Merge pull request #40 from Jakob-Naucke/v0.2.4

release: v0.2.4
Merge pull request #32 from Tim-Zhang/fix-clippy
2026-08-05 02:13:23 +00:00 · 2021-03-03 15:39:15 +08:00 · 2021-03-03 15:38:37 +08:00 · 2021-03-03 13:46:19 +08:00 · 2021-03-03 13:44:29 +08:00 · 2021-03-03 00:17:54 +08:00
22 changed files with 478 additions and 362 deletions
--- a/.github/workflows/bvt.yaml
+++ b/.github/workflows/bvt.yaml
@@ -17,6 +17,13 @@ jobs:
      - uses: actions/checkout@v2
      - run: rustup component add rustfmt
      - run: make fmt
+  clippy:
+    name: Clippy Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: rustup component add clippy
+      - run: make clippy
  test:
    name: Run Unit Test
    runs-on: ubuntu-latest
@@ -24,3 +31,4 @@ jobs:
      - uses: actions/checkout@v2
      - run: make test

+
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ repository = "https://github.com/kata-containers/cgroups-rs"
 keywords = ["linux", "cgroup", "containers", "isolation"]
 categories = ["os", "api-bindings", "os::unix-apis"]
 license = "MIT OR Apache-2.0"
-version = "0.2.3"
+version = "0.2.4"
 authors = ["The Kata Containers community <kata-dev@lists.katacontainers.io>", "Levente Kurusa <lkurusa@acm.org>", "Sam Wilson <tecywiz121@hotmail.com>"]
 edition = "2018"
 homepage = "https://github.com/kata-containers/cgroups-rs"
@@ -14,7 +14,7 @@ readme = "README.md"
 [dependencies]
 log = "0.4"
 regex = "1.1"
-nix = "0.18.0"
+nix = "0.20.0"
 libc = "0.2"

 [dev-dependencies]
--- a/src/blkio.rs
+++ b/src/blkio.rs
@@ -84,14 +84,14 @@ pub struct IoStat {

 fn parse_io_service(s: String) -> Result<Vec<IoService>> {
    s.lines()
-        .filter(|x| x.split_whitespace().collect::<Vec<_>>().len() == 3)
+        .filter(|x| x.split_whitespace().count() == 3)
        .map(|x| {
            let mut spl = x.split_whitespace();
-            (spl.nth(0).unwrap(), spl.nth(0).unwrap(), spl.nth(0).unwrap())
+            (spl.next().unwrap(), spl.next().unwrap(), spl.next().unwrap())
        })
        .map(|(a, b, c)| {
-            let mut spl = a.split(":");
-            (spl.nth(0).unwrap(), spl.nth(0).unwrap(), b, c)
+            let mut spl = a.split(':');
+            (spl.next().unwrap(), spl.next().unwrap(), b, c)
        })
        .collect::<Vec<_>>()
        .chunks(5)
@@ -131,15 +131,14 @@ fn get_value(s: &str) -> String {
    arr[1].to_string()
 }

-fn parse_io_stat(s: String) -> Result<Vec<IoStat>> {
+fn parse_io_stat(s: String) -> Vec<IoStat> {
    // line:
    // 8:0 rbytes=180224 wbytes=0 rios=3 wios=0 dbytes=0 dios=0
-    let v = s
-        .lines()
-        .filter(|x| x.split_whitespace().collect::<Vec<_>>().len() == 7)
+    s.lines()
+        .filter(|x| x.split_whitespace().count() == 7)
        .map(|x| {
            let arr = x.split_whitespace().collect::<Vec<&str>>();
-            let device = arr[0].split(":").collect::<Vec<&str>>();
+            let device = arr[0].split(':').collect::<Vec<&str>>();
            let (major, minor) = (device[0], device[1]);

            IoStat {
@@ -153,14 +152,12 @@ fn parse_io_stat(s: String) -> Result<Vec<IoStat>> {
                dios: get_value(arr[6]).parse::<u64>().unwrap(),
            }
        })
-        .collect::<Vec<IoStat>>();
-
-    Ok(v)
+        .collect::<Vec<IoStat>>()
 }

 fn parse_io_service_total(s: String) -> Result<u64> {
    s.lines()
-        .filter(|x| x.split_whitespace().collect::<Vec<_>>().len() == 2)
+        .filter(|x| x.split_whitespace().count() == 2)
        .fold(Err(Error::new(ParseError)), |_, x| {
            match x.split_whitespace().collect::<Vec<_>>().as_slice() {
                ["Total", val] => val.parse::<u64>().map_err(|_| Error::new(ParseError)),
@@ -197,9 +194,9 @@ fn parse_blkio_data(s: String) -> Result<Vec<BlkIoData>> {
    });

    if err.is_err() {
-        return Err(Error::new(ParseError));
+        Err(Error::new(ParseError))
    } else {
-        return Ok(res);
+        Ok(res)
    }
 }

@@ -407,19 +404,19 @@ impl BlkIoController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }

    fn blkio_v2(&self) -> BlkIo {
-        let mut blkio: BlkIo = Default::default();
-        blkio.io_stat = self
-            .open_path("io.stat", false)
-            .and_then(read_string_from)
-            .and_then(parse_io_stat)
-            .unwrap_or(Vec::new());
-
-        blkio
+        BlkIo {
+            io_stat: self
+                .open_path("io.stat", false)
+                .and_then(read_string_from)
+                .map(parse_io_stat)
+                .unwrap_or_default(),
+            ..Default::default()
+        }
    }

