| Index: third_party/gsutil/boto/boto/dynamodb/types.py
|
| diff --git a/third_party/gsutil/boto/boto/dynamodb/types.py b/third_party/gsutil/boto/boto/dynamodb/types.py
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..e3b495884c177f8725180d3ec76cd8ec6f9cf56f
|
| --- /dev/null
|
| +++ b/third_party/gsutil/boto/boto/dynamodb/types.py
|
| @@ -0,0 +1,326 @@
|
| +# Copyright (c) 2011 Mitch Garnaat http://garnaat.org/
|
| +# Copyright (c) 2011 Amazon.com, Inc. or its affiliates. All Rights Reserved
|
| +#
|
| +# Permission is hereby granted, free of charge, to any person obtaining a
|
| +# copy of this software and associated documentation files (the
|
| +# "Software"), to deal in the Software without restriction, including
|
| +# without limitation the rights to use, copy, modify, merge, publish, dis-
|
| +# tribute, sublicense, and/or sell copies of the Software, and to permit
|
| +# persons to whom the Software is furnished to do so, subject to the fol-
|
| +# lowing conditions:
|
| +#
|
| +# The above copyright notice and this permission notice shall be included
|
| +# in all copies or substantial portions of the Software.
|
| +#
|
| +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
| +# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
|
| +# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
|
| +# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
| +# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
| +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
| +# IN THE SOFTWARE.
|
| +#
|
| +"""
|
| +Some utility functions to deal with mapping Amazon DynamoDB types to
|
| +Python types and vice-versa.
|
| +"""
|
| +import base64
|
| +from decimal import (Decimal, DecimalException, Context,
|
| + Clamped, Overflow, Inexact, Underflow, Rounded)
|
| +from exceptions import DynamoDBNumberError
|
| +
|
| +
|
| +DYNAMODB_CONTEXT = Context(
|
| + Emin=-128, Emax=126, rounding=None, prec=38,
|
| + traps=[Clamped, Overflow, Inexact, Rounded, Underflow])
|
| +
|
| +
|
| +# python2.6 cannot convert floats directly to
|
| +# Decimals. This is taken from:
|
| +# http://docs.python.org/release/2.6.7/library/decimal.html#decimal-faq
|
| +def float_to_decimal(f):
|
| + n, d = f.as_integer_ratio()
|
| + numerator, denominator = Decimal(n), Decimal(d)
|
| + ctx = DYNAMODB_CONTEXT
|
| + result = ctx.divide(numerator, denominator)
|
| + while ctx.flags[Inexact]:
|
| + ctx.flags[Inexact] = False
|
| + ctx.prec *= 2
|
| + result = ctx.divide(numerator, denominator)
|
| + return result
|
| +
|
| +
|
| +def is_num(n):
|
| + types = (int, long, float, bool, Decimal)
|
| + return isinstance(n, types) or n in types
|
| +
|
| +
|
| +def is_str(n):
|
| + return isinstance(n, basestring) or (isinstance(n, type) and
|
| + issubclass(n, basestring))
|
| +
|
| +
|
| +def is_binary(n):
|
| + return isinstance(n, Binary)
|
| +
|
| +
|
| +def serialize_num(val):
|
| + """Cast a number to a string and perform
|
| + validation to ensure no loss of precision.
|
| + """
|
| + if isinstance(val, bool):
|
| + return str(int(val))
|
| + return str(val)
|
| +
|
| +
|
| +def convert_num(s):
|
| + if '.' in s:
|
| + n = float(s)
|
| + else:
|
| + n = int(s)
|
| + return n
|
| +
|
| +
|
| +def convert_binary(n):
|
| + return Binary(base64.b64decode(n))
|
| +
|
| +
|
| +def get_dynamodb_type(val):
|
| + """
|
| + Take a scalar Python value and return a string representing
|
| + the corresponding Amazon DynamoDB type. If the value passed in is
|
| + not a supported type, raise a TypeError.
