Cap'n Proto
Protobuf
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Cap'n Proto | Protobuf | |
---|---|---|
66 | 171 | |
11,180 | 63,586 | |
1.6% | 1.0% | |
9.2 | 10.0 | |
1 day ago | 7 days ago | |
C++ | C++ | |
GNU General Public License v3.0 or later | GNU General Public License v3.0 or later |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Cap'n Proto
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Mysterious Moving Pointers
Yeah I pretty much only use my own alternate container implementations (from KJ[0]), which avoid these footguns, but the result is everyone complains our project is written in Kenton-Language rather than C++ and there's no Stack Overflow for it and we can't hire engineers who know how to write it... oops.
[0] https://github.com/capnproto/capnproto/blob/v2/kjdoc/tour.md
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Show HN: Comprehensive inter-process communication (IPC) toolkit in modern C++
- may massively reduce the latency involved.
Those sharing Cap'n Proto-encoded data may have particular interest. Cap'n Proto (https://capnproto.org) is fantastic at its core task - in-place serialization with zero-copy - and we wanted to make the IPC (inter-process communication) involving capnp-serialized messages be zero-copy, end-to-end.
That said, we paid equal attention to other varieties of payload; it's not limited to capnp-encoded messages. For example there is painless (<-- I hope!) zero-copy transmission of arbitrary combinations of STL-compliant native C++ data structures.
To help determine whether Flow-IPC is relevant to you we wrote an intro blog post. It works through an example, summarizes the available features, and has some performance results. https://www.linode.com/blog/open-source/flow-ipc-introductio...
Of course there's nothing wrong with going straight to the GitHub link and getting into the README and docs.
Currently Flow-IPC is for Linux. (macOS/ARM64 and Windows support could follow soon, depending on demand/contributions.)
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Condvars and atomics do not mix
FWIW, my C++ toolkit library, KJ, does the same thing.[0]
But presumably you could still write a condition predicate which looks at things which aren't actually part of the mutex-wrapped structure? Or does is the Rust type system able to enforce that the callback can only consider the mutex-wrapped value and values that are constant over the lifetime of the wait? (You need the latter e.g. if you are waiting for the mutex-wrapped value to compare equal to some local variable...)
[0] https://github.com/capnproto/capnproto/blob/e6ad6f919aeb381b...
- Cap'n'Proto: infinitely faster than Protobuf
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I don’t understand zero copy
The second one is to encode data in such a way that you can read it and operate on it directly from the buffer. You write data in a layout that is the same, or easily transformed as types in memory. To do that you usually need to encode with a known schema, only Sized types to efficiently compute fields locations as offsets in the buffer, and you usually represent pointers as offset into the encode. You can look at capnproto protocol for instance https://capnproto.org/
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OpenTF Renames Itself to OpenTofu
Worked well for Cap'n Proto (the cerealization protocol)! https://capnproto.org/
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A Critique of the Cap'n Proto Schema Language
With all due respect, you read completely wrong.
* The very first use case for which Cap'n Proto was designed was to be the protocol that Sandstorm.io used to talk between sandbox and supervisor -- an explicitly adversarial security scenario.
* The documentation explicitly calls out how implementations should manage resource exhaustion problems like deep recursion depth (stack overflow risk).
* The implementation has been fuzz-tested multiple ways, including as part of Google's oss-fuzz.
* When there are security bugs, I issue advisories like this:
https://github.com/capnproto/capnproto/tree/v2/security-advi...
* The primary aim of the entire project is to be a Capability-Based Security RPC protocol.
- Cap'n Proto: serialization/RPC system – core tools and C++ library
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Sandstorm: Open-source platform for self-hosting web app
I like how they use capability-based security [0] and use Cap'n Proto protocol. This is another technology that is slow to get broad adoption, but has many things going for when compared to e.g. Protocol Buffers (Cap'n Proto is created by the primary author of Protobuf v2, Kenton Varda).
[0] https://sandstorm.io/how-it-works#capabilities
[1] https://capnproto.org
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Flatty - flat message buffers with direct mapping to Rust types without packing/unpacking
Related but not Rust-specific: FlatBuffers, Cap'n Proto.
