email style fix

(nros)

Update to texlive rev 41611

(markd)

Update to texlive rev 41769

(markd)

Update to texlive rev 41694

(markd)

Update to texlive rev 41676

(markd)

Update to texlive rev 41654

(markd)

Update to texlive rev 41452

(markd)

Update to texlive rev 41662

(markd)

Update to texlive rev 41614

(markd)

Update to texlive rev 41661

(markd)

Update to texlive rev 41610

(markd)

Update to texlive rev 41445

(markd)

Update to texlive rev 41695

(markd)

Update to texlive rev 41736

(markd)

Update to texlive rev 41779

(markd)

Update to texlive rev 41634

(markd)

Update to 2016.41616
  Adjust for tex-graphics-def

(markd)

Updated devel/p5-MouseX-Getopt to 0.37

(wen)

Update to 0.37

Upstream changes:
0.37 2016-07-13T03:23:39Z
  * Cope with GLD output changes in version 0.100 (#10, by pghmcfc)

(wen)

Updated geography/py-obspy to 1.0.2

(wen)

Update tex-pst-pdf{,-doc} to 1.2a
  Adjust to tex-graphics-def

(markd)

Update to 1.0.2

Upstream changes:
1.0.2: (doi: 10.5281/zenodo.49636)
- obspy.core:
  * Added workaround for numpy issue where many FFTs of various lengths fill
    a cache that never gets cleared, effectively creating a memory leak
    (see #1424).
  * Trace.filter and Stream.filter don't work on masked arrays anymore because
    it produced unpredictable results due to the un-initialized data-chunk.
    The uninitialized masked gap is now also initialized to np.nan in case
    of floating point data which and a consistent fill value in case of
    integer data. (see #1363)
- obspy.clients.fdsn:
  * Fixing issue with location codes potentially resulting in unwanted data
    to be requested. (see #1422)
  * Included low-gain seismometers in default channel filters in
    mass-downloader, also included non-oriented channels by default
    (see #1373).
- obspy.db:
  * Fixed a bug in obspy-indexer command line script (see #1369,
    command line script was not working, probably since 0.10.0)
- obspy.imaging:
  * Fixed a bug that leads to pressure/tension color blending when plotting
    semi-transparent DC beachball patches (i.e. with "alpha" not equal to 1,
    see #1464)
  * Fixed a bug when plotting non-DC beachball patches without fill colors
    (i.e. with "nofill=True", see #1464)
  * Fix arbitrary units in waveform section plot's offset axis, making it
    possible to add customizations to the plot afterwards (see #1382, see
    #1383)
- obspy.io.ascii:
  * Fixed a bug that lead to wrong header information in output files when
    writing non-integer sampling rate data to SLIST or TSPAIR formats
    (see #1447)
- obspy.io.cmtsolution:
  * Make sure newer CMTSOLUTION files can also be read (see #1479).
- obspy.io.gse2:
  * Fixed a bug that could lead to network code not present in GSE2 output
    (see #1448)
- obspy.io.mseed:
  * Fixed a bug in obspy-mseed-recordanalyzer (see #1386)
- obspy.io.nlloc:
  * Use geographic coordinates from the NonLinLoc Hypocenter-Phase file if
    no custom coordinate converter is provided. (see #1390)
  * Fix reading NonLinLoc Hypocenter-Phase files with more than one
    hypocenter in it. (see #1480)
  * Fix reading NonLinLoc Hypocenter-Phase files with unicode characters in
    them. (see #1483)
- obspy.io.quakeml:
  * Fixed issue with improperly raised warnings when the same file is read
    twice. (#1376)
  * Fix writing empty network/station/channel codes in WaveformStreamID
    objects to QuakeML. (see #1483)
- obspy.io.sac:
  * Try to set SAC distances (dist, az, baz, gcarc) on read, if "lcalda" is
    true.  If "dist" header is found, distances aren't calculated.
  * SACTrace class returns header values as native Python types instead of
    NumPy types.
  * SACTrace.iqual is no longer accepts enumerated string values, but
    arbitrary integer values. (see #1472)
  * SACTrace.read now replaces non-ASCII and null-termination characters in
    string headers with whitespace unless the "debug_strings=True" flag is
    used. (see #1432)
- obspy.io.stationxml:
  * Always set the number attribute for poles and zeros. (see #1481)
- obspy.signal:
  * PPSD.plot(): fix plotting of percentiles, mode and mean and setting
    period limits when using "xaxis_frequency=True" (see #1406, #1416)
  * Work around a bug in SciPy that results in wrong results for bandpass
    filter when using Nyquist frequency (or higher) as high corner of the
    passband (see #1451)
- obspy.taup:
  * Fixing path for Pn. (see #1392)

