feat: Custom stack size

If a user reports a crash from stacksize - we can try different stack
memory sizes to try and figure out the cause.

Do not try and initialise rayon on 32 bit builds

Fix rayon initialisation, may not have been called before due to badly
formed closure

src/main.rs

@@ -27,7 +27,6 @@ use config::get_config;
 use dir_walker::walk_it;
 use filter::get_biggest;
 use filter_type::get_all_file_types;
-use rayon::ThreadPoolBuildError;
 use regex::Regex;
 use std::cmp::max;
 use std::path::PathBuf;
@@ -177,11 +176,8 @@ fn main() {
         follow_links,
         progress_data: indicator.data.clone(),
     };
-
-    let result = panic::catch_unwind(|| init_rayon);
-    if result.is_err() {
-        eprintln!("Problem initializing rayon, try: export RAYON_NUM_THREADS=1")
-    }
+    let stack_size = config.get_custom_stack_size(&options);
+    init_rayon(&stack_size);
 
     let top_level_nodes = walk_it(simplified_dirs, walk_data);
 
@@ -227,18 +223,34 @@ fn main() {
     }
 }
 
-fn init_rayon() -> Result<(), ThreadPoolBuildError> {
-    let large_stack = usize::pow(1024, 3);
-    let mut s = System::new();
-    s.refresh_memory();
-    let available = s.available_memory();
+fn init_rayon(stack_size: &Option<usize>) {
+    // Rayon seems to raise this error on 32-bit builds
+    // The global thread pool has not been initialized.: ThreadPoolBuildError { kind: GlobalPoolAlreadyInitialized }
+    if cfg!(target_pointer_width = "64") {
+        let result = panic::catch_unwind(|| {
+            match stack_size {
+                Some(n) => rayon::ThreadPoolBuilder::new()
+                    .stack_size(*n)
+                    .build_global(),
+                None => {
+                    let large_stack = usize::pow(1024, 3);
+                    let mut s = System::new();
+                    s.refresh_memory();
+                    let available = s.available_memory();
 
-    if available > large_stack.try_into().unwrap() {
-        // Larger stack size to handle cases with lots of nested directories
-        rayon::ThreadPoolBuilder::new()
-            .stack_size(large_stack)
-            .build_global()
-    } else {
-        rayon::ThreadPoolBuilder::new().build_global()
+                    if available > large_stack.try_into().unwrap() {
+                        // Larger stack size to handle cases with lots of nested directories
+                        rayon::ThreadPoolBuilder::new()
+                            .stack_size(large_stack)
+                            .build_global()
+                    } else {
+                        rayon::ThreadPoolBuilder::new().build_global()
+                    }
+                }
+            }
+        });
+        if result.is_err() {
+            eprintln!("Problem initializing rayon, try: export RAYON_NUM_THREADS=1")
+        }
     }
 }