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| 1 from __future__ import absolute_import |
| 2 from collections import Mapping, MutableMapping |
| 3 try: |
| 4 from threading import RLock |
| 5 except ImportError: # Platform-specific: No threads available |
| 6 class RLock: |
| 7 def __enter__(self): |
| 8 pass |
| 9 |
| 10 def __exit__(self, exc_type, exc_value, traceback): |
| 11 pass |
| 12 |
| 13 |
| 14 try: # Python 2.7+ |
| 15 from collections import OrderedDict |
| 16 except ImportError: |
| 17 from .packages.ordered_dict import OrderedDict |
| 18 from .packages.six import iterkeys, itervalues, PY3 |
| 19 |
| 20 |
| 21 __all__ = ['RecentlyUsedContainer', 'HTTPHeaderDict'] |
| 22 |
| 23 |
| 24 _Null = object() |
| 25 |
| 26 |
| 27 class RecentlyUsedContainer(MutableMapping): |
| 28 """ |
| 29 Provides a thread-safe dict-like container which maintains up to |
| 30 ``maxsize`` keys while throwing away the least-recently-used keys beyond |
| 31 ``maxsize``. |
| 32 |
| 33 :param maxsize: |
| 34 Maximum number of recent elements to retain. |
| 35 |
| 36 :param dispose_func: |
| 37 Every time an item is evicted from the container, |
| 38 ``dispose_func(value)`` is called. Callback which will get called |
| 39 """ |
| 40 |
| 41 ContainerCls = OrderedDict |
| 42 |
| 43 def __init__(self, maxsize=10, dispose_func=None): |
| 44 self._maxsize = maxsize |
| 45 self.dispose_func = dispose_func |
| 46 |
| 47 self._container = self.ContainerCls() |
| 48 self.lock = RLock() |
| 49 |
| 50 def __getitem__(self, key): |
| 51 # Re-insert the item, moving it to the end of the eviction line. |
| 52 with self.lock: |
| 53 item = self._container.pop(key) |
| 54 self._container[key] = item |
| 55 return item |
| 56 |
| 57 def __setitem__(self, key, value): |
| 58 evicted_value = _Null |
| 59 with self.lock: |
| 60 # Possibly evict the existing value of 'key' |
| 61 evicted_value = self._container.get(key, _Null) |
| 62 self._container[key] = value |
| 63 |
| 64 # If we didn't evict an existing value, we might have to evict the |
| 65 # least recently used item from the beginning of the container. |
| 66 if len(self._container) > self._maxsize: |
| 67 _key, evicted_value = self._container.popitem(last=False) |
| 68 |
| 69 if self.dispose_func and evicted_value is not _Null: |
| 70 self.dispose_func(evicted_value) |
| 71 |
| 72 def __delitem__(self, key): |
| 73 with self.lock: |
| 74 value = self._container.pop(key) |
| 75 |
| 76 if self.dispose_func: |
| 77 self.dispose_func(value) |
| 78 |
| 79 def __len__(self): |
| 80 with self.lock: |
| 81 return len(self._container) |
| 82 |
| 83 def __iter__(self): |
| 84 raise NotImplementedError('Iteration over this class is unlikely to be t
hreadsafe.') |
| 85 |
| 86 def clear(self): |
| 87 with self.lock: |
| 88 # Copy pointers to all values, then wipe the mapping |
| 89 values = list(itervalues(self._container)) |
| 90 self._container.clear() |
| 91 |
| 92 if self.dispose_func: |
| 93 for value in values: |
| 94 self.dispose_func(value) |
| 95 |
| 96 def keys(self): |
| 97 with self.lock: |
| 98 return list(iterkeys(self._container)) |
| 99 |
| 100 |
| 101 class HTTPHeaderDict(MutableMapping): |
| 102 """ |
| 103 :param headers: |
| 104 An iterable of field-value pairs. Must not contain multiple field names |
| 105 when compared case-insensitively. |
| 106 |
| 107 :param kwargs: |
| 108 Additional field-value pairs to pass in to ``dict.update``. |
| 109 |
| 110 A ``dict`` like container for storing HTTP Headers. |
| 111 |
| 112 Field names are stored and compared case-insensitively in compliance with |
| 113 RFC 7230. Iteration provides the first case-sensitive key seen for each |
