = self.parsed.netloc.rpartition('@')[-1]
         else:
             self.request.headers["Host"] = self.parsed.netloc
     username, password = None, None
     if self.parsed.username is not None:
         username, password = self.parsed.username, self.parsed.password
     elif self.request.auth_username is not None:
         username = self.request.auth_username
         password = self.request.auth_password or ''
     if username is not None:
         auth = utf8(username) + b":" + utf8(password)
         self.request.headers["Authorization"] = (b"Basic " +
                                                  base64.b64encode(auth))
     if self.request.user_agent:
         self.request.headers["User-Agent"] = self.request.user_agent
     if not self.request.allow_nonstandard_methods:
         if self.request.method in ("POST", "PATCH", "PUT"):
             assert self.request.body is not None
         else:
             assert self.request.body is None
     if self.request.body is not None:
         self.request.headers["Content-Length"] = str(len(
             self.request.body))
     if (self.request.method == "POST" and
             "Content-Type" not in self.request.headers):
         self.request.headers["Content-Type"] = "application/x-www-form-urlencoded"
     if self.request.use_gzip:
         self.request.headers["Accept-Encoding"] = "gzip"
     req_path = ((self.parsed.path or '/') +
                (('?' + self.parsed.query) if self.parsed.query else ''))
     request_lines = [utf8("%s %s HTTP/1.1" % (self.request.method,
                                               req_path))]
     for k, v in self.request.headers.get_all():
         line = utf8(k) + b": " + utf8(v)
         if b'\n' in line:
             raise ValueError('Newline in header: ' + repr(line))
         request_lines.append(line)
     self.stream.write(b"\r\n".join(request_lines) + b"\r\n\r\n")
     if self.request.body is not None:
         self.stream.write(self.request.body)
     self.stream.read_until_regex(b"\r?\n\r?\n", self._on_headers)
示例#2
0
    def parse_image(self, url, filename = None):
        """处理img标签的src并映射到本地文件"""
        url = escape.utf8(url)
        image_guid = hashlib.sha1(url).hexdigest()

        x = url.split('.')
        ext = 'jpg'
        if len(x) > 1:
            ext = x[-1]

            if len(ext) > 4:
                ext = ext[0:3]

            ext = re.sub('[^a-zA-Z]', '', ext)
            ext = ext.lower()

            if ext not in ['jpg', 'jpeg', 'gif', 'png', 'bmp']:
                ext = 'jpg'

        y = url.split('/')
        h = hashlib.sha1(str(y[2])).hexdigest()

        hash_dir = os.path.join(h[0:1], h[1:2])
        filename = image_guid + '.' + ext

        img_dir = os.path.join(self.work_dir, 'data', 'images', hash_dir)
        fullname = os.path.join(img_dir, filename)
        
        if not os.path.exists(img_dir):
            os.makedirs(img_dir)
        
        localimage = 'images/%s/%s' % (hash_dir, filename)
        return localimage, fullname
示例#3
0
    def parse_image(self, url, filename=None):
        """处理img标签的src并映射到本地文件"""
        url = escape.utf8(url)
        image_guid = hashlib.sha1(url).hexdigest()

        x = url.split('.')
        ext = 'jpg'
        if len(x) > 1:
            ext = x[-1]

            if len(ext) > 4:
                ext = ext[0:3]

            ext = re.sub('[^a-zA-Z]', '', ext)
            ext = ext.lower()

            if ext not in ['jpg', 'jpeg', 'gif', 'png', 'bmp']:
                ext = 'jpg'

        y = url.split('/')
        h = hashlib.sha1(str(y[2])).hexdigest()

        hash_dir = os.path.join(h[0:1], h[1:2])
        filename = image_guid + '.' + ext

        img_dir = os.path.join(krconfig.work_dir, 'data', 'images', hash_dir)
        fullname = os.path.join(img_dir, filename)

        if not os.path.exists(img_dir):
            os.makedirs(img_dir)

