https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.3.0

Planned Future Changes

• There are some changes that are not included in this release but are planned for the near future:
  • Preserve unknown fields in proto3: please read this doc for the timeline and follow up this github issue for discussion.
  • Make C++ implementation C++11 only: we plan to require C++11 to build protobuf code starting from 3.4.0 or 3.5.0 release. Please join this github issue to provide your feedback.

C++

• Fixed map fields serialization of DynamicMessage to correctly serialize both key and value regardless of their presence.
• Parser now rejects field number 0 correctly.
• New API Message::SpaceUsedLong() that’s equivalent to Message::SpaceUsed() but returns the value in size_t.
• JSON support
  • New flag always_print_enums_as_ints in JsonPrintOptions.
  • New flag preserve_proto_field_names in JsonPrintOptions. It will instruct the JSON printer to use the original field name declared in the .proto file instead of converting them to lowerCamelCase when printing JSON.
  • JsonPrintOptions.always_print_primtive_fields now works for oneof message fields.
  • Fixed a bug that doesn’t allow different fields to set the same json_name value.
  • Fixed a performance bug that causes excessive memory copy when printing large messages.
• Various performance optimizations.

Java

• Map field setters eagerly validate inputs and throw NullPointerExceptions as appropriate.
• Added ByteBuffer overloads to the generated parsing methods and the Parser interface.
• proto3 enum's getNumber() method now throws on UNRECOGNIZED values.
• Output of JsonFormat is now locale independent.

Python

• Added FindServiceByName() in the pure-Python DescriptorPool. This works only for descriptors added with DescriptorPool.Add(). Generated descriptor_pool does not support this yet.
• Added a descriptor_pool parameter for parsing Any in text_format.Parse().
• descriptor_pool.FindFileContainingSymbol() now is able to find nested extensions.
• Extending empty [] to repeated field now sets parent message presence.

PHP

• Added file option php_class_prefix. The prefix will be prepended to all generated classes defined in the file.
• When encoding, negative int32 values are sign-extended to int64.
• Repeated/Map field setter accepts a regular PHP array. Type checking is done on the array elements.
• encode/decode are renamed to serializeToString/mergeFromString.
• Added mergeFrom, clear method on Message.
• Fixed a bug that oneof accessor didn’t return the field name that is actually set.
• C extension now works with php7.
• This is the first GA release of PHP. We guarantee that old generated code can always work with new runtime and new generated code.

Objective-C

• Fixed help for GPBTimestamp for dates before the epoch that contain fractional seconds.
• Added GPBMessageDropUnknownFieldsRecursively() to remove unknowns from a message and any sub messages.
• Addressed a threading race in extension registration/lookup.
• Increased the max message parsing depth to 100 to match the other languages.
• Removed some use of dispatch_once in favor of atomic compare/set since it needs to be heap based.
• Fixes for new Xcode 8.3 warnings.

C#

• Fixed MapField.Values.CopyTo, which would throw an exception unnecessarily if provided exactly the right size of array to copy to.
• Fixed enum JSON formatting when multiple names mapped to the same numeric value.
• Added JSON formatting option to format enums as integers.
• Modified RepeatedField to implement IReadOnlyList.
• Introduced the start of custom option handling; it's not as pleasant as it might be, but the information is at least present. We expect to extend code generation to improve this in the future.
• Introduced ByteString.FromStream and ByteString.FromStreamAsync to efficiently create a ByteString from a stream.
• Added whole-message deprecation, which decorates the class with [Obsolete].

Ruby

• Fixed Message#to_h for messages with map fields.
• Fixed memcpy() in binary gems to work for old glibc, without breaking the build for non-glibc libc’s like musl.

Javascript

• Added compatibility tests for version 3.0.0.
• Added conformance tests.
• Fixed serialization of extensions: we need to emit a value even if it is falsy (like the number 0).
• Use closurebuilder.py in favor of calcdeps.py for compiling JavaScript.

- C++
Published by xfxyjwf over 9 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.2.0

General

• Added protoc version number to protoc plugin protocol. It can be used by
  protoc plugin to detect which version of protoc is used with the plugin and
  mitigate known problems in certain version of protoc.

C++

• The default parsing byte size limit has been raised from 64MB to 2GB.
• Added rvalue setters for non-arena string fields.
• Enabled debug logging for Android.
• Fixed a double-free problem when using Reflection::SetAllocatedMessage()
  with extension fields.
• Fixed several deterministic serialization bugs:
• MessageLite::SerializeAsString() now respects the global deterministic
  serialization flag.
• Extension fields are serialized deterministically as well. Fixed protocol
  compiler to correctly report importing-self as an error.
• Fixed FileDescriptor::DebugString() to print custom options correctly.
• Various performance/codesize optimizations and cleanups.

Java

• The default parsing byte size limit has been raised from 64MB to 2GB.
• Added recursion limit when parsing JSON.
• Fixed a bug that enumType.getDescriptor().getOptions() doesn't have custom
  options.
• Fixed generated code to support field numbers up to 2^29-1.

Python

• You can now assign NumPy scalars/arrays (np.int32, np.int64) to protobuf
  fields, and assigning other numeric types has been optimized for
  performance.
• Pure-Python: message types are now garbage-collectable.
• Python/C++: a lot of internal cleanup/refactoring.

PHP (Alpha)

• For 64-bit integers type (int64/uint64/sfixed64/fixed64/sint64), use PHP
  integer on 64-bit environment and PHP string on 32-bit environment.
• PHP generated code also conforms to PSR-4 now.
• Fixed ZTS build for c extension.
• Fixed c extension build on Mac.
• Fixed c extension build on 32-bit linux.
• Fixed the bug that message without namespace is not found in the descriptor
  pool. (#2240)
• Fixed the bug that repeated field is not iterable in c extension.
• Message names Empty will be converted to GPBEmpty in generated code.
• Added phpdoc in generated files.
• The released API is almost stable. Unless there is large problem, we won't
  change it. See
  https://developers.google.com/protocol-buffers/docs/reference/php-generated
  for more details.

Objective-C

• Added support for push/pop of the stream limit on CodedInputStream for
  anyone doing manual parsing.

C#

• No changes.

Ruby

• Message objects now support #respond_to? for field getters/setters.
• You can now compare “message == non_message_object” and it will return false
  instead of throwing an exception.
• JRuby: fixed #hashCode to properly reflect the values in the message.

