Scripts to download files from google storage based on sha1 sums

third_party/gsutil/boto/dynamodb/item.py

+# Copyright (c) 2012 Mitch Garnaat http://garnaat.org/
+# Copyright (c) 2012 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.
+#
+
+from boto.dynamodb.exceptions import DynamoDBItemError
+
+
+class Item(dict):
+    """
+    An item in Amazon DynamoDB.
+
+    :ivar hash_key: The HashKey of this item.
+    :ivar range_key: The RangeKey of this item or None if no RangeKey
+        is defined.
+    :ivar hash_key_name: The name of the HashKey associated with this item.
+    :ivar range_key_name: The name of the RangeKey associated with this item.
+    :ivar table: The Table this item belongs to.
+    """
+    
+    def __init__(self, table, hash_key=None, range_key=None, attrs=None):
+        self.table = table
+        self._updates = None
+        self._hash_key_name = self.table.schema.hash_key_name
+        self._range_key_name = self.table.schema.range_key_name
+        if attrs == None:
+            attrs = {}
+        if hash_key == None:
+            hash_key = attrs.get(self._hash_key_name, None)
+        self[self._hash_key_name] = hash_key
+        if self._range_key_name:
+            if range_key == None:
+                range_key = attrs.get(self._range_key_name, None)
+            self[self._range_key_name] = range_key
+        for key, value in attrs.items():
+            if key != self._hash_key_name and key != self._range_key_name:
+                self[key] = value
+        self.consumed_units = 0
+        self._updates = {}
+
+    @property
+    def hash_key(self):
+        return self[self._hash_key_name]
+
+    @property
+    def range_key(self):
+        return self.get(self._range_key_name)
+
+    @property
+    def hash_key_name(self):
+        return self._hash_key_name
+
+    @property
+    def range_key_name(self):
+        return self._range_key_name
+
+    def add_attribute(self, attr_name, attr_value):
+        """
+        Queue the addition of an attribute to an item in DynamoDB.
+        This will eventually result in an UpdateItem request being issued
+        with an update action of ADD when the save method is called.
+
+        :type attr_name: str
+        :param attr_name: Name of the attribute you want to alter.
+
+        :type attr_value: int|long|float|set
+        :param attr_value: Value which is to be added to the attribute.
+        """
+        self._updates[attr_name] = ("ADD", attr_value)
+
+    def delete_attribute(self, attr_name, attr_value=None):
+        """
+        Queue the deletion of an attribute from an item in DynamoDB.
+        This call will result in a UpdateItem request being issued
+        with update action of DELETE when the save method is called.
+
+        :type attr_name: str
+        :param attr_name: Name of the attribute you want to alter.
+
+        :type attr_value: set
+        :param attr_value: A set of values to be removed from the attribute.
+            This parameter is optional. If None, the whole attribute is
+            removed from the item.
+        """
+        self._updates[attr_name] = ("DELETE", attr_value)
+
+    def put_attribute(self, attr_name, attr_value):
+        """
+        Queue the putting of an attribute to an item in DynamoDB.
+        This call will result in an UpdateItem request being issued
+        with the update action of PUT when the save method is called.
+
+        :type attr_name: str
+        :param attr_name: Name of the attribute you want to alter.
+
+        :type attr_value: int|long|float|str|set
+        :param attr_value: New value of the attribute.
+        """
+        self._updates[attr_name] = ("PUT", attr_value)
+
+    def save(self, expected_value=None, return_values=None):
+        """
+        Commits pending updates to Amazon DynamoDB.
+
+        :type expected_value: dict
+        :param expected_value: A dictionary of name/value pairs that
+            you expect.  This dictionary should have name/value pairs
+            where the name is the name of the attribute and the value is
+            either the value you are expecting or False if you expect
+            the attribute not to exist.
+
+        :type return_values: str
+        :param return_values: Controls the return of attribute name/value pairs
+            before they were updated. Possible values are: None, 'ALL_OLD',
+            'UPDATED_OLD', 'ALL_NEW' or 'UPDATED_NEW'. If 'ALL_OLD' is
+            specified and the item is overwritten, the content of the old item
+            is returned. If 'ALL_NEW' is specified, then all the attributes of
+            the new version of the item are returned. If 'UPDATED_NEW' is
+            specified, the new versions of only the updated attributes are
+            returned.
+        """
+        return self.table.layer2.update_item(self, expected_value,
+                                             return_values)
+
+    def delete(self, expected_value=None, return_values=None):
+        """
+        Delete the item from DynamoDB.
+
+        :type expected_value: dict
+        :param expected_value: A dictionary of name/value pairs that
+            you expect.  This dictionary should have name/value pairs
+            where the name is the name of the attribute and the value
+            is either the value you are expecting or False if you expect
+            the attribute not to exist.
+
+        :type return_values: str
+        :param return_values: Controls the return of attribute
+            name-value pairs before then were changed.  Possible
+            values are: None or 'ALL_OLD'. If 'ALL_OLD' is
+            specified and the item is overwritten, the content
+            of the old item is returned.
+        """
+        return self.table.layer2.delete_item(self, expected_value,
+                                             return_values)
+
+    def put(self, expected_value=None, return_values=None):
+        """
+        Store a new item or completely replace an existing item
+        in Amazon DynamoDB.
+
+        :type expected_value: dict
+        :param expected_value: A dictionary of name/value pairs that
+            you expect.  This dictionary should have name/value pairs
+            where the name is the name of the attribute and the value
+            is either the value you are expecting or False if you expect
+            the attribute not to exist.
+
+        :type return_values: str
+        :param return_values: Controls the return of attribute
+            name-value pairs before then were changed.  Possible
+            values are: None or 'ALL_OLD'. If 'ALL_OLD' is
+            specified and the item is overwritten, the content
+            of the old item is returned.
+        """
+        return self.table.layer2.put_item(self, expected_value, return_values)
+
+    def __setitem__(self, key, value):
+        """Overrwrite the setter to instead update the _updates
+        method so this can act like a normal dict"""
+        if self._updates is not None:
+            self.put_attribute(key, value)
+        dict.__setitem__(self, key, value)
+
+    def __delitem__(self, key):
+        """Remove this key from the items"""
+        if self._updates is not None:
+            self.delete_attribute(key)
+        dict.__delitem__(self, key)