        localimage = 'images/%s/%s' % (hash_dir, filename)
        return localimage, fullname
示例#4
0
 def environ(request):
     """Converts a `tornado.httpserver.HTTPRequest` to a WSGI environment.
     """
     hostport = request.host.split(":")
     if len(hostport) == 2:
         host = hostport[0]
         port = int(hostport[1])
     else:
         host = request.host
         port = 443 if request.protocol == "https" else 80
     environ = {
         "REQUEST_METHOD": request.method,
         "SCRIPT_NAME": "",
         "PATH_INFO": to_wsgi_str(escape.url_unescape(request.path, encoding=None)),
         "QUERY_STRING": request.query,
         "REMOTE_ADDR": request.remote_ip,
         "SERVER_NAME": host,
         "SERVER_PORT": str(port),
         "SERVER_PROTOCOL": request.version,
         "wsgi.version": (1, 0),
         "wsgi.url_scheme": request.protocol,
         "wsgi.input": BytesIO(escape.utf8(request.body)),
         "wsgi.errors": sys.stderr,
         "wsgi.multithread": False,
         "wsgi.multiprocess": True,
         "wsgi.run_once": False,
     }
     if "Content-Type" in request.headers:
         environ["CONTENT_TYPE"] = request.headers.pop("Content-Type")
     if "Content-Length" in request.headers:
         environ["CONTENT_LENGTH"] = request.headers.pop("Content-Length")
     for key, value in request.headers.items():
         environ["HTTP_" + key.replace("-", "_").upper()] = value
     return environ
示例#5
0
 def resolve(self, host, port, family=0):
     # getHostByName doesn't accept IP addresses, so if the input
     # looks like an IP address just return it immediately.
     if twisted.internet.abstract.isIPAddress(host):
         resolved = host
         resolved_family = socket.AF_INET
     elif twisted.internet.abstract.isIPv6Address(host):
         resolved = host
         resolved_family = socket.AF_INET6
     else:
         deferred = self.resolver.getHostByName(utf8(host))
         resolved = yield gen.Task(deferred.addCallback)
         if twisted.internet.abstract.isIPAddress(resolved):
             resolved_family = socket.AF_INET
         elif twisted.internet.abstract.isIPv6Address(resolved):
             resolved_family = socket.AF_INET6
         else:
             resolved_family = socket.AF_UNSPEC
     if family != socket.AF_UNSPEC and family != resolved_family:
         raise Exception('Requested socket family %d but got %d' %
                         (family, resolved_family))
     result = [
         (resolved_family, (resolved, port)),
     ]
     raise gen.Return(result)
示例#6
0
    def down_image(self, url, referer=None, filename=None):
        """download image"""

        print "download: %s" % url,

        url = escape.utf8(url)
        image_guid = hashlib.sha1(url).hexdigest()
        convert_image = self.get_config('reader', 'convert_image')

        x = url.split('.')
        ext = 'jpg'
        if len(x) > 1:
            ext = x[-1]

            if len(ext) > 4:
                ext = ext[0:3]

            ext = re.sub('[^a-zA-Z]','', ext)
            ext = ext.lower()

            if ext not in ['jpg', 'jpeg', 'gif','png','bmp']:
                ext = 'jpg'

        y = url.split('/')
        h = hashlib.sha1(str(y[2])).hexdigest()

        hash_dir = os.path.join(h[0:1], h[1:2])
        filename = image_guid + '.' + ext

        img_dir  = os.path.join(self.work_dir, 'data', 'images', hash_dir)
        fullname = os.path.join(img_dir, filename)

        localimage = 'images/%s/%s' % (hash_dir, filename)
        if os.path.isfile(fullname) is False:
            if not os.path.exists(img_dir):
                os.makedirs( img_dir )
            try:
                req = urllib2.Request(url)
                req.add_header('User-Agent', self.user_agent)
                req.add_header('Accept-Language', 'zh-cn,zh;q=0.7,nd;q=0.3')

                if referer is not None:
                    req.add_header('Referer', referer)

                response = urllib2.urlopen(req)

                localFile = open(fullname, 'wb')
                localFile.write(response.read())

                response.close()
                localFile.close()
                if convert_image :
                    os.system('convert -colorspace gray  \'%s[0]\' \
                            %s'% (fullname, fullname)
                            )
                print "done."
            except Exception, e:
                print 'fail: %s' % e
                localimage = False
            finally:
示例#7
0
    def down_image(self, url, referer=None, filename=None):
        """download image"""