Javascript

• Deserialization of repeated fields no longer has quadratic performance
  behavior.
• UTF-8 encoding/decoding now properly supports high codepoints.
• Added convenience methods for some well-known types: Any, Struct, and
  Timestamp. These make it easier to convert data between native JavaScript
  types and the well-known protobuf types.

- C++
Published by TeBoring over 9 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.2.0rc2

Release candidate for v3.2.0.

- C++
Published by TeBoring over 9 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.1.0

General

• Proto3 support in PHP (alpha).
• Various bug fixes.

C++

• Added MessageLite::ByteSizeLong() that’s equivalent to
  MessageLite::ByteSize() but returns the value in size_t. Useful to check
  whether a message is over the 2G size limit that protobuf can support.
• Moved default_instances to global variables. This allows default_instance
  addresses to be known at compile time.
• Adding missing generic gcc 64-bit atomicops.
• Restore New*Callback into google::protobuf namespace since these are used
  by the service stubs code
• JSON support.
  • Fixed some conformance issues.
• Fixed a JSON serialization bug for bytes fields.

Java

• Fixed a bug in TextFormat that doesn’t accept empty repeated fields (i.e.,
  “field: [ ]”).
• JSON support
  • Fixed JsonFormat to do correct snake_case-to-camelCase conversion for
    non-style-conforming field names.
  • Fixed JsonFormat to parse empty Any message correctly.
  • Added an option to JsonFormat.Parser to ignore unknown fields.
• Experimental API
  • Added UnsafeByteOperations.unsafeWrap(byte[]) to wrap a byte array into
    ByteString without copy.

Python

• JSON support
  • Fixed some conformance issues.

PHP (Alpha)

• We have added the proto3 support for PHP via both a pure PHP package and a
  native c extension. The pure PHP package is intended to provide usability
  to wider range of PHP platforms, while the c extension is intended to
  provide higher performance. Both implementations provide the same runtime
  APIs and share the same generated code. Users don’t need to re-generate
  code for the same proto definition when they want to switch the
  implementation later. The pure PHP package is included in the php/src
  directory, and the c extension is included in the php/ext directory.

  Both implementations provide idiomatic PHP APIs:

  • All messages and enums are defined as PHP classes.
  • All message fields can only be accessed via getter/setter.
  • Both repeated field elements and map elements are stored in containers
    that act like a normal PHP array.

  Unlike several existing third-party PHP implementations for protobuf, our
  implementations are built on a "strongly-typed" philosophy: message fields
  and array/map containers will throw exceptions eagerly when values of the
  incorrect type (not including those that can be type converted, e.g.,
  double <-> integer <-> numeric string) are inserted.

  Currently, pure PHP runtime supports php5.5, 5.6 and 7 on linux. C
  extension runtime supports php5.5 and 5.6 on linux.

  See php/README.md for more details about installment. See
  https://developers.google.com/protocol-buffers/docs/phptutorial for more
  details about APIs.

Objective-C

• Helpers are now provided for working the the Any well known type (see
  GPBWellKnownTypes.h for the api additions).
• Some improvements in startup code (especially when extensions aren’t used).

Javascript

• Fixed missing import of jspb.Map
• Fixed valueWriterFn variable name

Ruby

• Fixed hash computation for JRuby's RubyMessage
• Make sure map parsing frames are GC-rooted.
• Added API support for well-known types.

C#

• Removed check on dependency in the C# reflection API.

- C++
Published by TeBoring almost 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.2

General

• Various bug fixes.

Objective C

• Fix for oneofs in proto3 syntax files where fields were set to the zero
  value.
• Fix for embedded null character in strings.
• CocoaDocs support

Ruby

• Fixed memory corruption bug in parsing that could occur under GC pressure.

Javascript

• jspb.Map is now properly exported to CommonJS modules.

C#

• Removed legacy_enum_values flag.

- C++
Published by liujisi almost 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0

Version 3.0.0

This change log summarizes all the changes since the last stable release
(v2.6.1). See the last section about changes since v3.0.0-beta-4.

Proto3

• Introduced Protocol Buffers language version 3 (aka proto3).

  When protocol buffers was initially open sourced it implemented Protocol
  Buffers language version 2 (aka proto2), which is why the version number
  started from v2.0.0. From v3.0.0, a new language version (proto3) is
  introduced while the old version (proto2) will continue to be supported.

  The main intent of introducing proto3 is to clean up protobuf before pushing
  the language as the foundation of Google's new API platform. In proto3, the
  language is simplified, both for ease of use and to make it available in a
  wider range of programming languages. At the same time a few features are
  added to better support common idioms found in APIs.

  The following are the main new features in language version 3:

  1. Removal of field presence logic for primitive value fields, removal of
     required fields, and removal of default values. This makes proto3
     significantly easier to implement with open struct representations, as
     in languages like Android Java, Objective C, or Go.
  2. Removal of unknown fields.
  3. Removal of extensions, which are instead replaced by a new standard
     type called Any.
  4. Fix semantics for unknown enum values.
  5. Addition of maps (back-ported to proto2)
  6. Addition of a small set of standard types for representation of time,
     dynamic data, etc (back-ported to proto2)
  7. A well-defined encoding in JSON as an alternative to binary proto
     encoding.

  A new notion "syntax" is introduced to specify whether a .proto file
  uses proto2 or proto3:

  // foo.proto
  syntax = "proto3";
  message Bar {...}
  

  If omitted, the protocol buffer compiler generates a warning and "proto2" is
  used as the default. This warning will be turned into an error in a future
  release.

  We recommend that new Protocol Buffers users use proto3. However, we do not
  generally recommend that existing users migrate from proto2 from proto3 due
  to API incompatibility, and we will continue to support proto2 for a long
  time.

  Other significant changes in proto3.

• Explicit "optional" keyword are disallowed in proto3 syntax, as fields are
  optional by default; required fields are no longer supported.

• Removed non-zero default values and field presence logic for non-message
  fields. e.g. has_xxx() methods are removed; primitive fields set to default
  values (0 for numeric fields, empty for string/bytes fields) will be skipped
  during serialization.

• Group fields are no longer supported in proto3 syntax.

• Changed repeated primitive fields to use packed serialization by default in
  proto3 (implemented for C++, Java, Python in this release). The user can
  still disable packed serialization by setting packed to false for now.

• Added well-known type protos (any.proto, empty.proto, timestamp.proto,
  duration.proto, etc.). Users can import and use these protos just like
  regular proto files. Additional runtime support are available for each
  language.