Protobuf
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Reverse Engineering Protobuf Definitions from Compiled Binaries
For at least 4 years protobuf has had decent support for self-describing messages (very similar to avro) as well as reflection
https://github.com/protocolbuffers/protobuf/blob/main/src/go...
Xgooglers trying to make do on the cheap will just create a Union of all their messages and include the message def in a self-describing message pattern. Super-sensitive network I/O can elide the message def (empty buffer) and any for RecordIO clone well file compression takes care of the definition.
Definitely useful to be able to dig out old defs but protobuf maintainers have surprisingly added useful features so you don’t have to.
Bonus points tho for extracting the protobuf defs that e.g. Apple bakes into their binaries.
- Show HN: AuthWin – Authenticator App for Windows
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Create Production-Ready SDKs With gRPC Gateway
gRPC Gateway is a protoc plugin that reads gRPC service definitions and generates a reverse proxy server that translates a RESTful JSON API into gRPC.
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Create Production-Ready SDKs with Goa
To use more recent versions of protoc in future applications, you can download them from the Protobuf repository.
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Roll your own auth with Rust and Protobuf
Use the Protobuf CLI protoc and the plugin protoc-gen-tonic.
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Add extra stuff to a “standard” encoding? Sure, why not
> didn’t find any standard for separating protobuf messages
The fact that protobufs are not self-delimiting is an endless source of frustration, but I know of 2 standards:
- SerializeDelimited* is part of the protobuf library: https://github.com/protocolbuffers/protobuf/blob/main/src/go...
- Riegeli is "a file format for storing a sequence of string records, typically serialized protocol buffers. It supports dense compression, fast decoding, seeking, detection and optional skipping of data corruption, filtering of proto message fields for even faster decoding, and parallel encoding": https://github.com/google/riegeli
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Block YouTube Ads on AppleTV by Decrypting and Stripping Ads from Profobuf
It looks like it is in fact universal. Just glancing at the code here, it looks like the tool searches any arbitrary file for bytes that look like encoded protobuf descriptors, specifically looking for bytes that are plausibly the beginning of a FileDescriptorProto message defined here:
https://github.com/protocolbuffers/protobuf/blob/main/src/go...
This takes advantage of the fact that such descriptors are commonly compiled into programs that use protobuf. The descriptors are usually embedded as constant byte arrays. That said, not all protobuf implementations embed the descriptors and those that do often have an option to inhibit such embedding (at the expense of losing some dynamic introspection features).
- How to learn to use protoc in 21 easily infuriating steps
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What's involved in protobuf encoding?
Not much. You can check the source code in https://github.com/protocolbuffers/protobuf. For example, for serializing a boolean in C#: https://github.com/protocolbuffers/protobuf/blob/main/csharp/src/Google.Protobuf/WritingPrimitives.cs#L165. Strings and objects are a bit more complicated, but it is all about turning the data into its byte representation.
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Trying To Solve The Confusion of Choice Between gRPC vs REST🕵
One of the key feature of gRPC is protobuf .proto file(nothing but just a contract for me between two communicator code components) This file and protobuff compiler is so mature, then it generates a direct client implementation using protoccompiler. ref
What are some alternatives?
gRPC - The C based gRPC (C++, Python, Ruby, Objective-C, PHP, C#)
FlatBuffers - FlatBuffers: Memory Efficient Serialization Library
SBE - Simple Binary Encoding (SBE) - High Performance Message Codec
ZeroMQ - ZeroMQ core engine in C++, implements ZMTP/3.1
MessagePack - MessagePack implementation for C and C++ / msgpack.org[C/C++]
Apache Thrift - Apache Thrift
cereal - A C++11 library for serialization
MessagePack - MessagePack serializer implementation for Java / msgpack.org[Java]
Apache Parquet - Apache Parquet
nanomsg - nanomsg library
Bond - Bond is a cross-platform framework for working with schematized data. It supports cross-language de/serialization and powerful generic mechanisms for efficiently manipulating data. Bond is broadly used at Microsoft in high scale services.