|
| + """
|
| + dynamodb_type = None
|
| + if is_num(val):
|
| + dynamodb_type = 'N'
|
| + elif is_str(val):
|
| + dynamodb_type = 'S'
|
| + elif isinstance(val, (set, frozenset)):
|
| + if False not in map(is_num, val):
|
| + dynamodb_type = 'NS'
|
| + elif False not in map(is_str, val):
|
| + dynamodb_type = 'SS'
|
| + elif False not in map(is_binary, val):
|
| + dynamodb_type = 'BS'
|
| + elif isinstance(val, Binary):
|
| + dynamodb_type = 'B'
|
| + if dynamodb_type is None:
|
| + msg = 'Unsupported type "%s" for value "%s"' % (type(val), val)
|
| + raise TypeError(msg)
|
| + return dynamodb_type
|
| +
|
| +
|
| +def dynamize_value(val):
|
| + """
|
| + Take a scalar Python value and return a dict consisting
|
| + of the Amazon DynamoDB type specification and the value that
|
| + needs to be sent to Amazon DynamoDB. If the type of the value
|
| + is not supported, raise a TypeError
|
| + """
|
| + dynamodb_type = get_dynamodb_type(val)
|
| + if dynamodb_type == 'N':
|
| + val = {dynamodb_type: serialize_num(val)}
|
| + elif dynamodb_type == 'S':
|
| + val = {dynamodb_type: val}
|
| + elif dynamodb_type == 'NS':
|
| + val = {dynamodb_type: map(serialize_num, val)}
|
| + elif dynamodb_type == 'SS':
|
| + val = {dynamodb_type: [n for n in val]}
|
| + elif dynamodb_type == 'B':
|
| + val = {dynamodb_type: val.encode()}
|
| + elif dynamodb_type == 'BS':
|
| + val = {dynamodb_type: [n.encode() for n in val]}
|
| + return val
|
| +
|
| +
|
| +class Binary(object):
|
| + def __init__(self, value):
|
| + self.value = value
|
| +
|
| + def encode(self):
|
| + return base64.b64encode(self.value)
|
| +
|
| + def __eq__(self, other):
|
| + if isinstance(other, Binary):
|
| + return self.value == other.value
|
| + else:
|
| + return self.value == other
|
| +
|
| + def __ne__(self, other):
|
| + return not self.__eq__(other)
|
| +
|
| + def __repr__(self):
|
| + return 'Binary(%s)' % self.value
|
| +
|
| + def __str__(self):
|
| + return self.value
|
| +
|
| + def __hash__(self):
|
| + return hash(self.value)
|
| +
|
| +
|
| +def item_object_hook(dct):
|
| + """
|
| + A custom object hook for use when decoding JSON item bodys.
|
| + This hook will transform Amazon DynamoDB JSON responses to something
|
| + that maps directly to native Python types.
|
| + """
|
| + if len(dct.keys()) > 1:
|
| + return dct
|
| + if 'S' in dct:
|
| + return dct['S']
|
| + if 'N' in dct:
|
| + return convert_num(dct['N'])
|
| + if 'SS' in dct:
|
| + return set(dct['SS'])
|
| + if 'NS' in dct:
|
| + return set(map(convert_num, dct['NS']))
|
| + if 'B' in dct:
|
| + return convert_binary(dct['B'])
|
| + if 'BS' in dct:
|
| + return set(map(convert_binary, dct['BS']))
|
| + return dct
|
| +
|
| +
|
| +class Dynamizer(object):
|
| + """Control serialization/deserialization of types.
|
| +
|
| + This class controls the encoding of python types to the
|
| + format that is expected by the DynamoDB API, as well as
|
| + taking DynamoDB types and constructing the appropriate
|
| + python types.
|
| +
|
| + If you want to customize this process, you can subclass
|
| + this class and override the encoding/decoding of
|
| + specific types. For example::
|
| +
|
| + 'foo' (Python type)
|
| + |
|
| + v
|
| + encode('foo')
|
| + |
|
| + v
|
| + _encode_s('foo')
|
| + |
|
| + v
|
| + {'S': 'foo'} (Encoding sent to/received from DynamoDB)
|
| + |
|
| + V
|
| + decode({'S': 'foo'})
|
| + |
|
| + v
|
| + _decode_s({'S': 'foo'})
|
| + |
|
| + v
|
| + 'foo' (Python type)
|
| +
|
| + """
|
| + def _get_dynamodb_type(self, attr):
|
| + return get_dynamodb_type(attr)
|
| +
|
| + def encode(self, attr):
|
| + """
|
| + Encodes a python type to the format expected
|
| + by DynamoDB.
