| commit | 0eed533e997d39f56636732b09775944b9c4593e | [log] [tgz] |
|---|---|---|
| author | Julien Desprez <jdesprez@google.com> | Thu Feb 11 20:47:48 2021 +0000 |
| committer | Julien Desprez <jdesprez@google.com> | Thu Feb 11 20:47:50 2021 +0000 |
| tree | 6e4d3b1c9ab986f8fbd8f58306ba38add67dd444 | |
| parent | dc437b048a17e74203fc08e57111ba607d69462f [diff] |
Clean up rust_test_host TEST_MAPPING after default update After b/177689340, rust_test_host doesn't need TEST_MAPPING config anymore to run in presubmit. Change-Id: Iba9abb330be04985c6eb16e41644f51ac07e6b5f Test: presubmit Bug: 178646865
- src/
- LICENSE ⇨ LICENSE-APACHE
- .cargo_vcs_info.json
- .gitignore
- Android.bp
- Cargo.toml
- Cargo.toml.orig
- CODE_OF_CONDUCT.md
- LICENSE-APACHE
- LICENSE-MIT
- METADATA
- MODULE_LICENSE_APACHE2
- OWNERS
- README.md
- TEST_MAPPING
rustc-hash
A speedy hash algorithm used within rustc. The hashmap in liballoc by default uses SipHash which isn't quite as speedy as we want. In the compiler we're not really worried about DOS attempts, so we use a fast non-cryptographic hash.
This is the same as the algorithm used by Firefox -- which is a homespun one not based on any widely-known algorithm -- though modified to produce 64-bit hash values instead of 32-bit hash values. It consistently out-performs an FNV-based hash within rustc itself -- the collision rate is similar or slightly worse than FNV, but the speed of the hash function itself is much higher because it works on up to 8 bytes at a time.
Usage
use rustc_hash::FxHashMap; let mut map: FxHashMap<u32, u32> = FxHashMap::default(); map.insert(22, 44);
no_std
This crate can be used as a no_std crate by disabling the std feature, which is on by default, as follows:
rustc-hash = { version = "1.0", default-features = false }
In this configuration, FxHasher is the only export, and the FxHashMap/FxHashSet type aliases are omitted.