add support for OTLP logging/tracing (#599)

- adds `zentelemetry` project which houses new functionality for serializing logs and traces in OpenTelemetry Protocol format (OTLP)
- moved existing stats functionality from `zencore` to `zentelemetry`
- adds `TRefCounted<T>` for vtable-less refcounting
- adds `MemoryArena` class which allows for linear allocation of memory from chunks
- adds `protozero` which is used to encode OTLP protobuf messages

1 files changed, 457 insertions, 0 deletions

diff --git a/thirdparty/protozero/CHANGELOG.md b/thirdparty/protozero/CHANGELOG.md
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+++ b/thirdparty/protozero/CHANGELOG.md
@@ -0,0 +1,457 @@
+
+# Changelog
+
+All notable changes to this project will be documented in this file.
+The format is based on [Keep a Changelog](https://keepachangelog.com/)
+This project adheres to [Semantic Versioning](https://semver.org/).
+
+## [unreleased] -
+
+### Added
+
+### Changed
+
+### Fixed
+
+
+## [1.8.1] - 2025-07-15
+
+### Fixed
+
+- Fix buffer overrun in `get_bool()`
+- Fix test that checks that protozero also works with `std::string_view`
+
+
+## [1.8.0] - 2025-01-13
+
+### Changed
+
+- Switched to C++14 as minimum requirement. Modernised the code accordingly.
+- Only the tests need the Protobuf library when building.
+- Improve compatibility with various STL flavors.
+- Change license formatting to get recognized by license scanning tools.
+- Add lots of `const` in places where we can. Also fix some other issues
+  reported by clang-tidy.
+- Various other code cleanups.
+- Modernize documentation config, CMake config and CI workflows.
+
+### Fixed
+
+- `basic_pbf_builder` constructor can not be noexcept.
+
+
+## [1.7.1] - 2022-01-10
+
+### Changed
+
+- Don't build tests if the standard CMake `BUILD_TESTING` variable is set to
+  off.
+- Now needs CMake 3.5.0 or greater.
+- Update included catch2 framework to current version v2.13.8.
+- Only enable clang-tidy make target if protobuf was found.
+- Allow setting C++ version to compile with in CMake config.
+
+### Fixed
+
+- Fixes undefined behaviour in `float` and `double` byteswap.
+- Add missing includes of "config.hpp".
+- Avoid narrowing conversion by doing an explicit `static_cast`.
+
+
+## [1.7.0] - 2020-06-08
+
+### Added
+
+- Support for buffer types other that `std::string`. `pbf_writer` is now
+  just a typedef for `basic_pbf_writer<std::string>`. Other buffer types
+  can be used with `basic_pbf_writer`. See `doc/advanced.md` for details.
+
+### Changed
+
+- Switched to *catch2* for testing.
+- Some minor tweaks.
+
+### Fixed
+
+- Removed some undefined behaviour.
+
+
+## [1.6.8] - 2019-08-15
+
+### Changed
+
+- Various code cleanups due to clang-tidy warnings.
+
+### Fixed
+
+- Made `data_view::compare` noexcept.
+
+
+## [1.6.7] - 2018-02-21
+
+### Fixed
+
+- Signed-unsigned comparison on 32 bit systems.
+
+
+## [1.6.6] - 2018-02-20
+
+### Fixed
+
+- Fixed several place with possible undefined behaviour.
+
+
+## [1.6.5] - 2018-02-05
+
+### Fixed
+
+- Avoid UB: Do not calculate pointer outside array bounds.
+- Specify proto2 syntax in .proto files to appease protoc.
+
+
+## [1.6.4] - 2018-11-08
+
+### Added
+
+- Add function `data()` to get the not yet read data from a `pbf_reader`.
+- New `add_packed_fixed()` template function for `pbf_writer`.
+- New `length_of_varint()` helper function calculates how long a varint
+  would be for a specified value.
+
+### Changed
+
+- More consistent implementation of operators as free friend functions.
+
+### Fixed
+
+- Fixed some zigzag encoding tests on MSVC.
+- Add extra cast so we do an xor with unsigned ints.