|
| +
|
| + """
|
| + dynamodb_type = self._get_dynamodb_type(attr)
|
| + try:
|
| + encoder = getattr(self, '_encode_%s' % dynamodb_type.lower())
|
| + except AttributeError:
|
| + raise ValueError("Unable to encode dynamodb type: %s" %
|
| + dynamodb_type)
|
| + return {dynamodb_type: encoder(attr)}
|
| +
|
| + def _encode_n(self, attr):
|
| + try:
|
| + if isinstance(attr, float) and not hasattr(Decimal, 'from_float'):
|
| + # python2.6 does not support creating Decimals directly
|
| + # from floats so we have to do this ourself.
|
| + n = str(float_to_decimal(attr))
|
| + else:
|
| + n = str(DYNAMODB_CONTEXT.create_decimal(attr))
|
| + if filter(lambda x: x in n, ('Infinity', 'NaN')):
|
| + raise TypeError('Infinity and NaN not supported')
|
| + return n
|
| + except (TypeError, DecimalException), e:
|
| + msg = '{0} numeric for `{1}`\n{2}'.format(
|
| + e.__class__.__name__, attr, str(e) or '')
|
| + raise DynamoDBNumberError(msg)
|
| +
|
| + def _encode_s(self, attr):
|
| + if isinstance(attr, unicode):
|
| + attr = attr.encode('utf-8')
|
| + elif not isinstance(attr, str):
|
| + attr = str(attr)
|
| + return attr
|
| +
|
| + def _encode_ns(self, attr):
|
| + return map(self._encode_n, attr)
|
| +
|
| + def _encode_ss(self, attr):
|
| + return [self._encode_s(n) for n in attr]
|
| +
|
| + def _encode_b(self, attr):
|
| + return attr.encode()
|
| +
|
| + def _encode_bs(self, attr):
|
| + return [self._encode_b(n) for n in attr]
|
| +
|
| + def decode(self, attr):
|
| + """
|
| + Takes the format returned by DynamoDB and constructs
|
| + the appropriate python type.
|
| +
|
| + """
|
| + if len(attr) > 1 or not attr:
|
| + return attr
|
| + dynamodb_type = attr.keys()[0]
|
| + try:
|
| + decoder = getattr(self, '_decode_%s' % dynamodb_type.lower())
|
| + except AttributeError:
|
| + return attr
|
| + return decoder(attr[dynamodb_type])
|
| +
|
| + def _decode_n(self, attr):
|
| + return DYNAMODB_CONTEXT.create_decimal(attr)
|
| +
|
| + def _decode_s(self, attr):
|
| + return attr
|
| +
|
| + def _decode_ns(self, attr):
|
| + return set(map(self._decode_n, attr))
|
| +
|
| + def _decode_ss(self, attr):
|
| + return set(map(self._decode_s, attr))
|
| +
|
| + def _decode_b(self, attr):
|
| + return convert_binary(attr)
|
| +
|
| + def _decode_bs(self, attr):
|
| + return set(map(self._decode_b, attr))
|
| +
|
| +
|
| +class LossyFloatDynamizer(Dynamizer):
|
| + """Use float/int instead of Decimal for numeric types.
|
| +
|
| + This class is provided for backwards compatibility. Instead of
|
| + using Decimals for the 'N', 'NS' types it uses ints/floats.
|
| +
|
| + This class is deprecated and its usage is not encouraged,
|
| + as doing so may result in loss of precision. Use the
|
| + `Dynamizer` class instead.
|
| +
|
| + """
|
| + def _encode_n(self, attr):
|
| + return serialize_num(attr)
|
| +
|
| + def _encode_ns(self, attr):
|
| + return [str(i) for i in attr]
|
| +
|
| + def _decode_n(self, attr):
|
| + return convert_num(attr)
|
| +
|
| + def _decode_ns(self, attr):
|
| + return set(map(self._decode_n, attr))
|
|
|