    /// Gathers statistics about and reports the state of the block devices used by the control
@@ -433,222 +430,222 @@ impl BlkIoController {
                .open_path("blkio.io_merged", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_merged_total: self
                .open_path("blkio.io_merged", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_merged_recursive: self
                .open_path("blkio.io_merged_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_merged_recursive_total: self
                .open_path("blkio.io_merged_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_queued: self
                .open_path("blkio.io_queued", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_queued_total: self
                .open_path("blkio.io_queued", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_queued_recursive: self
                .open_path("blkio.io_queued_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_queued_recursive_total: self
                .open_path("blkio.io_queued_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_service_bytes: self
                .open_path("blkio.io_service_bytes", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_service_bytes_total: self
                .open_path("blkio.io_service_bytes", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_service_bytes_recursive: self
                .open_path("blkio.io_service_bytes_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_service_bytes_recursive_total: self
                .open_path("blkio.io_service_bytes_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_serviced: self
                .open_path("blkio.io_serviced", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_serviced_total: self
                .open_path("blkio.io_serviced", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_serviced_recursive: self
                .open_path("blkio.io_serviced_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_serviced_recursive_total: self
                .open_path("blkio.io_serviced_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_service_time: self
                .open_path("blkio.io_service_time", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_service_time_total: self
                .open_path("blkio.io_service_time", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_service_time_recursive: self
                .open_path("blkio.io_service_time_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_service_time_recursive_total: self
                .open_path("blkio.io_service_time_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_wait_time: self
                .open_path("blkio.io_wait_time", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_wait_time_total: self
                .open_path("blkio.io_wait_time", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            io_wait_time_recursive: self
                .open_path("blkio.io_wait_time_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_wait_time_recursive_total: self
                .open_path("blkio.io_wait_time_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_io_service_total)
-                .unwrap_or(0),
+                .unwrap_or_default(),
            leaf_weight: self
                .open_path("blkio.leaf_weight", false)
-                .and_then(|file| read_u64_from(file))
+                .and_then(read_u64_from)
                .unwrap_or(0u64),
            leaf_weight_device: self
                .open_path("blkio.leaf_weight_device", false)
                .and_then(read_string_from)
                .and_then(parse_blkio_data)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            sectors: self
                .open_path("blkio.sectors", false)
                .and_then(read_string_from)
                .and_then(parse_blkio_data)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            sectors_recursive: self
                .open_path("blkio.sectors_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_blkio_data)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            throttle: BlkIoThrottle {
                io_service_bytes: self
                    .open_path("blkio.throttle.io_service_bytes", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                io_service_bytes_total: self
                    .open_path("blkio.throttle.io_service_bytes", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service_total)
-                    .unwrap_or(0),
+                    .unwrap_or_default(),
                io_service_bytes_recursive: self
                    .open_path("blkio.throttle.io_service_bytes_recursive", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                io_service_bytes_recursive_total: self
                    .open_path("blkio.throttle.io_service_bytes_recursive", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service_total)
-                    .unwrap_or(0),
+                    .unwrap_or_default(),
                io_serviced: self
                    .open_path("blkio.throttle.io_serviced", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                io_serviced_total: self
                    .open_path("blkio.throttle.io_serviced", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service_total)
-                    .unwrap_or(0),
+                    .unwrap_or_default(),
                io_serviced_recursive: self
                    .open_path("blkio.throttle.io_serviced_recursive", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                io_serviced_recursive_total: self
                    .open_path("blkio.throttle.io_serviced_recursive", false)
                    .and_then(read_string_from)
                    .and_then(parse_io_service_total)
-                    .unwrap_or(0),
+                    .unwrap_or_default(),
                read_bps_device: self
                    .open_path("blkio.throttle.read_bps_device", false)
                    .and_then(read_string_from)
                    .and_then(parse_blkio_data)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                read_iops_device: self
                    .open_path("blkio.throttle.read_iops_device", false)
                    .and_then(read_string_from)
                    .and_then(parse_blkio_data)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                write_bps_device: self
                    .open_path("blkio.throttle.write_bps_device", false)
                    .and_then(read_string_from)
                    .and_then(parse_blkio_data)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
                write_iops_device: self
                    .open_path("blkio.throttle.write_iops_device", false)
                    .and_then(read_string_from)
                    .and_then(parse_blkio_data)
-                    .unwrap_or(Vec::new()),
+                    .unwrap_or_default(),
            },
            time: self
                .open_path("blkio.time", false)
                .and_then(read_string_from)
                .and_then(parse_blkio_data)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            time_recursive: self
                .open_path("blkio.time_recursive", false)
                .and_then(read_string_from)
                .and_then(parse_blkio_data)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            weight: self
                .open_path("blkio.weight", false)
-                .and_then(|file| read_u64_from(file))
+                .and_then(read_u64_from)
                .unwrap_or(0u64),
            weight_device: self
                .open_path("blkio.weight_device", false)
                .and_then(read_string_from)
                .and_then(parse_blkio_data)
-                .unwrap_or(Vec::new()),
+                .unwrap_or_default(),
            io_stat: Vec::new(),
        }
    }
--- a/src/cgroup.rs
+++ b/src/cgroup.rs
@@ -62,7 +62,7 @@ impl Cgroup {
    /// Create this control group.
    fn create(&self) {
        if self.hier.v2() {
-            let _ret = create_v2_cgroup(self.hier.root().clone(), &self.path);
+            let _ret = create_v2_cgroup(self.hier.root(), &self.path);
        } else {
            for subsystem in &self.subsystems {
                subsystem.to_controller().create();
@@ -112,13 +112,11 @@ impl Cgroup {
                .collect::<Vec<_>>();
        }

-        let cg = Cgroup {
+        Cgroup {
            path: path.to_str().unwrap().to_string(),
-            subsystems: subsystems,
+            subsystems,
            hier,
-        };
-
-        cg
+        }
    }

    /// Create a handle for a control group in the hierarchy `hier`, with name `path` and `relative_paths`
@@ -146,7 +144,7 @@ impl Cgroup {
                    let cn = x.controller_name();
                    if relative_paths.contains_key(&cn) {
                        let rp = relative_paths.get(&cn).unwrap();
-                        let valid_path = rp.trim_start_matches("/").to_string();
+                        let valid_path = rp.trim_start_matches('/').to_string();
                        let mut p = PathBuf::from(valid_path);
                        p.push(path);
                        x.enter(p.as_ref())
@@ -157,13 +155,11 @@ impl Cgroup {
                .collect::<Vec<_>>();
        }

-        let cg = Cgroup {
-            subsystems: subsystems,
+        Cgroup {
+            subsystems,
            hier,
            path: path.to_str().unwrap().to_string(),
-        };
-
-        cg
+        }
    }

    /// The list of subsystems that this control group supports.
@@ -179,8 +175,8 @@ impl Cgroup {
    /// will change.
    pub fn delete(&self) -> Result<()> {
        if self.v2() {
-            if self.path != "" {
-                let mut p = self.hier.root().clone();
+            if !self.path.is_empty() {
+                let mut p = self.hier.root();
                p.push(self.path.clone());
                return fs::remove_dir(p).map_err(|e| Error::with_cause(RemoveFailed, e));
            }
@@ -222,7 +218,7 @@ impl Cgroup {
    /// let cpu: &CpuController = control_group.controller_of()
    ///                             .expect("No cpu controller attached!");
    /// ```
-    pub fn controller_of<'a, T>(self: &'a Self) -> Option<&'a T>
+    pub fn controller_of<'a, T>(&'a self) -> Option<&'a T>
    where
        &'a T: From<&'a Subsystem>,
        T: Controller + ControllIdentifier,
@@ -249,7 +245,7 @@ impl Cgroup {
    pub fn add_task(&self, pid: CgroupPid) -> Result<()> {
        if self.v2() {
            let subsystems = self.subsystems();
-            if subsystems.len() > 0 {
+            if !subsystems.is_empty() {
                let c = subsystems[0].to_controller();
                c.add_task(&pid)
            } else {
@@ -291,7 +287,7 @@ impl Cgroup {
        // Collect the tasks from all subsystems
        let mut v = if self.v2() {
            let subsystems = self.subsystems();
-            if subsystems.len() > 0 {
+            if !subsystems.is_empty() {
                let c = subsystems[0].to_controller();
                c.tasks()
            } else {
@@ -313,9 +309,9 @@ impl Cgroup {
    }
 }

-pub const UNIFIED_MOUNTPOINT: &'static str = "/sys/fs/cgroup";
+pub const UNIFIED_MOUNTPOINT: &str = "/sys/fs/cgroup";

-fn enable_controllers(controllers: &Vec<String>, path: &PathBuf) {
+fn enable_controllers(controllers: &[String], path: &PathBuf) {
    let mut f = path.clone();
    f.push("cgroup.subtree_control");
    for c in controllers {
@@ -327,8 +323,8 @@ fn enable_controllers(controllers: &Vec<String>, path: &PathBuf) {
 fn supported_controllers() -> Vec<String> {
    let p = format!("{}/{}", UNIFIED_MOUNTPOINT, "cgroup.controllers");
    let ret = fs::read_to_string(p.as_str());
-    ret.unwrap_or(String::new())
-        .split(" ")
+    ret.unwrap_or_default()
+        .split(' ')
        .map(|x| x.to_string())
        .collect::<Vec<String>>()
 }
@@ -342,16 +338,15 @@ fn create_v2_cgroup(root: PathBuf, path: &str) -> Result<()> {
    enable_controllers(&controllers, &fp);

    // path: "a/b/c"
-    let elements = path.split("/").collect::<Vec<&str>>();
+    let elements = path.split('/').collect::<Vec<&str>>();
    let last_index = elements.len() - 1;
    for (i, ele) in elements.iter().enumerate() {
        // ROOT/a
        fp.push(ele);
        // create dir, need not check if is a file or directory
        if !fp.exists() {
-            match ::std::fs::create_dir(fp.clone()) {
-                Err(e) => return Err(Error::with_cause(ErrorKind::FsError, e)),
-                Ok(_) => {}
+            if let Err(e) = std::fs::create_dir(fp.clone()) {
+                return Err(Error::with_cause(ErrorKind::FsError, e));
            }
        }

