Source code for aiohttp.helpers

"""Various helper functions"""
__all__ = ['BasicAuth', 'FormData', 'parse_mimetype']

import base64
import binascii
import io
import os
import uuid
import urllib.parse
from collections import namedtuple
from wsgiref.handlers import format_date_time

from . import multidict


[docs]class BasicAuth(namedtuple('BasicAuth', ['login', 'password', 'encoding'])): """Http basic authentication helper. :param str login: Login :param str password: Password :param str encoding: (optional) encoding ('latin1' by default) """ def __new__(cls, login, password='', encoding='latin1'): if login is None: raise ValueError('None is not allowed as login value') if password is None: raise ValueError('None is not allowed as password value') return super().__new__(cls, login, password, encoding)
[docs] def encode(self): """Encode credentials.""" creds = ('%s:%s' % (self.login, self.password)).encode(self.encoding) return 'Basic %s' % base64.b64encode(creds).decode(self.encoding)
[docs]class FormData: """Helper class for multipart/form-data and application/x-www-form-urlencoded body generation.""" def __init__(self, fields=()): self._fields = [] self._is_multipart = False self._boundary = uuid.uuid4().hex if isinstance(fields, dict): fields = list(fields.items()) elif not isinstance(fields, (list, tuple)): fields = (fields,) self.add_fields(*fields) @property
[docs] def is_multipart(self): return self._is_multipart
@property
[docs] def content_type(self): if self._is_multipart: return 'multipart/form-data; boundary=%s' % self._boundary else: return 'application/x-www-form-urlencoded'
[docs] def add_field(self, name, value, *, content_type=None, filename=None, content_transfer_encoding=None): if isinstance(value, io.IOBase): self._is_multipart = True type_options = multidict.MutableMultiDict({'name': name}) if filename is None and isinstance(value, io.IOBase): filename = guess_filename(value, name) if filename is not None: type_options['filename'] = filename self._is_multipart = True headers = {} if content_type is not None: headers['Content-Type'] = content_type self._is_multipart = True if content_transfer_encoding is not None: headers['Content-Transfer-Encoding'] = content_transfer_encoding self._is_multipart = True supported_tranfer_encoding = { 'base64': binascii.b2a_base64, 'quoted-printable': binascii.b2a_qp } conv = supported_tranfer_encoding.get(content_transfer_encoding) if conv is not None: value = conv(value) self._fields.append((type_options, headers, value))
[docs] def add_fields(self, *fields): to_add = list(fields) while to_add: rec = to_add.pop(0) if isinstance(rec, io.IOBase): k = guess_filename(rec, 'unknown') self.add_field(k, rec) elif isinstance(rec, multidict.MultiDict): to_add.extend(rec.items(getall=True)) elif isinstance(rec, (list, tuple)) and len(rec) == 2: k, fp = rec self.add_field(k, fp) else: raise TypeError('Only io.IOBase, multidict and (name, file) ' 'pairs allowed, use .add_field() for passing ' 'more complex parameters')
def _gen_form_urlencoded(self, encoding): # form data (x-www-form-urlencoded) data = [] for type_options, headers, value in self._fields: data.append((type_options['name'], value)) data = urllib.parse.urlencode(data, doseq=True) return data.encode(encoding) def _gen_form_data(self, encoding='utf-8', chunk_size=8192): """Encode a list of fields using the multipart/form-data MIME format""" boundary = self._boundary.encode('latin1') for type_options, headers, value in self._fields: yield b'--' + boundary + b'\r\n' out_headers = [] opts = '; '.join('{0[0]}="{0[1]}"'.format(i) for i in type_options.items()) out_headers.append( ('Content-Disposition: form-data; ' + opts).encode(encoding) + b'\r\n') for k, v in headers.items(): out_headers.append('{}: {}\r\n'.format(k, v).encode(encoding)) out_headers.append(b'\r\n') yield b''.join(out_headers) if isinstance(value, str): yield value.encode(encoding) else: if isinstance(value, (bytes, bytearray)): value = io.BytesIO(value) while True: chunk = value.read(chunk_size) if not chunk: break yield str_to_bytes(chunk, encoding) yield b'\r\n' yield b'--' + boundary + b'--\r\n' def __call__(self, encoding): if self._is_multipart: return self._gen_form_data(encoding) else: return self._gen_form_urlencoded(encoding)