        print "download: %s" % url,

        url = escape.utf8(url)
        image_guid = hashlib.sha1(url).hexdigest()
        convert_image = self.get_config('reader', 'convert_image')

        x = url.split('.')
        ext = 'jpg'
        if len(x) > 1:
            ext = x[-1]

            if len(ext) > 4:
                ext = ext[0:3]

            ext = re.sub('[^a-zA-Z]', '', ext)
            ext = ext.lower()

            if ext not in ['jpg', 'jpeg', 'gif', 'png', 'bmp']:
                ext = 'jpg'

        y = url.split('/')
        h = hashlib.sha1(str(y[2])).hexdigest()

        hash_dir = os.path.join(h[0:1], h[1:2])
        filename = image_guid + '.' + ext

        img_dir = os.path.join(self.work_dir, 'data', 'images', hash_dir)
        fullname = os.path.join(img_dir, filename)

        localimage = 'images/%s/%s' % (hash_dir, filename)
        if os.path.isfile(fullname) is False:
            if not os.path.exists(img_dir):
                os.makedirs(img_dir)
            try:
                req = urllib2.Request(url)
                req.add_header('User-Agent', self.user_agent)
                req.add_header('Accept-Language', 'zh-cn,zh;q=0.7,nd;q=0.3')

                if referer is not None:
                    req.add_header('Referer', referer)

                response = urllib2.urlopen(req)

                localFile = open(fullname, 'wb')
                localFile.write(response.read())

                response.close()
                localFile.close()
                if convert_image:
                    os.system('convert -colorspace gray  \'%s[0]\' \
                            %s' % (fullname, fullname))
                print "done."
            except Exception, e:
                print 'fail: %s' % e
                localimage = False
            finally:
示例#8
0
    def generate(self, writer):
        value = self.value

        # Compress lots of white space to a single character. If the whitespace
        # breaks a line, have it continue to break a line, but just with a
        # single \n character
        if writer.compress_whitespace and "<pre>" not in value:
            value = re.sub(r"([\t ]+)", " ", value)
            value = re.sub(r"(\s*\n\s*)", "\n", value)

        if value:
            writer.write_line('_append(%r)' % escape.utf8(value), self.line)
示例#9
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    def __call__(self, request):
        data = {}
        response = []

        def start_response(status, response_headers, exc_info=None):
            data["status"] = status
            data["headers"] = response_headers
            return response.append
        app_response = self.wsgi_application(
            WSGIContainer.environ(request), start_response)
        response.extend(app_response)
        body = b"".join(response)
        if hasattr(app_response, "close"):
            app_response.close()
        if not data:
            raise Exception("WSGI app did not call start_response")

        status_code = int(data["status"].split()[0])
        headers = data["headers"]
        header_set = set(k.lower() for (k, v) in headers)
        body = escape.utf8(body)
        if status_code != 304:
            if "content-length" not in header_set:
                headers.append(("Content-Length", str(len(body))))
            if "content-type" not in header_set:
                headers.append(("Content-Type", "text/html; charset=UTF-8"))
        if "server" not in header_set:
            headers.append(("Server", "TornadoServer/%s" % tornado.version))

        parts = [escape.utf8("HTTP/1.1 " + data["status"] + "\r\n")]
        for key, value in headers:
            parts.append(escape.utf8(key) + b": " + escape.utf8(value) + b"\r\n")
        parts.append(b"\r\n")
        parts.append(body)
        request.write(b"".join(parts))
        request.finish()
        self._log(status_code, request)
示例#10
0
def parse_body_arguments(content_type, body, arguments, files):
    """Parses a form request body.