--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -116,7 +116,7 @@ impl CpuController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }

@@ -133,7 +133,7 @@ impl CpuController {
                        Err(e) => Err(Error::with_cause(ReadFailed, e)),
                    }
                })
-                .unwrap_or("".to_string()),
+                .unwrap_or_default(),
        }
    }

@@ -299,8 +299,5 @@ fn parse_cfs_quota_and_period(mut file: File) -> Result<CFSQuotaAndPeriod> {
        .parse::<u64>()
        .map_err(|e| Error::with_cause(ParseError, e))?;

-    Ok(CFSQuotaAndPeriod {
-        quota: quota,
-        period: period,
-    })
+    Ok(CFSQuotaAndPeriod { quota, period })
 }
--- a/src/cpuacct.rs
+++ b/src/cpuacct.rs
@@ -111,35 +111,35 @@ impl CpuAcctController {
        CpuAcct {
            stat: self
                .open_path("cpuacct.stat", false)
-                .and_then(|file| read_string_from(file))
-                .unwrap_or("".to_string()),
+                .and_then(read_string_from)
+                .unwrap_or_default(),
            usage: self
                .open_path("cpuacct.usage", false)
-                .and_then(|file| read_u64_from(file))
+                .and_then(read_u64_from)
                .unwrap_or(0),
            usage_all: self
                .open_path("cpuacct.usage_all", false)
-                .and_then(|file| read_string_from(file))
-                .unwrap_or("".to_string()),
+                .and_then(read_string_from)
+                .unwrap_or_default(),
            usage_percpu: self
                .open_path("cpuacct.usage_percpu", false)
-                .and_then(|file| read_string_from(file))
-                .unwrap_or("".to_string()),
+                .and_then(read_string_from)
+                .unwrap_or_default(),
            usage_percpu_sys: self
                .open_path("cpuacct.usage_percpu_sys", false)
-                .and_then(|file| read_string_from(file))
-                .unwrap_or("".to_string()),
+                .and_then(read_string_from)
+                .unwrap_or_default(),
            usage_percpu_user: self
                .open_path("cpuacct.usage_percpu_user", false)
-                .and_then(|file| read_string_from(file))
-                .unwrap_or("".to_string()),
+                .and_then(read_string_from)
+                .unwrap_or_default(),
            usage_sys: self
                .open_path("cpuacct.usage_sys", false)
-                .and_then(|file| read_u64_from(file))
+                .and_then(read_u64_from)
                .unwrap_or(0),
            usage_user: self
                .open_path("cpuacct.usage_user", false)
-                .and_then(|file| read_u64_from(file))
+                .and_then(read_u64_from)
                .unwrap_or(0),
        }
    }
--- a/src/cpuset.rs
+++ b/src/cpuset.rs
@@ -146,7 +146,7 @@ fn find_no_empty_parent(from: &str, file: &str) -> Result<(String, Vec<PathBuf>)
                Err(e) => return Err(Error::with_cause(ReadFailed, e)),
            };

-        if current_value != "" {
+        if !current_value.is_empty() {
            return Ok((current_value, v));
        }
        v.push(current_path.clone());
@@ -167,7 +167,7 @@ fn copy_from_parent(current: &str, file: &str) -> Result<()> {
    // find not empty cpus/memes from current directory.
    let (value, parents) = find_no_empty_parent(current, file)?;

-    if value == "" || parents.len() == 0 {
+    if value.is_empty() || parents.is_empty() {
        return Ok(());
    }

@@ -208,17 +208,17 @@ impl<'a> From<&'a Subsystem> for &'a CpuSetController {
 fn parse_range(s: String) -> Result<Vec<(u64, u64)>> {
    let mut fin = Vec::new();

-    if s == "".to_string() {
+    if s.is_empty() {
        return Ok(fin);
    }

    // first split by commas
-    let comma_split = s.split(",");
+    let comma_split = s.split(',');

    for sp in comma_split {
-        if sp.contains("-") {
+        if sp.contains('-') {
            // this is a true range
-            let dash_split = sp.split("-").collect::<Vec<_>>();
+            let dash_split = sp.split('-').collect::<Vec<_>>();
            if dash_split.len() != 2 {
                return Err(Error::new(ParseError));
            }
@@ -247,7 +247,7 @@ impl CpuSetController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }

@@ -257,7 +257,7 @@ impl CpuSetController {
        CpuSet {
            cpu_exclusive: {
                self.open_path("cpuset.cpu_exclusive", false)
-                    .and_then(|file| read_u64_from(file))
+                    .and_then(read_u64_from)
                    .map(|x| x == 1)
                    .unwrap_or(false)
            },
@@ -265,19 +265,19 @@ impl CpuSetController {
                self.open_path("cpuset.cpus", false)
                    .and_then(read_string_from)
                    .and_then(parse_range)
-                    .unwrap_or(Vec::new())
+                    .unwrap_or_default()
            },
            effective_cpus: {
                self.open_path("cpuset.effective_cpus", false)
                    .and_then(read_string_from)
                    .and_then(parse_range)
-                    .unwrap_or(Vec::new())
+                    .unwrap_or_default()
            },
            effective_mems: {
                self.open_path("cpuset.effective_mems", false)
                    .and_then(read_string_from)
                    .and_then(parse_range)
-                    .unwrap_or(Vec::new())
+                    .unwrap_or_default()
            },
            mem_exclusive: {
                self.open_path("cpuset.mem_exclusive", false)
@@ -324,7 +324,7 @@ impl CpuSetController {
                self.open_path("cpuset.mems", false)
                    .and_then(read_string_from)
                    .and_then(parse_range)
-                    .unwrap_or(Vec::new())
+                    .unwrap_or_default()
            },
            sched_load_balance: {
                self.open_path("cpuset.sched_load_balance", false)
--- a/src/devices.rs
+++ b/src/devices.rs
@@ -102,7 +102,7 @@ impl DevicePermissions {

    /// Checks whether the string is a valid descriptor of DevicePermissions.
    pub fn is_valid(s: &str) -> bool {
-        if s == "" {
+        if s.is_empty() {
            return false;
        }
        for i in s.chars() {
@@ -110,7 +110,7 @@ impl DevicePermissions {
                return false;
            }
        }
-        return true;
+        true
    }

    /// Returns a Vec will all the permissions that a device can have.
@@ -123,9 +123,10 @@ impl DevicePermissions {
    }

    /// Convert a string into DevicePermissions.
+    #[allow(clippy::should_implement_trait)]
    pub fn from_str(s: &str) -> Result<Vec<DevicePermissions>> {
        let mut v = Vec::new();
-        if s == "" {
+        if s.is_empty() {
            return Ok(v);
        }
        for e in s.chars() {
@@ -206,7 +207,7 @@ impl DevicesController {
        devtype: DeviceType,
        major: i64,
        minor: i64,
-        perm: &Vec<DevicePermissions>,
+        perm: &[DevicePermissions],
    ) -> Result<()> {
        let perms = perm
            .iter()
@@ -238,7 +239,7 @@ impl DevicesController {
        devtype: DeviceType,
        major: i64,
        minor: i64,
-        perm: &Vec<DevicePermissions>,
+        perm: &[DevicePermissions],
    ) -> Result<()> {
        let perms = perm
            .iter()
@@ -274,13 +275,13 @@ impl DevicesController {
                            error!("allowed_devices: acc: {:?}, ls: {:?}", acc, ls);
                            Err(Error::new(ParseError))
                        } else {
-                            let devtype = DeviceType::from_char(ls[0].chars().nth(0));
+                            let devtype = DeviceType::from_char(ls[0].chars().next());
                            let mut major = ls[1].parse::<i64>();
                            let mut minor = ls[2].parse::<i64>();
-                            if major.is_err() && ls[1] == "*".to_string() {
+                            if major.is_err() && ls[1] == "*" {
                                major = Ok(-1);
                            }
-                            if minor.is_err() && ls[2] == "*".to_string() {
+                            if minor.is_err() && ls[2] == "*" {
                                minor = Ok(-1);
                            }
                            if devtype.is_none() || major.is_err() || minor.is_err() || !DevicePermissions::is_valid(&ls[3]) {
@@ -295,7 +296,7 @@ impl DevicesController {
                                    devtype: devtype.unwrap(),
                                    major: major.unwrap(),
                                    minor: minor.unwrap(),
-                                    access: access,
+                                    access,
                                });
                                Ok(acc)
                            }
--- a/src/events.rs
+++ b/src/events.rs
@@ -53,7 +53,7 @@ fn register_memory_event(

