Use scoped threads for parallelism

rustywind-cli/Cargo.toml

@@ -47,3 +47,6 @@ ignore = "0.4"
 # parsing
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+
+# parallelism
+num_cpus = "1.16"

rustywind-cli/src/heard.rs

@@ -0,0 +1,41 @@
+/// Heard is a struct that handles running the rustywind on a list of files
+/// in parallel. It uses the num_cpus crate to determine the number of
+/// physical cores on the machine. It then spawns a thread for each core
+/// and runs the rustywind on the file paths.
+use crate::options::Options;
+use std::{path::PathBuf, sync::Arc};
+
+#[derive(Debug)]
+pub struct Heard {
+    cpus: usize,
+    options: Arc<Options>,
+}
+
+impl Heard {
+    pub fn new(options: Arc<Options>) -> Self {
+        let cpus = num_cpus::get_physical();
+        Self { cpus, options }
+    }
+
+    pub fn run_on_file_paths(self, file_paths: Vec<PathBuf>) {
+        log::debug!("checking {} files", file_paths.len());
+
+        let total_chunks = self.cpus;
+        let chunks_of = file_paths.len() / total_chunks;
+        let options = &self.options;
+
+        std::thread::scope(|s| {
+            file_paths.chunks(chunks_of).for_each(|chunk| {
+                s.spawn(|| {
+                    run_on_file_paths(chunk, options);
+                });
+            });
+        })
+    }
+}
+
+fn run_on_file_paths(file_paths: &[PathBuf], options: &Options) {
+    for file_path in file_paths {
+        crate::run_on_file_path(file_path, options);
+    }
+}

rustywind-cli/src/main.rs

@@ -1,9 +1,11 @@
 mod cli;
+mod heard;
 mod options;
 
 use ahash::AHashSet as HashSet;
 use clap::Parser;
 use eyre::Result;
+use heard::Heard;
 use indoc::indoc;
 use once_cell::sync::Lazy;
 use options::Options;
@@ -14,6 +16,7 @@ use std::path::Path;
 use std::path::PathBuf;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::Ordering;
+use std::sync::Arc;
 
 static EXIT_ERROR: Lazy<AtomicBool> = Lazy::new(|| AtomicBool::new(false));
 static GRAY: Lazy<colored::CustomColor> = Lazy::new(|| colored::CustomColor::new(120, 120, 120));
@@ -99,7 +102,12 @@ fn main() -> Result<()> {
     color_eyre::install()?;
 
     let cli = Cli::parse();
-    let options = Options::new_from_cli(cli)?;
+
+    let mut options = Options::new_from_cli(cli)?;
+
+    let search_paths = std::mem::take(&mut options.search_paths);
+
+    let options = Arc::new(options);
     let rustywind = &options.rustywind;
 
     match &options.write_mode {
@@ -132,9 +140,8 @@ fn main() -> Result<()> {
             eprint!("[WARN] No classes were found in STDIN");
         }
     } else {
-        for file_path in options.search_paths.iter() {
-            run_on_file_paths(file_path, &options)
-        }
+        let heard = Heard::new(options.clone());
+        heard.run_on_file_paths(search_paths);
 
         // after running on all files, if there was an error, exit with 1
         if EXIT_ERROR.load(Ordering::Relaxed) {
@@ -145,7 +152,7 @@ fn main() -> Result<()> {
     Ok(())
 }
 
-fn run_on_file_paths(file_path: &Path, options: &Options) {
+pub fn run_on_file_path(file_path: &Path, options: &Options) {
     // if the file is in the ignored_files list return early
     if should_ignore_current_file(&options.ignored_files, file_path) {
         log::debug!("file path {file_path:#?} found in ignored_files, will not sort");
@@ -175,7 +182,7 @@ fn run_on_file_paths(file_path: &Path, options: &Options) {
                     (true, WriteMode::ToConsole) => print_file_contents(&sorted_content),
                     (false, WriteMode::ToConsole) => print_file_contents(&sorted_content),
 
-                    (_, WriteMode::CheckFormatted) => {
+                    (contents_changed, WriteMode::CheckFormatted) => {
                         print_changed_files(file_path, contents_changed, options);
                     }
                 }

rustywind-core/src/app.rs

@@ -10,7 +10,7 @@ use aho_corasick::{Anchored, Input};
 use regex::Captures;
 
 /// The options to pass to the sorter.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct RustyWind {
     pub regex: FinderRegex,
     pub sorter: Sorter,

rustywind-core/src/sorter.rs

@@ -16,7 +16,7 @@ pub(crate) static SORTER_EXTRACTOR_RE: Lazy<Regex> =
     Lazy::new(|| Regex::new(r"^(\.[^\s]+)[ ]").unwrap());
 
 /// Use either our default regex in [crate::defaults::RE] or a custom regex.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum FinderRegex {
     DefaultRegex,
     CustomRegex(Regex),
@@ -34,7 +34,7 @@ impl Deref for FinderRegex {
 }
 
 /// Use either our default sorter in [crate::defaults::SORTER] or a custom sorter.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum Sorter {
     DefaultSorter,
     CustomSorter(HashMap<String, usize>),