https://github.com/flier/rust-t1ha
Rust implementation for T1HA (Fast Positive Hash)
https://github.com/flier/rust-t1ha
Last synced: over 1 year ago
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Rust implementation for T1HA (Fast Positive Hash)
- Host: GitHub
- URL: https://github.com/flier/rust-t1ha
- Owner: flier
- License: other
- Created: 2019-03-05T11:20:43.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2024-02-19T10:19:11.000Z (over 2 years ago)
- Last Synced: 2024-04-23T23:15:37.532Z (over 2 years ago)
- Language: Rust
- Homepage:
- Size: 59.6 KB
- Stars: 85
- Watchers: 8
- Forks: 10
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# rust-t1ha [](https://github.com/flier/rust-t1ha/actions/workflows/ci.yaml) [](https://ci.appveyor.com/project/flier/rust-t1ha) [](https://crates.io/crates/t1ha) [](https://docs.rs/t1ha)
An implementation of the [T1HA (Fast Positive Hash)](https://github.com/leo-yuriev/t1ha) hash function.
### Briefly, it is a portable 64-bit hash function:
* Intended for 64-bit little-endian platforms, predominantly for Elbrus and x86_64, but portable and without penalties it can run on any 64-bit CPU.
* In most cases up to 15% faster than StadtX hash, xxHash, mum-hash, metro-hash, etc. and all others portable hash-functions (which do not use specific hardware tricks).
* Provides a set of terraced hash functions.
* Currently not suitable for cryptography.
* Licensed under [zlib License](https://en.wikipedia.org/wiki/Zlib_License).
## Usage
To include this crate in your program, add the following to your `Cargo.toml`:
```toml
[dependencies]
t1ha = "0.1"
```
### Using `t1ha` in a `HashMap`
The `T1haHashMap` type alias is the easiest way to use the standard library’s `HashMap` with `t1ha`.
```rust
use t1ha::T1haHashMap;
let mut map = T1haHashMap::default();
map.insert(1, "one");
map.insert(2, "two");
map = T1haHashMap::with_capacity_and_hasher(10, Default::default());
map.insert(1, "one");
map.insert(2, "two");
```
**Note:** the standard library’s `HashMap::new` and `HashMap::with_capacity` are only implemented for the `RandomState` hasher, so using `Default` to get the hasher is the next best option.
### Using `t1ha` in a `HashSet`
Similarly, `T1haHashSet` is a type alias for the standard library’s `HashSet` with `t1ha.
```rust
use t1ha::T1haHashSet;
let mut set = T1haHashSet::default();
set.insert(1);
set.insert(2);
set = T1haHashSet::with_capacity_and_hasher(10, Default::default());
set.insert(1);
set.insert(2);
```
## Performance
`t1ha` can use AES, AVX or AVX2 instructions as hardware acceleration.
| Implementation | Platform/CPU |
| :---------------------- | :------------------------------------- |
| `t1ha0_ia32aes_avx()` | x86 with AES-NI and AVX extensions |
| `t1ha0_ia32aes_avx2()` | x86 with AES-NI and AVX2 extensions |
| `t1ha0_ia32aes_noavx()` | x86 with AES-NI without AVX extensions |
| `t1ha0_32le()` | 32-bit little-endian |
| `t1h0a_32be()` | 32-bit big-endian |
| `t1ha1_le()` | 64-bit little-endian |
| `t1ha1_be()` | 64-bit big-endian |
| `t1ha2_atonce()` | 64-bit little-endian |
You could choose the right implementation base on your `target_cpu`.
```sh
$ RUSTFLAGS="-C target-cpu=native" cargo build
```
### Benchmark
`rust-t1ha` provide [a rough performance comparison](https://www.reddit.com/r/rust/comments/ayla9m/rust_implementation_for_t1ha_fast_positive_hash/) to other `Rust` implemenation of non-cryptographic hash functions, you can run the benchmark base on your envrionment and usage scenario.
```sh
$ RUSTFLAGS="-C target-cpu=native" cargo bench
```
### Native `t1ha` Library
`rust-t1ha` major focus `Rust` implementation, if you intent to use the origin native `t1ha` library, please check [rust-fasthash](https://github.com/flier/rust-fasthash) project and it's benchmark, which provides a suite of non-cryptographic hash functions from [SMHasher](https://github.com/rurban/smhasher/).