63 lines
2.3 KiB
Python
63 lines
2.3 KiB
Python
# Copyright 2009 10gen, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Tools for representing binary data to be stored in MongoDB.
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"""
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class Binary(str):
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"""Representation of binary data to be stored in or retrieved from MongoDB.
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This is necessary because we want to store Python strings as the BSON
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string type. We need to wrap binary data so we can tell the difference
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between what should be considered binary data and what should be considered
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a string when we encode to BSON.
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Raises TypeError if `data` is not an instance of str or `subtype` is
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not an instance of int. Raises ValueError if `subtype` is not in [0, 256).
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:Parameters:
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- `data`: the binary data to represent
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- `subtype` (optional): the `binary subtype
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<http://www.mongodb.org/display/DOCS/BSON#BSON-noteondatabinary>`_
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to use
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"""
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def __new__(cls, data, subtype=2):
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if not isinstance(data, str):
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raise TypeError("data must be an instance of str")
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if not isinstance(subtype, int):
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raise TypeError("subtype must be an instance of int")
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if subtype >= 256 or subtype < 0:
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raise ValueError("subtype must be contained in [0, 256)")
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self = str.__new__(cls, data)
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self.__subtype = subtype
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return self
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@property
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def subtype(self):
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"""Subtype of this binary data.
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"""
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return self.__subtype
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def __eq__(self, other):
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if isinstance(other, Binary):
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return (self.__subtype, str(self)) == (other.subtype, str(other))
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# We don't return NotImplemented here because if we did then
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# Binary("foo") == "foo" would return True, since Binary is a subclass
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# of str...
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return False
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def __repr__(self):
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return "Binary(%s, %s)" % (str.__repr__(self), self.__subtype)
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