• Proto3 JSON is supported in several languages (fully supported in C++, Java,
  Python and C# partially supported in Ruby). The JSON spec is defined in the
  proto3 language guide:

  https://developers.google.com/protocol-buffers/docs/proto3#json

  We will publish a more detailed spec to define the exact behavior of
  proto3-conformant JSON serializers and parsers. Until then, do not rely
  on specific behaviors of the implementation if it’s not documented in
  the above spec.

• Proto3 enforces strict UTF-8 checking. Parsing will fail if a string
  field contains non UTF-8 data.

General

• Introduced new language implementations (C#, JavaScript, Ruby, Objective-C)
  to proto3.

• Added support for map fields (implemented in both proto2 and proto3).
  Map fields can be declared using the following syntax:

  message Foo {
    map<string, string> values = 1;
  }
  

  The data of a map field is stored in memory as an unordered map and
  can be accessed through generated accessors.

• Added a "reserved" keyword in both proto2 and proto3 syntax. Users can use
  this keyword to declare reserved field numbers and names to prevent them
  from being reused by other fields in the same message.

  To reserve field numbers, add a reserved declaration in your message:

  message TestMessage {
    reserved 2, 15, 9 to 11, 3;
  }
  

  This reserves field numbers 2, 3, 9, 10, 11 and 15. If a user uses any of
  these as field numbers, the protocol buffer compiler will report an error.

  Field names can also be reserved:

  message TestMessage {
    reserved "foo", "bar";
  }
  

• Added a deterministic serialization API (currently available in C++). The
  deterministic serialization guarantees that given a binary, equal messages
  will be serialized to the same bytes. This allows applications like
  MapReduce to group equal messages based on the serialized bytes. The
  deterministic serialization is, however, NOT canonical across languages; it
  is also unstable across different builds with schema changes due to unknown
  fields. Users who need canonical serialization, e.g. persistent storage in
  a canonical form, fingerprinting, etc, should define their own
  canonicalization specification and implement the serializer using reflection
  APIs rather than relying on this API.

• Added a new field option "json_name". By default proto field names are
  converted to "lowerCamelCase" in proto3 JSON format. This option can be
  used to override this behavior and specify a different JSON name for the
  field.

• Added conformance tests to ensure implementations are following proto3 JSON
  specification.

C++

• Added arena allocation support (for both proto2 and proto3).

  Profiling shows memory allocation and deallocation constitutes a significant
  fraction of CPU-time spent in protobuf code and arena allocation is a
  technique introduced to reduce this cost. With arena allocation, new
  objects are allocated from a large piece of preallocated memory and
  deallocation of these objects is almost free. Early adoption shows 20% to
  50% improvement in some Google binaries.

  To enable arena support, add the following option to your .proto file:

  option cc_enable_arenas = true;
  

  The protocol buffer compiler will generate additional code to make the generated
  message classes work with arenas. This does not change the existing API
  of protobuf messages and does not affect wire format. Your existing code
  should continue to work after adding this option. In the future we will
  make this option enabled by default.

  To actually take advantage of arena allocation, you need to use the arena
  APIs when creating messages. A quick example of using the arena API:

  {
    google::protobuf::Arena arena;
    // Allocate a protobuf message in the arena.
    MyMessage* message = Arena::CreateMessage<MyMessage>(&arena);
    // All submessages will be allocated in the same arena.
    if (!message->ParseFromString(data)) {
      // Deal with malformed input data.
    }
    // Must not delete the message here. It will be deleted automatically
    // when the arena is destroyed.
  }
  

  Currently arena allocation does not work with map fields. Enabling arenas in a .proto
  file containing map fields will result in compile errors in the generated
  code. This will be addressed in a future release.

• Added runtime support for the Any type. To use Any in your proto file, first
  import the definition of Any:

  // foo.proto
  import "google/protobuf/any.proto";
  message Foo {
    google.protobuf.Any any_field = 1;
  }
  message Bar {
    int32 value = 1;
  }
  

  Then in C++ you can access the Any field using PackFrom()/UnpackTo()
  methods:

  Foo foo;
  Bar bar = ...;
  foo.mutable_any_field()->PackFrom(bar);
  ...
  if (foo.any_field().IsType<Bar>()) {
    foo.any_field().UnpackTo(&bar);
    ...
  }
  

• In text format, the entries of a map field will be sorted by key.

• Introduced new utility functions/classes in the google/protobuf/util
  directory:

  • MessageDifferencer: compare two proto messages and report their
    differences.
  • JsonUtil: support converting protobuf binary format to/from JSON.
  • TimeUtil: utility functions to work with well-known types Timestamp
    and Duration.
  • FieldMaskUtil: utility functions to work with FieldMask.

• Introduced a deterministic serialization API in
  CodedOutputStream::SetSerializationDeterministic(bool). See the notes about
  deterministic serialization in the General section.

Java

• Introduced a new util package that will be distributed as a separate
  artifact in maven. It contains:
  • JsonFormat: convert proto messages to/from JSON.
  • Timestamps/Durations: utility functions to work with Timestamp and Duration.
  • FieldMaskUtil: utility functions to work with FieldMask.
• 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.
• Performance optimizations for String fields serialization.
• The static PARSER in each generated message is deprecated, and it will
  be removed in a future release. A static parser() getter is generated
  for each message type instead.
• File option "java_generate_equals_and_hash" is now deprecated. equals() and
  hashCode() methods are generated by default.

Python

• Python has received several updates, most notably support for proto3
  semantics in any .proto file that declares syntax="proto3".
  Messages declared in proto3 files no longer represent field presence
  for scalar fields (number, enums, booleans, or strings). You can
  no longer call HasField() for such fields, and they are serialized
  based on whether they have a non-zero/empty/false value.
• One other notable change is in the C++-accelerated implementation.
  Descriptor objects (which describe the protobuf schema and allow
  reflection over it) are no longer duplicated between the Python
  and C++ layers. The Python descriptors are now simple wrappers
  around the C++ descriptors. This change should significantly
  reduce the memory usage of programs that use a lot of message
  types.
• Added map support.
  • maps now have a dict-like interface (msg.map_field[key] = value)
  • existing code that modifies maps via the repeated field interface
    will need to be updated.
• Added proto3 JSON format utility. It includes support for all field types and a few well-known types.
• Added runtime support for Any, Timestamp, Duration and FieldMask.
• "[ ]" is now accepted for repeated scalar fields in text format parser.
• Removed legacy Python 2.5 support.
• Moved to a single Python 2.x/3.x-compatible codebase

Ruby

• We have added proto3 support for Ruby via a native C/JRuby extension.

