File size: 4,629 Bytes
84d2a97
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
#[derive(Debug)]
pub struct Mem {
    #[cfg(target_os = "linux")]
    cgroups: Option<cgroups_mem::CgroupsMem>,
    sysinfo: sysinfo_mem::SysinfoMem,
}

impl Mem {
    #[allow(clippy::new_without_default)]
    pub fn new() -> Self {
        Self {
            #[cfg(target_os = "linux")]
            cgroups: cgroups_mem::CgroupsMem::new(),
            sysinfo: sysinfo_mem::SysinfoMem::new(),
        }
    }

    pub fn refresh(&mut self) {
        #[cfg(target_os = "linux")]
        if let Some(cgroups) = &mut self.cgroups {
            cgroups.refresh();
        }

        self.sysinfo.refresh();
    }

    pub fn total_memory_bytes(&self) -> u64 {
        #[cfg(target_os = "linux")]
        if let Some(cgroups) = &self.cgroups {
            if let Some(memory_limit_bytes) = cgroups.memory_limit_bytes() {
                return memory_limit_bytes;
            }
        }

        self.sysinfo.total_memory_bytes()
    }

    pub fn available_memory_bytes(&self) -> u64 {
        #[cfg(target_os = "linux")]
        if let Some(cgroups) = &self.cgroups {
            if let Some(memory_limit_bytes) = cgroups.memory_limit_bytes() {
                return memory_limit_bytes.saturating_sub(cgroups.used_memory_bytes());
            }
        }

        self.sysinfo.available_memory_bytes()
    }
}

#[cfg(target_os = "linux")]
mod cgroups_mem {
    use cgroups_rs::{hierarchies, memory, Cgroup};
    use procfs::process::Process;

    #[derive(Clone, Debug)]
    pub struct CgroupsMem {
        mem_controller: memory::MemController,
        memory_limit_bytes: Option<u64>,
        used_memory_bytes: u64,
    }

    impl CgroupsMem {
        pub fn new() -> Option<Self> {
            let memory_cgroup_path = match get_current_process_memory_cgroup_path() {
                Ok(memory_cgroup_path) => memory_cgroup_path?,
                Err(err) => {
                    log::error!(
                        "Failed to query current process info \
                         while initializing CgroupsMem: {err}"
                    );

                    return None;
                }
            };

            let cgroup = Cgroup::load(
                hierarchies::auto(),
                memory_cgroup_path.trim_start_matches('/'),
            );

            let mut mem = Self {
                mem_controller: cgroup.controller_of::<memory::MemController>()?.clone(),
                memory_limit_bytes: None,
                used_memory_bytes: 0,
            };

            mem.refresh();

            Some(mem)
        }

        pub fn refresh(&mut self) {
            let stat = self.mem_controller.memory_stat();
            self.memory_limit_bytes = stat.limit_in_bytes.try_into().ok();
            self.used_memory_bytes = stat.usage_in_bytes;
        }

        pub fn memory_limit_bytes(&self) -> Option<u64> {
            self.memory_limit_bytes
        }

        pub fn used_memory_bytes(&self) -> u64 {
            self.used_memory_bytes
        }
    }

    fn get_current_process_memory_cgroup_path() -> procfs::ProcResult<Option<String>> {
        let process = Process::myself()?;
        let cgroups = process.cgroups()?;

        for cgroup in cgroups {
            // TODO: Can a process belong to multiple v2 cgroups!?
            let is_v2_cgroup = cgroup.controllers.is_empty()
                || cgroup
                    .controllers
                    .iter()
                    .all(|controller| controller.is_empty());

            // TODO: Can a process belong to multiple v1 cgroups, with some of these cgroups having the same controllers (e.g., memory)!?
            let is_v1_memory_cgroup = cgroup
                .controllers
                .iter()
                .any(|controller| controller == "memory");

            if is_v2_cgroup || is_v1_memory_cgroup {
                return Ok(Some(cgroup.pathname));
            }
        }

        Ok(None)
    }
}

mod sysinfo_mem {
    use sysinfo::{MemoryRefreshKind, RefreshKind, System};

    #[derive(Debug)]
    pub struct SysinfoMem {
        system: System,
    }

    impl SysinfoMem {
        pub fn new() -> Self {
            let system = System::new_with_specifics(
                RefreshKind::new().with_memory(MemoryRefreshKind::everything()),
            );
            Self { system }
        }

        pub fn refresh(&mut self) {
            self.system.refresh_memory();
        }

        pub fn total_memory_bytes(&self) -> u64 {
            self.system.total_memory()
        }

        pub fn available_memory_bytes(&self) -> u64 {
            self.system.available_memory()
        }
    }
}