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1from datetime import (
2    date,
3    datetime,
4    )
5
6import re
7
8from webob.byterange import (
9    ContentRange,
10    Range,
11    )
12
13from webob.compat import (
14    PY3,
15    text_type,
16    )
17
18from webob.datetime_utils import (
19    parse_date,
20    serialize_date,
21    )
22
23from webob.util import (
24    header_docstring,
25    warn_deprecation,
26    )
27
28
29CHARSET_RE = re.compile(r';\s*charset=([^;]*)', re.I)
30SCHEME_RE = re.compile(r'^[a-z]+:', re.I)
31
32
33_not_given = object()
34
35def environ_getter(key, default=_not_given, rfc_section=None):
36    if rfc_section:
37        doc = header_docstring(key, rfc_section)
38    else:
39        doc = "Gets and sets the ``%s`` key in the environment." % key
40    if default is _not_given:
41        def fget(req):
42            return req.environ[key]
43        def fset(req, val):
44            req.environ[key] = val
45        fdel = None
46    else:
47        def fget(req):
48            return req.environ.get(key, default)
49        def fset(req, val):
50            if val is None:
51                if key in req.environ:
52                    del req.environ[key]
53            else:
54                req.environ[key] = val
55        def fdel(req):
56            del req.environ[key]
57    return property(fget, fset, fdel, doc=doc)
58
59
60def environ_decoder(key, default=_not_given, rfc_section=None,
61                    encattr=None):
62    if rfc_section:
63        doc = header_docstring(key, rfc_section)
64    else:
65        doc = "Gets and sets the ``%s`` key in the environment." % key
66    if default is _not_given:
67        def fget(req):
68            return req.encget(key, encattr=encattr)
69        def fset(req, val):
70            return req.encset(key, val, encattr=encattr)
71        fdel = None
72    else:
73        def fget(req):
74            return req.encget(key, default, encattr=encattr)
75        def fset(req, val):
76            if val is None:
77                if key in req.environ:
78                    del req.environ[key]
79            else:
80                return req.encset(key, val, encattr=encattr)
81        def fdel(req):
82            del req.environ[key]
83    return property(fget, fset, fdel, doc=doc)
84
85def upath_property(key):
86    if PY3: # pragma: no cover
87        def fget(req):
88            encoding = req.url_encoding
89            return req.environ.get(key, '').encode('latin-1').decode(encoding)
90        def fset(req, val):
91            encoding = req.url_encoding
92            req.environ[key] = val.encode(encoding).decode('latin-1')
93    else:
94        def fget(req):
95            encoding = req.url_encoding
96            return req.environ.get(key, '').decode(encoding)
97        def fset(req, val):
98            encoding = req.url_encoding
99            if isinstance(val, text_type):
100                val = val.encode(encoding)
101            req.environ[key] = val
102    return property(fget, fset, doc='upath_property(%r)' % key)
103
104
105def deprecated_property(attr, name, text, version): # pragma: no cover
106    """
107    Wraps a descriptor, with a deprecation warning or error
108    """
109    def warn():
110        warn_deprecation('The attribute %s is deprecated: %s'
111            % (name, text),
112            version,
113            3
114        )
115    def fget(self):
116        warn()
117        return attr.__get__(self, type(self))
118    def fset(self, val):
119        warn()
120        attr.__set__(self, val)
121    def fdel(self):
122        warn()
123        attr.__delete__(self)
124    return property(fget, fset, fdel,
125        '<Deprecated attribute %s>' % name
126    )
127
128
129def header_getter(header, rfc_section):
130    doc = header_docstring(header, rfc_section)
131    key = header.lower()
132
133    def fget(r):
134        for k, v in r._headerlist:
135            if k.lower() == key:
136                return v
137
138    def fset(r, value):
139        fdel(r)
140        if value is not None:
141            if isinstance(value, text_type) and not PY3:
142                value = value.encode('latin-1')
143            r._headerlist.append((header, value))
144
145    def fdel(r):
146        items = r._headerlist
147        for i in range(len(items)-1, -1, -1):
148            if items[i][0].lower() == key:
149                del items[i]
150
151    return property(fget, fset, fdel, doc)
152
153
154
155
156def converter(prop, parse, serialize, convert_name=None):
157    assert isinstance(prop, property)
158    convert_name = convert_name or "``%s`` and ``%s``" % (parse.__name__,
159                                                  serialize.__name__)
160    doc = prop.__doc__ or ''
161    doc += "  Converts it using %s." % convert_name
162    hget, hset = prop.fget, prop.fset
163    def fget(r):
164        return parse(hget(r))
165    def fset(r, val):
166        if val is not None:
167            val = serialize(val)
168        hset(r, val)
169    return property(fget, fset, prop.fdel, doc)
170
171
172
173def list_header(header, rfc_section):
174    prop = header_getter(header, rfc_section)
175    return converter(prop, parse_list, serialize_list, 'list')
176
177def parse_list(value):
178    if not value:
179        return None
180    return tuple(filter(None, [v.strip() for v in value.split(',')]))
181
182def serialize_list(value):
183    if isinstance(value, (text_type, bytes)):
184        return str(value)
185    else:
186        return ', '.join(map(str, value))
187
188
189
190
191def converter_date(prop):
192    return converter(prop, parse_date, serialize_date, 'HTTP date')
193
194def date_header(header, rfc_section):
195    return converter_date(header_getter(header, rfc_section))
196
197
198
199
200
201
202
203
204
205########################
206## Converter functions
207########################
208
209
210_rx_etag = re.compile(r'(?:^|\s)(W/)?"((?:\\"|.)*?)"')