    let event_control_path = cg_dir.join("cgroup.event_control");
    let data;
-    if arg == "" {
+    if arg.is_empty() {
        data = format!("{} {}", eventfd, event_file.as_raw_fd());
    } else {
        data = format!("{} {} {}", eventfd, event_file.as_raw_fd(), arg);
@@ -70,11 +70,8 @@ fn register_memory_event(
    thread::spawn(move || {
        loop {
            let mut buf = [0; 8];
-            match eventfd_file.read(&mut buf) {
-                Err(_err) => {
-                    return;
-                }
-                Ok(_) => {}
+            if eventfd_file.read(&mut buf).is_err() {
+                return;
            }

            // When a cgroup is destroyed, an event is sent to eventfd.
--- a/src/freezer.rs
+++ b/src/freezer.rs
@@ -87,7 +87,7 @@ impl FreezerController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }

--- a/src/hierarchies.rs
+++ b/src/hierarchies.rs
@@ -268,6 +268,12 @@ impl V1 {
    }
 }

+impl Default for V1 {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl V2 {
    /// Finds where control groups are mounted to and returns a hierarchy in which control groups
    /// can be created.
@@ -278,7 +284,13 @@ impl V2 {
    }
 }

-pub const UNIFIED_MOUNTPOINT: &'static str = "/sys/fs/cgroup";
+impl Default for V2 {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+pub const UNIFIED_MOUNTPOINT: &str = "/sys/fs/cgroup";

 #[cfg(all(target_os = "linux", not(target_env = "musl")))]
 pub fn is_cgroup2_unified_mode() -> bool {
@@ -294,7 +306,7 @@ pub fn is_cgroup2_unified_mode() -> bool {
    fs_stat.unwrap().filesystem_type() == statfs::CGROUP2_SUPER_MAGIC
 }

-pub const INIT_CGROUP_PATHS: &'static str = "/proc/1/cgroup";
+pub const INIT_CGROUP_PATHS: &str = "/proc/1/cgroup";

 #[cfg(all(target_os = "linux", target_env = "musl"))]
 pub fn is_cgroup2_unified_mode() -> bool {
--- a/src/hugetlb.rs
+++ b/src/hugetlb.rs
@@ -92,8 +92,8 @@ impl HugeTlbController {
        Self {
            base: root.clone(),
            path: root,
-            sizes: sizes,
-            v2: v2,
+            sizes,
+            v2,
        }
    }

@@ -115,7 +115,7 @@ impl HugeTlbController {
        self.open_path(&format!("hugetlb.{}.events", hugetlb_size), false)
            .and_then(flat_keyed_to_vec)
            .and_then(|x| {
-                if x.len() == 0 {
+                if x.is_empty() {
                    return Err(Error::from_string(format!(
                        "get empty from hugetlb.{}.events",
                        hugetlb_size
@@ -175,7 +175,7 @@ impl HugeTlbController {
    }
 }

-pub const HUGEPAGESIZE_DIR: &'static str = "/sys/kernel/mm/hugepages";
+pub const HUGEPAGESIZE_DIR: &str = "/sys/kernel/mm/hugepages";
 use regex::Regex;
 use std::collections::HashMap;
 use std::fs;
@@ -264,8 +264,8 @@ fn parse_size(s: &str, m: &HashMap<String, u128>) -> Result<u128> {
    let caps = re.unwrap().captures(s).unwrap();

    let num = caps.name("num");
-    let size: u128 = if num.is_some() {
-        let n = num.unwrap().as_str().trim().parse::<u128>();
+    let size: u128 = if let Some(num) = num {
+        let n = num.as_str().trim().parse::<u128>();
        if n.is_err() {
            return Err(Error::new(InvalidBytesSize));
        }
@@ -275,10 +275,10 @@ fn parse_size(s: &str, m: &HashMap<String, u128>) -> Result<u128> {
    };

    let q = caps.name("mul");
-    let mul: u128 = if q.is_some() {
-        let t = m.get(q.unwrap().as_str());
-        if t.is_some() {
-            *t.unwrap()
+    let mul: u128 = if let Some(q) = q {
+        let t = m.get(q.as_str());
+        if let Some(t) = t {
+            *t
        } else {
            return Err(Error::new(InvalidBytesSize));
        }
@@ -289,7 +289,7 @@ fn parse_size(s: &str, m: &HashMap<String, u128>) -> Result<u128> {
    Ok(size * mul)
 }

-fn custom_size(mut size: f64, base: f64, m: &Vec<String>) -> String {
+fn custom_size(mut size: f64, base: f64, m: &[String]) -> String {
    let mut i = 0;
    while size >= base && i < m.len() - 1 {
        size /= base;
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,9 +4,11 @@
 // SPDX-License-Identifier: Apache-2.0 or MIT
 //

+#![allow(clippy::unnecessary_unwrap)]
 use log::*;

 use std::collections::HashMap;
+use std::fmt;
 use std::fs::{self, File};
 use std::io::{BufRead, BufReader, Read, Write};
 use std::path::{Path, PathBuf};
@@ -123,23 +125,23 @@ pub enum Controllers {
    Systemd,
 }

-impl Controllers {
-    pub fn to_string(&self) -> String {
+impl fmt::Display for Controllers {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
-            Controllers::Pids => return "pids".to_string(),
-            Controllers::Mem => return "memory".to_string(),
-            Controllers::CpuSet => return "cpuset".to_string(),
-            Controllers::CpuAcct => return "cpuacct".to_string(),
-            Controllers::Cpu => return "cpu".to_string(),
-            Controllers::Devices => return "devices".to_string(),
-            Controllers::Freezer => return "freezer".to_string(),
-            Controllers::NetCls => return "net_cls".to_string(),
-            Controllers::BlkIo => return "blkio".to_string(),
-            Controllers::PerfEvent => return "perf_event".to_string(),
-            Controllers::NetPrio => return "net_prio".to_string(),
-            Controllers::HugeTlb => return "hugetlb".to_string(),
-            Controllers::Rdma => return "rdma".to_string(),
-            Controllers::Systemd => return "name=systemd".to_string(),
+            Controllers::Pids => write!(f, "pids"),
+            Controllers::Mem => write!(f, "memory"),
+            Controllers::CpuSet => write!(f, "cpuset"),
+            Controllers::CpuAcct => write!(f, "cpuacct"),
+            Controllers::Cpu => write!(f, "cpu"),
+            Controllers::Devices => write!(f, "devices"),
+            Controllers::Freezer => write!(f, "freezer"),
+            Controllers::NetCls => write!(f, "net_cls"),
+            Controllers::BlkIo => write!(f, "blkio"),
+            Controllers::PerfEvent => write!(f, "perf_event"),
+            Controllers::NetPrio => write!(f, "net_prio"),
+            Controllers::HugeTlb => write!(f, "hugetlb"),
+            Controllers::Rdma => write!(f, "rdma"),
+            Controllers::Systemd => write!(f, "name=systemd"),
        }
    }
 }
@@ -179,13 +181,13 @@ mod sealed {

            if w {
                match File::create(&path) {
-                    Err(e) => return Err(Error::with_cause(ErrorKind::WriteFailed, e)),
-                    Ok(file) => return Ok(file),
+                    Err(e) => Err(Error::with_cause(ErrorKind::WriteFailed, e)),
+                    Ok(file) => Ok(file),
                }
            } else {
                match File::open(&path) {
-                    Err(e) => return Err(Error::with_cause(ErrorKind::ReadFailed, e)),
-                    Ok(file) => return Ok(file),
+                    Err(e) => Err(Error::with_cause(ErrorKind::ReadFailed, e)),
+                    Ok(file) => Ok(file),
                }
            }
        }
@@ -203,7 +205,7 @@ mod sealed {