[docs]def parse_mimetype(mimetype): """Parses a MIME type into its components. :param str mimetype: MIME type :returns: 4 element tuple for MIME type, subtype, suffix and parameters :rtype: tuple Example: >>> parse_mimetype('text/html; charset=utf-8') ('text', 'html', '', {'charset': 'utf-8'}) """ if not mimetype: return '', '', '', {} parts = mimetype.split(';') params = [] for item in parts[1:]: if not item: continue key, value = item.split('=', 1) if '=' in item else (item, '') params.append((key.lower().strip(), value.strip(' "'))) params = dict(params) fulltype = parts[0].strip().lower() if fulltype == '*': fulltype = '*/*' mtype, stype = fulltype.split('/', 1) \ if '/' in fulltype else (fulltype, '') stype, suffix = stype.split('+', 1) if '+' in stype else (stype, '') return mtype, stype, suffix, params
def str_to_bytes(s, encoding='utf-8'): if isinstance(s, str): return s.encode(encoding) return s def guess_filename(obj, default=None): name = getattr(obj, 'name', None) if name and name[0] != '<' and name[-1] != '>': return os.path.split(name)[-1] return default def parse_remote_addr(forward): if isinstance(forward, str): # we only took the last one # http://en.wikipedia.org/wiki/X-Forwarded-For if ',' in forward: forward = forward.rsplit(',', 1)[-1].strip() # find host and port on ipv6 address if '[' in forward and ']' in forward: host = forward.split(']')[0][1:].lower() elif ':' in forward and forward.count(':') == 1: host = forward.split(':')[0].lower() else: host = forward forward = forward.split(']')[-1] if ':' in forward and forward.count(':') == 1: port = forward.split(':', 1)[1] else: port = 80 remote = (host, port) else: remote = forward return remote[0], str(remote[1]) def atoms(message, environ, response, transport, request_time): """Gets atoms for log formatting.""" if message: r = '{} {} HTTP/{}.{}'.format( message.method, message.path, message.version[0], message.version[1]) headers = message.headers else: r = '' headers = {} remote_addr = parse_remote_addr( transport.get_extra_info('addr', '127.0.0.1')) atoms = { 'h': remote_addr[0], 'l': '-', 'u': '-', 't': format_date_time(None), 'r': r, 's': str(getattr(response, 'status', '')), 'b': str(getattr(response, 'output_length', '')), 'f': headers.get('REFERER', '-'), 'a': headers.get('USER-AGENT', '-'), 'T': str(int(request_time)), 'D': str(request_time).split('.', 1)[-1][:5], 'p': "<%s>" % os.getpid() } return atoms class SafeAtoms(dict): """Copy from gunicorn""" def __init__(self, atoms, i_headers, o_headers): dict.__init__(self) self._i_headers = i_headers self._o_headers = o_headers for key, value in atoms.items(): self[key] = value.replace('"', '\\"') def __getitem__(self, k): if k.startswith('{'): if k.endswith('}i'): headers = self._i_headers elif k.endswith('}o'): headers = self._o_headers else: headers = None if headers is not None: return headers.get(k[1:-2], '-') if k in self: return super(SafeAtoms, self).__getitem__(k) else: return '-' class reify(object): """ Use as a class method decorator. It operates almost exactly like the Python ``@property`` decorator, but it puts the result of the method it decorates into the instance dict after the first call, effectively replacing the function it decorates with an instance variable. It is, in Python parlance, a non-data descriptor. """ def __init__(self, wrapped): self.wrapped = wrapped try: self.__doc__ = wrapped.__doc__ except: # pragma: no cover pass def __get__(self, inst, objtype=None): if inst is None: # pragma: no cover return self val = self.wrapped(inst) setattr(inst, self.wrapped.__name__, val) return val