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- from __future__ import absolute_import
- try:
- from collections.abc import Mapping, MutableMapping
- except ImportError:
- from collections import Mapping, MutableMapping
- try:
- from threading import RLock
- except ImportError: # Platform-specific: No threads available
- class RLock:
- def __enter__(self):
- pass
- def __exit__(self, exc_type, exc_value, traceback):
- pass
- from collections import OrderedDict
- from .exceptions import InvalidHeader
- from .packages import six
- from .packages.six import iterkeys, itervalues
- __all__ = ["RecentlyUsedContainer", "HTTPHeaderDict"]
- _Null = object()
- class RecentlyUsedContainer(MutableMapping):
- """
- Provides a thread-safe dict-like container which maintains up to
- ``maxsize`` keys while throwing away the least-recently-used keys beyond
- ``maxsize``.
- :param maxsize:
- Maximum number of recent elements to retain.
- :param dispose_func:
- Every time an item is evicted from the container,
- ``dispose_func(value)`` is called. Callback which will get called
- """
- ContainerCls = OrderedDict
- def __init__(self, maxsize=10, dispose_func=None):
- self._maxsize = maxsize
- self.dispose_func = dispose_func
- self._container = self.ContainerCls()
- self.lock = RLock()
- def __getitem__(self, key):
- # Re-insert the item, moving it to the end of the eviction line.
- with self.lock:
- item = self._container.pop(key)
- self._container[key] = item
- return item
- def __setitem__(self, key, value):
- evicted_value = _Null
- with self.lock:
- # Possibly evict the existing value of 'key'
- evicted_value = self._container.get(key, _Null)
- self._container[key] = value
- # If we didn't evict an existing value, we might have to evict the
- # least recently used item from the beginning of the container.
- if len(self._container) > self._maxsize:
- _key, evicted_value = self._container.popitem(last=False)
- if self.dispose_func and evicted_value is not _Null:
- self.dispose_func(evicted_value)
- def __delitem__(self, key):
- with self.lock:
- value = self._container.pop(key)
- if self.dispose_func:
- self.dispose_func(value)
- def __len__(self):
- with self.lock:
- return len(self._container)
- def __iter__(self):
- raise NotImplementedError(
- "Iteration over this class is unlikely to be threadsafe."
- )
- def clear(self):
- with self.lock:
- # Copy pointers to all values, then wipe the mapping
- values = list(itervalues(self._container))
- self._container.clear()
- if self.dispose_func:
- for value in values:
- self.dispose_func(value)
- def keys(self):
- with self.lock:
- return list(iterkeys(self._container))
- class HTTPHeaderDict(MutableMapping):
- """
- :param headers:
- An iterable of field-value pairs. Must not contain multiple field names
- when compared case-insensitively.
- :param kwargs:
- Additional field-value pairs to pass in to ``dict.update``.
- A ``dict`` like container for storing HTTP Headers.
- Field names are stored and compared case-insensitively in compliance with
- RFC 7230. Iteration provides the first case-sensitive key seen for each
- case-insensitive pair.
- Using ``__setitem__`` syntax overwrites fields that compare equal
- case-insensitively in order to maintain ``dict``'s api. For fields that
- compare equal, instead create a new ``HTTPHeaderDict`` and use ``.add``
- in a loop.
- If multiple fields that are equal case-insensitively are passed to the
- constructor or ``.update``, the behavior is undefined and some will be
- lost.
- >>> headers = HTTPHeaderDict()
- >>> headers.add('Set-Cookie', 'foo=bar')
- >>> headers.add('set-cookie', 'baz=quxx')
- >>> headers['content-length'] = '7'
- >>> headers['SET-cookie']
- 'foo=bar, baz=quxx'
- >>> headers['Content-Length']
- '7'
- """
- def __init__(self, headers=None, **kwargs):
- super(HTTPHeaderDict, self).__init__()
- self._container = OrderedDict()
- if headers is not None:
- if isinstance(headers, HTTPHeaderDict):
- self._copy_from(headers)
- else:
- self.extend(headers)
- if kwargs:
- self.extend(kwargs)
- def __setitem__(self, key, val):
- self._container[key.lower()] = [key, val]
- return self._container[key.lower()]
- def __getitem__(self, key):
- val = self._container[key.lower()]
- return ", ".join(val[1:])
- def __delitem__(self, key):
- del self._container[key.lower()]
- def __contains__(self, key):
- return key.lower() in self._container
- def __eq__(self, other):
- if not isinstance(other, Mapping) and not hasattr(other, "keys"):
- return False
- if not isinstance(other, type(self)):
- other = type(self)(other)
- return dict((k.lower(), v) for k, v in self.itermerged()) == dict(
- (k.lower(), v) for k, v in other.itermerged()
- )
- def __ne__(self, other):
- return not self.__eq__(other)
- if six.PY2: # Python 2
- iterkeys = MutableMapping.iterkeys
- itervalues = MutableMapping.itervalues
- __marker = object()
- def __len__(self):
- return len(self._container)
- def __iter__(self):
- # Only provide the originally cased names
- for vals in self._container.values():
- yield vals[0]
- def pop(self, key, default=__marker):
- """D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
- If key is not found, d is returned if given, otherwise KeyError is raised.