        #[doc(hidden)]
        fn path_exists(&self, p: &str) -> bool {
-            if let Err(_) = self.verify_path() {
+            if self.verify_path().is_err() {
                return false;
            }

@@ -295,7 +297,7 @@ where
    /// Create this controller
    fn create(&self) {
        self.verify_path()
-            .expect(format!("path should be valid: {:?}", self.path()).as_str());
+            .unwrap_or_else(|_| panic!("path should be valid: {:?}", self.path()));

        match ::std::fs::create_dir_all(self.get_path()) {
            Ok(_) => self.post_create(),
@@ -360,7 +362,7 @@ where
            file = "cgroup.procs";
        }
        self.open_path(file, false)
-            .and_then(|file| {
+            .map(|file| {
                let bf = BufReader::new(file);
                let mut v = Vec::new();
                for line in bf.lines() {
@@ -369,9 +371,9 @@ where
                        v.push(n);
                    }
                }
-                Ok(v.into_iter().map(CgroupPid::from).collect())
+                v.into_iter().map(CgroupPid::from).collect()
            })
-            .unwrap_or(vec![])
+            .unwrap_or_default()
    }

    fn v2(&self) -> bool {
@@ -387,17 +389,15 @@ fn remove_dir(dir: &PathBuf) -> Result<()> {
        return Ok(());
    }

-    if dir.exists() {
-        if dir.is_dir() {
-            for entry in fs::read_dir(dir).map_err(|e| Error::with_cause(ReadFailed, e))? {
-                let entry = entry.map_err(|e| Error::with_cause(ReadFailed, e))?;
-                let path = entry.path();
-                if path.is_dir() {
-                    remove_dir(&path)?;
-                }
+    if dir.exists() && dir.is_dir() {
+        for entry in fs::read_dir(dir).map_err(|e| Error::with_cause(ReadFailed, e))? {
+            let entry = entry.map_err(|e| Error::with_cause(ReadFailed, e))?;
+            let path = entry.path();
+            if path.is_dir() {
+                remove_dir(&path)?;
            }
-            fs::remove_dir(dir).map_err(|e| Error::with_cause(RemoveFailed, e))?;
        }
+        fs::remove_dir(dir).map_err(|e| Error::with_cause(RemoveFailed, e))?;
    }

    Ok(())
@@ -641,75 +641,61 @@ impl<'a> From<&'a std::process::Child> for CgroupPid {
 impl Subsystem {
    fn enter(self, path: &Path) -> Self {
        match self {
-            Subsystem::Pid(cont) => Subsystem::Pid({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Pid(mut cont) => Subsystem::Pid({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::Mem(cont) => Subsystem::Mem({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Mem(mut cont) => Subsystem::Mem({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::CpuSet(cont) => Subsystem::CpuSet({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::CpuSet(mut cont) => Subsystem::CpuSet({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::CpuAcct(cont) => Subsystem::CpuAcct({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::CpuAcct(mut cont) => Subsystem::CpuAcct({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::Cpu(cont) => Subsystem::Cpu({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Cpu(mut cont) => Subsystem::Cpu({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::Devices(cont) => Subsystem::Devices({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Devices(mut cont) => Subsystem::Devices({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::Freezer(cont) => Subsystem::Freezer({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Freezer(mut cont) => Subsystem::Freezer({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::NetCls(cont) => Subsystem::NetCls({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::NetCls(mut cont) => Subsystem::NetCls({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::BlkIo(cont) => Subsystem::BlkIo({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::BlkIo(mut cont) => Subsystem::BlkIo({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::PerfEvent(cont) => Subsystem::PerfEvent({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::PerfEvent(mut cont) => Subsystem::PerfEvent({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::NetPrio(cont) => Subsystem::NetPrio({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::NetPrio(mut cont) => Subsystem::NetPrio({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::HugeTlb(cont) => Subsystem::HugeTlb({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::HugeTlb(mut cont) => Subsystem::HugeTlb({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::Rdma(cont) => Subsystem::Rdma({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Rdma(mut cont) => Subsystem::Rdma({
+                cont.get_path_mut().push(path);
+                cont
            }),
-            Subsystem::Systemd(cont) => Subsystem::Systemd({
-                let mut c = cont.clone();
-                c.get_path_mut().push(path);
-                c
+            Subsystem::Systemd(mut cont) => Subsystem::Systemd({
+                cont.get_path_mut().push(path);
+                cont
            }),
        }
    }
@@ -760,16 +746,18 @@ impl MaxValue {
            MaxValue::Value(num) => *num,
        }
    }
+}

-    fn to_string(&self) -> String {
+impl fmt::Display for MaxValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
-            MaxValue::Max => "max".to_string(),
-            MaxValue::Value(num) => num.to_string(),
+            MaxValue::Max => write!(f, "max"),
+            MaxValue::Value(num) => write!(f, "{}", num.to_string()),
        }
    }
 }

-pub fn parse_max_value(s: &String) -> Result<MaxValue> {
+pub fn parse_max_value(s: &str) -> Result<MaxValue> {
    if s.trim() == "max" {
        return Ok(MaxValue::Max);
    }
@@ -791,11 +779,8 @@ pub fn flat_keyed_to_vec(mut file: File) -> Result<Vec<(String, i64)>> {
    for line in content.lines() {
        let parts: Vec<&str> = line.split(' ').collect();
        if parts.len() == 2 {
-            match parts[1].parse::<i64>() {
-                Ok(i) => {
-                    v.push((parts[0].to_string(), i));
-                }
-                Err(_) => {}
+            if let Ok(i) = parts[1].parse::<i64>() {
+                v.push((parts[0].to_string(), i));
            }
        }
    }
@@ -814,11 +799,8 @@ pub fn flat_keyed_to_hashmap(mut file: File) -> Result<HashMap<String, i64>> {
    for line in content.lines() {
        let parts: Vec<&str> = line.split(' ').collect();
        if parts.len() == 2 {
-            match parts[1].parse::<i64>() {
-                Ok(i) => {
-                    h.insert(parts[0].to_string(), i);
-                }
-                Err(_) => {}
+            if let Ok(i) = parts[1].parse::<i64>() {
+                h.insert(parts[0].to_string(), i);
            }
        }
    }
@@ -836,18 +818,15 @@ pub fn nested_keyed_to_hashmap(mut file: File) -> Result<HashMap<String, HashMap
    let mut h = HashMap::new();
    for line in content.lines() {
        let parts: Vec<&str> = line.split(' ').collect();
-        if parts.len() == 0 {
+        if parts.is_empty() {
            continue;
        }
        let mut th = HashMap::new();
-        for item in parts[1..].into_iter() {
+        for item in parts[1..].iter() {
            let fields: Vec<&str> = item.split('=').collect();
            if fields.len() == 2 {
-                match fields[1].parse::<i64>() {
-                    Ok(i) => {
-                        th.insert(fields[0].to_string(), i);
-                    }
-                    Err(_) => {}
+                if let Ok(i) = fields[1].parse::<i64>() {
+                    th.insert(fields[0].to_string(), i);
                }
            }
        }
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -56,13 +56,32 @@ pub struct OomControl {
    pub oom_kill: u64,
 }

+#[allow(clippy::unnecessary_wraps)]
 fn parse_oom_control(s: String) -> Result<OomControl> {
    let spl = s.split_whitespace().collect::<Vec<_>>();