  For the moment we only support proto3. Proto2 support is planned, but not
  yet implemented. Proto3 JSON is supported, but the special JSON mappings
  for the well-known types are not yet implemented.

  The Ruby extension itself is included in the ruby/ directory, and details on
  building and installing the extension are in ruby/README.md. The extension
  is also be published as a Ruby gem. Code generator support is included as
  part of protoc with the --ruby_out flag.

  The Ruby extension implements a user-friendly DSL to define message types
  (also generated by the code generator from .proto files). Once a message
  type is defined, the user may create instances of the message that behave in
  ways idiomatic to Ruby. For example:

  • Message fields are present as ordinary Ruby properties (getter method
    foo and setter method foo=).
  • Repeated field elements are stored in a container that acts like a native
    Ruby array, and map elements are stored in a container that acts like a
    native Ruby hashmap.
  • The usual well-known methods, such as #to_s, #dup, and the like, are
    present.

  Unlike several existing third-party Ruby extensions for protobuf, this
  extension is built on a "strongly-typed" philosophy: message fields and
  array/map containers will throw exceptions eagerly when values of the
  incorrect type are inserted.

  See ruby/README.md for details.

Objective-C

• Objective-C includes a code generator and a native objective-c runtime
  library. By adding “--objc_out” to protoc, the code generator will generate
  a header(.pbobjc.h) and an implementation file(.pbobjc.m) for each proto
  file.

  In this first release, the generated interface provides: enums, messages,
  field support(single, repeated, map, oneof), proto2 and proto3 syntax
  support, parsing and serialization. It’s compatible with ARC and non-ARC
  usage. In addition, users can access it via the swift bridging header.

C#

• C# support is derived from the project at
  https://github.com/jskeet/protobuf-csharp-port, which is now in maintenance mode.
• The primary differences between the previous project and the proto3 version are that
  message types are now mutable, and the codegen is integrated in protoc
• There are two NuGet packages: Google.Protobuf (the support library) and
  Google.Protobuf.Tools (containing protoc)
• Target platforms now .NET 4.5, selected portable subsets and .NET Core.
• Null values are used to represent "no value" for message type fields, and for wrapper
  types such as Int32Value which map to C# nullable value types.
• Proto3 semantics supported; proto2 files are prohibited for C# codegen.
• Enum values are 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_LIGHT_GRAY would generate a value of just LightGray).

JavaScript

• Added proto2/proto3 support for JavaScript. The runtime is written in pure
  JavaScript and works in browsers and in Node.js. To generate JavaScript
  code for your proto, invoke protoc with "--js_out". See js/README.md
  for more build instructions.
• JavaScript has support for binary protobuf format, but not proto3 JSON.
  There is also no support for reflection, since the code size impacts from this
  are often not the right choice for the browser.
• There is support for both CommonJS imports and Closure goog.require().

Lite

• Supported Proto3 lite-runtime in Java for mobile platforms.
  A new "lite" generator parameter was introduced in the protoc for C++ 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.

  For Java, --javalite_out code generator is supported as a separate compiler
  plugin in a separate branch.

• Performance optimizations for Java Lite runtime on Android:
  - Reduced allocations
  - Reduced method overhead after ProGuarding
  - Reduced code size after ProGuarding

• Java Lite protos now implement deep equals/hashCode/toString

Compatibility Notice

• v3.0.0 is the first API stable release of the v3.x series. We do not expect
  any future API breaking changes.
• For C++, Java Lite and Objective-C, source level compatibility is
  guaranteed. Upgrading from v3.0.0 to newer minor version releases will be
  source compatible. For example, if your code compiles against protobuf
  v3.0.0, it will continue to compile after you upgrade protobuf library to
  v3.1.0.
• For other languages, both source level compatibility and binary level
  compatibility are guaranteed. For example, if you have a Java binary built
  against protobuf v3.0.0. After switching the protobuf runtime binary to
  v3.1.0, your built binary should continue to work.
• Compatibility is only guaranteed for documented API and documented
  behaviors. If you are using undocumented API (e.g., use anything in the C++
  internal namespace), it can be broken by minor version releases in an
  undetermined manner.

Changes since v3.0.0-beta-4

Ruby

• When you assign a string field a.string_field = “X”, we now call
  #encode(UTF-8) on the string and freeze the copy. This saves you from
  needing to ensure the string is already encoded as UTF-8. It also prevents
  you from mutating the string after it has been assigned (this is how we
  ensure it stays valid UTF-8).
• The generated file for foo.proto is now foo_pb.rb instead of just
  foo.rb. This makes it easier to see which imports/requires are from
  protobuf generated code, and also prevents conflicts with any foo.rb file
  you might have written directly in Ruby. It is a backward-incompatible
  change: you will need to update all of your require statements.
• For package names like foo_bar, we now translate this to the Ruby module
  FooBar. This is more idiomatic Ruby than what we used to do (Foo_bar).

JavaScript

• Scalar fields like numbers and boolean now return defaults instead of
  undefined or null when they are unset. You can test for presence
  explicitly by calling hasFoo(), which we now generate for scalar fields in
  proto2.

Java Lite

• Java Lite is now implemented as a separate plugin, maintained in the
  javalite branch. Both lite runtime and protoc artifacts will be available
  in Maven.

C#

• Target platforms now .NET 4.5, selected portable subsets and .NET Core.
• legacy_enum_values option is no longer supported.

- C++
Published by liujisi about 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-beta-4

Version 3.0.0-beta-4

General

• Added a deterministic serialization API for C++. The deterministic
  serialization guarantees that given a binary, equal messages will be
  serialized to the same bytes. This allows applications like MapReduce to
  group equal messages based on the serialized bytes. The deterministic
  serialization is, however, NOT canonical across languages; it is also
  unstable across different builds with schema changes due to unknown fields.
  Users who need canonical serialization, e.g. persistent storage in a
  canonical form, fingerprinting, etc, should define their own
  canonicalization specification and implement the serializer using reflection
  APIs rather than relying on this API.

• Added OneofOptions. You can now define custom options for oneof groups.

  import "google/protobuf/descriptor.proto";
  extend google.protobuf.OneofOptions {
    optional int32 my_oneof_extension = 12345;
  }
  message Foo {
    oneof oneof_group {
      (my_oneof_extension) = 54321;
      ...
    }
  }
  

C++ (beta)

• Introduced a deterministic serialization API in
  CodedOutputStream::SetSerializationDeterministic(bool). See the notes about
  deterministic serialization in the General section.
• Added google::protobuf::Map::swap() to swap two map fields.
• Fixed a memory leak when calling Reflection::ReleaseMessage() on a message
  allocated on arena.
• Improved error reporting when parsing text format protos.
• JSON
  • Added a new parser option to ignore unknown fields when parsing JSON.
  • Added convenient methods for message to/from JSON conversion.
• Various performance optimizations.

