Minor stylistic fixes.

CHANGELOG.md

@@ -26,11 +26,11 @@ New features
 * Normal loops return `()` as the value.
 * Loop expressions can be enabled/disabled via `Engine::set_allow_loop_expressions`
 
-### Stable hashing
+### Static hashing
 
-* It is now possible to specify a fixed _seed_ for use with the `ahash` hasher, via an environment variable, in order to force stable (i.e. deterministic) hashes for function signatures.
+* It is now possible to specify a fixed _seed_ for use with the `ahash` hasher, via a static function `rhai::config::hashing::set_ahash_seed` or an environment variable, in order to force static (i.e. deterministic) hashes for function signatures.
 * This is necessary when using Rhai across shared-library boundaries.
-* A build script is used to extract the environment variable (`RHAI_AHASH_SEED`) and splice it into the source code before compilation.
+* A build script is used to extract the environment variable (`RHAI_AHASH_SEED`, if any) and splice it into the source code before compilation.
 
 ### No Timestamps
 

build.template

@@ -1,2 +1,3 @@
-// This file is automatically set during build time by build.rs and build.template.
+//! This file is automatically recreated during build time by `build.rs` from `build.template`.
+
 pub(crate) const AHASH_SEED: Option<[u64; 4]> = {{AHASH_SEED}};

src/config/hashing.rs

@@ -2,18 +2,30 @@
 //!
 //! Set to [`None`] to disable stable hashing.
 //!
-//! See [`set_rhai_ahash_seed`] for more.
+//! See [`set_rhai_ahash_seed`].
 //!
-//! Alternatively, You can also set this at compile time by setting the `RHAI_AHASH_SEED`
+//! # Example
-//! environment variable instead.
 //!
-//! E.g. `env RHAI_AHASH_SEED ="[236,800,954,213]"`
+//! ```rust
+//! // Set the hashing seed to [1, 2, 3, 4]
+//! rhai::config::hashing::set_ahash_seed(Some([1, 2, 3, 4])).unwrap();
+//! ```
+//! Alternatively, set this at compile time via the `RHAI_AHASH_SEED` environment variable.
+//!
+//! # Example
+//!
+//! ```sh
+//! env RHAI_AHASH_SEED ="[236,800,954,213]"
+//! ```
 // [236,800,954,213], haha funny yume nikki reference epic uboachan face numberworld nexus moment 100
 
 use crate::config::hashing_env;
-use core::{
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+use std::{
     cell::UnsafeCell,
     marker::PhantomData,
+    mem,
     mem::MaybeUninit,
     panic::{RefUnwindSafe, UnwindSafe},
     sync::atomic::{AtomicBool, AtomicUsize, Ordering},
@@ -23,23 +35,25 @@ use core::{
 // what does this do?
 // so what this does is keep track of a global address in memory that acts as a global lock
 // i stole this from crossbeam so read their docs for more
+#[must_use]
 struct HokmaLock {
     lock: AtomicUsize,
 }
 
 impl HokmaLock {
+    #[inline(always)]
     pub const fn new() -> Self {
         Self {
             lock: AtomicUsize::new(0),
         }
     }
 
-    pub fn write(&'static self) -> WhenTheHokmaSupression {
+    pub fn write(&'static self) -> WhenTheHokmaSuppression {
         loop {
             let previous = self.lock.swap(1, Ordering::SeqCst);
 
             if previous != 1 {
-                return WhenTheHokmaSupression {
+                return WhenTheHokmaSuppression {
                     hokma: self,
                     state: previous,
                 };
@@ -48,21 +62,21 @@ impl HokmaLock {
     }
 }
 
-struct WhenTheHokmaSupression {
+struct WhenTheHokmaSuppression {
     hokma: &'static HokmaLock,
-
     state: usize,
 }
 
-impl WhenTheHokmaSupression {
+impl WhenTheHokmaSuppression {
+    #[inline]
     pub fn the_price_of_silence(self) {
         self.hokma.lock.store(self.state, Ordering::SeqCst);
-
+        mem::forget(self)
-        core::mem::forget(self)
     }
 }
 
-impl Drop for WhenTheHokmaSupression {
+impl Drop for WhenTheHokmaSuppression {
+    #[inline]
     fn drop(&mut self) {
         self.hokma
             .lock
@@ -70,6 +84,8 @@ impl Drop for WhenTheHokmaSupression {
     }
 }
 
+#[inline(always)]
+#[must_use]
 fn hokmalock(address: usize) -> &'static HokmaLock {
     const LEN: usize = 787;
     const LCK: HokmaLock = HokmaLock::new();
@@ -79,11 +95,12 @@ fn hokmalock(address: usize) -> &'static HokmaLock {
 }
 
 // Safety: lol, there is a reason its called "SusLock<T>"
+#[must_use]
 struct SusLock<T>
 where
     T: 'static + Copy,
 {
-    initalized: AtomicBool,
+    initialized: AtomicBool,
     data: UnsafeCell<MaybeUninit<T>>,
     _marker: PhantomData<T>,
 }
@@ -92,17 +109,19 @@ impl<T> SusLock<T>
 where
     T: 'static + Copy,
 {
+    #[inline]
     pub const fn new() -> SusLock<T> {
         SusLock {
-            initalized: AtomicBool::new(false),
+            initialized: AtomicBool::new(false),
             data: UnsafeCell::new(MaybeUninit::uninit()),
             _marker: PhantomData,
         }
     }
 
