introduce rust

src/fs.rs

@@ -0,0 +1,43 @@
+use log::warn;
+use std::io::Result;
+use tokio::fs;
+
+pub async fn walk_dir(dir: &str) -> Vec<String> {
+    let mut todo = Vec::new();
+    if let Ok(rd) = read_dir(dir).await {
+        todo.push(rd);
+    }
+
+    let mut results = Vec::new();
+
+    while let Some(rd) = todo.pop() {
+        for (path, is_dir) in rd {
+            if is_dir {
+                let Ok(child_rd) = (read_dir(&path).await)
+                    .inspect_err(|e| warn!("reading dir {path} failed: {e}"))
+                else {
+                    continue;
+                };
+                todo.push(child_rd);
+            } else {
+                results.push(path);
+            }
+        }
+    }
+
+    results
+}
+
+async fn read_dir(dir: &str) -> Result<Vec<(String, bool)>> {
+    let mut rd = fs::read_dir(dir).await?;
+    let mut entries = Vec::new();
+
+    while let Some(entry) = rd.next_entry().await? {
+        if let Some(path) = entry.path().to_str() {
+            entries.push((path.to_string(), entry.file_type().await?.is_dir()));
+        }
+    }
+
+    entries.sort(); // we want a deterministic & intuitive order
+    Ok(entries)
+}