Java (beta)

• File option "java_generate_equals_and_hash" is now deprecated. equals() and
  hashCode() methods are generated by default.
• Added a new JSON printer option "omittingInsignificantWhitespace" to produce
  a more compact JSON output. The printer will pretty-print by default.
• Updated Java runtime to be compatible with 2.5.0/2.6.1 generated protos.

Python (beta)

• Added support to pretty print Any messages in text format.
• Added a flag to ignore unknown fields when parsing JSON.
• Bugfix: "@type" field of a JSON Any message is now correctly put before
  other fields.

Objective-C (beta)

• Updated the code to support compiling with more compiler warnings
  enabled. (Issue 1616)
• Exposing more detailed errors for parsing failures. (PR 1623)
• Small (breaking) change to the naming of some methods on the support classes
  for map<>. There were collisions with the system provided KVO support, so
  the names were changed to avoid those issues. (PR 1699)
• Fixed for proper Swift bridging of error handling during parsing. (PR 1712)
• Complete support for generating sources that will go into a Framework and
  depend on generated sources from other Frameworks. (Issue 1457)

C# (beta)

• RepeatedField optimizations.
• Support for .NET Core.
• Minor bug fixes.
• Ability to format a single value in JsonFormatter (advanced usage only).
• Modifications to attributes applied to generated code.

Javascript (alpha)

• Maps now have a real map API instead of being treated as repeated fields.
• Well-known types are now provided in the google-protobuf package, and the
  code generator knows to require() them from that package.
• Bugfix: non-canonical varints are correctly decoded.

Ruby (alpha)

• Accessors for oneof fields now return default values instead of nil.

Java Lite

• Java lite support is removed from protocol compiler. It will be supported
  as a protocol compiler plugin in a separate code branch.

- C++
Published by xfxyjwf about 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-beta-3.1

Fix iOS framework.

- C++
Published by TeBoring about 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-beta-3

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.

- C++
Published by liujisi over 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-beta-2

Version 3.0.0-beta-2

General

• Introduced a new language implementation: JavaScript.
• Added a new field option "json_name". By default proto field names are
  converted to "lowerCamelCase" in proto3 JSON format. This option can be
  used to override this behavior and specify a different JSON name for the
  field.
• Added conformance tests to ensure implementations are following proto3 JSON
  specification.

C++ (Beta)

• Various bug fixes and improvements to the JSON support utility:
  • Duplicate map keys in JSON are now rejected (i.e., translation will
    fail).
  • Fixed wire-format for google.protobuf.Value/ListValue.
  • Fixed precision loss when converting google.protobuf.Timestamp.
  • Fixed a bug when parsing invalid UTF-8 code points.
  • Fixed a memory leak.
  • Reduced call stack usage.

Java (Beta)

• Cleaned up some unused methods on CodedOutputStream.
• Presized lists for packed fields during parsing in the lite runtime to
  reduce allocations and improve performance.
• Improved the performance of unknown fields in the lite runtime.
• Introduced UnsafeByteStrings to support zero-copy ByteString creation.
• Various bug fixes and improvements to the JSON support utility:
  • Fixed a thread-safety bug.
  • Added a new option “preservingProtoFieldNames” to JsonFormat.
  • Added a new option “includingDefaultValueFields” to JsonFormat.
  • Updated the JSON utility to comply with proto3 JSON specification.

Python (Beta)

• Added proto3 JSON format utility. It includes support for all field types
  and a few well-known types except for Any and Struct.
• Added runtime support for Any, Timestamp, Duration and FieldMask.
• "[ ]" is now accepted for repeated scalar fields in text format parser.

Objective-C (Beta)

• Various bug-fixes and code tweaks to pass more strict compiler warnings.
• Now has conformance test coverage and is passing all tests.

C# (Beta)

• Various bug-fixes.
• Code generation: Files generated in directories based on namespace.
• Code generation: Include comments from .proto files in XML doc
  comments (naively)
• Code generation: Change organization/naming of "reflection class" (access
  to file descriptor)
• Code generation and library: Add Parser property to MessageDescriptor,
  and introduce a non-generic parser type.
• Library: Added TypeRegistry to support JSON parsing/formatting of Any.
• Library: Added Any.Pack/Unpack support.
• Library: Implemented JSON parsing.

Javascript (Alpha)

• Added proto3 support for JavaScript. The runtime is written in pure
  JavaScript and works in browsers and in Node.js. To generate JavaScript
  code for your proto, invoke protoc with "--js_out". See js/README.md
  for more build instructions.

- C++
Published by xfxyjwf over 10 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-beta-1

Version 3.0.0-beta-1

Supported languages

• C++/Java/Python/Ruby/Nano/Objective-C/C#

About Beta

• This is the first beta release of protobuf v3.0.0. Not all languages
  have reached beta stage. Languages not marked as beta are still in
  alpha (i.e., be prepared for API breaking changes).

General

• Proto3 JSON is supported in several languages (fully supported in C++
  and Java, partially supported in Ruby/C#). The JSON spec is defined in
  the proto3 language guide:

  https://developers.google.com/protocol-buffers/docs/proto3#json

  We will publish a more detailed spec to define the exact behavior of
  proto3-conformant JSON serializers and parsers. Until then, do not rely
  on specific behaviors of the implementation if it’s not documented in
  the above spec. More specifically, the behavior is not yet finalized for
  the following:

  • Parsing invalid JSON input (e.g., input with trailing commas).
  • Non-camelCase names in JSON input.
  • The same field appears multiple times in JSON input.
  • JSON arrays contain “null” values.
  • The message has unknown fields.

• Proto3 now enforces strict UTF-8 checking. Parsing will fail if a string
  field contains non UTF-8 data.

C++ (Beta)

• Introduced new utility functions/classes in the google/protobuf/util
  directory:
  • MessageDifferencer: compare two proto messages and report their
    differences.
  • JsonUtil: support converting protobuf binary format to/from JSON.
  • TimeUtil: utility functions to work with well-known types Timestamp
    and Duration.
  • FieldMaskUtil: utility functions to work with FieldMask.
• Performance optimization of arena construction and destruction.
• Bug fixes for arena and maps support.
• Changed to use cmake for Windows Visual Studio builds.
• Added Bazel support.

