perf(core): read files in parallel

Author: JamieMason

Cargo.toml

@@ -36,7 +36,12 @@ serde = { version = "1.0.228", features = ["derive"] }
 serde_json = { version = "1.0.145", features = ["preserve_order"] }
 serde_yaml = "0.9"
 thiserror = "2.0.17"
-tokio = { version = "1", features = ["macros", "rt-multi-thread", "sync"] }
+tokio = { version = "1", features = [
+  "macros",
+  "rt-multi-thread",
+  "sync",
+  "fs",
+] }
 
 [features]
 default = []

src/main.rs

@@ -59,7 +59,7 @@ async fn main() {
   debug!("{:#?}", config.cli);
   debug!("{:#?}", config.rcfile);
 
-  let packages = Packages::from_config(&config);
+  let packages = Packages::from_config(&config).await;
 
   match packages.all.len() {
     0 => {

src/package_json.rs

@@ -3,7 +3,12 @@ use {
   log::error,
   serde::Serialize,
   serde_json::{ser::PrettyFormatter, Serializer, Value},
-  std::{cell::RefCell, fs, path::PathBuf, rc::Rc},
+  std::{
+    cell::RefCell,
+    fs,
+    path::{Path, PathBuf},
+    rc::Rc,
+  },
 };
 
 #[derive(Debug)]
@@ -50,31 +55,34 @@ pub enum FormatMismatchVariant {
 }
 
 impl PackageJson {
-  /// Read a package.json file from the given location
+  /// Parse a package.json from already-read JSON content
+  pub fn from_json(file_path: &Path, json: String) -> Option<Self> {
+    serde_json::from_str(&json)
+      .inspect_err(|_| {
+        error!("Invalid JSON: {}", &file_path.to_str().unwrap());
+      })
+      .map(|contents: Value| Self {
+        name: contents
+          .pointer("/name")
+          .and_then(|name| name.as_str())
+          .unwrap_or("NAME_IS_MISSING")
+          .to_string(),
+        file_path: file_path.to_path_buf(),
+        formatting_mismatches: RefCell::new(vec![]),
+        json: RefCell::new(contents.to_string()),
+        contents: RefCell::new(contents),
+      })
+      .ok()
+  }
+
+  /// Read a package.json file from the given location (sync)
   pub fn from_file(file_path: &PathBuf) -> Option<Self> {
     fs::read_to_string(file_path)
       .inspect_err(|_| {
         error!("package.json not readable at {}", &file_path.to_str().unwrap());
       })
       .ok()
-      .and_then(|json| {
-        serde_json::from_str(&json)
-          .inspect_err(|_| {
-            error!("Invalid JSON: {}", &file_path.to_str().unwrap());
-          })
-          .map(|contents: Value| Self {
-            name: contents
-              .pointer("/name")
-              .and_then(|name| name.as_str())
-              .unwrap_or("NAME_IS_MISSING")
-              .to_string(),
-            file_path: file_path.clone(),
-            formatting_mismatches: RefCell::new(vec![]),
-            json: RefCell::new(contents.to_string()),
-            contents: RefCell::new(contents),
-          })
-          .ok()
-      })
+      .and_then(|json| Self::from_json(file_path, json))
   }
 
   /// Does a property exist at this path of the parsed package.json?

src/packages.rs

@@ -19,6 +19,7 @@ use {
     path::{Path, PathBuf},
     rc::Rc,
   },
+  tokio::fs as tokio_fs,
 };
 
 #[derive(Debug)]
@@ -33,14 +34,38 @@ impl Packages {
   }
 
   /// Get every package.json file matched by the user's source patterns
-  pub fn from_config(config: &Config) -> Self {
+  pub async fn from_config(config: &Config) -> Self {
     let file_paths = get_file_paths(config);
+
+    // Read all file contents in parallel using tokio
+    let tasks: Vec<_> = file_paths
+      .into_iter()
+      .map(|file_path| {
+        tokio::spawn(async move {
+          tokio_fs::read_to_string(&file_path)
+            .await
+            .ok()
+            .map(|contents| (file_path, contents))
+        })
+      })
+      .collect();
+
+    // Wait for all tasks to complete and collect results
+    let mut file_contents = Vec::new();
+    for task in tasks {
+      if let Ok(Some((path, content))) = task.await {
+        file_contents.push((path, content));
+      }
+    }
+
+    // Parse JSON synchronously (to avoid Send issues with Rc)
     let mut packages = Self::new();
-    file_paths.iter().for_each(|file_path| {
-      if let Some(package_json) = PackageJson::from_file(file_path) {
+    for (file_path, json) in file_contents {
+      if let Some(package_json) = PackageJson::from_json(&file_path, json) {
         packages.add_package(package_json);
       }
-    });
+    }
+
     packages
   }