January 2023 - Boost - lists.preview.boost.org

Library proposal - indexed_array
by Julien Blanc 12 Oct '23

12 Oct '23

Hi, I've written and released a (rather small) library which allows defining arrays with arbitrary index mechanisms (hence the name, indexed_array). This especially allows indexing with scoped enums, use non zero-starting indexes, or use sparse indexes. This is not a view, but an array in the sense that it owns the data, and provides the same guarantees and functionalities as std::array, such as triviality propagation, being able to reside in read-only program sections, etc. It also supports multidimensional indexing, and provides an indexed_span template class to access lower dimension content (which can be used outside indexed_array). Finally, it provides an opt-in safer way to initialize the array content, which is especially useful when using complex and/or changing indexing schemes (like based on externally generated files). The library is available here: https://github.com/Julien-Blanc-tgcm/indexed_array And the doc is here: https://julien-blanc-tgcm.github.io/indexed_array/ It requires C++17 and mp11, and has first-class support for describe-d enums. If there is some interest, i'd like to propose it for inclusion in boost. So i'm looking for people who would endorse it. Thanks and best regards, Julien

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Boost.Buffers: network-agnostic buffer types and algorithms
by Vinnie Falco 07 Feb '23

07 Feb '23

Greetings. I am asking if there is any interest in a Boost.Buffers library, which consists of the following: * ConstBuffer, MutableBuffer concepts * ConstBuffers, MutableBuffers concepts * const_buffer, mutable_buffer types * DynamicBuffer concept * `source` and `sink` abstract interfaces used to define the Source and Sink concepts * metafunctions for checking all type requirements * implementations of common buffers and dynamic buffers: - buffers_pair - array_of_buffers - circular_buffer - dynamic_string_buffer * Algorithms: - buffer_copy - buffer_size The twist is that this library has no dependency on Asio or Boost.Asio (but Asio will still recognize them thanks to some template heroics and a splash of forward declarations). Why am I proposing this? Well, let me tell you some things... I am currently working on these two libraries: Boost.Http.Proto Boost.Http.Io The Proto library implements HTTP/1 to a fuller feature set than Beast and fixes all the design flaws in Beast (but it is completely not API compatible). This library does not do any network I/O, it is expressed purely in terms of buffer concepts (i.e. depends on Boost.Buffer and not Boost.Asio). The Io library depends on Asio and the Proto library to provide the network algorithms which use Asio to implement HTTP/1. This is the equivalent HTTP functionality of what Beast offers today. Websockets is not included but when I am done with Http I will redo websockets with improvements and new features, and similarly they will be developed as two libraries: Boost.Websockets.Proto Boost.Websockets.Io My motivation for splitting libraries this way is as follows: * Each library is smaller and compiles more quickly * CI turnarounds are faster * Separation of concerns The HTTP Protocol library is designed in a way that much of an application's HTTP business logic can be expressed independently of Asio using only the constructs found in Http.Proto. This especially means fewer templates and faster compilation because Http.Proto is designed from the ground up to avoid templates whenever possible. However during the development of Http.Proto I find myself having to reach for the same buffer algorithms and containers that I developed for Beast (such as the circular buffer and the dynamic buffer). So Http.Proto has been steadily growing these things: <https://github.com/CPPAlliance/http_proto/blob/a3a284f06597ad12ca6cc1782beb…> Extract this independent buffer functionality into a separate library Boost.Buffers would bring these benefits: * Again a smaller library, faster compilation * Faster CI turnarounds * Separation of concerns Additionally, algorithms can be expressed in terms of asio-independent buffer types and concepts. For example, Boost.JSON could implement the boost::buffers::sink and boost::buffers::source interfaces which would enable its use in Boost.Http.Proto and Boost.Requests (an upcoming HTTP client library from Klemens), without having to depend on either of those libraries or Asio. Is this style of development of smaller, fine grained libraries that separate concerns something that is desirable for Boost? Glad for any feedback. -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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Decommissioning Trac (svn.boost.org)
by Glen Fernandes 31 Jan '23

31 Jan '23

We have Trac in read-only mode after we migrated to Git, but we're still paying for the server. Do people still want to preserve any part of the content in some way? The wiki aside, there are old issues, with comments, and some of them have patches attached. Peter had the idea of generating static HTML content from Trac and hosting that on an archive section on boost.org. (I don't know how difficult this is to do). Thoughts? Suggestions? Glen

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Boost TCP socket read/write issues
by Rahul K R 31 Jan '23