Java (Beta)

• Introduced a new util package that will be distributed as a separate
  artifact in maven. It contains:
  • JsonFormat: convert proto messages to/from JSON.
  • TimeUtil: utility functions to work with Timestamp and Duration.
  • FieldMaskUtil: utility functions to work with FieldMask.
• The static PARSER in each generated message is deprecated, and it will
  be removed in a future release. A static parser() getter is generated
  for each message type instead.
• Performance optimizations for String fields serialization.
• Performance optimizations for Lite runtime on Android:
  • Reduced allocations
  • Reduced method overhead after ProGuarding
  • Reduced code size after ProGuarding

Python (Alpha)

• Removed legacy Python 2.5 support.
• Moved to a single Python 2.x/3.x-compatible codebase, instead of using 2to3.
• Fixed build/tests on Python 2.6, 2.7, 3.3, and 3.4.
  • Pure-Python works on all four.
  • Python/C++ implementation works on all but 3.4, due to changes in the
    Python/C++ API in 3.4.
• Some preliminary work has been done to allow for multiple DescriptorPools
  with Python/C++.

Ruby (Alpha)

• Many bugfixes:
  • fixed parsing/serialization of bytes, sint, sfixed types
  • other parser bugfixes
  • fixed memory leak affecting Ruby 2.2

JavaNano (Alpha)

• JavaNano generated code now will be put in a nano package by default to
  avoid conflicts with Java generated code.

Objective-C (Alpha)

• Added non-null markup to ObjC library. Requires SDK 8.4+ to build.
• Many bugfixes:
  • Removed the class/enum filter.
  • Renamed some internal types to avoid conflicts with the well-known types
    protos.
  • Added missing support for parsing repeated primitive fields in packed or
    unpacked forms.
  • Added *Count for repeated and map<> fields to avoid auto-create when
    checking for them being set.

C# (Alpha)

• Namespace changed to Google.Protobuf (and NuGet package will be named
  correspondingly).
• Target platforms now .NET 4.5 and selected portable subsets only.
• Removed lite runtime.
• Reimplementation to use mutable message types.
• Null references used to represent "no value" for message type fields.
• Proto3 semantics supported; proto2 files are prohibited for C# codegen.
  Most proto3 features supported:
  • JSON formatting (a.k.a. serialization to JSON), including well-known
    types (except for Any).
  • Wrapper types mapped to nullable value types (or string/ByteString
    allowing nullability). JSON parsing is not supported yet.
  • maps
  • oneof
  • enum unknown value preservation

- C++
Published by xfxyjwf almost 11 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-alpha-3

Version 3.0.0-alpha-3 (C++/Java/Python/Ruby/JavaNano/Objective-C/C#)

General

• Introduced two new language implementations (Objective-C, C#) to proto3.

• Explicit "optional" keyword are disallowed in proto3 syntax, as fields are
  optional by default.

• Group fields are no longer supported in proto3 syntax.

• Changed repeated primitive fields to use packed serialization by default in
  proto3 (implemented for C++, Java, Python in this release). The user can
  still disable packed serialization by setting packed to false for now.

• Added well-known type protos (any.proto, empty.proto, timestamp.proto,
  duration.proto, etc.). Users can import and use these protos just like
  regular proto files. Addtional runtime support will be added for them in
  future releases (in the form of utility helper functions, or having them
  replaced by language specific types in generated code).

• Added a "reserved" keyword in both proto2 and proto3 syntax. User can use
  this keyword to declare reserved field numbers and names to prevent them
  from being reused by other fields in the same message.

  To reserve field numbers, add a reserved declaration in your message:

  message TestMessage {
    reserved 2, 15, 9 to 11, 3;
  }
  

  This reserves field numbers 2, 3, 9, 10, 11 and 15. If a user uses any of
  these as field numbers, the protocol buffer compiler will report an error.

  Field names can also be reserved:

  message TestMessage {
    reserved "foo", "bar";
  }
  

• Various bug fixes since 3.0.0-alpha-2

Objective-C

• Objective-C includes a code generator and a native objective-c runtime
  library. By adding “--objc_out” to protoc, the code generator will generate
  a header(.pbobjc.h) and an implementation file(.pbobjc.m) for each proto
  file.

  In this first release, the generated interface provides: enums, messages,
  field support(single, repeated, map, oneof), proto2 and proto3 syntax
  support, parsing and serialization. It’s compatible with ARC and non-ARC
  usage. Besides, user can also access it via the swift bridging header.

  See objectivec/README.md for details.

C#

• C# protobufs are based on project
  https://github.com/jskeet/protobuf-csharp-port. The original project was
  frozen and all the new development will happen here.

• Codegen plugin for C# was completely rewritten to C++ and is now an
  intergral part of protoc.

• Some refactorings and cleanup has been applied to the C# runtime library.

• Only proto2 is supported in C# at the moment, proto3 support is in
  progress and will likely bring significant breaking changes to the API.

  See csharp/README.md for details.

C++

• Added runtime support for Any type. To use Any in your proto file, first
  import the definition of Any:

  // foo.proto
  import "google/protobuf/any.proto";
  message Foo {
    google.protobuf.Any any_field = 1;
  }
  message Bar {
    int32 value = 1;
  }
  

  Then in C++ you can access the Any field using PackFrom()/UnpackTo()
  methods:

  Foo foo;
  Bar bar = ...;
  foo.mutable_any_field()->PackFrom(bar);
  ...
  if (foo.any_field().IsType<Bar>()) {
    foo.any_field().UnpackTo(&bar);
    ...
  }
  

• In text format, entries of a map field will be sorted by key.

Java

• Continued optimizations on the lite runtime to improve performance for
  Android.

Python

• Added map support.
  • maps now have a dict-like interface (msg.map_field[key] = value)
  • existing code that modifies maps via the repeated field interface
    will need to be updated.

Ruby

• Improvements to RepeatedField's emulation of the Ruby Array API.
• Various speedups and internal cleanups.

- C++
Published by TeBoring about 11 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v2.4.1

Version 2.4.1

C++

• Fixed the frendship problem for old compilers to make the library now gcc 3
  compatible again.
• Fixed vcprojects/extract_includes.bat to extract compiler/plugin.h.

Java

• Removed usages of JDK 1.6 only features to make the library now JDK 1.5
  compatible again.
• Fixed a bug about negative enum values.
• serialVersionUID is now defined in generated messages for java serializing.
• Fixed protoc to use java.lang.Object, which makes "Object" now a valid
  message name again.

Python

• Experimental C++ implementation now requires C++ protobuf library installed.
  See the README.txt in the python directory for details.