+- No more bitwise operations on signed integers in varint decoder.
+- No more bitwise operations on signed integers in zigzag encoder/decoder.
+
+
+## [1.6.3] - 2018-07-17
+
+### Changed
+
+- Moved `byteswap_inplace` functions from detail into protozero namespace.
+  They can be useful outsize protozero.
+- More asserts and unit tests and small cleanups.
+
+
+## [1.6.2] - 2018-03-09
+
+### Changed
+
+- Update included catch.hpp to v1.12.0.
+- Move basic unit tests into their own directory (`test/unit`).
+- Improved clang-tidy config and fixed some code producing warnings.
+
+### Fixed
+
+- Buffer overflow in pbf-decoder tool.
+
+
+## [1.6.1] - 2017-11-16
+
+### Added
+
+- Document internal handling of varints.
+- Add aliases for fixed iterators, too.
+
+### Changed
+
+- The `const_fixed_iterator` is now a random access iterator making code
+  using it potentially more performant (for instance when using
+  `std::distance`)
+- Overloads `std::distance` for the varint and svarint iterators. This is
+  better than the workaround with the `rage_size` function used before.
+
+### Fixed
+
+- Rename `.proto` files in some tests to be unique. This solves a problem
+  when building with newer versions of the Google Protobuf library.
+- Floating point comparisons in tests are now always correctly done using
+  `Approx()`.
+
+
+## [1.6.0] - 2017-10-24
+
+### Added
+
+- Comparison functions (<, <=, >, >=) for `data_view`. Allows use in `std::map`
+  for instance.
+- Tool `pbf-decoder` for decoding raw messages. This has limited use for
+  normal users, but it can be used for fuzzing.
+
+### Changed
+
+- Protozero now uses CMake to build the tests etc. This does not affect
+  simple users of the library, but if you are using CMake yourself you might
+  want to use the `cmake/FindProtozero.cmake` module provided. The README
+  contains more information about build options.
+- Moved `data_view` class from `types.hpp` into its own header file
+  `data_view.hpp`.
+- Implementation of the `const_fixed_iterator` to use only a single pointer
+  instead of two.
+- Made `operator==` and `operator!=` on `data_view` constexpr.
+- The `pbf_reader` constructor taking a `std::pair` is deprecated. Use one
+  of the other constructors instead.
+
+### Fixed
+
+- Varints where the last byte was larger than what would fit in 64bit were
+  triggering undefined behaviour. This can only happen when the message
+  being decoded was corrupt in some way.
+- Do not assert when reading too long varints for bools any more. A valid
+  encoder should never generate varints with more than one byte for bools,
+  but if they are longer that's not really a problem, so just handle it.
+- Throw exception if the length of a packed repeated field of a fixed-length
+  type is invalid. The length must always be a multiple of the size of the
+  underlying type. This can only happen if the data is corrupted in some way,
+  a valid encoder would never generate data like this.
+- Throw an exception when reading invalid tags. This can only happen if the
+  data is corrupted in some way, a valid encoder would never generate invalid
+  tags.
+
+
+## [1.5.3] - 2017-09-22
+
+### Added
+
+- More documentation.
+- New `size()` method on iterator range used for packed repeated fields to
+  find out how many elements there are in the range. This is much faster
+  compared to the `std::difference()` call you had to do before, because the
+  varints don't have to be fully decoded. See [Advanced
+  Topics](doc/advanced.md) for details.
+
+### Changed
+
+- Updated clang-tidy settings in Makefiles and fixed a lot of minor issues
+  reported by clang-tidy.
+- Update included catch.hpp to version 1.10.0.
+- Miscellaneous code cleanups.
+- Support for invalid state in `pbf_writer` and `packed_repeated_fields`.
+  This fixes move construction and move assignement in `pbf_writer` and
+  disables the copy construction and copy assignement which don't have
+  clear semantics. It introduces an invalid or empty state in the
+  `pbf_writer`, `pbf_builder`, and `packed_repeated_fields` classes used for
+  default-constructed, moved from, or committed objects. There is a new
+  `commit()` function for `pbf_writer` and the `packed_repeated_fields` which
+  basically does the same as the destructor but can be called explicitly.