31 Jan '23

Hello All, As part of my project activity, I have to create an asynchronous TCP server application using the boost library. I have created a sample application and it's working. But the issue I am facing is the boost::asio::read API takes a long time to read from the TCP socket, almost 5 seconds. I am using boost library version 1.76.0. I have the following queries regarding this, 1. Is there any known issues for boost::asio::read to consume more time? 2. I am doing reading and writing to the same socket from two threads parallelly, Is that possible with the boost? 3. Is the boost lib can perform well if we get too many requests at a time and process parallelly? I am attaching the sample application code herewith. Please let me know your feedback asap. Regards Rahul

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GSoC 2023 (Google Summer of Code)
by David Bellot 31 Jan '23

31 Jan '23

Hi Boost community, the GSoC 2023 organisation application is now open. Boost is again a candidate this year. We're just waiting for the results to see if we're accepted. In the meantime, we are "recruiting" mentors. Some of you already contacted me a few weeks ago, but maybe some others would be interested to join this fascinating journey. Please contact me now, by mailing list or private email if you're interested. Best, David

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Building the proposed Boost.Mustache
by Peter Dimov 30 Jan '23

30 Jan '23

It's been pointed out that the proposed Boost.Mustache https://github.com/pdimov/mustache (whose formal review is upcoming) is relatively hard to evaluate, because the contents of the repository are in a form that is intended for inclusion into a Boost release. Here's how to build the library, starting from scratch: 1. Clone Boost from Github: git clone --recurse-submodules https://github.com/boostorg/boost 2. Clone the Mustache library into the Boost tree: cd boost/libs git clone https://github.com/pdimov/mustache cd .. 3. Build b2: ./bootstrap.sh (We assume Linux and g++ from now on. On Windows, it's just `booststrap`.) 4. Generate the header links in the boost/ directory: ./b2 headers 5. Build the Mustache library and its dependencies (e.g. JSON): ./b2 --with-mustache This will place the compiled libraries into the stage/lib directory. It should contain libboost_container.a/.so, libboost_json.a/.so, and liboost_mustache.a/.so. You can now build and run the Mustache examples by using e.g. g++ libs/mustache/example/html.cpp -o html -I . -L stage/lib -lboost_mustache -lboost_json ./html

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aedis is ACCEPTED into boost with conditions
by Klemens Morgenstern 28 Jan '23

28 Jan '23

Boost.aedis is ACCEPTED with conditions. Accept: 3 ( + 1 late one) Conditional: 1 Reject: 4 All but one rejections asked for changes that were not fundamental to the design, but rather were about particular implementation details or high-level API design issues. Thus I conclude, based on the reviews, that there is no need for another mini-review. This is also based on Marcelo's engagement, so I am confident that many issues will be addressed in the future . These are the conditions - name it boost.redis - clearly document/specify the behaviour of async_exec, async_receive & async_run, how they interact and all the edge cases (and unit test them) - unit tests for error handling, especially for pipes. - add a design discussion & FAQ page. That should mostly copy & paste from the review discussions. - from_bulk & to_bulk should either us tag_invoke or be be renamed to aedis_from_bulk or aedis_to_bulk - remove memory_resource usage and optimize the allocation strategy of a request object (using new/delete), so that it ideally allocates once and then reuses the memory Please note that the inclusion into boost does not mean that it has to be shipped with the next release. I also strongly recommend development of typed commands, possibly with code generation. This is however not a condition and does not need to be in the first release that's included in boost. Another recommendation is to add some very basic explanation of redis, as some users will read your doc before they look into redis. I want to thank everyone who submitted reviews, especially Ruben who really drilled down on some details and brought in his experience from MySQL. Thank you Zach for getting the discussion started on type-safe command access; based on the discussions I am confident that some feature like that will be added on top of the existing APIs. Similarly I want to thank Дмитрий, Sam & Alan, who's review helped me to formulate the conditions. I am also grateful for (who I think are) first time reviewers, Mohammed Nejati, Robert Leahy, Sam Hartsfield & Miguel, and of course our boost veterans Vinnie & Christian. Likewise I want to thank Marcelo for all his responses to reviews and questions and of course for all the work that went into developing aedis. Congratulations Marcelo!

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[Aedis] Formal Review: We could have done better
by Vinnie Falco 26 Jan '23

