From 150aee088d7e68c7f0e4f216fd992e5987ebe5f9 Mon Sep 17 00:00:00 2001
From: Ruoqing He <heruoqing@iscas.ac.cn>
Date: Tue, 26 Aug 2025 08:25:38 +0000
Subject: [PATCH] libs: Fix clippy `len_zero`

Fix `len_zero` clippy warning as suggested by rust 1.85.1, since
`mem-agent` is now a member of `libs` workspace.

```console
error: length comparison to zero
   --> mem-agent/src/memcg.rs:225:61
    |
225 |             let (keep, moved) = vec.drain(..).partition(|c| c.numa_id.len() > 0);
    |                                                             ^^^^^^^^^^^^^^^^^^^ help: using `!is_empty` is clearer and more explicit: `!c.numa_id.is_empty()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
```

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
---
 src/libs/mem-agent/src/agent.rs |  2 +-
 src/libs/mem-agent/src/memcg.rs | 14 +++++++-------
 src/libs/mem-agent/src/mglru.rs |  6 +++---
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/libs/mem-agent/src/agent.rs b/src/libs/mem-agent/src/agent.rs
index 2114fdbba5..f745c7f2ef 100644
--- a/src/libs/mem-agent/src/agent.rs
+++ b/src/libs/mem-agent/src/agent.rs
@@ -105,7 +105,7 @@ async fn async_get_remaining_tokio_duration(
 
 fn agent_work(mut memcg: memcg::MemCG, mut comp: compact::Compact) -> Result<Duration> {
     let memcg_work_list = memcg.get_timeout_list();
-    if memcg_work_list.len() > 0 {
+    if !memcg_work_list.is_empty() {
         info!("memcg.work start");
         memcg
             .work(&memcg_work_list)
diff --git a/src/libs/mem-agent/src/memcg.rs b/src/libs/mem-agent/src/memcg.rs
index 4858d82e2f..d5b6220bcc 100644
--- a/src/libs/mem-agent/src/memcg.rs
+++ b/src/libs/mem-agent/src/memcg.rs
@@ -222,7 +222,7 @@ impl Config {
 
         // make sure the empty numa_id CgroupConfig at the end of Cgroup
         for vec in self.cgroups.values_mut() {
-            let (keep, moved) = vec.drain(..).partition(|c| c.numa_id.len() > 0);
+            let (keep, moved) = vec.drain(..).partition(|c| !c.numa_id.is_empty());
             *vec = keep;
             vec.extend(moved);
         }
@@ -534,9 +534,9 @@ impl MemCgroups {
                     }
                     should_keep
                 });
-                path_cgs.len() != 0
+                !path_cgs.is_empty()
             });
-            period_cgs.cgs.len() != 0
+            !period_cgs.cgs.is_empty()
         });
 
         self.cgroups.retain(|path, cgroup| {
@@ -718,7 +718,7 @@ impl MemCgroups {
                     }
                 }
 
-                if info_ret.len() > 0 {
+                if !info_ret.is_empty() {
                     infos_ret.push((single_config.clone(), info_ret));
                 }
             }
@@ -1024,7 +1024,7 @@ impl MemCG {
 
         let mut mgs = self.memcgs.blocking_write();
 
-        if target_paths.len() == 0 {
+        if target_paths.is_empty() {
             mgs.remove_changed(&mg_hash);
         }
         mgs.update_and_add(&mg_hash, true);
@@ -1135,7 +1135,7 @@ impl MemCG {
 
         let mut ret = Ok(());
 
-        'main_loop: while infov.len() != 0 {
+        'main_loop: while !infov.is_empty() {
             // update infov
             let path_set: HashSet<String> = infov.iter().map(|info| info.path.clone()).collect();
             match self.refresh(&path_set) {
@@ -1373,6 +1373,6 @@ mod tests {
     fn test_memcg_get_timeout_list() {
         let is_cg_v2 = crate::cgroup::is_cgroup_v2().unwrap();
         let m = MemCG::new(is_cg_v2, Config::default()).unwrap();
-        assert!(m.get_timeout_list().len() > 0);
+        assert!(!m.get_timeout_list().is_empty());
     }
 }
diff --git a/src/libs/mem-agent/src/mglru.rs b/src/libs/mem-agent/src/mglru.rs
index 5565cfb1ea..24e32c7778 100644
--- a/src/libs/mem-agent/src/mglru.rs
+++ b/src/libs/mem-agent/src/mglru.rs
@@ -77,7 +77,7 @@ impl MGenLRU {
 fn lru_gen_lines_parse(reader: &mut BufReader<File>) -> Result<(String, HashMap<usize, MGenLRU>)> {
     let mut line = String::new();
     let mut ret_hash = HashMap::new();
-    while line.len() > 0
+    while !line.is_empty()
         || reader
             .read_line(&mut line)
             .map_err(|e| anyhow!("read file {} failed: {}", LRU_GEN_PATH, e))?
@@ -180,7 +180,7 @@ fn lru_gen_file_parse(
 ) -> Result<HashMap<String, (usize, HashMap<usize, MGenLRU>)>> {
     let mut line = String::new();
     let mut ret_hash = HashMap::new();
-    while line.len() > 0
+    while !line.is_empty()
         || reader
             .read_line(&mut line)
             .map_err(|e| anyhow!("read file {} failed: {}", LRU_GEN_PATH, e))?
@@ -189,7 +189,7 @@ fn lru_gen_file_parse(
         let mut clear_line = true;
         // Not handle the Err of lru_gen_head_parse because all lines of file will be checked.
         if let Ok((id, path)) = lru_gen_head_parse(&line) {
-            if target_patchs.len() == 0 || target_patchs.contains(&path) {
+            if target_patchs.is_empty() || target_patchs.contains(&path) {
                 let seq_data = if parse_line {
                     let (ret_line, data) = lru_gen_lines_parse(&mut reader).map_err(|e| {
                         anyhow!(