Switch to rayon-core for faster build

Cargo.toml

@@ -29,7 +29,7 @@ std = []
 # `update_rayon` and (in combination with `mmap` below) `update_mmap_rayon`
 # methods, for multithreaded hashing. However, even if this feature is enabled,
 # all other APIs remain single-threaded.
-rayon = ["dep:rayon", "std"]
+rayon = ["dep:rayon-core", "std"]
 
 # The `mmap` feature (disabled by default, but enabled for docs.rs) adds the
 # `update_mmap` and (in combination with `rayon` above) `update_mmap_rayon`
@@ -98,7 +98,7 @@ constant_time_eq = "0.3.0"
 cfg-if = "1.0.0"
 digest = { version = "0.10.1", features = [ "mac" ], optional = true }
 memmap2 = { version = "0.9", optional = true }
-rayon = { version = "1.2.1", optional = true }
+rayon-core = { version = "1.12.1", optional = true }
 serde = { version = "1.0", default-features = false, features = ["derive"], optional = true }
 zeroize = { version = "1", default-features = false, features = ["zeroize_derive"], optional = true }
 

b3sum/Cargo.toml

@@ -18,7 +18,7 @@ anyhow = "1.0.25"
 blake3 = { version = "1", path = "..", features = ["mmap", "rayon"] }
 clap = { version = "4.0.8", features = ["derive", "wrap_help"] }
 hex = "0.4.0"
-rayon = "1.2.1"
+rayon-core = "1.12.1"
 wild = "2.0.3"
 
 [dev-dependencies]

b3sum/src/main.rs

@@ -475,7 +475,7 @@ fn check_one_checkfile(path: &Path, args: &Args, files_failed: &mut u64) -> Resu
 
 fn main() -> Result<()> {
     let args = Args::parse()?;
-    let mut thread_pool_builder = rayon::ThreadPoolBuilder::new();
+    let mut thread_pool_builder = rayon_core::ThreadPoolBuilder::new();
     if let Some(num_threads) = args.num_threads() {
         thread_pool_builder = thread_pool_builder.num_threads(num_threads);
     }

src/join.rs

@@ -67,7 +67,7 @@ impl Join for RayonJoin {
         RA: Send,
         RB: Send,
     {
-        rayon::join(oper_a, oper_b)
+        rayon_core::join(oper_a, oper_b)
     }
 }