/thirdparty/breakpad/third_party/protobuf/protobuf/python/google/protobuf/internal/message_listener.py
http://github.com/tomahawk-player/tomahawk · Python · 78 lines · 25 code · 8 blank · 45 comment · 3 complexity · e390820c1fa93b817eafc22327b68e4b MD5 · raw file
- # 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.
- """Defines a listener interface for observing certain
- state transitions on Message objects.
- Also defines a null implementation of this interface.
- """
- __author__ = 'robinson@google.com (Will Robinson)'
- class MessageListener(object):
- """Listens for modifications made to a message. Meant to be registered via
- Message._SetListener().
- Attributes:
- dirty: If True, then calling Modified() would be a no-op. This can be
- used to avoid these calls entirely in the common case.
- """
- def Modified(self):
- """Called every time the message is modified in such a way that the parent
- message may need to be updated. This currently means either:
- (a) The message was modified for the first time, so the parent message
- should henceforth mark the message as present.
- (b) The message's cached byte size became dirty -- i.e. the message was
- modified for the first time after a previous call to ByteSize().
- Therefore the parent should also mark its byte size as dirty.
- Note that (a) implies (b), since new objects start out with a client cached
- size (zero). However, we document (a) explicitly because it is important.
- Modified() will *only* be called in response to one of these two events --
- not every time the sub-message is modified.
- Note that if the listener's |dirty| attribute is true, then calling
- Modified at the moment would be a no-op, so it can be skipped. Performance-
- sensitive callers should check this attribute directly before calling since
- it will be true most of the time.
- """
- raise NotImplementedError
- class NullMessageListener(object):
- """No-op MessageListener implementation."""
- def Modified(self):
- pass