+    let oom_kill_disable = if spl.len() > 1 {
+        spl[1].parse::<u64>().unwrap() == 1
+    } else {
+        false
+    };
+
+    let under_oom = if spl.len() > 3 {
+        spl[3].parse::<u64>().unwrap() == 1
+    } else {
+        false
+    };
+
+    let oom_kill = if spl.len() > 5 {
+        spl[5].parse::<u64>().unwrap()
+    } else {
+        0
+    };
+
    Ok(OomControl {
-        oom_kill_disable: spl[1].parse::<u64>().unwrap() == 1,
-        under_oom: spl[3].parse::<u64>().unwrap() == 1,
-        oom_kill: spl[5].parse::<u64>().unwrap(),
+        oom_kill_disable,
+        under_oom,
+        oom_kill,
    })
 }

@@ -104,18 +123,19 @@ pub struct NumaStat {
    pub hierarchical_unevictable_pages_per_node: Vec<u64>,
 }

+#[allow(clippy::unnecessary_wraps)]
 fn parse_numa_stat(s: String) -> Result<NumaStat> {
    // Parse the number of nodes
-    let _nodes = (s.split_whitespace().collect::<Vec<_>>().len() - 8) / 8;
+    let _nodes = (s.split_whitespace().count() - 8) / 8;
    let mut ls = s.lines();
    let total_line = ls.next().unwrap();
    let file_line = ls.next().unwrap();
    let anon_line = ls.next().unwrap();
    let unevict_line = ls.next().unwrap();
-    let hier_total_line = ls.next().unwrap();
-    let hier_file_line = ls.next().unwrap();
-    let hier_anon_line = ls.next().unwrap();
-    let hier_unevict_line = ls.next().unwrap();
+    let hier_total_line = ls.next().unwrap_or_default();
+    let hier_file_line = ls.next().unwrap_or_default();
+    let hier_anon_line = ls.next().unwrap_or_default();
+    let hier_unevict_line = ls.next().unwrap_or_default();

    Ok(NumaStat {
        total_pages: total_line
@@ -124,10 +144,10 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
            .parse::<u64>()
            .unwrap_or(0),
        total_pages_per_node: {
-            let spl = &total_line.split(" ").collect::<Vec<_>>()[1..];
+            let spl = &total_line.split(' ').collect::<Vec<_>>()[1..];
            spl.iter()
                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
+                    x.split('=').collect::<Vec<_>>()[1]
                        .parse::<u64>()
                        .unwrap_or(0)
                })
@@ -139,10 +159,10 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
            .parse::<u64>()
            .unwrap_or(0),
        file_pages_per_node: {
-            let spl = &file_line.split(" ").collect::<Vec<_>>()[1..];
+            let spl = &file_line.split(' ').collect::<Vec<_>>()[1..];
            spl.iter()
                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
+                    x.split('=').collect::<Vec<_>>()[1]
                        .parse::<u64>()
                        .unwrap_or(0)
                })
@@ -154,10 +174,10 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
            .parse::<u64>()
            .unwrap_or(0),
        anon_pages_per_node: {
-            let spl = &anon_line.split(" ").collect::<Vec<_>>()[1..];
+            let spl = &anon_line.split(' ').collect::<Vec<_>>()[1..];
            spl.iter()
                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
+                    x.split('=').collect::<Vec<_>>()[1]
                        .parse::<u64>()
                        .unwrap_or(0)
                })
@@ -169,74 +189,114 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
            .parse::<u64>()
            .unwrap_or(0),
        unevictable_pages_per_node: {
-            let spl = &unevict_line.split(" ").collect::<Vec<_>>()[1..];
+            let spl = &unevict_line.split(' ').collect::<Vec<_>>()[1..];
            spl.iter()
                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
+                    x.split('=').collect::<Vec<_>>()[1]
                        .parse::<u64>()
                        .unwrap_or(0)
                })
                .collect()
        },
-        hierarchical_total_pages: hier_total_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
-            .parse::<u64>()
-            .unwrap_or(0),
+        hierarchical_total_pages: {
+            if !hier_total_line.is_empty() {
+                hier_total_line
+                    .split(|x| x == ' ' || x == '=')
+                    .collect::<Vec<_>>()[1]
+                    .parse::<u64>()
+                    .unwrap_or(0)
+            } else {
+                0
+            }
+        },
        hierarchical_total_pages_per_node: {
-            let spl = &hier_total_line.split(" ").collect::<Vec<_>>()[1..];
-            spl.iter()
-                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
-                        .parse::<u64>()
-                        .unwrap_or(0)
-                })
-                .collect()
+            if !hier_total_line.is_empty() {
+                let spl = &hier_total_line.split(' ').collect::<Vec<_>>()[1..];
+                spl.iter()
+                    .map(|x| {
+                        x.split('=').collect::<Vec<_>>()[1]
+                            .parse::<u64>()
+                            .unwrap_or(0)
+                    })
+                    .collect()
+            } else {
+                Vec::new()
+            }
+        },
+        hierarchical_file_pages: {
+            if !hier_file_line.is_empty() {
+                hier_file_line
+                    .split(|x| x == ' ' || x == '=')
+                    .collect::<Vec<_>>()[1]
+                    .parse::<u64>()
+                    .unwrap_or(0)
+            } else {
+                0
+            }
        },
-        hierarchical_file_pages: hier_file_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
-            .parse::<u64>()
-            .unwrap_or(0),
        hierarchical_file_pages_per_node: {
-            let spl = &hier_file_line.split(" ").collect::<Vec<_>>()[1..];
-            spl.iter()
-                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
-                        .parse::<u64>()
-                        .unwrap_or(0)
-                })
-                .collect()
+            if !hier_file_line.is_empty() {
+                let spl = &hier_file_line.split(' ').collect::<Vec<_>>()[1..];
+                spl.iter()
+                    .map(|x| {
+                        x.split('=').collect::<Vec<_>>()[1]
+                            .parse::<u64>()
+                            .unwrap_or(0)
+                    })
+                    .collect()
+            } else {
+                Vec::new()
+            }
+        },
+        hierarchical_anon_pages: {
+            if !hier_anon_line.is_empty() {
+                hier_anon_line
+                    .split(|x| x == ' ' || x == '=')
+                    .collect::<Vec<_>>()[1]
+                    .parse::<u64>()
+                    .unwrap_or(0)
+            } else {
+                0
+            }
        },
-        hierarchical_anon_pages: hier_anon_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
-            .parse::<u64>()
-            .unwrap_or(0),
        hierarchical_anon_pages_per_node: {
-            let spl = &hier_anon_line.split(" ").collect::<Vec<_>>()[1..];
-            spl.iter()
-                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
-                        .parse::<u64>()
-                        .unwrap_or(0)
-                })
-                .collect()
+            if !hier_anon_line.is_empty() {
+                let spl = &hier_anon_line.split(' ').collect::<Vec<_>>()[1..];
+                spl.iter()
+                    .map(|x| {
+                        x.split('=').collect::<Vec<_>>()[1]
+                            .parse::<u64>()
+                            .unwrap_or(0)
+                    })
+                    .collect()
+            } else {
+                Vec::new()
+            }
+        },
+        hierarchical_unevictable_pages: {
+            if !hier_unevict_line.is_empty() {
+                hier_unevict_line
+                    .split(|x| x == ' ' || x == '=')
+                    .collect::<Vec<_>>()[1]
+                    .parse::<u64>()
+                    .unwrap_or(0)
+            } else {
+                0
+            }
        },
-        hierarchical_unevictable_pages: hier_unevict_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
-            .parse::<u64>()
-            .unwrap_or(0),
        hierarchical_unevictable_pages_per_node: {
-            let spl = &hier_unevict_line.split(" ").collect::<Vec<_>>()[1..];
-            spl.iter()
-                .map(|x| {
-                    x.split("=").collect::<Vec<_>>()[1]
-                        .parse::<u64>()
-                        .unwrap_or(0)
-                })
-                .collect()
+            if !hier_unevict_line.is_empty() {
+                let spl = &hier_unevict_line.split(' ').collect::<Vec<_>>()[1..];
+                spl.iter()
+                    .map(|x| {
+                        x.split('=').collect::<Vec<_>>()[1]
+                            .parse::<u64>()
+                            .unwrap_or(0)
+                    })
+                    .collect()
+            } else {
+                Vec::new()
+            }
        },
    })
 }
@@ -282,6 +342,7 @@ pub struct MemoryStat {
    pub raw: HashMap<String, u64>,
 }

