Scripts to download files from google storage based on sha1 sums

third_party/gsutil/boto/sdb/item.py

+# Copyright (c) 2006,2007 Mitch Garnaat http://garnaat.org/
+#
+# 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.
+
+import base64
+
+class Item(dict):
+    """
+    A ``dict`` sub-class that serves as an object representation of a
+    SimpleDB item. An item in SDB is similar to a row in a relational
+    database. Items belong to a :py:class:`Domain <boto.sdb.domain.Domain>`,
+    which is similar to a table in a relational database.
+    
+    The keys on instances of this object correspond to attributes that are
+    stored on the SDB item. 
+    
+    .. tip:: While it is possible to instantiate this class directly, you may
+        want to use the convenience methods on :py:class:`boto.sdb.domain.Domain`
+        for that purpose. For example, :py:meth:`boto.sdb.domain.Domain.get_item`.
+    """
+    def __init__(self, domain, name='', active=False):
+        """
+        :type domain: :py:class:`boto.sdb.domain.Domain`
+        :param domain: The domain that this item belongs to.
+        
+        :param str name: The name of this item. This name will be used when
+            querying for items using methods like 
+            :py:meth:`boto.sdb.domain.Domain.get_item`
+        """
+        dict.__init__(self)
+        self.domain = domain
+        self.name = name
+        self.active = active
+        self.request_id = None
+        self.encoding = None
+        self.in_attribute = False
+        self.converter = self.domain.connection.converter
+
+    def startElement(self, name, attrs, connection):
+        if name == 'Attribute':
+            self.in_attribute = True
+        self.encoding = attrs.get('encoding', None)
+        return None
+
+    def decode_value(self, value):
+        if self.encoding == 'base64':
+            self.encoding = None
+            return base64.decodestring(value)
+        else:
+            return value
+
+    def endElement(self, name, value, connection):
+        if name == 'ItemName':
+            self.name = self.decode_value(value)
+        elif name == 'Name':
+            if self.in_attribute:
+                self.last_key = self.decode_value(value)
+            else:
+                self.name = self.decode_value(value)
+        elif name == 'Value':
+            if self.last_key in self:
+                if not isinstance(self[self.last_key], list):
+                    self[self.last_key] = [self[self.last_key]]
+                value = self.decode_value(value)
+                if self.converter:
+                    value = self.converter.decode(value)
+                self[self.last_key].append(value)
+            else:
+                value = self.decode_value(value)
+                if self.converter:
+                    value = self.converter.decode(value)
+                self[self.last_key] = value
+        elif name == 'BoxUsage':
+            try:
+                connection.box_usage += float(value)
+            except:
+                pass
+        elif name == 'RequestId':
+            self.request_id = value
+        elif name == 'Attribute':
+            self.in_attribute = False
+        else:
+            setattr(self, name, value)
+
+    def load(self):
+        """
+        Loads or re-loads this item's attributes from SDB.
+        
+        .. warning:: 
+            If you have changed attribute values on an Item instance,
+            this method will over-write the values if they are different in
+            SDB. For any local attributes that don't yet exist in SDB,
+            they will be safe.
+        """
+        self.domain.get_attributes(self.name, item=self)
+
+    def save(self, replace=True):
+        """
+        Saves this item to SDB.
+        
+        :param bool replace: If ``True``, delete any attributes on the remote
+            SDB item that have a ``None`` value on this object.
+        """
+        self.domain.put_attributes(self.name, self, replace)
+        # Delete any attributes set to "None"
+        if replace:
+            del_attrs = []
+            for name in self:
+                if self[name] == None:
+                    del_attrs.append(name)
+            if len(del_attrs) > 0:
+                self.domain.delete_attributes(self.name, del_attrs)
+
+    def add_value(self, key, value):
+        """
+        Helps set or add to attributes on this item. If you are adding a new
+        attribute that has yet to be set, it will simply create an attribute
+        named ``key`` with your given ``value`` as its value. If you are
+        adding a value to an existing attribute, this method will convert the
+        attribute to a list (if it isn't already) and append your new value 
+        to said list.
+        
+        For clarification, consider the following interactive session:
+        
+        .. code-block:: python
+
+            >>> item = some_domain.get_item('some_item')
+            >>> item.has_key('some_attr')
+            False
+            >>> item.add_value('some_attr', 1)
+            >>> item['some_attr']
+            1
+            >>> item.add_value('some_attr', 2)
+            >>> item['some_attr']
+            [1, 2]
+        
+        :param str key: The attribute to add a value to.
+        :param object value: The value to set or append to the attribute. 
+        """
+        if key in self:
+            # We already have this key on the item.
+            if not isinstance(self[key], list):
+                # The key isn't already a list, take its current value and
+                # convert it to a list with the only member being the
+                # current value.
+                self[key] = [self[key]]
+            # Add the new value to the list.
+            self[key].append(value)
+        else:
+            # This is a new attribute, just set it.
+            self[key] = value
+
+    def delete(self):
+        """
+        Deletes this item in SDB.
+        
+        .. note:: This local Python object remains in its current state
+            after deletion, this only deletes the remote item in SDB.
+        """
+        self.domain.delete_item(self)
+
+        
+        
+