From 2fac4be88e5c8f49ac1cd04ae4237eb9091dd050 Mon Sep 17 00:00:00 2001
From: koushiro <koushiro.cqx@gmail.com>
Date: Sat, 24 Aug 2024 20:12:01 +0800
Subject: [PATCH] update get_path_label

---
 core/src/layers/prometheus_client.rs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/core/src/layers/prometheus_client.rs b/core/src/layers/prometheus_client.rs
index d8a973c13e4f..137f3d95bdf0 100644
--- a/core/src/layers/prometheus_client.rs
+++ b/core/src/layers/prometheus_client.rs
@@ -828,6 +828,9 @@ impl<R: oio::BlockingWrite> oio::BlockingWrite for PrometheusClientMetricWrapper
 
 fn get_path_label(path: &str, path_level: usize) -> Option<&str> {
     if path_level > 0 {
+        if path.is_empty() {
+            return None;
+        }
         let label_value = path
             .char_indices()
             .filter(|&(_, c)| c == '/')
@@ -838,3 +841,20 @@ fn get_path_label(path: &str, path_level: usize) -> Option<&str> {
         None
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_get_path_label() {
+        let path = "abc/def/ghi";
+        assert_eq!(get_path_label(path, 0), None);
+        assert_eq!(get_path_label(path, 1), Some("abc"));
+        assert_eq!(get_path_label(path, 2), Some("abc/def"));
+        assert_eq!(get_path_label(path, 3), Some("abc/def/ghi"));
+        assert_eq!(get_path_label(path, usize::MAX), Some("abc/def/ghi"));
+
+        assert_eq!(get_path_label("", 1), None);
+    }
+}