+    #[must_use]
     pub fn get(&self) -> Option<T> {
-        if self.initalized.load(Ordering::SeqCst) {
+        if self.initialized.load(Ordering::SeqCst) {
-            let hokma = hokmalock(unsafe { core::mem::transmute(self.data.get()) });
+            let hokma = hokmalock(unsafe { mem::transmute(self.data.get()) });
             // we forgo the optimistic read, because we don't really care
             let guard = hokma.write();
             let val = {
@@ -116,11 +135,12 @@ where
         }
     }
 
+    #[must_use]
     pub fn get_or_init(&self, f: impl FnOnce() -> T) -> Option<T> {
         let value = f();
-        if !self.initalized.load(Ordering::SeqCst) {
+        if !self.initialized.load(Ordering::SeqCst) {
-            self.initalized.store(true, Ordering::SeqCst);
+            self.initialized.store(true, Ordering::SeqCst);
-            let hokma = hokmalock(unsafe { core::mem::transmute(self.data.get()) });
+            let hokma = hokmalock(unsafe { mem::transmute(self.data.get()) });
             hokma.write();
             unsafe {
                 self.data.get().write(MaybeUninit::new(value));
@@ -131,7 +151,7 @@ where
     }
 
     pub fn set(&self, value: T) -> Result<(), T> {
-        if self.initalized.load(Ordering::SeqCst) {
+        if self.initialized.load(Ordering::SeqCst) {
             Err(value)
         } else {
             let _ = self.get_or_init(|| value);
@@ -148,8 +168,9 @@ impl<T> Drop for SusLock<T>
 where
     T: 'static + Copy,
 {
+    #[inline]
     fn drop(&mut self) {
-        if self.initalized.load(Ordering::SeqCst) {
+        if self.initialized.load(Ordering::SeqCst) {
             unsafe { (&mut *self.data.get()).assume_init_drop() };
         }
     }
@@ -157,27 +178,44 @@ where
 
 static AHASH_SEED: SusLock<Option<[u64; 4]>> = SusLock::new();
 
-// #[doc(cfg(feature = "stable_hash"))]
+/// Set the hashing seed. This is used to hash functions etc.
-/// Sets the Rhai Ahash seed. This is used to hash functions and the like.
 ///
-/// This is a global variable, and thus will affect every Rhai instance.
+/// This is a static global value and affects every Rhai instance.
 /// This should not be used _unless_ you know you need it.
 ///
-/// # Warnings
+/// # Warning
-/// - You can only call this function **ONCE** for the whole of your program execution.
-/// - You should gracefully handle the `Err(())`.
-/// - You **MUST** call this before **ANY** Rhai operation occurs (e.g. creating an [`Engine`]).
 ///
-/// # Errors
+/// * You can only call this function **ONCE** for the entire duration of program execution.
-/// This will error if the AHashSeed is already set.
+/// * You **MUST** call this before performing **ANY** Rhai operation (e.g. creating an [`Engine`]).
+///
+/// # Error
+///
+/// Returns an error containing the existing hashing seed if already set.
+///
+/// # Example
+///
+/// ```rust
+/// # use rhai::Engine;
+/// // Set the hashing seed to [1, 2, 3, 4]
+/// rhai::config::hashing::set_ahash_seed(Some([1, 2, 3, 4])).unwrap();
+///
+/// // Use Rhai AFTER setting the hashing seed
+/// let engine = Engine::new();
+/// ```
+#[inline(always)]
 pub fn set_ahash_seed(new_seed: Option<[u64; 4]>) -> Result<(), Option<[u64; 4]>> {
     AHASH_SEED.set(new_seed)
 }
 
-/// Gets the current Rhai Ahash Seed. If the seed is not yet defined, this will automatically set a seed.
+/// Get the current hashing Seed.
-/// The default seed is not stable and may change between versions.
+///
+/// If the seed is not yet defined, the `RHAI_AHASH_SEED` environment variable (if any) is used.
+///
+/// Otherwise, the hashing seed is randomized to protect against DOS attacks.
 ///
 /// See [`set_rhai_ahash_seed`] for more.
+#[inline]
+#[must_use]
 pub fn get_ahash_seed() -> Option<[u64; 4]> {
     AHASH_SEED.get_or_init(|| hashing_env::AHASH_SEED).flatten()
 }

src/config/hashing_env.rs

@@ -1,2 +1,3 @@
-// This file is automatically set during build time by build.rs and build.template.
+//! This file is automatically recreated during build time by `build.rs` from `build.template`.
+
 pub(crate) const AHASH_SEED: Option<[u64; 4]> = None;

src/config/mod.rs

@@ -1,4 +1,4 @@
-//! Contains Configuration for Rhai.
+//! Configuration for Rhai.
 
 pub mod hashing;
 mod hashing_env;