26 Jan '23

In hindsight, I feel like perhaps we collectively failed the review process. I think that Boost.Aedis was in fact not ready for a review and it did a disservice both to the library and the author that we rushed to review it. Instead, the relevant subject matter experts such as I, Alan de Freitas, Klemens Morgenstern, Reuben Perez, to a lesser extent Christian Mazakas, Mohammed, and a few others should have taken Aedis under our wing and helped to "get it into shape" before the review. Speaking for myself I wish I had put more time into helping the author get the library into the best possible condition. Instead of waiting until the review, I should have helped Marcelo address the flaws ahead of time. For example: <https://github.com/mzimbres/aedis/issues/51> and <https://github.com/mzimbres/aedis/issues/47> The library should not have gone into the review without one or more revisions to the documentation so that common questions that came up during the review were already answered, perhaps in a FAQ section. In particular, reviewers should not have had to ask why async_run or async_exec (see my example exposition in issue 51 above). I also think that the library would have benefited from a concerted effort to get it in the hands of users. I spent a bunch of energy ahead of time to get users for Beast before submitting it for review. It was already deployed in production systems, and there were other projects that started integrating it both open source and closed. We should have at the very least advertised Aedis in places like the redis++ repository (perhaps with a new GitHub issue). Forums, and such. And looked for individual C++ projects already using Redis and informed them of Aedis. For any new libraries we should look at the lesson of Aedis and consider whether or not a similar treatment would result in a better review of the candidate library. Regardless, I have the highest regard for Marcelo as he demonstrates a mastery of Asio and a commitment to quality, even if the library's outcome of the review is not favorable. -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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Fwd: aedis review starts today
by Vinnie Falco 25 Jan '23

25 Jan '23

The following review came in after the review period ended. I am reposting it with permission. A copy was also sent by the reviewer to the review manager. ---------- Forwarded message --------- From: M P <miguelportilla64(a)gmail.com> Date: Wed, Jan 25, 2023 at 11:14 AM Subject: RE: [boost] aedis review starts today To: <klemensdavidmorgenstern(a)gmail.com>, Vinnie Falco <vinnie.falco(a)gmail.com> > Please explicitly state that you either *accept* or *reject* the inclusion of this library into boost. I ACCEPT this library into boost. My only concern is that although Redis may be the flavor of the day, project popularities fade. If Redis is supplanted, I wonder how effective boost maintainers down the road will be to remove it. > Also please indicate the time & effort spent on the evaluation and give the reasons for your decision. > Additionally, stating your knowledge of redis and asio would be helpful for Me. I had no prior knowledge of Redis before reviewing Aedis, but I am familiar with Boost and Asio. Before diving into Aedis, I began by studying Redis, its RESP protocol, and real-world use to help me understand why the Aedis project might be useful to the c++ community. It quickly became apparent that Redis is very popular. It is the most popular database used on Amazon Web Services, the world’s largest cloud service provider. It is also ranked first in its category and the top ten of all categories by DB-Engines. In today’s full-stack web applications, users expect responsiveness, and Redis is an important component in scaling architecture to meet demands. Aedis grants c++ developers Redis access, empowering their software to participate in this evolving sphere of technologies. I spent about three days learning about Redis, RESP3, and Aedis. While evaluating Aedis, I built the project in Linux and Windows and performed tests using Visual Studio 2022. The project examples provide a variety of scenarios that may be useful as starting points for folks with different requirements. > - Does this library bring real benefit to C++ developers for real world use-case? Absolutely. Any c++ project with heavy utilization of Relational Databases can benefit from the cache performance Redis provides. Projects that do use a Relational Database may also be able to use Redis as a mechanism to share data across servers. There are many real-world use cases ranging from web, multi-user games, fintech, and blockchain. > - Do you have an application for this library? I do not have a software application at the moment that uses Redis. I am working on a project that might end up using Redis and if so, would likely use Aedis. > - Does the API match with current best practices? Yes, the API is well-matched with current practices. Aedis is based on Asio and it does a good job of keeping in line with it. > - Is the documentation helpful and clear? The documentation within the sources (Doxygen) is helpful. The project readme.md file can be improved. Having steps to build the project for various operating systems would be nice. Providing cmake examples to generate project solutions for Visual Studio might be a good idea. Eg. cmake -G "Visual Studio 17 2022" -A x64 -B bin64 -DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake Although seemingly trivial to some, it helps reduce friction (and frustration) to newcomers and increase adoption. > - Did you try to use it? What problems or surprises did you encounter? Yes, I built the included examples and tested them with a Redis server. It may not be obvious to new users that most functions can throw an exception. Some exception messages should be elaborated. For instance, upon a failure to a server that refused a connection, the exception message was "multiple exceptions". Small nits… May want to consider renaming the function 'healthy_checker' to 'health_check'. Rename the abbreviated response variable 'resp' in the examples to `response`. `resp` can be confusing in this context considering RESP is an acronym for the communication protocol. It might be helpful to use an enumeration (or something else) for request commands. Not only would it provide type safety but it also aids in knowing the commands without having to reference them in the docs. > - What is your evaluation of the implementation? Overall I believe Aedis is well-designed and written, Marcelo has done an excellent job. Unfortunately, this library requires c++ 17 with an emphasis on c++ 20. This likely eliminates a large population of c++ users. Best, Mickey -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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aedis review period has ended
by Klemens Morgenstern 25 Jan '23

25 Jan '23

The review for aedis has concluded. I will announce the result soon. Thanks to everyone who participated in the review and discussion.

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