+#[allow(clippy::unnecessary_wraps)]
 fn parse_memory_stat(s: String) -> Result<MemoryStat> {
    let mut raw = HashMap::new();

@@ -335,7 +396,7 @@ fn parse_memory_stat(s: String) -> Result<MemoryStat> {
        total_inactive_file: *raw.get("total_inactive_file").unwrap_or(&0),
        total_active_file: *raw.get("total_active_file").unwrap_or(&0),
        total_unevictable: *raw.get("total_unevictable").unwrap_or(&0),
-        raw: raw,
+        raw,
    })
 }

@@ -474,7 +535,7 @@ impl MemController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }

@@ -489,8 +550,8 @@ impl MemController {
        for value in values {
            let v = value.0;
            let f = value.1;
-            if v.is_some() {
-                let v = v.unwrap().to_string();
+            if let Some(v) = v {
+                let v = v.to_string();
                self.open_path(f, true).and_then(|mut file| {
                    file.write_all(v.as_ref())
                        .map_err(|e| Error::with_cause(WriteFailed, e))
@@ -531,7 +592,7 @@ impl MemController {
                .open_path("memory.stat", false)
                .and_then(read_string_from)
                .and_then(parse_memory_stat)
-                .unwrap_or(MemoryStat::default()),
+                .unwrap_or_default(),
            swappiness: self
                .open_path("memory.swap.current", false)
                .and_then(read_u64_from)
@@ -575,12 +636,12 @@ impl MemController {
                .open_path("memory.numa_stat", false)
                .and_then(read_string_from)
                .and_then(parse_numa_stat)
-                .unwrap_or(NumaStat::default()),
+                .unwrap_or_default(),
            oom_control: self
                .open_path("memory.oom_control", false)
                .and_then(read_string_from)
                .and_then(parse_oom_control)
-                .unwrap_or(OomControl::default()),
+                .unwrap_or_default(),
            soft_limit_in_bytes: self
                .open_path("memory.soft_limit_in_bytes", false)
                .and_then(read_i64_from)
@@ -589,7 +650,7 @@ impl MemController {
                .open_path("memory.stat", false)
                .and_then(read_string_from)
                .and_then(parse_memory_stat)
-                .unwrap_or(MemoryStat::default()),
+                .unwrap_or_default(),
            swappiness: self
                .open_path("memory.swappiness", false)
                .and_then(read_u64_from)
@@ -623,7 +684,7 @@ impl MemController {
            slabinfo: self
                .open_path("memory.kmem.slabinfo", false)
                .and_then(read_string_from)
-                .unwrap_or("".to_string()),
+                .unwrap_or_default(),
        }
    }

@@ -655,7 +716,7 @@ impl MemController {
            fail_cnt: self
                .open_path("memory.swap.events", false)
                .and_then(flat_keyed_to_hashmap)
-                .and_then(|x| Ok(*x.get("fail").unwrap_or(&0) as u64))
+                .map(|x| *x.get("fail").unwrap_or(&0) as u64)
                .unwrap(),
            limit_in_bytes: self
                .open_path("memory.swap.max", false)
@@ -878,6 +939,7 @@ mod tests {
    use crate::memory::{
        parse_memory_stat, parse_numa_stat, parse_oom_control, MemoryStat, NumaStat, OomControl,
    };
+
    static GOOD_VALUE: &str = "\
 total=51189 N0=51189 N1=123
 file=50175 N0=50175 N1=123
@@ -889,7 +951,24 @@ hierarchical_anon=770402 N0=770402 N1=123
 hierarchical_unevictable=20 N0=20 N1=123
 ";

-    static GOOD_OOMCONTROL_VAL: &str = "\
+    static GOOD_VALUE_NON_HIERARCHICAL: &str = "\
+total=51189 N0=51189 N1=123
+file=50175 N0=50175 N1=123
+anon=1014 N0=1014 N1=123
+unevictable=0 N0=0 N1=123
+";
+
+    static GOOD_OOMCONTROL_VAL_1: &str = "\
+oom_kill_disable 0
+oom_kill 1337
+";
+
+    static GOOD_OOMCONTROL_VAL_2: &str = "\
+oom_kill_disable 0
+under_oom 1
+";
+
+    static GOOD_OOMCONTROL_VAL_3: &str = "\
 oom_kill_disable 0
 under_oom 1
 oom_kill 1337
@@ -959,11 +1038,61 @@ total_unevictable 81920
                hierarchical_unevictable_pages_per_node: vec![20, 123],
            }
        );
+        let ok = parse_numa_stat(GOOD_VALUE_NON_HIERARCHICAL.to_string()).unwrap();
+        assert_eq!(
+            ok,
+            NumaStat {
+                total_pages: 51189,
+                total_pages_per_node: vec![51189, 123],
+                file_pages: 50175,
+                file_pages_per_node: vec![50175, 123],
+                anon_pages: 1014,
+                anon_pages_per_node: vec![1014, 123],
+                unevictable_pages: 0,
+                unevictable_pages_per_node: vec![0, 123],
+
+                hierarchical_total_pages: 0,
+                hierarchical_total_pages_per_node: vec![],
+                hierarchical_file_pages: 0,
+                hierarchical_file_pages_per_node: vec![],
+                hierarchical_anon_pages: 0,
+                hierarchical_anon_pages_per_node: vec![],
+                hierarchical_unevictable_pages: 0,
+                hierarchical_unevictable_pages_per_node: vec![],
+            }
+        );
    }

    #[test]
    fn test_parse_oom_control() {
-        let ok = parse_oom_control(GOOD_OOMCONTROL_VAL.to_string()).unwrap();
+        let ok = parse_oom_control("".to_string()).unwrap();
+        assert_eq!(
+            ok,
+            OomControl {
+                oom_kill_disable: false,
+                under_oom: false,
+                oom_kill: 0,
+            }
+        );
+        let ok = parse_oom_control(GOOD_OOMCONTROL_VAL_1.to_string()).unwrap();
+        assert_eq!(
+            ok,
+            OomControl {
+                oom_kill_disable: false,
+                under_oom: false,
+                oom_kill: 0,
+            }
+        );
+        let ok = parse_oom_control(GOOD_OOMCONTROL_VAL_2.to_string()).unwrap();
+        assert_eq!(
+            ok,
+            OomControl {
+                oom_kill_disable: false,
+                under_oom: true,
+                oom_kill: 0,
+            }
+        );
+        let ok = parse_oom_control(GOOD_OOMCONTROL_VAL_3.to_string()).unwrap();
        assert_eq!(
            ok,
            OomControl {
@@ -1017,7 +1146,7 @@ total_unevictable 81920
                total_inactive_file: 1272135680,
                total_active_file: 2338816000,
                total_unevictable: 81920,
-                raw: raw,
+                raw,
            }
        );
    }
--- a/src/net_cls.rs
+++ b/src/net_cls.rs
@@ -49,7 +49,7 @@ impl ControllerInternal for NetClsController {

        update_and_test!(self, set_class, res.class_id, get_class);