- C++
Published by xfxyjwf over 11 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v2.5.0

Version 2.5.0

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.

- C++
Published by xfxyjwf over 11 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-alpha-2

Version 3.0.0-alpha-2 (C++/Java/Python/Ruby/JavaNano)

General

• Introduced Protocol Buffers language version 3 (aka proto3).

  When protobuf was initially opensourced it implemented Protocol Buffers
  language version 2 (aka proto2), which is why the version number
  started from v2.0.0. From v3.0.0, a new language version (proto3) is
  introduced while the old version (proto2) will continue to be supported.

  The main intent of introducing proto3 is to clean up protobuf before
  pushing the language as the foundation of Google's new API platform.
  In proto3, the language is simplified, both for ease of use and to
  make it available in a wider range of programming languages. At the
  same time a few features are added to better support common idioms
  found in APIs.

  The following are the main new features in language version 3:

  1. Removal of field presence logic for primitive value fields, removal
     of required fields, and removal of default values. This makes proto3
     significantly easier to implement with open struct representations,
     as in languages like Android Java, Objective C, or Go.
  2. Removal of unknown fields.
  3. Removal of extensions, which are instead replaced by a new standard
     type called Any.
  4. Fix semantics for unknown enum values.
  5. Addition of maps.
  6. Addition of a small set of standard types for representation of time,
     dynamic data, etc.
  7. A well-defined encoding in JSON as an alternative to binary proto
     encoding.

  This release (v3.0.0-alpha-2) includes partial proto3 support for C++,
  Java, Python, Ruby and JavaNano. Items 6 (well-known types) and 7
  (JSON format) in the above feature list are not implemented.

  A new notion "syntax" is introduced to specify whether a .proto file
  uses proto2 or proto3:

  // foo.proto
  syntax = "proto3";
  message Bar {...}
  

  If omitted, the protocol compiler will generate a warning and "proto2" will
  be used as the default. This warning will be turned into an error in a
  future release.

  We recommend that new Protocol Buffers users use proto3. However, we do not
  generally recommend that existing users migrate from proto2 from proto3 due
  to API incompatibility, and we will continue to support proto2 for a long
  time.

• Added support for map fields (implemented in proto2 and proto3 C++/Java/JavaNano and proto3 Ruby).

  Map fields can be declared using the following syntax:

  message Foo {
    map<string, string> values = 1;
  }
  

  Data of a map field will be stored in memory as an unordered map and it
  can be accessed through generated accessors.

C++

• Added arena allocation support (for both proto2 and proto3).

  Profiling shows memory allocation and deallocation constitutes a significant
  fraction of CPU-time spent in protobuf code and arena allocation is a
  technique introduced to reduce this cost. With arena allocation, new
  objects will be allocated from a large piece of preallocated memory and
  deallocation of these objects is almost free. Early adoption shows 20% to
  50% improvement in some Google binaries.

  To enable arena support, add the following option to your .proto file:

  option cc_enable_arenas = true;
  

  Protocol compiler will generate additional code to make the generated
  message classes work with arenas. This does not change the existing API
  of protobuf messages and does not affect wire format. Your existing code
  should continue to work after adding this option. In the future we will
  make this option enabled by default.

  To actually take advantage of arena allocation, you need to use the arena
  APIs when creating messages. A quick example of using the arena API:

  {
    google::protobuf::Arena arena;
    // Allocate a protobuf message in the arena.
    MyMessage* message = Arena::CreateMessage<MyMessage>(&arena);
    // All submessages will be allocated in the same arena.
    if (!message->ParseFromString(data)) {
      // Deal with malformed input data.
    }
    // Must not delete the message here. It will be deleted automatically
    // when the arena is destroyed.
  }
  

  Currently arena does not work with map fields. Enabling arena in a .proto
  file containing map fields will result in compile errors in the generated
  code. This will be addressed in a future release.

Python

• Python has received several updates, most notably support for proto3
  semantics in any .proto file that declares syntax="proto3".
  Messages declared in proto3 files no longer represent field presence
  for scalar fields (number, enums, booleans, or strings). You can
  no longer call HasField() for such fields, and they are serialized
  based on whether they have a non-zero/empty/false value.
• One other notable change is in the C++-accelerated implementation.
  Descriptor objects (which describe the protobuf schema and allow
  reflection over it) are no longer duplicated between the Python
  and C++ layers. The Python descriptors are now simple wrappers
  around the C++ descriptors. This change should significantly
  reduce the memory usage of programs that use a lot of message
  types.

Ruby

• We have added proto3 support for Ruby via a native C extension.

  The Ruby extension itself is included in the ruby/ directory, and details on
  building and installing the extension are in ruby/README.md. The extension
  will also be published as a Ruby gem. Code generator support is included as
  part of protoc with the --ruby_out flag.

  The Ruby extension implements a user-friendly DSL to define message types
  (also generated by the code generator from .proto files). Once a message
  type is defined, the user may create instances of the message that behave in
  ways idiomatic to Ruby. For example:

  • Message fields are present as ordinary Ruby properties (getter method
    foo and setter method foo=).
  • Repeated field elements are stored in a container that acts like a native
    Ruby array, and map elements are stored in a container that acts like a
    native Ruby hashmap.
  • The usual well-known methods, such as #to_s, #dup, and the like, are
    present.

  Unlike several existing third-party Ruby extensions for protobuf, this
  extension is built on a "strongly-typed" philosophy: message fields and
  array/map containers will throw exceptions eagerly when values of the
  incorrect type are inserted.

  See ruby/README.md for details.

JavaNano

• JavaNano is a special code generator and runtime library designed especially
  for resource-restricted systems, like Android. It is very resource-friendly
  in both the amount of code and the runtime overhead. Here is an an overview
  of JavaNano features compared with the official Java protobuf:

  • No descriptors or message builders.
  • All messages are mutable; fields are public Java fields.
  • For optional fields only, encapsulation behind setter/getter/hazzer/
    clearer functions is opt-in, which provide proper 'has' state support.
  • For proto2, if not opted in, has state (field presence) is not available.
    Serialization outputs all fields not equal to their defaults.
    The behavior is consistent with proto3 semantics.
  • Required fields (proto2 only) are always serialized.
  • Enum constants are integers; protection against invalid values only
    when parsing from the wire.
  • Enum constants can be generated into container interfaces bearing
    the enum's name (so the referencing code is in Java style).
  • CodedInputByteBufferNano can only take byte[](not InputStream).
  • Similarly CodedOutputByteBufferNano can only write to byte[].
  • Repeated fields are in arrays, not ArrayList or Vector. Null array
    elements are allowed and silently ignored.
  • Full support for serializing/deserializing repeated packed fields.
  • Support extensions (in proto2).
  • Unset messages/groups are null, not an immutable empty default
    instance.
  • toByteArray(...) and mergeFrom(...) are now static functions of
    MessageNano.
  • The 'bytes' type translates to the Java type byte[].