(wen)

Adjust for tex-graphics-def

(markd)

email style fix

(nros)

email style fix

(nros)

Add tex-graphics-def{,-doc}

(markd)

Initial import tex-graphics-def{,-doc} 2016

This bundle is a combined distribution consisting of dvips.def,
pdftex.def, luatex.def, xetex.def, dvipdfmx.def, and
dvisvgm.def driver option files for the LaTeX graphics and
color packages. It is hoped that by combining their source
repositories at https://github.com/latex3/graphics-def it will
be easier to coordinate updates.

(markd)

Updated devel/p5-MetaCPAN-Client to 1.022003

(wen)

Update to 1.022003
Update DEPENDS

Upstream changes:
1.022003    06.08.16
            * Fixed a warning in $file->pod (Mickey)

1.022002    06.08.16
            * Added LWP::Protocol::https as test dependency (Mickey)

1.022001    05.08.16
            * check user provided UA for 'get' and 'post' methods (Mickey)
            * document updates (Mickey)

1.022000    04.08.16
            * Rework type checking - enforce expected types, inc.
              single-valued array-ref unwrapping; doesn't break
              types that are expected to be array-refs (Mickey)

1.021000    27.07.16
            * Fix result values in v1 - single valued arrayref in ES
              result will be turned to a scalar (Mickey)

(wen)

Added devel/p5-Ref-Util version 0.020

(wen)

Update some texlive packages to latest versions.
Precise changes unknown
Updated print/tex-amsmath(,-doc} to 2.15d
Updated print/tex-caption(,-doc} to 20160522
Updated print/tex-csplain to 2016.41764
Updated print/tex-csquotes(,-doc} to 5.1h
Updated print/tex-datatool(,-doc} to 2.27
Updated print/tex-dvips(,-doc} to 2016.41704
Updated print/tex-etex-pkg(,-doc} to 2.7
Updated print/tex-glossaries(,-doc} to 4.25
Updated print/tex-hyperref(,-doc} to 6.83q
Updated print/tex-koma-script to 3.21
Updated print/tex-latex(,-doc} to 2016.41765
Updated print/tex-lollipop(,-doc} to 1.07
Updated print/tex-luatex85(,-doc} to 1.4
Updated print/tex-marginnote(,-doc} to 1.2
Updated print/tex-media9(,-doc} to 0.69
Updated print/tex-minted(,-doc} to 2.4
Updated print/tex-musixtex(,-doc} to 1.23
Updated print/tex-oberdiek(,-doc} to 2016.41346
Updated print/tex-pdfcomment(,-doc} to 2.4
Updated print/tex-ptex-base(,-doc} to 0.0.2016.41420
Updated print/tex-readarray(,-doc} to 1.3
Updated print/tex-showlabels(,-doc} to 1.8
Updated print/tex-sttools(,-doc} to 1.9
Updated print/tex-tex4ht(,-doc} to 2016.41726
Updated print/tex-texinfo to 5.1.41792
Updated print/tex-textpos(,-doc} to 1.8
Updated print/tex-tools(,-doc} to 2016.41688
Updated print/tex-toptesi(,-doc} to 5.92
Updated print/tex-unicode-data(,-doc} to 1.5
Updated print/tex-updmap-map to 2016.41585

(markd)

Add p5-Ref-Util

(wen)

Import Ref-Util-0.020 as devel/p5-Ref-Util.

Ref::Util introduces several functions to help identify references
in a faster and smarter way.

