diff options
author | Aspen Smith <root@gws.fyi> | 2024-07-28T16·11-0400 |
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committer | clbot <clbot@tvl.fyi> | 2024-08-07T12·38+0000 |
commit | b8f92a6d535af09c24ac887855eb230ca25af1ed (patch) | |
tree | 82cea6a4d3979e0c48e9f97285b8564a24e9ceb0 /tvix/eval/src/value/string.rs | |
parent | 1d7ba89c19b231898a997f1af3c13ed8c7247793 (diff) |
feat(tvix/eval): Forbid Hash{Map,Set}, use Fx instead r/8453
Per https://nnethercote.github.io/perf-book/hashing.html, we have basically no reason to use the default hasher over a faster, non-DoS-resistant hasher. This gives a nice perf boost basically for free: hello outpath time: [704.76 ms 714.91 ms 725.63 ms] change: [-7.2391% -6.1018% -4.9189%] (p = 0.00 < 0.05) Performance has improved. Change-Id: If5587f444ed3af69f8af4eead6af3ea303b4ae68 Reviewed-on: https://cl.tvl.fyi/c/depot/+/12046 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de> Reviewed-by: Ilan Joselevich <personal@ilanjoselevich.com> Autosubmit: aspen <root@gws.fyi>
Diffstat (limited to 'tvix/eval/src/value/string.rs')
-rw-r--r-- | tvix/eval/src/value/string.rs | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/tvix/eval/src/value/string.rs b/tvix/eval/src/value/string.rs index 3e991890ea5a..5c1f31db7eea 100644 --- a/tvix/eval/src/value/string.rs +++ b/tvix/eval/src/value/string.rs @@ -5,9 +5,9 @@ //! paying the cost when creating new strings. use bstr::{BStr, BString, ByteSlice, Chars}; use rnix::ast; +use rustc_hash::FxHashSet; use std::alloc::{alloc, dealloc, handle_alloc_error, Layout}; use std::borrow::{Borrow, Cow}; -use std::collections::HashSet; use std::ffi::c_void; use std::fmt::{self, Debug, Display}; use std::hash::Hash; @@ -40,23 +40,29 @@ pub enum NixContextElement { /// operations, e.g. concatenation, interpolation and other string operations. #[repr(transparent)] #[derive(Clone, Debug, Serialize, Default)] -pub struct NixContext(HashSet<NixContextElement>); +pub struct NixContext(FxHashSet<NixContextElement>); impl From<NixContextElement> for NixContext { fn from(value: NixContextElement) -> Self { - Self([value].into()) + let mut set = FxHashSet::default(); + set.insert(value); + Self(set) } } -impl From<HashSet<NixContextElement>> for NixContext { - fn from(value: HashSet<NixContextElement>) -> Self { +impl From<FxHashSet<NixContextElement>> for NixContext { + fn from(value: FxHashSet<NixContextElement>) -> Self { Self(value) } } impl<const N: usize> From<[NixContextElement; N]> for NixContext { fn from(value: [NixContextElement; N]) -> Self { - Self(HashSet::from(value)) + let mut set = FxHashSet::default(); + for elt in value { + set.insert(elt); + } + Self(set) } } |