| 114 case-insensitive pair. |
| 115 |
| 116 Using ``__setitem__`` syntax overwrites fields that compare equal |
| 117 case-insensitively in order to maintain ``dict``'s api. For fields that |
| 118 compare equal, instead create a new ``HTTPHeaderDict`` and use ``.add`` |
| 119 in a loop. |
| 120 |
| 121 If multiple fields that are equal case-insensitively are passed to the |
| 122 constructor or ``.update``, the behavior is undefined and some will be |
| 123 lost. |
| 124 |
| 125 >>> headers = HTTPHeaderDict() |
| 126 >>> headers.add('Set-Cookie', 'foo=bar') |
| 127 >>> headers.add('set-cookie', 'baz=quxx') |
| 128 >>> headers['content-length'] = '7' |
| 129 >>> headers['SET-cookie'] |
| 130 'foo=bar, baz=quxx' |
| 131 >>> headers['Content-Length'] |
| 132 '7' |
| 133 """ |
| 134 |
| 135 def __init__(self, headers=None, **kwargs): |
| 136 super(HTTPHeaderDict, self).__init__() |
| 137 self._container = OrderedDict() |
| 138 if headers is not None: |
| 139 if isinstance(headers, HTTPHeaderDict): |
| 140 self._copy_from(headers) |
| 141 else: |
| 142 self.extend(headers) |
| 143 if kwargs: |
| 144 self.extend(kwargs) |
| 145 |
| 146 def __setitem__(self, key, val): |
| 147 self._container[key.lower()] = (key, val) |
| 148 return self._container[key.lower()] |
| 149 |
| 150 def __getitem__(self, key): |
| 151 val = self._container[key.lower()] |
| 152 return ', '.join(val[1:]) |
| 153 |
| 154 def __delitem__(self, key): |
| 155 del self._container[key.lower()] |
| 156 |
| 157 def __contains__(self, key): |
| 158 return key.lower() in self._container |
| 159 |
| 160 def __eq__(self, other): |
| 161 if not isinstance(other, Mapping) and not hasattr(other, 'keys'): |
| 162 return False |
| 163 if not isinstance(other, type(self)): |
| 164 other = type(self)(other) |
| 165 return (dict((k.lower(), v) for k, v in self.itermerged()) == |
| 166 dict((k.lower(), v) for k, v in other.itermerged())) |
| 167 |
| 168 def __ne__(self, other): |
| 169 return not self.__eq__(other) |
| 170 |
| 171 if not PY3: # Python 2 |
| 172 iterkeys = MutableMapping.iterkeys |
| 173 itervalues = MutableMapping.itervalues |
| 174 |
| 175 __marker = object() |
| 176 |
| 177 def __len__(self): |
| 178 return len(self._container) |
| 179 |
| 180 def __iter__(self): |
| 181 # Only provide the originally cased names |
| 182 for vals in self._container.values(): |
| 183 yield vals[0] |
| 184 |
| 185 def pop(self, key, default=__marker): |
| 186 '''D.pop(k[,d]) -> v, remove specified key and return the corresponding
value. |
| 187 If key is not found, d is returned if given, otherwise KeyError is rai
sed. |
| 188 ''' |
| 189 # Using the MutableMapping function directly fails due to the private ma
rker. |
| 190 # Using ordinary dict.pop would expose the internal structures. |
| 191 # So let's reinvent the wheel. |
| 192 try: |
| 193 value = self[key] |
| 194 except KeyError: |
| 195 if default is self.__marker: |
| 196 raise |
| 197 return default |
| 198 else: |
| 199 del self[key] |
| 200 return value |
| 201 |
| 202 def discard(self, key): |
| 203 try: |
| 204 del self[key] |
| 205 except KeyError: |
| 206 pass |
| 207 |
| 208 def add(self, key, val): |
| 209 """Adds a (name, value) pair, doesn't overwrite the value if it already |
| 210 exists. |
| 211 |
| 212 >>> headers = HTTPHeaderDict(foo='bar') |
| 213 >>> headers.add('Foo', 'baz') |
| 214 >>> headers['foo'] |
| 215 'bar, baz' |
| 216 """ |
| 217 key_lower = key.lower() |
| 218 new_vals = key, val |
| 219 # Keep the common case aka no item present as fast as possible |
| 220 vals = self._container.setdefault(key_lower, new_vals) |