(wen)

Update some texlive packages to latest versions.
Precise changes unknown
Updated graphics/tex-animate{,-doc} to 20160727
Updated graphics/tex-epstopdf{,-doc} to 2.25
Updated graphics/tex-mcf2graph{,-doc} to 3.95
Updated graphics/tex-pstricks{,-doc} to 2.68
Updated graphics/tex-repere{,-doc} to 16.06

(markd)

Add tex-fonts-tlwg-doc

(markd)

Update some texlive packages to latest versions.
Precise changes unknown
Updated fonts/tex-academicons{,-doc} to 1.7.2
Updated fonts/tex-cs to 2016.41553
Updated fonts/tex-erewhon{,-doc} to 1.06
Updated fonts/tex-fbb{,-doc} to 1.11
Updated fonts/tex-fontawesome{,-doc} to 4.6.3.2
Updated fonts/tex-fonts-tlwg to 0.6.3
Added fonts/tex-fonts-tlwg-doc version 0.6.3
Updated fonts/tex-glyphlist to 2016
Updated fonts/tex-japanese-otf{,-doc} to 1.7b6.41546
Updated fonts/tex-luaotfload{,-doc} to 2.7.3
Updated fonts/tex-oldstandard{,-doc} to 2.2
Updated fonts/tex-xcharter{,-doc} to 1.078a

(markd)

Updated devel/p5-IO-Prompt to 0.997003

(wen)

Update to 0.997003

Upstream changes:
0.997003  Wed Aug 19 10:47:34 2015

    - Removed dependencies check for /dev/tty because it was
      messing up smoke testing (thanks, Jarkko!)

(wen)

Updated devel/p5-CPAN-Meta-Check to 0.013

(wen)

Update to 0.013

Upstream changes:
0.013    2016-07-20 22:26:07+02:00 Europe/Amsterdam
          Make tests more resilient against dev versions of dependencies

(wen)

Updated devel/p5-Config-IniFiles to 2.93

(wen)

Update to 2.93

Upstream changes:
2.93        2016-07-24
    * Add [MetaJSON] and META.json to the distribution.
        - Pull-request by Kent Fredric - thanks!
            - https://bitbucket.org/shlomif/perl-config-inifiles/pull-requests/5/ship-metajson-with-metajson/diff

(wen)

Updated devel/p5-Class-Base to 0.08

(wen)

Update to 0.08

Upstream changes:
0.08 2016.07.25
    Fix release (hopefully)

0.07 2016.07.25
    BUILD_REQUIRES vs TEST_REQUIRES  (Kent Fredric)

(wen)

Updated time/p5-DateTime to 1.36

(wen)

Update to 1.36

Upstream changes:
1.36  2016-08-06

- Require namespace::autoclean 0.19.

(wen)

these options does not exist
--disable-elf-dynstr-gc
--disable-installer
--disable-javaxpcom
--disable-mochitest
--disable-pedantic
--enable-canvas
--enable-crypto
--enable-mathml
--enable-pango
--enable-svg
--with-system-ply
you can see it:
cd /usr/pkgsrc/www/firefox/work/firefox-48.0
./configure --help

(szptvlfn)

Install patch for protobuf/patches/patch-gmock_configure

(kamil)

SunOS needs c99 and at the same time add option for 'fftw' enabling the use
of the Discrete Fourier Transforms library.

(richard)

Updated devel/cmocka to 1.0.1

(mef)

Updated devel/cmocka to 1.0.1
-----------------------------
Thu Mar 12 2015 Andreas Schneider <asn@cryptomilk.org>
    * cmocka: version 1.0.1
    * Added a macro for assert_ptr_equal().
    * Fixed test_realloc() if 0 size is passed.
    * Fixed objects packaging bug.
    * Fixed building with newer gcc versions.

(mef)

Updated security/p5-Module-Signature to 0.80

(mef)

Updated security/p5-Module-Signature to 0.80
--------------------------------------------
ChangeLog unknown for this version

(mef)

Updated math/octave to 4.0.3

(prlw1)

Update octave to 4.0.3

XXX installs lib/charset.alias - is this a problem?

