Remove stable_hash feature and use environment variable.

This commit is contained in:
Stephen Chung 2022-09-27 13:23:47 +08:00
parent a518ab62bb
commit 2ecf44a48e
6 changed files with 41 additions and 7 deletions

View File

@ -7,7 +7,9 @@ Version 1.11.0
New features New features
------------ ------------
* A new feature flag, `stable_hash`, is added that forces hashing to be consistent using a fixed seed. ### Stable hashing
* It is now possible to specify a fixed _seed_ for use with the `ahash` hasher in order to force stable (i.e. deterministic) hashes for function signatures.
Enhancements Enhancements
------------ ------------

View File

@ -62,7 +62,6 @@ metadata = ["serde", "serde_json", "rhai_codegen/metadata", "smartstring/serde"]
internals = [] # expose internal data structures internals = [] # expose internal data structures
debugging = ["internals"] # enable debugging debugging = ["internals"] # enable debugging
serde = ["dep:serde", "smartstring/serde", "smallvec/serde"] # implement serde for rhai types serde = ["dep:serde", "smartstring/serde", "smallvec/serde"] # implement serde for rhai types
stable_hash = [] # perform all hashing with fixed seed value
# compiling for no-std # compiling for no-std
no_std = ["no-std-compat", "num-traits/libm", "core-error", "libm", "ahash/compile-time-rng", "hashbrown/ahash-compile-time-rng"] no_std = ["no-std-compat", "num-traits/libm", "core-error", "libm", "ahash/compile-time-rng", "hashbrown/ahash-compile-time-rng"]

27
build.rs Normal file
View File

@ -0,0 +1,27 @@
use std::{env, fs::File, io::Write};
const WRITE_ERROR: &str = "cannot write to `config.rs`";
fn main() {
// Tell Cargo that if the given environment variable changes, to rerun this build script.
println!("cargo:rerun-if-env-changed=RHAI_AHASH_SEED");
let mut f = File::create("src/config.rs").expect("cannot create `config.rs`");
f.write_fmt(format_args!(
"//! Configuration settings for this Rhai build
#![allow(dead_code)]
"
))
.expect(WRITE_ERROR);
let seed = env::var("RHAI_AHASH_SEED").map_or_else(|_| "None".into(), |s| format!("Some({s})"));
f.write_fmt(format_args!(
"pub const AHASH_SEED: Option<[u64; 4]> = {seed};\n"
))
.expect(WRITE_ERROR);
f.flush().expect("cannot flush `config.rs`");
}

4
src/config.rs Normal file
View File

@ -0,0 +1,4 @@
//! Configuration settings for this Rhai build
#![allow(dead_code)]
pub const AHASH_SEED: Option<[u64; 4]> = None;

View File

@ -1,5 +1,6 @@
//! Module containing utilities to hash functions and function calls. //! Module containing utilities to hash functions and function calls.
use crate::config;
#[cfg(feature = "no_std")] #[cfg(feature = "no_std")]
use std::prelude::v1::*; use std::prelude::v1::*;
use std::{ use std::{
@ -74,8 +75,8 @@ impl BuildHasher for StraightHasherBuilder {
#[inline(always)] #[inline(always)]
#[must_use] #[must_use]
pub fn get_hasher() -> ahash::AHasher { pub fn get_hasher() -> ahash::AHasher {
if cfg!(feature = "stable_hash") { if let Some([seed1, seed2, seed3, seed4]) = config::AHASH_SEED {
ahash::RandomState::with_seeds(42, 999, 123, 0).build_hasher() ahash::RandomState::with_seeds(seed1, seed2, seed3, seed4).build_hasher()
} else { } else {
ahash::AHasher::default() ahash::AHasher::default()
} }

View File

@ -83,6 +83,7 @@ use std::prelude::v1::*;
// Internal modules // Internal modules
mod api; mod api;
mod ast; mod ast;
mod config;
mod engine; mod engine;
mod eval; mod eval;
mod func; mod func;
@ -224,7 +225,7 @@ pub mod debugger {
/// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most /// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most
/// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline. /// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline.
#[cfg(not(feature = "internals"))] #[cfg(not(feature = "internals"))]
pub(crate) type Identifier = SmartString; type Identifier = SmartString;
/// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most /// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most
/// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline. /// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline.
@ -237,7 +238,7 @@ pub use func::Shared;
/// Alias to [`RefCell`][std::cell::RefCell] or [`RwLock`][std::sync::RwLock] depending on the `sync` feature flag. /// Alias to [`RefCell`][std::cell::RefCell] or [`RwLock`][std::sync::RwLock] depending on the `sync` feature flag.
pub use func::Locked; pub use func::Locked;
pub(crate) use func::{calc_fn_hash, calc_fn_params_hash, calc_var_hash, combine_hashes}; use func::{calc_fn_hash, calc_fn_params_hash, calc_var_hash, combine_hashes};
pub use rhai_codegen::*; pub use rhai_codegen::*;
@ -429,7 +430,7 @@ type FnArgsVec<T> = smallvec::SmallVec<[T; 5]>;
#[cfg(feature = "no_closure")] #[cfg(feature = "no_closure")]
type FnArgsVec<T> = crate::StaticVec<T>; type FnArgsVec<T> = crate::StaticVec<T>;
pub(crate) type SmartString = smartstring::SmartString<smartstring::LazyCompact>; type SmartString = smartstring::SmartString<smartstring::LazyCompact>;
// Compiler guards against mutually-exclusive feature flags // Compiler guards against mutually-exclusive feature flags