smhasher
stb
smhasher | stb | |
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31 | 164 | |
1,737 | 25,575 | |
- | - | |
7.0 | 6.6 | |
19 days ago | 3 days ago | |
C++ | C | |
GNU General Public License v3.0 or later | GNU General Public License v3.0 or later |
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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.
smhasher
- Hash Function Quality And Speed Tests Leaderboard
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GxHash - A new (extremely) fast and robust hashing algorithm 🚀
The algorithm passes all SMHasher quality tests and uses rounds of AES block cipher internally, so it is quite robust! For comparison XxH3, t1ha0 and many others don't pass SMHasher (while being slower).
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The PolymurHash universal hash function
Confirmed, I tested it. https://github.com/rurban/smhasher
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Show HN: Discohash – simply, quality, fast hash
There's lots of great hash functions out there: some are super fast, like xxhash and highly optimized, others are also super fast umash and based on interesting math ideas from finite fields^1, while maintaining high quality (according to SMHasher). Others are also fast and interesting (tabulation hash, that may sometimes be seemingly universal), one of the main originators of those ideas are Mikkel Thorup^2. Anyway, a couple of years ago I also tried my hand at building hashes and created a few that passed SMHasher (tifuhash ~ a floating point hash, beamsplitter - a seemingly-universal tabulation style hash, and this one discohash - a "more traditional" ARX-based design (addition rotation xor)^3 ).
0: https://github.com/rurban/smhasher/blob/master/xxh3.h
1: https://pvk.ca/Blog/2022/12/29/fixing-hashing-modulo-alpha-e...
2: https://arxiv.org/abs/1505.01523
3: https://eprint.iacr.org/2018/898.pdf https://crypto.polito.it/content/download/480/2850/file/docu...
4: https://en.wikipedia.org/wiki/BLAKE_(hash_function)
Discohash (posted here) is the fastest one I made, it's simple and doesn't rely on any arch-specific optimizations or vector instructions (AVX etc ~ tho I suppose...they could be added? I'm definitely no expert in them, I barely get away with doing the C/C++ implementations!)
The main mixing round function is:
mix(const int A) {
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A Vulnerability in Implementations of SHA-3, Shake, EdDSA
ubsan, asan, valgrind tests are missing. some do offer symbolic verification of the algo, but not the implementations.
See my https://github.com/rurban/smhasher#crypto paragraph, and
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Academic Urban Legends
The spinach story reminds me a lot on the false recommendation of siphash for hash table DDOS prevention. https://github.com/rurban/smhasher#security
The authors came up in their widely cited paper with a proper solution to spread the random hash seed into the inner loop, vastly enhancing its security by avoiding trivial hash collision attacks. But a secure, slow hash function can never prevent from normal hash seed attacks, when the random seed is known somehow. esp. with dynamic languages it's trivial to get the seed externally.
Other trivial countermeasures must be used then, which also don't make hash tables 10x slower, keeping them practical.
- SHA-1 is out. NIST recommends switching to the SHA-2 and SHA-3 groups of hash algorithms as soon as possible, with an official deadline of Dec. 31, 2030.
- Adventures in Advent of Code
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New ScyllaDB Go Driver: Faster Than GoCQL and Its Rust Counterpart
This is the best, most comprehensive hash test suite I know of: https://github.com/rurban/smhasher/
you might want to particularly look into murmur, spooky, and metrohash. I'm not exactly sure of what the tradeoffs involved are, or what your need is, but that site should serve as a good starting point at least.
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What do you typically use for non-cryptographic hash functions?
Here is a good comparison table, as you can see, BLAKE can perform in secure way much faster than crc32, so my original point, - to use non weak hashes unless you really have a reason/requirement not to do so
stb
- Lessons learned about how to make a header-file library (2013)
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Nebula is an open-source and free-to-use modern C++ game engine
Have you considered not using an engine at all, in favor of libraries? There are many amazing libraries I've used for game development - all in C/C++ - that you can piece together:
* General: [stb](https://github.com/nothings/stb)
- STB: Single-file public domain libraries for C/C++
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Writing a TrueType font renderer
Great to see more accessible references on font internals. I have dabbled on this a bit last year and managed to have a parser and render the points of a glyph's contour (I stopped before Bezier and shape filling stuff). I still have not considered hinting, so it's nice that it's covered. What helped me was an article from the Handmade Network [1] and the source of stb_truetype [2] (also used in Dear ImGUI).