-        return Ok(());
+        Ok(())
    }
 }

@@ -96,6 +96,6 @@ impl NetClsController {
    /// Get the network class id of the outgoing packets of the control group's tasks.
    pub fn get_class(&self) -> Result<u64> {
        self.open_path("net_cls.classid", false)
-            .and_then(|file| read_u64_from(file))
+            .and_then(read_u64_from)
    }
 }
--- a/src/net_prio.rs
+++ b/src/net_prio.rs
@@ -94,6 +94,7 @@ impl NetPrioController {
    }

    /// A map of priorities for each network interface.
+    #[allow(clippy::iter_nth_zero, clippy::unnecessary_unwrap)]
    pub fn ifpriomap(&self) -> Result<HashMap<String, u64>> {
        self.open_path("net_prio.ifpriomap", false)
            .and_then(|file| {
@@ -105,6 +106,7 @@ impl NetPrioController {
                        let mut acc = acc.unwrap();
                        let l = line.unwrap();
                        let mut sp = l.split_whitespace();
+
                        let ifname = sp.nth(0);
                        let ifprio = sp.nth(1);
                        if ifname.is_none() || ifprio.is_none() {
--- a/src/pid.rs
+++ b/src/pid.rs
@@ -96,7 +96,7 @@ impl PidController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }

--- a/src/systemd.rs
+++ b/src/systemd.rs
@@ -66,7 +66,7 @@ impl SystemdController {
        Self {
            base: root.clone(),
            path: root,
-            v2: v2,
+            v2,
        }
    }
 }
--- a/tests/cgroup.rs
+++ b/tests/cgroup.rs
@@ -48,7 +48,7 @@ fn test_cgroup_with_relative_paths() {
    let cg = Cgroup::load(h, String::from(cgroup_name));
    {
        let subsystems = cg.subsystems();
-        subsystems.into_iter().for_each(|sub| match sub {
+        subsystems.iter().for_each(|sub| match sub {
            Subsystem::Pid(c) => {
                let cgroup_path = c.path().to_str().unwrap();
                let relative_path = "/pids/";
--- a/tests/cpuset.rs
+++ b/tests/cpuset.rs
@@ -36,7 +36,7 @@ fn test_cpuset_set_cpus() {
            assert_eq!(0, set.cpus.len());
        } else {
            // for cgroup v1, cpuset is copied from parent.
-            assert_eq!(true, set.cpus.len() > 0);
+            assert_eq!(true, !set.cpus.is_empty());
        }

        // 0
@@ -48,10 +48,9 @@ fn test_cpuset_set_cpus() {
        assert_eq!((0, 0), set.cpus[0]);

        // all cpus in system
-        let cpus =
-            fs::read_to_string("/sys/fs/cgroup/cpuset.cpus.effective").unwrap_or("".to_string());
+        let cpus = fs::read_to_string("/sys/fs/cgroup/cpuset.cpus.effective").unwrap_or_default();
        let cpus = cpus.trim();
-        if cpus != "" {
+        if !cpus.is_empty() {
            let r = cpuset.set_cpus(&cpus);
            assert_eq!(true, r.is_ok());
            let set = cpuset.cpuset();
@@ -73,14 +72,14 @@ fn test_cpuset_set_cpus_add_task() {
        assert_eq!(0, set.cpus.len());
    } else {
        // for cgroup v1, cpuset is copied from parent.
-        assert_eq!(true, set.cpus.len() > 0);
+        assert_eq!(true, !set.cpus.is_empty());
    }

    // Add a task to the control group.
    let pid_i = libc::pid_t::from(nix::unistd::getpid()) as u64;
    let _ = cg.add_task(CgroupPid::from(pid_i));
    let tasks = cg.tasks();
-    assert_eq!(true, tasks.len() > 0);
+    assert_eq!(true, !tasks.is_empty());
    println!("tasks after added: {:?}", tasks);

    // remove task
--- a/tests/devices.rs
+++ b/tests/devices.rs
@@ -27,7 +27,7 @@ fn test_devices_parsing() {
                DeviceType::All,
                -1,
                -1,
-                &vec![
+                &[
                    DevicePermissions::Read,
                    DevicePermissions::Write,
                    DevicePermissions::MkNod,
@@ -42,7 +42,7 @@ fn test_devices_parsing() {

        // Now add mknod access to /dev/null device
        devices
-            .allow_device(DeviceType::Char, 1, 3, &vec![DevicePermissions::MkNod])
+            .allow_device(DeviceType::Char, 1, 3, &[DevicePermissions::MkNod])
            .unwrap();
        let allowed_devices = devices.allowed_devices();
        assert!(allowed_devices.is_ok());
--- a/tests/pids.rs
+++ b/tests/pids.rs
@@ -62,7 +62,7 @@ fn test_pid_events_is_not_zero() {
        let before = pids.get_pid_events();
        let before = before.unwrap();

-        match fork() {
+        match unsafe { fork() } {
            Ok(ForkResult::Parent { child, .. }) => {
                // move the process into the control group
                let _ = pids.add_task(&(pid_t::from(child) as u64).into());
@@ -89,7 +89,7 @@ fn test_pid_events_is_not_zero() {
            Ok(ForkResult::Child) => loop {
                let pids_max = pids.get_pid_max();
                if pids_max.is_ok() && pids_max.unwrap() == MaxValue::Value(1) {
-                    if let Err(_) = fork() {
+                    if unsafe { fork() }.is_err() {
                        unsafe { libc::exit(0) };
                    } else {
                        unsafe { libc::exit(1) };
Author	SHA1	Message	Date
Bin Liu	af7a75ce9e	Merge pull request #40 from Jakob-Naucke/v0.2.4 release: v0.2.4	2021-03-03 15:39:15 +08:00
Bin Liu	fb56c817ca	Merge pull request #32 from Tim-Zhang/fix-clippy Fix clippy warnings	2021-03-03 15:38:37 +08:00
Tim Zhang	fdabe52401	github action: Add clippy check Because the existing warnings are all fixed. Signed-off-by: Tim Zhang <tim@hyper.sh>	2021-03-03 13:46:19 +08:00
Tim Zhang	9ec1010a15	Fix clippy warnings Fix clippy warnings. Signed-off-by: Tim Zhang <tim@hyper.sh>	2021-03-03 13:44:29 +08:00
Fupan Li	610071730d	Merge pull request #41 from bergwolf/fix-panic memory: fix parse_oom_control panic on older kernels	2021-03-03 00:17:54 +08:00
Peng Tao	0a3e4a828f	memory: fix parse_oom_control panic on older kernels Where the oom control fields might not be present. Fixes: #36 Signed-off-by: Peng Tao <bergwolf@hyper.sh>	2021-02-26 01:40:19 +08:00
Jakob Naucke	60820bfffb	release: v0.2.4 Bump version from 0.2.3 to 0.2.4 Signed-off-by: Jakob Naucke <jakob.naucke@ibm.com>	2021-02-25 11:22:47 +01:00
Fupan Li	2209189244	Merge pull request #39 from bergwolf/fix-panic memory: fix panic when no hierarchical numa stat is available	2021-02-25 14:57:39 +08:00
Peng Tao	8720aed656	memory: fix panic when no hierarchical numa stat is available For older kernels, it is possible that there is no hierarchical numa stats. Fixes: #36 Signed-off-by: Peng Tao <bergwolf@hyper.sh>	2021-02-25 11:00:48 +08:00
Fupan Li	16d73e1d59	Merge pull request #38 from Jakob-Naucke/update-nix Update nix to 0.20.0	2021-02-25 09:47:01 +08:00
Jakob Naucke	b9ca0a51f1	Update nix to 0.20.0 to pull in https://github.com/nix-rust/nix/pull/1372 and get statfs MAGIC constants on s390x. Additionally, fork() calls in tests now have to be marked unsafe. Fixes: #37 Signed-off-by: Jakob Naucke <jakob.naucke@ibm.com>	2021-02-22 14:28:16 +01:00