Bugs Fixed in GNU Octave 4.0.3

* doc: clarify differences between atan and atan2 (bug #48178)
* doc: delete mention of unsupported syntax for looping over structs
  (bug #48064)
* ver.m: return empty struct for unknown package (bug #48235).
* Update gnulib subrepo for texinfo formatting fixes (bug #48001)
* Fix typos in Java conversion of 32 and 64 bit integers (bug #48107)
* Create valid gnuplot commands even for single-entry colormaps
  (bug #48083).
* orderfields.m: Remove trailing bracket in docstring (bug #48063).
* Don't overly restrict options passed to Java jvm (bug #39063).
* Write integers with correct byte order on big-endian systems
  (bug #47434)
* doc: Document syntax for specifying color when using Tex
  interpreter (bug #47907).
* Round quantized pixel values before writing uintN images (bug #47746)
* Fix popen2 error on Windows when child writes to stderr (bug #43036)
* it_IT.ts: Correct Italian translation of "col:" (bug #47857).
* avoid crash in audiowrite argument processing (bug #47875)
* make __magick_read__ a built-in function (bug #41699)
* sortrows.m: Improve docstring (bug #47844).
* doc: Fix typo in exec docstring.
* Use correct URL for Online Documentation (bug #47835).
* Fix autoscale affecting legend axes objects (bug #47765).
* configure.ac: Remove AC_CHECK_FUNC for pipe now that gnulib::pipe used.
* doc: fix on manual the syntax to empty elements from cell array.
* octave.texi: Set document encoding to UTF-8.
* Enable the pipe function on Windows (bug #47614)
* avoid mulitple definitions of static function-scope vars (bug #47372)
* Array-sym.cc: Delete obsolete file.
* Initialize variable to stop unstable results for lgamma (bug #47524).
* call openmp function at initialization (bug #47372)
* macros.texi: Colorized links for PDF files with Texinfo 6.x.

(prlw1)

add patches to XSAs 178 and 180 from upstream
add an initialization for a pointer where the compiler doesn't
recognize it being assigned by posix_memalign (trivial compile fix)

(spz)

Updated mail/p5-Catalyst-View-Email to 0.36

(wen)

Update to 0.36

No upstream changelog found.

(wen)

mention 7.1.x goodness, asynchronous signal handling

(jdolecek)

Updated devel/protobuf to 3.0.0
Updated devel/py-protobuf to 3.0.0

(kamil)

Upgrade py-protobuf from 2.6.1 to 3.0.0

This version is backward compatible with proto2.

Upstream changelog:

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:
        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.
        Removal of unknown fields.
        Removal of extensions, which are instead replaced by a new standard type called Any.
        Fix semantics for unknown enum values.
        Addition of maps (back-ported to proto2)
        Addition of a small set of standard types for representation of time, dynamic data, etc (back-ported to proto2)
        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 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 --objc_ 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. 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_, 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.

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.

Protocol Buffers v3.0.0-beta-3.1

@TeBoring TeBoring released this on 14 Jun

Fix iOS framework.

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.

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  to JsonFormat.
        Added a new  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.

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 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  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

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 --objc_ 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. 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.

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:
        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.
        Removal of unknown fields.
        Removal of extensions, which are instead replaced by a new standard type called Any.
        Fix semantics for unknown enum values.
        Addition of maps.
        Addition of a small set of standard types for representation of time, dynamic data, etc.
        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.
        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.

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:
        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.
        Removal of unknown fields.
        Removal of extensions, which are instead replaced by a new standard type called Any.
        Fix semantics for unknown enum values.
        Addition of maps.
        Addition of a small set of standard types for representation of time, dynamic data, etc.
        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.

(kamil)

Updated lang/php71 to 7.1.0beta2

(jdolecek)

Upgrade protobuf from 2.6.1 to 3.0.0

This version is backward compatible with proto2.

Upstream changelog:

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:
        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.
        Removal of unknown fields.
        Removal of extensions, which are instead replaced by a new standard type called Any.
        Fix semantics for unknown enum values.
        Addition of maps (back-ported to proto2)
        Addition of a small set of standard types for representation of time, dynamic data, etc (back-ported to proto2)
        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 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 --objc_ 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. 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_, 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.

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.

Protocol Buffers v3.0.0-beta-3.1

@TeBoring TeBoring released this on 14 Jun

Fix iOS framework.

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.

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  to JsonFormat.
        Added a new  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.

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 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  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

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 --objc_ 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. 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.

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:
        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.
        Removal of unknown fields.
        Removal of extensions, which are instead replaced by a new standard type called Any.
        Fix semantics for unknown enum values.
        Addition of maps.
        Addition of a small set of standard types for representation of time, dynamic data, etc.
        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.
        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.

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:
        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.
        Removal of unknown fields.
        Removal of extensions, which are instead replaced by a new standard type called Any.
        Fix semantics for unknown enum values.
        Addition of maps.
        Addition of a small set of standard types for representation of time, dynamic data, etc.
        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.

(kamil)