211
212def parse_etag_response(value, strong=False):
213    """
214    Parse a response ETag.
215    See:
216        * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
217        * http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
218    """
219    if not value:
220        return None
221    m = _rx_etag.match(value)
222    if not m:
223        # this etag is invalid, but we'll just return it anyway
224        return value
225    elif strong and m.group(1):
226        # this is a weak etag and we want only strong ones
227        return None
228    else:
229        return m.group(2).replace('\\"', '"')
230
231def serialize_etag_response(value): #return '"%s"' % value.replace('"', '\\"')
232    strong = True
233    if isinstance(value, tuple):
234        value, strong = value
235    elif _rx_etag.match(value):
236        # this is a valid etag already
237        return value
238    # let's quote the value
239    r = '"%s"' % value.replace('"', '\\"')
240    if not strong:
241        r = 'W/' + r
242    return r
243
244def serialize_if_range(value):
245    if isinstance(value, (datetime, date)):
246        return serialize_date(value)
247    value = str(value)
248    return value or None
249
250def parse_range(value):
251    if not value:
252        return None
253    # Might return None too:
254    return Range.parse(value)
255
256def serialize_range(value):
257    if not value:
258        return None
259    elif isinstance(value, (list, tuple)):
260        return str(Range(*value))
261    else:
262        assert isinstance(value, str)
263        return value
264
265def parse_int(value):
266    if value is None or value == '':
267        return None
268    return int(value)
269
270def parse_int_safe(value):
271    if value is None or value == '':
272        return None
273    try:
274        return int(value)
275    except ValueError:
276        return None
277
278serialize_int = str
279
280def parse_content_range(value):
281    if not value or not value.strip():
282        return None
283    # May still return None
284    return ContentRange.parse(value)
285
286def serialize_content_range(value):
287    if isinstance(value, (tuple, list)):
288        if len(value) not in (2, 3):
289            raise ValueError(
290                "When setting content_range to a list/tuple, it must "
291                "be length 2 or 3 (not %r)" % value)
292        if len(value) == 2:
293            begin, end = value
294            length = None
295        else:
296            begin, end, length = value
297        value = ContentRange(begin, end, length)
298    value = str(value).strip()
299    if not value:
300        return None
301    return value
302
303
304
305
306_rx_auth_param = re.compile(r'([a-z]+)[ \t]*=[ \t]*(".*?"|[^,]*?)[ \t]*(?:\Z|, *)')
307
308def parse_auth_params(params):
309    r = {}
310    for k, v in _rx_auth_param.findall(params):
311        r[k] = v.strip('"')
312    return r
313
314# see http://lists.w3.org/Archives/Public/ietf-http-wg/2009OctDec/0297.html
315known_auth_schemes = ['Basic', 'Digest', 'WSSE', 'HMACDigest', 'GoogleLogin',
316                      'Cookie', 'OpenID']
317known_auth_schemes = dict.fromkeys(known_auth_schemes, None)
318
319def parse_auth(val):
320    if val is not None:
321        authtype, params = val.split(' ', 1)
322        if authtype in known_auth_schemes:
323            if authtype == 'Basic' and '"' not in params:
324                # this is the "Authentication: Basic XXXXX==" case
325                pass
326            else:
327                params = parse_auth_params(params)
328        return authtype, params
329    return val
330
331def serialize_auth(val):
332    if isinstance(val, (tuple, list)):
333        authtype, params = val
334        if isinstance(params, dict):
335            params = ', '.join(map('%s="%s"'.__mod__, params.items()))
336        assert isinstance(params, str)
337        return '%s %s' % (authtype, params)
338    return val
339