blob: fc3c6982b7cb02eff64bf6e69eda8133a670e13f [file] [log] [blame]
#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Contains container classes to represent different protocol buffer types.
This file defines container classes which represent categories of protocol
buffer field types which need extra maintenance. Currently these categories
are:
- Repeated scalar fields - These are all repeated fields which aren't
composite (e.g. they are of simple types like int32, string, etc).
- Repeated composite fields - Repeated fields which are composite. This
includes groups and nested messages.
"""
class BaseContainer(object):
"""Base container class."""
__slots__ = ['_message_listener', '_values']
def __init__(self, message_listener):
"""
Args:
message_listener: A MessageListener implementation.
The RepeatedScalarFieldContainer will call this object's
Modified() method when it is modified.
"""
self._message_listener = message_listener
self._values = []
def __getitem__(self, key):
"""Retrieves item by the specified key."""
return self._values[key]
def __len__(self):
"""Returns the number of elements in the container."""
return len(self._values)
def __ne__(self, other):
"""Checks if another instance isn't equal to this one."""
return not self == other
def __hash__(self):
raise TypeError('unhashable object')
def __repr__(self):
return repr(self._values)
def sort(self, *args, **kwargs):
if 'sort_function' in kwargs:
kwargs['cmp'] = kwargs.pop('sort_function')
self._values.sort(*args, **kwargs)
class RepeatedScalarFieldContainer(BaseContainer):
"""Simple, type-checked, list-like container for holding repeated scalars."""
__slots__ = ['_type_checker']
def __init__(self, message_listener, type_checker):
"""
Args:
message_listener: A MessageListener implementation.
The RepeatedScalarFieldContainer will call this object's
Modified() method when it is modified.
type_checker: A type_checkers.ValueChecker instance to run on elements
inserted into this container.
"""
super(RepeatedScalarFieldContainer, self).__init__(message_listener)
self._type_checker = type_checker
def append(self, value):
"""Appends an item to the list. Similar to list.append()."""
self._values.append(self._type_checker.CheckValue(value))
if not self._message_listener.dirty:
self._message_listener.Modified()
def insert(self, key, value):
"""Inserts the item at the specified position. Similar to list.insert()."""
self._values.insert(key, self._type_checker.CheckValue(value))
if not self._message_listener.dirty:
self._message_listener.Modified()
def extend(self, elem_seq):
"""Extends by appending the given sequence. Similar to list.extend()."""
if not elem_seq:
return
new_values = []
for elem in elem_seq:
new_values.append(self._type_checker.CheckValue(elem))
self._values.extend(new_values)
self._message_listener.Modified()
def MergeFrom(self, other):
"""Appends the contents of another repeated field of the same type to this
one. We do not check the types of the individual fields.
"""
self._values.extend(other._values)
self._message_listener.Modified()
def remove(self, elem):
"""Removes an item from the list. Similar to list.remove()."""
self._values.remove(elem)
self._message_listener.Modified()
def __setitem__(self, key, value):
"""Sets the item on the specified position."""
if isinstance(key, slice):
if key.step is not None:
raise ValueError('Extended slices not supported')
self.__setslice__(key.start, key.stop, value)
else:
self._values[key] = self._type_checker.CheckValue(value)
self._message_listener.Modified()
def __getslice__(self, start, stop):
"""Retrieves the subset of items from between the specified indices."""
return self._values[start:stop]
def __setslice__(self, start, stop, values):
"""Sets the subset of items from between the specified indices."""
new_values = []
for value in values:
new_values.append(self._type_checker.CheckValue(value))
self._values[start:stop] = new_values
self._message_listener.Modified()
def __delitem__(self, key):
"""Deletes the item at the specified position."""
del self._values[key]
self._message_listener.Modified()
def __delslice__(self, start, stop):
"""Deletes the subset of items from between the specified indices."""
del self._values[start:stop]
self._message_listener.Modified()
def __eq__(self, other):
"""Compares the current instance with another one."""
if self is other:
return True
if isinstance(other, self.__class__):
return other._values == self._values
return other == self._values
class RepeatedCompositeFieldContainer(BaseContainer):
"""Simple, list-like container for holding repeated composite fields."""
__slots__ = ['_message_descriptor']
def __init__(self, message_listener, message_descriptor):
"""
Note that we pass in a descriptor instead of the generated directly,
since at the time we construct a _RepeatedCompositeFieldContainer we
haven't yet necessarily initialized the type that will be contained in the
container.
Args:
message_listener: A MessageListener implementation.
The RepeatedCompositeFieldContainer will call this object's
Modified() method when it is modified.
message_descriptor: A Descriptor instance describing the protocol type
that should be present in this container. We'll use the
_concrete_class field of this descriptor when the client calls add().
"""
super(RepeatedCompositeFieldContainer, self).__init__(message_listener)
self._message_descriptor = message_descriptor
def add(self, **kwargs):
"""Adds a new element at the end of the list and returns it. Keyword
arguments may be used to initialize the element.
"""
new_element = self._message_descriptor._concrete_class(**kwargs)
new_element._SetListener(self._message_listener)
self._values.append(new_element)
if not self._message_listener.dirty:
self._message_listener.Modified()
return new_element
def extend(self, elem_seq):
"""Extends by appending the given sequence of elements of the same type
as this one, copying each individual message.
"""
message_class = self._message_descriptor._concrete_class
listener = self._message_listener
values = self._values
for message in elem_seq:
new_element = message_class()
new_element._SetListener(listener)
new_element.MergeFrom(message)
values.append(new_element)
listener.Modified()
def MergeFrom(self, other):
"""Appends the contents of another repeated field of the same type to this
one, copying each individual message.
"""
self.extend(other._values)
def remove(self, elem):
"""Removes an item from the list. Similar to list.remove()."""
self._values.remove(elem)
self._message_listener.Modified()
def __getslice__(self, start, stop):
"""Retrieves the subset of items from between the specified indices."""
return self._values[start:stop]
def __delitem__(self, key):
"""Deletes the item at the specified position."""
del self._values[key]
self._message_listener.Modified()
def __delslice__(self, start, stop):
"""Deletes the subset of items from between the specified indices."""
del self._values[start:stop]
self._message_listener.Modified()
def __eq__(self, other):
"""Compares the current instance with another one."""
if self is other:
return True
if not isinstance(other, self.__class__):
raise TypeError('Can only compare repeated composite fields against '
'other repeated composite fields.')
return self._values == other._values