- """
- # Using the MutableMapping function directly fails due to the private marker.
- # Using ordinary dict.pop would expose the internal structures.
- # So let's reinvent the wheel.
- try:
- value = self[key]
- except KeyError:
- if default is self.__marker:
- raise
- return default
- else:
- del self[key]
- return value
- def discard(self, key):
- try:
- del self[key]
- except KeyError:
- pass
- def add(self, key, val):
- """Adds a (name, value) pair, doesn't overwrite the value if it already
- exists.
- >>> headers = HTTPHeaderDict(foo='bar')
- >>> headers.add('Foo', 'baz')
- >>> headers['foo']
- 'bar, baz'
- """
- key_lower = key.lower()
- new_vals = [key, val]
- # Keep the common case aka no item present as fast as possible
- vals = self._container.setdefault(key_lower, new_vals)
- if new_vals is not vals:
- vals.append(val)
- def extend(self, *args, **kwargs):
- """Generic import function for any type of header-like object.
- Adapted version of MutableMapping.update in order to insert items
- with self.add instead of self.__setitem__
- """
- if len(args) > 1:
- raise TypeError(
- "extend() takes at most 1 positional "
- "arguments ({0} given)".format(len(args))
- )
- other = args[0] if len(args) >= 1 else ()
- if isinstance(other, HTTPHeaderDict):
- for key, val in other.iteritems():
- self.add(key, val)
- elif isinstance(other, Mapping):
- for key in other:
- self.add(key, other[key])
- elif hasattr(other, "keys"):
- for key in other.keys():
- self.add(key, other[key])
- else:
- for key, value in other:
- self.add(key, value)
- for key, value in kwargs.items():
- self.add(key, value)
- def getlist(self, key, default=__marker):
- """Returns a list of all the values for the named field. Returns an
- empty list if the key doesn't exist."""
- try:
- vals = self._container[key.lower()]
- except KeyError:
- if default is self.__marker:
- return []
- return default
- else:
- return vals[1:]
- # Backwards compatibility for httplib
- getheaders = getlist
- getallmatchingheaders = getlist
- iget = getlist
- # Backwards compatibility for http.cookiejar
- get_all = getlist
- def __repr__(self):
- return "%s(%s)" % (type(self).__name__, dict(self.itermerged()))
- def _copy_from(self, other):
- for key in other:
- val = other.getlist(key)
- if isinstance(val, list):
- # Don't need to convert tuples
- val = list(val)
- self._container[key.lower()] = [key] + val
- def copy(self):
- clone = type(self)()
- clone._copy_from(self)
- return clone
- def iteritems(self):
- """Iterate over all header lines, including duplicate ones."""
- for key in self:
- vals = self._container[key.lower()]
- for val in vals[1:]:
- yield vals[0], val
- def itermerged(self):
- """Iterate over all headers, merging duplicate ones together."""
- for key in self:
- val = self._container[key.lower()]
- yield val[0], ", ".join(val[1:])
- def items(self):
- return list(self.iteritems())
- @classmethod
- def from_httplib(cls, message): # Python 2
- """Read headers from a Python 2 httplib message object."""
- # python2.7 does not expose a proper API for exporting multiheaders
- # efficiently. This function re-reads raw lines from the message
- # object and extracts the multiheaders properly.
- obs_fold_continued_leaders = (" ", "\t")
- headers = []
- for line in message.headers:
- if line.startswith(obs_fold_continued_leaders):
- if not headers:
- # We received a header line that starts with OWS as described
- # in RFC-7230 S3.2.4. This indicates a multiline header, but
- # there exists no previous header to which we can attach it.
- raise InvalidHeader(
- "Header continuation with no previous header: %s" % line
- )
- else:
- key, value = headers[-1]
- headers[-1] = (key, value + " " + line.strip())
- continue
- key, value = line.split(":", 1)
- headers.append((key, value.strip()))
- return cls(headers)
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