Refactor: Replace unbounded thread spawning with rayon parallel iterators

- Add rayon 1.11.0 dependency to pet-conda and pet-homebrew crates
- Refactor get_conda_environments() in lib.rs to use par_iter()
- Refactor get_conda_environment_paths() in environment_locations.rs to use par_iter()
- Refactor get_known_symlinks() in sym_links.rs to use par_iter()

This provides controlled parallelism based on CPU count, better resource
management, and avoids potential thread exhaustion on systems with hundreds
of Python environments.

Co-authored-by: karthiknadig <3840081+karthiknadig@users.noreply.github.com>

Author: Copilot

Cargo.lock

@@ -19,6 +19,7 @@ regex = "1.10.4"
 pet-reporter = { path = "../pet-reporter" }
 env_logger = "0.10.2"
 yaml-rust2 = "0.8.1"
+rayon = "1.11.0"
 
 [features]
 ci = []

crates/pet-conda/Cargo.toml

@@ -9,6 +9,7 @@ use crate::{
 use log::trace;
 use pet_fs::path::{expand_path, norm_case};
 use pet_python_utils::platform_dirs::Platformdirs;
+use rayon::prelude::*;
 use std::{
     env, fs,
     path::{Path, PathBuf},
@@ -43,19 +44,11 @@ pub fn get_conda_environment_paths(
     env_paths.dedup();
     // For each env, check if we have a conda install directory in them and
     // & then iterate through the list of envs in the envs directory.
-    // let env_paths = vec![];
-    let mut threads = vec![];
-    for path in env_paths.iter().filter(|f| f.exists()) {
-        let path = path.clone();
-        threads.push(thread::spawn(move || get_environments(&path)));
-    }
-
-    let mut result = vec![];
-    for thread in threads {
-        if let Ok(envs) = thread.join() {
-            result.extend(envs);
-        }
-    }
+    let mut result: Vec<PathBuf> = env_paths
+        .par_iter()
+        .filter(|f| f.exists())
+        .flat_map(|path| get_environments(path))
+        .collect();
 
     result.sort();
     result.dedup();

crates/pet-conda/src/environment_locations.rs

@@ -18,6 +18,7 @@ use pet_core::{
     Locator, LocatorKind,
 };
 use pet_fs::path::norm_case;
+use rayon::prelude::*;
 use serde::{Deserialize, Serialize};
 use std::{
     collections::HashMap,
@@ -371,24 +372,8 @@ fn get_conda_environments(
     paths: &Vec<PathBuf>,
     manager: &Option<CondaManager>,
 ) -> Vec<CondaEnvironment> {
-    let mut threads = vec![];
-    for path in paths {
-        let path = path.clone();
-        let mgr = manager.clone();
-        threads.push(thread::spawn(move || {
-            if let Some(env) = get_conda_environment_info(&path, &mgr) {
-                vec![env]
-            } else {
-                vec![]
-            }
-        }));
-    }
-
-    let mut envs: Vec<CondaEnvironment> = vec![];
-    for thread in threads {
-        if let Ok(mut result) = thread.join() {
-            envs.append(&mut result);
-        }
-    }
-    envs
+    paths
+        .par_iter()
+        .filter_map(|path| get_conda_environment_info(path, manager))
+        .collect()
 }

crates/pet-conda/src/lib.rs

@@ -18,3 +18,4 @@ lazy_static = "1.4.0"
 pet-core = { path = "../pet-core" }
 log = "0.4.21"
 regex = "1.10.4"
+rayon = "1.11.0"

crates/pet-homebrew/Cargo.toml

@@ -4,6 +4,7 @@
 use lazy_static::lazy_static;
 use pet_fs::path::resolve_symlink;
 use pet_python_utils::executable::find_executables;
+use rayon::prelude::*;
 use regex::Regex;
 use std::{
     fs,
@@ -30,32 +31,26 @@ pub fn get_known_symlinks(
     // Go through all the exes in all of the above bin directories and verify we have a list of all of them.
     // They too could be symlinks, e.g. we could have `/opt/homebrew/bin/python3` & also `/opt/homebrew/bin/python`
     // And possible they are all symlnks to the same exe.
-    let threads = symlinks
-        .iter()
-        .map(|symlink| {
-            let symlink = symlink.clone();
-            let known_symlinks = symlinks.clone();
-            std::thread::spawn(move || {
-                if let Some(bin) = symlink.parent() {
-                    let mut symlinks = vec![];
-                    for possible_symlink in find_executables(bin) {
-                        if let Some(symlink) = resolve_symlink(&possible_symlink) {
-                            if known_symlinks.contains(&symlink) {
-                                symlinks.push(possible_symlink);
-                            }
+    let known_symlinks = symlinks.clone();
+    let other_symlinks: Vec<PathBuf> = symlinks
+        .par_iter()
+        .flat_map(|symlink| {
+            if let Some(bin) = symlink.parent() {
+                find_executables(bin)
+                    .into_iter()
+                    .filter(|possible_symlink| {
+                        if let Some(resolved) = resolve_symlink(possible_symlink) {
+                            known_symlinks.contains(&resolved)
+                        } else {
+                            false
                         }
-                    }
-                    symlinks
-                } else {
-                    vec![]
-                }
-            })
+                    })
+                    .collect::<Vec<_>>()
+            } else {
+                vec![]
+            }
         })
-        .collect::<Vec<_>>();
-    let other_symlinks = threads
-        .into_iter()
-        .flat_map(|t| t.join().unwrap())
-        .collect::<Vec<_>>();
+        .collect();
     symlinks.extend(other_symlinks);
 
     symlinks.sort();