requests/requests/models.py

# -*- coding: utf-8 -*-

"""
requests.models
~~~~~~~~~~~~~~~

"""

import urllib
import zlib
from Cookie import SimpleCookie

from urlparse import urlparse, urlunparse, urljoin
from datetime import datetime


from .auth import dispatch as auth_dispatch
from .hooks import dispatch_hook
from .structures import CaseInsensitiveDict
from .status_codes import codes
from .packages.urllib3.exceptions import MaxRetryError
from .exceptions import (
    Timeout, URLRequired, TooManyRedirects, HTTPError, ConnectionError)
from .utils import (
    dict_from_cookiejar, get_unicode_from_response,
    stream_decode_response_unicode, decode_gzip, stream_decode_gzip)


REDIRECT_STATI = (codes.moved, codes.found, codes.other, codes.temporary_moved)



class Request(object):
    """The :class:`Request <Request>` object. It carries out all functionality of
    Requests. Recommended interface is with the Requests functions.
    """

    def __init__(self,
        url=None,
        headers=dict(),
        files=None,
        method=None,
        data=dict(),
        params=dict(),
        auth=None,
        cookies=None,
        timeout=None,
        redirect=False,
        allow_redirects=False,
        proxies=None,
        hooks=None,
        config=None,
        _poolmanager=None):

        #: Float describes the timeout of the request.
        #  (Use socket.setdefaulttimeout() as fallback)
        self.timeout = timeout

        #: Request URL.
        self.url = url

        #: Dictionary of HTTP Headers to attach to the :class:`Request <Request>`.
        self.headers = dict(headers or [])

        #: Dictionary of files to multipart upload (``{filename: content}``).
        self.files = files

        #: HTTP Method to use.
        self.method = method

        #: Dictionary or byte of request body data to attach to the
        #: :class:`Request <Request>`.
        self.data = None

        #: Dictionary or byte of querystring data to attach to the
        #: :class:`Request <Request>`.
        self.params = None

        #: True if :class:`Request <Request>` is part of a redirect chain (disables history
        #: and HTTPError storage).
        self.redirect = redirect

        #: Set to True if full redirects are allowed (e.g. re-POST-ing of data at new ``Location``)
        self.allow_redirects = allow_redirects

        # Dictionary mapping protocol to the URL of the proxy (e.g. {'http': 'foo.bar:3128'})
        self.proxies = dict(proxies or [])

        self.data, self._enc_data = self._encode_params(data)
        self.params, self._enc_params = self._encode_params(params)

        #: :class:`Response <Response>` instance, containing
        #: content and metadata of HTTP Response, once :attr:`sent <send>`.
        self.response = Response()

        #: Authentication tuple to attach to :class:`Request <Request>`.
        self._auth = auth
        self.auth = auth_dispatch(auth)

        #: CookieJar to attach to :class:`Request <Request>`.
        self.cookies = dict(cookies or [])

        #: Dictionary of configurations for this request.
        self.config = dict(config or [])

        #: True if Request has been sent.
        self.sent = False

        #: Event-handling hooks.
        self.hooks = hooks

        if headers:
            headers = CaseInsensitiveDict(self.headers)
        else:
            headers = CaseInsensitiveDict()

        for (k, v) in self.config.get('base_headers', {}).items():
            if k not in headers:
                headers[k] = v

        self.headers = headers
        self._poolmanager = _poolmanager

        # Pre-request hook.
        r = dispatch_hook('pre_request', hooks, self)
        self.__dict__.update(r.__dict__)


    def __repr__(self):
        return '<Request [%s]>' % (self.method)


    def _build_response(self, resp, is_error=False):
        """Build internal :class:`Response <Response>` object
        from given response.
        """


        def build(resp):

            response = Response()

            # Pass settings over.
            response.config = self.config

            if resp:

                # Fallback to None if there's no staus_code, for whatever reason.
                response.status_code = getattr(resp, 'status', None)

                # Make headers case-insensitive.
                response.headers = CaseInsensitiveDict(getattr(resp, 'headers', None))

                # Start off with our local cookies.
                cookies = self.cookies or dict()

                # Add new cookies from the server.
                if 'set-cookie' in response.headers:
                    cookie_header = response.headers['set-cookie']

                    c = SimpleCookie()
                    c.load(cookie_header)

                    for k,v in c.items():
                        cookies.update({k: v.value})

                # Save cookies in Response.
                response.cookies = cookies