    Supports ``application/x-www-form-urlencoded`` and
    ``multipart/form-data``.  The ``content_type`` parameter should be
    a string and ``body`` should be a byte string.  The ``arguments``
    and ``files`` parameters are dictionaries that will be updated
    with the parsed contents.
    """
    if content_type.startswith("application/x-www-form-urlencoded"):
        uri_arguments = parse_qs_bytes(native_str(body), keep_blank_values=True)
        for name, values in uri_arguments.items():
            if values:
                arguments.setdefault(name, []).extend(values)
    elif content_type.startswith("multipart/form-data"):
        fields = content_type.split(";")
        for field in fields:
            k, sep, v = field.strip().partition("=")
            if k == "boundary" and v:
                parse_multipart_form_data(utf8(v), body, arguments, files)
                break
        else:
            gen_log.warning("Invalid multipart/form-data")
示例#11
0
    def __init__(self, url, method="GET", headers=None, body=None,
                 auth_username=None, auth_password=None,
                 connect_timeout=None, request_timeout=None,
                 if_modified_since=None, follow_redirects=None,
                 max_redirects=None, user_agent=None, use_gzip=None,
                 network_interface=None, streaming_callback=None,
                 header_callback=None, prepare_curl_callback=None,
                 proxy_host=None, proxy_port=None, proxy_username=None,
                 proxy_password=None, allow_nonstandard_methods=None,
                 validate_cert=None, ca_certs=None,
                 allow_ipv6=None,
                 client_key=None, client_cert=None):
        r"""All parameters except ``url`` are optional.

        :arg string url: URL to fetch
        :arg string method: HTTP method, e.g. "GET" or "POST"
        :arg headers: Additional HTTP headers to pass on the request
        :type headers: `~tornado.httputil.HTTPHeaders` or `dict`
        :arg string auth_username: Username for HTTP "Basic" authentication
        :arg string auth_password: Password for HTTP "Basic" authentication
        :arg float connect_timeout: Timeout for initial connection in seconds
        :arg float request_timeout: Timeout for entire request in seconds
        :arg if_modified_since: Timestamp for ``If-Modified-Since`` header
        :type if_modified_since: `datetime` or `float`
        :arg bool follow_redirects: Should redirects be followed automatically
           or return the 3xx response?
        :arg int max_redirects: Limit for ``follow_redirects``
        :arg string user_agent: String to send as ``User-Agent`` header
        :arg bool use_gzip: Request gzip encoding from the server
        :arg string network_interface: Network interface to use for request
        :arg callable streaming_callback: If set, ``streaming_callback`` will
           be run with each chunk of data as it is received, and
           ``HTTPResponse.body`` and ``HTTPResponse.buffer`` will be empty in
           the final response.
        :arg callable header_callback: If set, ``header_callback`` will
           be run with each header line as it is received (including the
           first line, e.g. ``HTTP/1.0 200 OK\r\n``, and a final line
           containing only ``\r\n``.  All lines include the trailing newline
           characters).  ``HTTPResponse.headers`` will be empty in the final
           response.  This is most useful in conjunction with
           ``streaming_callback``, because it's the only way to get access to
           header data while the request is in progress.
        :arg callable prepare_curl_callback: If set, will be called with
           a ``pycurl.Curl`` object to allow the application to make additional
           ``setopt`` calls.
        :arg string proxy_host: HTTP proxy hostname.  To use proxies,
           ``proxy_host`` and ``proxy_port`` must be set; ``proxy_username`` and
           ``proxy_pass`` are optional.  Proxies are currently only supported
           with ``curl_httpclient``.
        :arg int proxy_port: HTTP proxy port
        :arg string proxy_username: HTTP proxy username
        :arg string proxy_password: HTTP proxy password
        :arg bool allow_nonstandard_methods: Allow unknown values for ``method``
           argument?
        :arg bool validate_cert: For HTTPS requests, validate the server's
           certificate?
        :arg string ca_certs: filename of CA certificates in PEM format,
           or None to use defaults.  Note that in ``curl_httpclient``, if
           any request uses a custom ``ca_certs`` file, they all must (they
           don't have to all use the same ``ca_certs``, but it's not possible
           to mix requests with ``ca_certs`` and requests that use the defaults.
        :arg bool allow_ipv6: Use IPv6 when available?  Default is false in
           ``simple_httpclient`` and true in ``curl_httpclient``
        :arg string client_key: Filename for client SSL key, if any
        :arg string client_cert: Filename for client SSL certificate, if any
        """
        if headers is None:
            headers = httputil.HTTPHeaders()
        if if_modified_since:
            headers["If-Modified-Since"] = httputil.format_timestamp(
                if_modified_since)
        self.proxy_host = proxy_host
        self.proxy_port = proxy_port
        self.proxy_username = proxy_username
        self.proxy_password = proxy_password
        self.url = url
        self.method = method
        self.headers = headers
        self.body = utf8(body)
        self.auth_username = auth_username
        self.auth_password = auth_password
        self.connect_timeout = connect_timeout
        self.request_timeout = request_timeout
        self.follow_redirects = follow_redirects
        self.max_redirects = max_redirects
        self.user_agent = user_agent
        self.use_gzip = use_gzip
        self.network_interface = network_interface
        self.streaming_callback = stack_context.wrap(streaming_callback)
        self.header_callback = stack_context.wrap(header_callback)
        self.prepare_curl_callback = stack_context.wrap(prepare_curl_callback)
        self.allow_nonstandard_methods = allow_nonstandard_methods
        self.validate_cert = validate_cert
        self.ca_certs = ca_certs
        self.allow_ipv6 = allow_ipv6
        self.client_key = client_key
        self.client_cert = client_cert
        self.start_time = time.time()
示例#12
0
def _curl_setup_request(curl, request, buffer, headers):
    curl.setopt(pycurl.URL, native_str(request.url))

