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Protocol Buffers v3.0.0-beta-3

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@liujisi liujisi released this 16 May 20:32

Version 3.0.0-beta-3

General

  • Supported Proto3 lite-runtime in C++/Java for mobile platforms.
  • Any type now supports APIs to specify prefixes other than
    type.googleapis.com
  • Removed javanano_use_deprecated_package option; Nano will always has its own
    ".nano" package.

C++ (Beta)

  • Improved hash maps.
    • Improved hash maps comments. In particular, please note that equal hash
      maps will not necessarily have the same iteration order and
      serialization.
    • Added a new hash maps implementation that will become the default in a
      later release.
  • Arenas
    • Several inlined methods in Arena were moved to out-of-line to improve
      build performance and code size.
    • Added SpaceAllocatedAndUsed() to report both space used and allocated
    • Added convenient class UnsafeArenaAllocatedRepeatedPtrFieldBackInserter
  • Any
    • Allow custom type URL prefixes in Any packing.
    • TextFormat now expand the Any type rather than printing bytes.
  • Performance optimizations and various bug fixes.

Java (Beta)

  • Introduced an ExperimentalApi annotation. Annotated APIs are experimental
    and are subject to change in a backward incompatible way in future releases.
  • Introduced zero-copy serialization as an ExperimentalApi
    • Introduction of the ByteOutput interface. This is similar to
      OutputStream but provides semantics for lazy writing (i.e. no
      immediate copy required) of fields that are considered to be immutable.
    • ByteString now supports writing to a ByteOutput, which will directly
      expose the internals of the ByteString (i.e. byte[] or ByteBuffer)
      to the ByteOutput without copying.
    • CodedOutputStream now supports writing to a ByteOutput. ByteString
      instances that are too large to fit in the internal buffer will be
      (lazily) written to the ByteOutput directly.
    • This allows applications using large ByteString fields to avoid
      duplication of these fields entirely. Such an application can supply a
      ByteOutput that chains together the chunks received from
      CodedOutputStream before forwarding them onto the IO system.
  • Other related changes to CodedOutputStream
    • Additional use of sun.misc.Unsafe where possible to perform fast
      access to byte[] and ByteBuffer values and avoiding unnecessary
      range checking.
    • ByteBuffer-backed CodedOutputStream now writes directly to the
      ByteBuffer rather than to an intermediate array.
  • Improved lite-runtime.
    • Lite protos now implement deep equals/hashCode/toString
    • Significantly improved the performance of Builder#mergeFrom() and
      Builder#mergeDelimitedFrom()
  • Various bug fixes and small feature enhancement.
    • Fixed stack overflow when in hashCode() for infinite recursive oneofs.
    • Fixed the lazy field parsing in lite to merge rather than overwrite.
    • TextFormat now supports reporting line/column numbers on errors.
    • Updated to add appropriate @OverRide for better compiler errors.

Python (Beta)

  • Added JSON format for Any, Struct, Value and ListValue
  • "[ ]" is now accepted for both repeated scalar fields and repeated message
    fields in text format parser.
  • Numerical field name is now supported in text format.
  • Added DiscardUnknownFields API for python protobuf message.

Objective-C (Beta)

  • Proto comments now come over as HeaderDoc comments in the generated sources
    so Xcode can pick them up and display them.
  • The library headers have been updated to use HeaderDoc comments so Xcode can
    pick them up and display them.
  • The per message and per field overhead in both generated code and runtime
    object sizes was reduced.
  • Generated code now include deprecated annotations when the proto file
    included them.

C# (Beta)

In general: some changes are breaking, which require regenerating messages.
Most user-written code will not be impacted except for the renaming of enum
values.

  • Allow custom type URL prefixes in Any packing, and ignore them when
    unpacking
  • protoc is now in a separate NuGet package (Google.Protobuf.Tools)
  • New option: internal_access to generate internal classes
  • Enum values are now PascalCased, and if there's a prefix which matches the
    name of the enum, that is removed (so an enum COLOR with a value
    COLOR_BLUE would generate a value of just Blue). An option
    (legacy_enum_values) is temporarily available to disable this, but the
    option will be removed for GA.
  • json_name option is now honored
  • If group tags are encountered when parsing, they are validated more
    thoroughly (although we don't support actual groups)
  • NuGet dependencies are better specified
  • Breaking: Preconditions is renamed to ProtoPreconditions
  • Breaking: GeneratedCodeInfo is renamed to GeneratedClrTypeInfo
  • JsonFormatter now allows writing to a TextWriter
  • New interface, ICustomDiagnosticMessage to allow more compact
    representations from ToString
  • CodedInputStream and CodedOutputStream now implement IDisposable,
    which simply disposes of the streams they were constructed with
  • Map fields no longer support null values (in line with other languages)
  • Improvements in JSON formatting and parsing

Javascript (Alpha)

  • Better support for "bytes" fields: bytes fields can be read as either a
    base64 string or UInt8Array (in environments where TypedArray is supported).
  • New support for CommonJS imports. This should make it easier to use the
    JavaScript support in Node.js and tools like WebPack. See js/README.md for
    more information.
  • Some significant internal refactoring to simplify and modularize the code.

Ruby (Alpha)

  • JSON serialization now properly uses camelCased names, with a runtime option
    that will preserve original names from .proto files instead.
  • Well-known types are now included in the distribution.
  • Release now includes binary gems for Windows, Mac, and Linux instead of just
    source gems.
  • Bugfix for serializing oneofs.

C++/Java Lite (Alpha)

A new "lite" generator parameter was introduced in the protoc for C++ and
Java for Proto3 syntax messages. Example usage:

 ./protoc --cpp_out=lite:$OUTPUT_PATH foo.proto

The protoc will treat the current input and all the transitive dependencies
as LITE. The same generator parameter must be used to generate the
dependencies.

In Proto3 syntax files, "optimized_for=LITE_RUNTIME" is no longer supported.