[1] https://handmade.network/forums/articles/t/7330-implementing....
[2] https://github.com/nothings/stb/blob/master/stb_truetype.h
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Capturing the WebGPU Ecosystem
So I read through the materials on mesh shaders and work graphs and looked at sample code. These won't really work (see below). As I implied previously, it's best to research/discuss these sort of matters with professional graphics programmers who have experience actually using the technologies under consideration.
So for the sake of future web searchers who discover this thread: there are only two proven ways to efficiently draw thousands of unique textures of different sizes with a single draw call that are actually used by experienced graphics programmers in production code as of 2023.
Proven method #1: Pack these thousands of textures into a texture atlas.
Proven method #2: Use bindless resources, which is still fairly bleeding edge, and will require fallback to atlases if targeting the PC instead of only high end console (Xbox Series S|X...).
Mesh shaders by themselves won't work: These have similar texture access limitations to the old geometry/tessellation stage they improve upon. A limited, fixed number of textures still must be bound before each draw call (say, 16 or 32 textures, not 1000s), unless bindless resources are used. So mesh shaders must be used with an atlas or with bindless resources.
Work graphs by themselves won't work: This feature is bleeding edge shader model 6.8 whereas bindless resources are SM 6.6. (Xbox Series X|S might top out at SM 6.7, I can't find an authoritative answer.) It looks like work graphs might only work well on nVidia GPUs and won't work well on Intel GPUs anytime soon (but, again, I'm not knowledgeable enough to say this authoritatively). Furthermore, this feature may have a hard dependency on using bindless to begin with. That is, I can't tell if one is allowed to execute a work graph that binds and unbinds individual texture resources. And if one could do such a thing, it would certainly be slower than using bindless. The cost of bindless is paid "up front" when the textures are uploaded.
Some programmers use Texture2DArray/GL_TEXTURE_2D_ARRAY as an alternative to atlases but two limitations are (1) the max array length (e.g. GL_MAX_ARRAY_TEXTURE_LAYERS) might only be 256 (e.g. for OpenGL 3.0), (2) all textures must be the same size.
Finally, for the sake of any web searcher who lands on this thread in the years to come, to pack an atlas well a good packing algorithm is needed. It's harder to pack triangles than rectangles but triangles use atlas memory more efficiently and a good triangle packing will outperform the fancy new bindless rendering. Some open source starting points for packing:
https://github.com/nothings/stb/blob/master/stb_rect_pack.h
https://github.com/ands/trianglepacker
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Www Which WASM Works
The STB headers are mostly built like that: https://github.com/nothings/stb
You could also add an optional 'convenience API' over the lower-level flexible-but-inconvenient core API, as long as core library can be compiled on its own.
In essence it's just a way to decouple the actually important library code from runtime environment details which might be better implemented outside the C/C++ stdlib.
It's already as simple as the stdlib IO functions not being asynchrononous while many operating systems provide more modern alternatives. For a specific type of library (such an image decoder) it's often better to delegate such details to the library user instead of circumventing the stdlib and talking directly to OS APIs.
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File for Divorce from LLVM
My stuff for instance:
https://github.com/floooh/sokol
...inspired by:
https://github.com/nothings/stb
But it's not so much about the build system, but requiring a separate C/C++ compiler toolchain (Rust needs this, Zig currently does not - unless the proposal is implemented).
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What C libraries do you use the most?
STB Libraries: https://github.com/nothings/stb
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[Noob Question] How do C programmers get around not having hash maps?
stb_ds is also very popular.
- Is there an existing multidimensional hash table implementation in C?
What are some alternatives?
xxHash - Extremely fast non-cryptographic hash algorithm
Vcpkg - C++ Library Manager for Windows, Linux, and MacOS
wyhash - The FASTEST QUALITY hash function, random number generators (PRNG) and hash map.
imgui-node-editor - Node Editor built using Dear ImGui
BLAKE3 - the official Rust and C implementations of the BLAKE3 cryptographic hash function
ZXing - ZXing ("Zebra Crossing") barcode scanning library for Java, Android
Hashids.java - Hashids algorithm v1.0.0 implementation in Java
ImageMagick - 🧙♂️ ImageMagick 7
png-decoder - A pure-Rust, no_std compatible PNG decoder
freetype-gl - OpenGL text using one vertex buffer, one texture and FreeType
rustls - A modern TLS library in Rust
Cppcheck - static analysis of C/C++ code