    # libcurl's magic "Expect: 100-continue" behavior causes delays
    # with servers that don't support it (which include, among others,
    # Google's OpenID endpoint).  Additionally, this behavior has
    # a bug in conjunction with the curl_multi_socket_action API
    # (https://sourceforge.net/tracker/?func=detail&atid=100976&aid=3039744&group_id=976),
    # which increases the delays.  It's more trouble than it's worth,
    # so just turn off the feature (yes, setting Expect: to an empty
    # value is the official way to disable this)
    if "Expect" not in request.headers:
        request.headers["Expect"] = ""

    # libcurl adds Pragma: no-cache by default; disable that too
    if "Pragma" not in request.headers:
        request.headers["Pragma"] = ""

    # Request headers may be either a regular dict or HTTPHeaders object
    if isinstance(request.headers, httputil.HTTPHeaders):
        curl.setopt(pycurl.HTTPHEADER,
                    [native_str("%s: %s" % i) for i in request.headers.get_all()])
    else:
        curl.setopt(pycurl.HTTPHEADER,
                    [native_str("%s: %s" % i) for i in request.headers.items()])

    if request.header_callback:
        curl.setopt(pycurl.HEADERFUNCTION, request.header_callback)
    else:
        curl.setopt(pycurl.HEADERFUNCTION,
                    lambda line: _curl_header_callback(headers, line))
    if request.streaming_callback:
        write_function = request.streaming_callback
    else:
        write_function = buffer.write
    if bytes_type is str:  # py2
        curl.setopt(pycurl.WRITEFUNCTION, write_function)
    else:  # py3
        # Upstream pycurl doesn't support py3, but ubuntu 12.10 includes
        # a fork/port.  That version has a bug in which it passes unicode
        # strings instead of bytes to the WRITEFUNCTION.  This means that
        # if you use a WRITEFUNCTION (which tornado always does), you cannot
        # download arbitrary binary data.  This needs to be fixed in the
        # ported pycurl package, but in the meantime this lambda will
        # make it work for downloading (utf8) text.
        curl.setopt(pycurl.WRITEFUNCTION, lambda s: write_function(utf8(s)))
    curl.setopt(pycurl.FOLLOWLOCATION, request.follow_redirects)
    curl.setopt(pycurl.MAXREDIRS, request.max_redirects)
    curl.setopt(pycurl.CONNECTTIMEOUT_MS, int(1000 * request.connect_timeout))
    curl.setopt(pycurl.TIMEOUT_MS, int(1000 * request.request_timeout))
    if request.user_agent:
        curl.setopt(pycurl.USERAGENT, native_str(request.user_agent))
    else:
        curl.setopt(pycurl.USERAGENT, "Mozilla/5.0 (compatible; pycurl)")
    if request.network_interface:
        curl.setopt(pycurl.INTERFACE, request.network_interface)
    if request.use_gzip:
        curl.setopt(pycurl.ENCODING, "gzip,deflate")
    else:
        curl.setopt(pycurl.ENCODING, "none")
    if request.proxy_host and request.proxy_port:
        curl.setopt(pycurl.PROXY, request.proxy_host)
        curl.setopt(pycurl.PROXYPORT, request.proxy_port)
        if request.proxy_username:
            credentials = '%s:%s' % (request.proxy_username,
                                     request.proxy_password)
            curl.setopt(pycurl.PROXYUSERPWD, credentials)
    else:
        curl.setopt(pycurl.PROXY, '')
    if request.validate_cert:
        curl.setopt(pycurl.SSL_VERIFYPEER, 1)
        curl.setopt(pycurl.SSL_VERIFYHOST, 2)
    else:
        curl.setopt(pycurl.SSL_VERIFYPEER, 0)
        curl.setopt(pycurl.SSL_VERIFYHOST, 0)
    if request.ca_certs is not None:
        curl.setopt(pycurl.CAINFO, request.ca_certs)
    else:
        # There is no way to restore pycurl.CAINFO to its default value
        # (Using unsetopt makes it reject all certificates).
        # I don't see any way to read the default value from python so it
        # can be restored later.  We'll have to just leave CAINFO untouched
        # if no ca_certs file was specified, and require that if any
        # request uses a custom ca_certs file, they all must.
        pass