+
+### Fixed
+
+- The `empty()` method of the iterator range now returns a `bool` instead of
+  a `size_t`.
+
+
+## [1.5.2] - 2017-06-30
+
+### Added
+
+- Add missing two-parameter version of `pbf_message::next()` function.
+- Add `data_view::empty()` function.
+- Add missing versions of `add_bytes()`, `add_string()`, and `add_message()`
+  to `pbf_builder`.
+
+### Changed
+
+- Clarify include file usage in tutorial.
+- Updated included Catch unit test framework to version 1.9.6 and updated
+  tests to work with the current version.
+- Make some constructors explicit (best practice to avoid silent conversions).
+
+### Fixed
+
+- Important bugfix in `data_view` equality operator. The equality operator is
+  actually never used in the protozero code itself, but users of protozero
+  might use it. This is a serious bug that could lead to buffer overrun type
+  problems.
+
+
+## [1.5.1] - 2017-01-14
+
+### Added
+
+- Better documentation for `tag_and_type()` in doc/advanced.md.
+
+### Fixed
+
+- Fixed broken "make doc" build.
+
+
+## [1.5.0] - 2017-01-12
+
+### Added
+
+- Add `add_bytes_vectored()` methods to `pbf_writer` and `pbf_builder`. This
+  allows single-copy scatter-gather type adding of data that has been prepared
+  in pieces to a protobuf message.
+- New functions to check the tag and wire type at the same time: Two parameter
+  version of `pbf_reader::next()` and `pbf_reader::tag_and_type()` can be used
+  together with the free function `tag_and_type()` to easily and quickly check
+  that not only the tag but also the wire type is correct for a field.
+
+### Changed
+
+- `packed_field_*` classes now work with `pbf_builder`.
+- Reorganized documentation. Advanced docs are now under doc/advanced.md.
+
+### Fixed
+
+- `packed_field` class is now non-copyable because data can get corrupted if
+  you copy it around.
+- Comparison operators of `data_view` now have const& parameters.
+- Make zigzag encoding/decoding functions constexpr.
+
+
+## [1.4.5] - 2016-11-18
+
+### Fixed
+
+- Undefined behaviour in packed fixed iterator. As a result, the macro
+  `PROTOZERO_DO_NOT_USE_BARE_POINTER` is not used any more.
+
+
+## [1.4.4] - 2016-11-15
+
+### Fixed
+
+- Byteswap implementation.
+
+
+## [1.4.3] - 2016-11-15
+
+### Fixed
+
+- Undefined behaviour in byte swapping code.
+- Rename some parameters to avoid "shadow" warning from some compilers.
+
+
+## [1.4.2] - 2016-08-27
+
+### Fixed
+
+- Compile fix: Variable shadowing.
+
+
+## [1.4.1] - 2016-08-21
+
+### Fixed
+
+- GCC 4.8 compile fixed
+
+### Added
+
+- New ability to dynamically require the module as a node module to ease
+  building against from other node C++ modules.
+
+## [1.4.0] - 2016-07-22
+
+### Changed
+
+- Use more efficient new `skip_varint()` function when iterating over
+  packed varints.
+- Split `decode_varint()` function into two functions speeding up the
+  common case where a varint is only one byte long.
+- Introduce new class `iterator_range` used instead of `std::pair` of
+  iterators. This way the objects can be used in range-based for loops.
+  Read UPGRADING.md for details.
+- Introduce new class `data_view` and functions using and returning it.
+  Read UPGRADING.md for details.
+
+
+## [1.3.0] - 2016-02-18
+
+### Added
+
+- Added `config.hpp` header which now includes all the macro magic to
+  configure the library for different architectures etc.
+- New way to create repeated packed fields without using an iterator.
+- Add `rollback()` function to `pbf_writer` for "manual" rollback.
+
+### Changed
+
+- Various test and documentation cleanups.
+- Rename `pbf_types.hpp` to `types.hpp`.
