General
- New notion "import public" that allows a proto file to forward the content
it imports to its importers. For example,
// foo.proto
import public "bar.proto";
import "baz.proto";
// qux.proto
import "foo.proto";
// Stuff defined in bar.proto may be used in this file, but stuff from
// baz.proto may NOT be used without importing it explicitly.
This is useful for moving proto files. To move a proto file, just leave
a single "import public" in the old proto file.
- New enum option "allow_alias" that specifies whether different symbols can
be assigned the same numeric value. Default value is "true". Setting it to
false causes the compiler to reject enum definitions where multiple symbols
have the same numeric value.
Note: We plan to flip the default value to "false" in a future release.
Projects using enum aliases should set the option to "true" in their .proto
files.
C++
- New generated method set_allocated_foo(Type\* foo) for message and string
fields. This method allows you to set the field to a pre-allocated object
and the containing message takes the ownership of that object.
- Added SetAllocatedExtension() and ReleaseExtension() to extensions API.
- Custom options are now formatted correctly when descriptors are printed in
text format.
- Various speed optimizations.
Java
- Comments in proto files are now collected and put into generated code as
comments for corresponding classes and data members.
- Added Parser to parse directly into messages without a Builder. For
example,
Foo foo = Foo.PARSER.ParseFrom(input);
Using Parser is ~25% faster than using Builder to parse messages.
- Added getters/setters to access the underlying ByteString of a string field
directly.
- ByteString now supports more operations: substring(), prepend(), and
append(). The implementation of ByteString uses a binary tree structure
to support these operations efficiently.
- New method findInitializationErrors() that lists all missing required
fields.
- Various code size and speed optimizations.
Python
- Added support for dynamic message creation. DescriptorDatabase,
DescriptorPool, and MessageFactory work like their C++ couterparts to
simplify Descriptor construction from *DescriptorProtos, and MessageFactory
provides a message instance from a Descriptor.
- Added pickle support for protobuf messages.
- Unknown fields are now preserved after parsing.
- Fixed bug where custom options were not correctly populated. Custom
options can be accessed now.
- Added EnumTypeWrapper that provides better accessibility to enum types.
- Added ParseMessage(descriptor, bytes) to generate a new Message instance
from a descriptor and a byte string.