    if request.allow_ipv6 is False:
        # Curl behaves reasonably when DNS resolution gives an ipv6 address
        # that we can't reach, so allow ipv6 unless the user asks to disable.
        # (but see version check in _process_queue above)
        curl.setopt(pycurl.IPRESOLVE, pycurl.IPRESOLVE_V4)

    # Set the request method through curl's irritating interface which makes
    # up names for almost every single method
    curl_options = {
        "GET": pycurl.HTTPGET,
        "POST": pycurl.POST,
        "PUT": pycurl.UPLOAD,
        "HEAD": pycurl.NOBODY,
    }
    custom_methods = set(["DELETE"])
    for o in curl_options.values():
        curl.setopt(o, False)
    if request.method in curl_options:
        curl.unsetopt(pycurl.CUSTOMREQUEST)
        curl.setopt(curl_options[request.method], True)
    elif request.allow_nonstandard_methods or request.method in custom_methods:
        curl.setopt(pycurl.CUSTOMREQUEST, request.method)
    else:
        raise KeyError('unknown method ' + request.method)

    # Handle curl's cryptic options for every individual HTTP method
    if request.method in ("POST", "PUT"):
        request_buffer = BytesIO(utf8(request.body))
        curl.setopt(pycurl.READFUNCTION, request_buffer.read)
        if request.method == "POST":
            def ioctl(cmd):
                if cmd == curl.IOCMD_RESTARTREAD:
                    request_buffer.seek(0)
            curl.setopt(pycurl.IOCTLFUNCTION, ioctl)
            curl.setopt(pycurl.POSTFIELDSIZE, len(request.body))
        else:
            curl.setopt(pycurl.INFILESIZE, len(request.body))

    if request.auth_username is not None:
        userpwd = "%s:%s" % (request.auth_username, request.auth_password or '')
        curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_BASIC)
        curl.setopt(pycurl.USERPWD, native_str(userpwd))
        gen_log.debug("%s %s (username: %r)", request.method, request.url,
                      request.auth_username)
    else:
        curl.unsetopt(pycurl.USERPWD)
        gen_log.debug("%s %s", request.method, request.url)

    if request.client_cert is not None:
        curl.setopt(pycurl.SSLCERT, request.client_cert)

    if request.client_key is not None:
        curl.setopt(pycurl.SSLKEY, request.client_key)

    if threading.activeCount() > 1:
        # libcurl/pycurl is not thread-safe by default.  When multiple threads
        # are used, signals should be disabled.  This has the side effect
        # of disabling DNS timeouts in some environments (when libcurl is
        # not linked against ares), so we don't do it when there is only one
        # thread.  Applications that use many short-lived threads may need
        # to set NOSIGNAL manually in a prepare_curl_callback since
        # there may not be any other threads running at the time we call
        # threading.activeCount.
        curl.setopt(pycurl.NOSIGNAL, 1)
    if request.prepare_curl_callback is not None:
        request.prepare_curl_callback(curl)