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Diffstat (limited to 'python/google/protobuf/internal/containers.py')
| -rwxr-xr-x | python/google/protobuf/internal/containers.py | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/python/google/protobuf/internal/containers.py b/python/google/protobuf/internal/containers.py new file mode 100755 index 0000000..d8a825d --- /dev/null +++ b/python/google/protobuf/internal/containers.py @@ -0,0 +1,227 @@ +# Protocol Buffers - Google's data interchange format +# Copyright 2008 Google Inc. All rights reserved. +# http://code.google.com/p/protobuf/ +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following disclaimer +# in the documentation and/or other materials provided with the +# distribution. +# * Neither the name of Google Inc. nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +"""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. +""" + +__author__ = 'petar@google.com (Petar Petrov)' + + +class BaseContainer(object): + + """Base container class.""" + + # Minimizes memory usage and disallows assignment to other attributes. + __slots__ = ['_message_listener', '_values'] + + def __init__(self, message_listener): + """ + Args: + message_listener: A MessageListener implementation. + The RepeatedScalarFieldContainer will call this object's + TransitionToNonempty() method when it transitions from being empty to + being nonempty. + """ + 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.""" + # The concrete classes should define __eq__. + return not self == other + + +class RepeatedScalarFieldContainer(BaseContainer): + + """Simple, type-checked, list-like container for holding repeated scalars.""" + + # Disallows assignment to other attributes. + __slots__ = ['_type_checker'] + + def __init__(self, message_listener, type_checker): + """ + Args: + message_listener: A MessageListener implementation. + The RepeatedScalarFieldContainer will call this object's + TransitionToNonempty() method when it transitions from being empty to + being nonempty. + 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.insert(len(self._values), value) + + def insert(self, key, value): + """Inserts the item at the specified position. Similar to list.insert().""" + self._type_checker.CheckValue(value) + self._values.insert(key, value) + self._message_listener.ByteSizeDirty() + if len(self._values) == 1: + self._message_listener.TransitionToNonempty() + + def extend(self, elem_seq): + """Extends by appending the given sequence. Similar to list.extend().""" + if not elem_seq: + return + + orig_empty = len(self._values) == 0 + new_values = [] + for elem in elem_seq: + self._type_checker.CheckValue(elem) + new_values.append(elem) + self._values.extend(new_values) + self._message_listener.ByteSizeDirty() + if orig_empty: + self._message_listener.TransitionToNonempty() + + def remove(self, elem): + """Removes an item from the list. Similar to list.remove().""" + self._values.remove(elem) + self._message_listener.ByteSizeDirty() + + def __setitem__(self, key, value): + """Sets the item on the specified position.""" + # No need to call TransitionToNonempty(), since if we're able to + # set the element at this index, we were already nonempty before + # this method was called. + self._message_listener.ByteSizeDirty() + self._type_checker.CheckValue(value) + self._values[key] = value + + 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: + self._type_checker.CheckValue(value) + new_values.append(value) + self._values[start:stop] = new_values + self._message_listener.ByteSizeDirty() + + def __delitem__(self, key): + """Deletes the item at the specified position.""" + del self._values[key] + self._message_listener.ByteSizeDirty() + + def __delslice__(self, start, stop): + """Deletes the subset of items from between the specified indices.""" + del self._values[start:stop] + self._message_listener.ByteSizeDirty() + + def __eq__(self, other): + """Compares the current instance with another one.""" + if self is other: + return True + # Special case for the same type which should be common and fast. + if isinstance(other, self.__class__): + return other._values == self._values + # We are presumably comparing against some other sequence type. + return other == self._values + + +class RepeatedCompositeFieldContainer(BaseContainer): + + """Simple, list-like container for holding repeated composite fields.""" + + # Disallows assignment to other attributes. + __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 + TransitionToNonempty() method when it transitions from being empty to + being nonempty. + 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): + new_element = self._message_descriptor._concrete_class() + new_element._SetListener(self._message_listener) + self._values.append(new_element) + self._message_listener.ByteSizeDirty() + self._message_listener.TransitionToNonempty() + return new_element + + 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.ByteSizeDirty() + + def __delslice__(self, start, stop): + """Deletes the subset of items from between the specified indices.""" + del self._values[start:stop] + self._message_listener.ByteSizeDirty() + + 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 |