| 221 if new_vals is not vals: |
| 222 # new_vals was not inserted, as there was a previous one |
| 223 if isinstance(vals, list): |
| 224 # If already several items got inserted, we have a list |
| 225 vals.append(val) |
| 226 else: |
| 227 # vals should be a tuple then, i.e. only one item so far |
| 228 # Need to convert the tuple to list for further extension |
| 229 self._container[key_lower] = [vals[0], vals[1], val] |
| 230 |
| 231 def extend(self, *args, **kwargs): |
| 232 """Generic import function for any type of header-like object. |
| 233 Adapted version of MutableMapping.update in order to insert items |
| 234 with self.add instead of self.__setitem__ |
| 235 """ |
| 236 if len(args) > 1: |
| 237 raise TypeError("extend() takes at most 1 positional " |
| 238 "arguments ({0} given)".format(len(args))) |
| 239 other = args[0] if len(args) >= 1 else () |
| 240 |
| 241 if isinstance(other, HTTPHeaderDict): |
| 242 for key, val in other.iteritems(): |
| 243 self.add(key, val) |
| 244 elif isinstance(other, Mapping): |
| 245 for key in other: |
| 246 self.add(key, other[key]) |
| 247 elif hasattr(other, "keys"): |
| 248 for key in other.keys(): |
| 249 self.add(key, other[key]) |
| 250 else: |
| 251 for key, value in other: |
| 252 self.add(key, value) |
| 253 |
| 254 for key, value in kwargs.items(): |
| 255 self.add(key, value) |
| 256 |
| 257 def getlist(self, key): |
| 258 """Returns a list of all the values for the named field. Returns an |
| 259 empty list if the key doesn't exist.""" |
| 260 try: |
| 261 vals = self._container[key.lower()] |
| 262 except KeyError: |
| 263 return [] |
| 264 else: |
| 265 if isinstance(vals, tuple): |
| 266 return [vals[1]] |
| 267 else: |
| 268 return vals[1:] |
| 269 |
| 270 # Backwards compatibility for httplib |
| 271 getheaders = getlist |
| 272 getallmatchingheaders = getlist |
| 273 iget = getlist |
| 274 |
| 275 def __repr__(self): |
| 276 return "%s(%s)" % (type(self).__name__, dict(self.itermerged())) |
| 277 |
| 278 def _copy_from(self, other): |
| 279 for key in other: |
| 280 val = other.getlist(key) |
| 281 if isinstance(val, list): |
| 282 # Don't need to convert tuples |
| 283 val = list(val) |
| 284 self._container[key.lower()] = [key] + val |
| 285 |
| 286 def copy(self): |
| 287 clone = type(self)() |
| 288 clone._copy_from(self) |
| 289 return clone |
| 290 |
| 291 def iteritems(self): |
| 292 """Iterate over all header lines, including duplicate ones.""" |
| 293 for key in self: |
| 294 vals = self._container[key.lower()] |
| 295 for val in vals[1:]: |
| 296 yield vals[0], val |
| 297 |
| 298 def itermerged(self): |
| 299 """Iterate over all headers, merging duplicate ones together.""" |
| 300 for key in self: |
| 301 val = self._container[key.lower()] |
| 302 yield val[0], ', '.join(val[1:]) |
| 303 |
| 304 def items(self): |
| 305 return list(self.iteritems()) |
| 306 |
| 307 @classmethod |
| 308 def from_httplib(cls, message): # Python 2 |
| 309 """Read headers from a Python 2 httplib message object.""" |
| 310 # python2.7 does not expose a proper API for exporting multiheaders |
| 311 # efficiently. This function re-reads raw lines from the message |
| 312 # object and extracts the multiheaders properly. |
| 313 headers = [] |
| 314 |
| 315 for line in message.headers: |
| 316 if line.startswith((' ', '\t')): |
| 317 key, value = headers[-1] |
| 318 headers[-1] = (key, value + '\r\n' + line.rstrip()) |
| 319 continue |
| 320 |
| 321 key, value = line.split(':', 1) |
| 322 headers.append((key, value.strip())) |
| 323 |
| 324 return cls(headers) |
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