  See javanano/README.txt for details.

- C++
Published by liujisi over 11 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v3.0.0-alpha-1

Version 3.0.0-alpha-1 (C++/Java)

General

• Introduced Protocol Buffers language version 3 (aka proto3).

  When protobuf was initially opensourced it implemented Protocol Buffers
  language version 2 (aka proto2), which is why the version number
  started from v2.0.0. From v3.0.0, a new language version (proto3) is
  introduced while the old version (proto2) will continue to be supported.

  The main intent of introducing proto3 is to clean up protobuf before
  pushing the language as the foundation of Google's new API platform.
  In proto3, the language is simplified, both for ease of use and to
  make it available in a wider range of programming languages. At the
  same time a few features are added to better support common idioms
  found in APIs.

  The following are the main new features in language version 3:

  1. Removal of field presence logic for primitive value fields, removal
     of required fields, and removal of default values. This makes proto3
     significantly easier to implement with open struct representations,
     as in languages like Android Java, Objective C, or Go.
  2. Removal of unknown fields.
  3. Removal of extensions, which are instead replaced by a new standard
     type called Any.
  4. Fix semantics for unknown enum values.
  5. Addition of maps.
  6. Addition of a small set of standard types for representation of time,
     dynamic data, etc.
  7. A well-defined encoding in JSON as an alternative to binary proto
     encoding.

  This release (v3.0.0-alpha-1) includes partial proto3 support for C++ and
  Java. Items 6 (well-known types) and 7 (JSON format) in the above feature
  list are not impelmented.

  A new notion "syntax" is introduced to specify whether a .proto file
  uses proto2 or proto3:

  // foo.proto
  syntax = "proto3";
  message Bar {...}
  

  If omitted, the protocol compiler will generate a warning and "proto2" will
  be used as the default. This warning will be turned into an error in a
  future release.

  We recommend that new Protocol Buffers users use proto3. However, we do not
  generally recommend that existing users migrate from proto2 from proto3 due
  to API incompatibility, and we will continue to support proto2 for a long
  time.

• Added support for map fields (implemented in C++/Java for both proto2 and
  proto3).

  Map fields can be declared using the following syntax:

  message Foo {
    map<string, string> values = 1;
  }
  

  Data of a map field will be stored in memory as an unordered map and it
  can be accessed through generated accessors.

C++

• Added arena allocation support (for both proto2 and proto3).

  Profiling shows memory allocation and deallocation constitutes a significant
  fraction of CPU-time spent in protobuf code and arena allocation is a
  technique introduced to reduce this cost. With arena allocation, new
  objects will be allocated from a large piece of preallocated memory and
  deallocation of these objects is almost free. Early adoption shows 20% to
  50% improvement in some Google binaries.

  To enable arena support, add the following option to your .proto file:

  option cc_enable_arenas = true;
  

  Protocol compiler will generate additional code to make the generated
  message classes work with arenas. This does not change the existing API
  of protobuf messages and does not affect wire format. Your existing code
  should continue to work after adding this option. In the future we will
  make this option enabled by default.

  To actually take advantage of arena allocation, you need to use the arena
  APIs when creating messages. A quick example of using the arena API:

  {
    google::protobuf::Arena arena;
    // Allocate a protobuf message in the arena.
    MyMessage* message = Arena::CreateMessage<MyMessage>(&arena);
    // All submessages will be allocated in the same arena.
    if (!message->ParseFromString(data)) {
      // Deal with malformed input data.
    }
    // Must not delete the message here. It will be deleted automatically
    // when the arena is destroyed.
  }
  

  Currently arena does not work with map fields. Enabling arena in a .proto
  file containing map fields will result in compile errors in the generated
  code. This will be addressed in a future release.

- C++
Published by xfxyjwf over 11 years ago

https://github.com/protocolbuffers/protobuf - Protocol Buffers v2.6.1

2014-10-20 version 2.6.1

C++

• Added atomicops support for Solaris.
• Released memory allocated by InitializeDefaultRepeatedFields() and GetEmptyString(). Some memory sanitizers reported them as memory leaks.

Java

• Updated DynamicMessage.setField() to handle repeated enum values correctly.
• Fixed a bug that caused NullPointerException to be thrown when converting manually constructed FileDescriptorProto to FileDescriptor.

Python

• Fixed WhichOneof() to work with de-serialized protobuf messages.
• Fixed a missing file problem of Python C++ implementation.

- C++
Published by xfxyjwf almost 12 years ago

https://github.com/protocolbuffers/protobuf - v2.6.0

2014-08-15 version 2.6.0

General

• Added oneofs(unions) feature. Fields in the same oneof will share
  memory and at most one field can be set at the same time. Use the
  oneof keyword to define a oneof like:

  message SampleMessage {
    oneof test_oneof {
      string name = 4;
      YourMessage sub_message = 9;
    }
  }
  

• Files, services, enums, messages, methods and enum values can be marked
  as deprecated now.

• Added Support for list values, including lists of mesaages, when
  parsing text-formatted protos in C++ and Java.

  For example:  foo: [1, 2, 3]
  

C++

• Enhanced customization on TestFormat printing.
• Added SwapFields() in reflection API to swap a subset of fields.
  Added SetAllocatedMessage() in reflection API.
• Repeated primitive extensions are now packable. The
  [packed=true] option only affects serializers. Therefore, it is
  possible to switch a repeated extension field to packed format
  without breaking backwards-compatibility.
• Various speed optimizations.

Java

• writeTo() method in ByteString can now write a substring to an
  output stream. Added endWith() method for ByteString.
• ByteString and ByteBuffer are now supported in CodedInputStream
  and CodedOutputStream.
• java_generate_equals_and_hash can now be used with the LITE_RUNTIME.

Python

• A new C++-backed extension module (aka "cpp api v2") that replaces the
  old ("cpp api v1") one. Much faster than the pure Python code. This one
  resolves many bugs and is recommended for general use over the
  pure Python when possible.
• Descriptors now have enum_types_by_name and extension_types_by_name dict
  attributes.
• Support for Python 3.

- C++
Published by xfxyjwf almost 12 years ago