# 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.
#
class Schema(object):
"""
Represents a DynamoDB schema.
:ivar hash_key_name: The name of the hash key of the schema.
:ivar hash_key_type: The DynamoDB type specification for the
hash key of the schema.
:ivar range_key_name: The name of the range key of the schema
or None if no range key is defined.
:ivar range_key_type: The DynamoDB type specification for the
range key of the schema or None if no range key is defined.
:ivar dict: The underlying Python dictionary that needs to be
passed to Layer1 methods.
"""
def __init__(self, schema_dict):
self._dict = schema_dict
def __repr__(self):
if self.range_key_name:
s = 'Schema(%s:%s)' % (self.hash_key_name, self.range_key_name)
else:
s = 'Schema(%s)' % self.hash_key_name
return s
@classmethod
def create(cls, hash_key, range_key=None):
"""Convenience method to create a schema object.
Example usage::
schema = Schema.create(hash_key=('foo', 'N'))
schema2 = Schema.create(hash_key=('foo', 'N'),
range_key=('bar', 'S'))
:type hash_key: tuple
:param hash_key: A tuple of (hash_key_name, hash_key_type)
:type range_key: tuple
:param hash_key: A tuple of (range_key_name, range_key_type)
"""
reconstructed = {
'HashKeyElement': {
'AttributeName': hash_key[0],
'AttributeType': hash_key[1],
}
}
if range_key is not None:
reconstructed['RangeKeyElement'] = {
'AttributeName': range_key[0],
'AttributeType': range_key[1],
}
instance = cls(None)
instance._dict = reconstructed
return instance
@property
def dict(self):
return self._dict
@property
def hash_key_name(self):
return self._dict['HashKeyElement']['AttributeName']
@property
def hash_key_type(self):
return self._dict['HashKeyElement']['AttributeType']
@property
def range_key_name(self):
name = None
if 'RangeKeyElement' in self._dict:
name = self._dict['RangeKeyElement']['AttributeName']
return name
@property
def range_key_type(self):
type = None
if 'RangeKeyElement' in self._dict:
type = self._dict['RangeKeyElement']['AttributeType']
return type
def __eq__(self, other):
return (self.hash_key_name == other.hash_key_name and
self.hash_key_type == other.hash_key_type and
self.range_key_name == other.range_key_name and
self.range_key_type == other.range_key_type)