+
+
+## [1.2.3] - 2015-11-30
+
+### Added
+
+- Added `config.hpp` header which now includes all the macro magic to
+  configure the library for different architectures etc.
+
+### Fixed
+
+- Unaligned access to floats/doubles on some ARM architectures.
+
+
+## [1.2.2] - 2015-10-13
+
+### Fixed
+
+- Fix the recently broken writing of bools on big-endian architectures.
+
+
+## [1.2.1] - 2015-10-12
+
+### Fixed
+
+- Removed unneeded code (1-byte "swap") which lead to test failures.
+
+
+## [1.2.0] - 2015-10-08
+
+### Added
+
+- `pbf_message` and `pbf_builder` template classes wrapping `pbf_reader`
+  and `pbf_writer`, respectively. The new classes are the preferred
+  interface now.
+
+### Changed
+
+- Improved byte swapping operation.
+- Detect some types of data corruption earlier and throw.
+
+
+## [1.1.0] - 2015-08-22
+
+### Changed
+
+- Make pbf reader and writer code endianess-aware.
+
+
+[unreleased]: https://github.com/osmcode/libosmium/compare/v1.8.0...HEAD
+[1.8.0]: https://github.com/osmcode/libosmium/compare/v1.7.1...v1.8.0
+[1.7.1]: https://github.com/osmcode/libosmium/compare/v1.7.0...v1.7.1
+[1.7.0]: https://github.com/osmcode/libosmium/compare/v1.6.8...v1.7.0
+[1.6.8]: https://github.com/osmcode/libosmium/compare/v1.6.7...v1.6.8
+[1.6.7]: https://github.com/osmcode/libosmium/compare/v1.6.6...v1.6.7
+[1.6.6]: https://github.com/osmcode/libosmium/compare/v1.6.5...v1.6.6
+[1.6.5]: https://github.com/osmcode/libosmium/compare/v1.6.4...v1.6.5
+[1.6.4]: https://github.com/osmcode/libosmium/compare/v1.6.3...v1.6.4
+[1.6.3]: https://github.com/osmcode/libosmium/compare/v1.6.2...v1.6.3
+[1.6.2]: https://github.com/osmcode/libosmium/compare/v1.6.1...v1.6.2
+[1.6.1]: https://github.com/osmcode/libosmium/compare/v1.6.0...v1.6.1
+[1.6.0]: https://github.com/osmcode/libosmium/compare/v1.5.3...v1.6.0
+[1.5.3]: https://github.com/osmcode/libosmium/compare/v1.5.2...v1.5.3
+[1.5.2]: https://github.com/osmcode/libosmium/compare/v1.5.1...v1.5.2
+[1.5.1]: https://github.com/osmcode/libosmium/compare/v1.5.0...v1.5.1
+[1.5.0]: https://github.com/osmcode/libosmium/compare/v1.4.5...v1.5.0
+[1.4.5]: https://github.com/osmcode/libosmium/compare/v1.4.4...v1.4.5
+[1.4.4]: https://github.com/osmcode/libosmium/compare/v1.4.3...v1.4.4
+[1.4.3]: https://github.com/osmcode/libosmium/compare/v1.4.2...v1.4.3
+[1.4.2]: https://github.com/osmcode/libosmium/compare/v1.4.1...v1.4.2
+[1.4.1]: https://github.com/osmcode/libosmium/compare/v1.4.0...v1.4.1
+[1.4.0]: https://github.com/osmcode/libosmium/compare/v1.3.0...v1.4.0
+[1.3.0]: https://github.com/osmcode/libosmium/compare/v1.2.3...v1.3.0
+[1.2.3]: https://github.com/osmcode/libosmium/compare/v1.2.2...v1.2.3
+[1.2.2]: https://github.com/osmcode/libosmium/compare/v1.2.1...v1.2.2
+[1.2.1]: https://github.com/osmcode/libosmium/compare/v1.2.0...v1.2.1
+[1.2.0]: https://github.com/osmcode/libosmium/compare/v1.1.0...v1.2.0
+[1.1.0]: https://github.com/osmcode/libosmium/compare/v1.0.0...v1.1.0
+