            # Save original resopnse for later.
            response.raw = resp

            if is_error:
                response.error = resp

            response.url = self._build_url()

            return response


        history = []

        r = build(resp)

        if r.status_code in REDIRECT_STATI and not self.redirect:

            while (
                ('location' in r.headers) and
                ((r.status_code is codes.see_other) or (self.allow_redirects))
            ):

                if not len(history) < self.config.get('max_redirects'):
                    raise TooManyRedirects()

                history.append(r)

                url = r.headers['location']

                # Handle redirection without scheme (see: RFC 1808 Section 4)
                if url.startswith('//'):
                    parsed_rurl = urlparse(r.url)
                    url = '%s:%s' % (parsed_rurl.scheme, url)

                # Facilitate non-RFC2616-compliant 'location' headers
                # (e.g. '/path/to/resource' instead of 'http://domain.tld/path/to/resource')
                if not urlparse(url).netloc:
                    url = urljoin(r.url, urllib.quote(urllib.unquote(url)))

                # http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.4
                if r.status_code is codes.see_other:
                    method = 'GET'
                else:
                    method = self.method

                request = Request(
                    url=url,
                    headers=self.headers,
                    files=self.files,
                    method=method,
                    # data=self.data,
                    # params=self.params,
                    auth=self._auth,
                    cookies=self.cookies,
                    redirect=True,
                    config=self.config,
                    _poolmanager=self._poolmanager
                )
                request.send()
                r = request.response

            r.history = history

        self.response = r
        self.response.request = self


    @staticmethod
    def _encode_params(data):
        """Encode parameters in a piece of data.

        If the data supplied is a dictionary, encodes each parameter in it, and
        returns a list of tuples containing the encoded parameters, and a urlencoded
        version of that.

        Otherwise, assumes the data is already encoded appropriately, and
        returns it twice.
        """

        if hasattr(data, '__iter__'):
            data = dict(data)

        if hasattr(data, 'items'):
            result = []
            for k, vs in data.items():
                for v in isinstance(vs, list) and vs or [vs]:
                    result.append((k.encode('utf-8') if isinstance(k, unicode) else k,
                                   v.encode('utf-8') if isinstance(v, unicode) else v))
            return result, urllib.urlencode(result, doseq=True)
        else:
            return data, data


    def _build_url(self):
        """Build the actual URL to use."""

        if not self.url:
            raise URLRequired()

        # Support for unicode domain names and paths.
        scheme, netloc, path, params, query, fragment = urlparse(self.url)

        if not scheme:
            raise ValueError()

        netloc = netloc.encode('idna')

        if isinstance(path, unicode):
            path = path.encode('utf-8')

        path = urllib.quote(urllib.unquote(path))
        self.url = str(urlunparse([ scheme, netloc, path, params, query, fragment ]))

        if self._enc_params:
            if urlparse(self.url).query:
                return '%s&%s' % (self.url, self._enc_params)
            else:
                return '%s?%s' % (self.url, self._enc_params)
        else:
            return self.url


    def send(self, anyway=False):
        """Sends the request. Returns True of successful, false if not.
        If there was an HTTPError during transmission,
        self.response.status_code will contain the HTTPError code.

        Once a request is successfully sent, `sent` will equal True.

        :param anyway: If True, request will be sent, even if it has
        already been sent.
        """

        # Logging
        if self.config.get('verbose'):
            self.config.get('verbose').write('%s   %s   %s\n' % (
                datetime.now().isoformat(), self.method, self.url
            ))

        # Build the URL
        url = self._build_url()

        # Nottin' on you.
        body = None
        content_type = None

        from .packages.urllib3.filepost import encode_multipart_formdata

        # Multi-part file uploads.
        if self.files:
            if not isinstance(self.data, basestring):

                try:
                    fields = self.data.copy()
                except AttributeError:
                    fields = dict(self.data)

                for (k, v) in self.files.items():
                    fields.update({k: (k, v.read())})
                (body, content_type) = encode_multipart_formdata(fields)
            else:
                pass
                # TODO: Conflict?
        else:
            if self.data:
                body = self._enc_data
                content_type = 'application/x-www-form-urlencoded'

        # TODO: Setup cookies.

        # Add content-type if it wasn't explicitly provided.
        if (content_type) and (not 'content-type' in self.headers):
            self.headers['Content-Type'] = content_type


        if self.auth:
            auth_func, auth_args = self.auth

            r = auth_func(self, *auth_args)

            self.__dict__.update(r.__dict__)


        conn = self._poolmanager.connection_from_url(url)

        if not self.sent or anyway:

            if self.cookies:

                # Skip if 'cookie' header is explicitly set.
                if 'cookie' not in self.headers:

                    # Simple cookie with our dict.
                    # TODO: Multi-value headers.
                    c = SimpleCookie()
                    c.load(self.cookies)

                    # Turn it into a header.
                    cookie_header = c.output(header='').strip()

                    # Attach Cookie header to request.
                    self.headers['Cookie'] = cookie_header

            try:
                # Create the connection.
                r = conn.urlopen(
                    method=self.method,
                    url=url,
                    body=body,
                    headers=self.headers,
                    redirect=False,
                    assert_same_host=False,
                    preload_content=False,
                    decode_content=False,
                    retries=self.config.get('max_retries', 0)
                )
            except MaxRetryError, e:
                if not self.config.get('safe_mode', False):
                    raise ConnectionError(e)
                else:
                    r = None

            self._build_response(r)

            # Response manipulation hook.
            self.response = dispatch_hook('response', self.hooks, self.response)

            # Post-request hook.
            r = dispatch_hook('post_request', self.hooks, self)
            self.__dict__.update(r.__dict__)

            return self.sent


class Response(object):
    """The core :class:`Response <Response>` object. All
    :class:`Request <Request>` objects contain a
    :class:`response <Response>` attribute, which is an instance
    of this class.
    """

    def __init__(self):

        self._content = None
        self._content_consumed = False

        #: Integer Code of responded HTTP Status.
        self.status_code = None

        #: Case-insensitive Dictionary of Response Headers.
        #: For example, ``headers['content-encoding']`` will return the
        #: value of a ``'Content-Encoding'`` response header.
        self.headers = CaseInsensitiveDict()

        #: File-like object representation of response (for advanced usage).
        self.raw = None

        #: Final URL location of Response.
        self.url = None

        #: Resulting :class:`HTTPError` of request, if one occurred.
        self.error = None

        #: A list of :class:`Response <Response>` objects from
        #: the history of the Request. Any redirect responses will end
        #: up here.
        self.history = []

        #: The :class:`Request <Request>` that created the Response.
        self.request = None

        #: A dictionary of Cookies the server sent back.
        self.cookies = None

        #: Dictionary of configurations for this request.
        self.config = None


    def __repr__(self):
        return '<Response [%s]>' % (self.status_code)

    def __nonzero__(self):
        """Returns true if :attr:`status_code` is 'OK'."""
        return self.ok

    @property
    def ok(self):
        try:
            self.raise_for_status()
        except HTTPError:
            return False
        return True


    def iter_content(self, chunk_size=10 * 1024, decode_unicode=None):
        """Iterates over the response data.  This avoids reading the content
        at once into memory for large responses.  The chunk size is the number
        of bytes it should read into memory.  This is not necessarily the
        length of each item returned as decoding can take place.
        """
        if self._content_consumed:
            raise RuntimeError(
                'The content for this response was already consumed'
            )

        def generate():
            while 1:
                chunk = self.raw.read(chunk_size)
                if not chunk:
                    break
                yield chunk
            self._content_consumed = True

        gen = generate()

        if 'gzip' in self.headers.get('content-encoding', ''):
            gen = stream_decode_gzip(gen)

        if decode_unicode is None:
            decode_unicode = self.config.get('decode_unicode')

        if decode_unicode:
            gen = stream_decode_response_unicode(gen, self)

        return gen


    @property
    def content(self):
        """Content of the response, in bytes or unicode
        (if available).
        """

        if self._content is not None:
            return self._content

        if self._content_consumed:
            raise RuntimeError('The content for this response was '
                               'already consumed')

        # Read the contents.
        try:
            self._content = self.raw.read()
        except AttributeError:
            return None


        # Decode GZip'd content.
        if 'gzip' in self.headers.get('content-encoding', ''):
            try:
                self._content = decode_gzip(self._content)
            except zlib.error:
                pass

        # Decode unicode content.
        if self.config.get('decode_unicode'):
            self._content = get_unicode_from_response(self)

        self._content_consumed = True
        return self._content


    def raise_for_status(self):
        """Raises stored :class:`HTTPError` or :class:`URLError`, if one occurred."""

        if self.error:
            raise self.error

        if (self.status_code >= 300) and (self.status_code < 400):
            raise HTTPError('%s Redirection' % self.status_code)

        elif (self.status_code >= 400) and (self.status_code < 500):
            raise HTTPError('%s Client Error' % self.status_code)

        elif (self.status_code >= 500) and (self.status_code < 600):
            raise HTTPError('%s Server Error' % self.status_code)