some progress on linux

src/data_collection/cpu.rs

@@ -18,6 +18,3 @@ pub struct CpuData {
 }
 
 pub type CpuHarvest = Vec<CpuData>;
-
-pub type PastCpuWork = f64;
-pub type PastCpuTotal = f64;

src/data_collection/memory.rs

@@ -19,6 +19,6 @@ pub mod arc;
 pub struct MemHarvest {
     pub used_bytes: u64,
     pub total_bytes: u64,
-    pub use_percent: Option<f64>, /* TODO: Might be find to just make this an f64, and any
+    pub use_percent: Option<f64>, /* TODO: Might be fine to just make this an f64, and any
                                    * consumer checks NaN. */
 }

src/new_data_collection/collectors/common.rs

@@ -1,19 +1,34 @@
 //! Common code amongst all data collectors.
 
-use crate::new_data_collection::{
-    error::CollectionResult,
-    sources::common::{
-        disk::DiskHarvest, processes::ProcessHarvest, temperature::TemperatureData,
+use crate::{
+    data_collection::Data,
+    new_data_collection::{
+        error::CollectionResult,
+        sources::{
+            cpu::CpuHarvest, disk::DiskHarvest, memory::MemHarvest, processes::ProcessHarvest,
+            temperature::TemperatureData,
+        },
     },
 };
 
+#[cfg(feature = "battery")]
+use crate::new_data_collection::sources::battery::BatteryHarvest;
+
+// /// Represents data collected at an instance.
+// #[derive(Debug)]
+// pub struct Data {
+//     pub collection_time: Instant,
+//     pub temperature_data: Option<Vec<TemperatureData>>,
+//     pub process_data: Option<Vec<ProcessHarvest>>,
+//     pub disk_data: Option<DiskHarvest>,
+// }
+
 /// The trait representing what a per-platform data collector should implement.
-pub(crate) trait DataCollector {
-    /// Refresh inner data sources to prepare them for gathering data.
+pub trait DataCollector {
+    /// Return data.
     ///
-    /// Note that depending on the implementation, this may
-    /// not actually need to do anything.
-    fn refresh_data(&mut self) -> CollectionResult<()>;
+    /// For now, this returns the old data type for cross-compatibility as we migrate.
+    fn get_data(&mut self) -> Data;
 
     /// Return temperature data.
     fn get_temperature_data(&mut self) -> CollectionResult<Vec<TemperatureData>>;
@@ -23,4 +38,14 @@ pub(crate) trait DataCollector {
 
     /// Return disk data.
     fn get_disk_data(&mut self) -> CollectionResult<DiskHarvest>;
+
+    /// Return CPU data.
+    fn get_cpu_data(&mut self) -> CollectionResult<CpuHarvest>;
+
+    /// Return memory data.
+    fn get_memory_data(&mut self) -> CollectionResult<MemHarvest>;
+
+    #[cfg(feature = "battery")]
+    /// Return battery data.
+    fn get_battery_data(&mut self) -> CollectionResult<Vec<BatteryHarvest>>;
 }

src/new_data_collection/collectors/freebsd.rs

@@ -1,36 +0,0 @@
-//! The data collector for FreeBSD.
-
-use crate::{
-    app::filter::Filter,
-    new_data_collection::{
-        error::CollectionResult,
-        sources::{
-            common::temperature::{TemperatureData, TemperatureType},
-            sysinfo::temperature::get_temperature_data,
-        },
-    },
-};
-
-use super::common::DataCollector;
-
-/// The [`DataCollector`] for FreeBSD.
-pub struct FreeBsdDataCollector {
-    temp_type: TemperatureType,
-    temp_filters: Option<Filter>,
-}
-
-impl DataCollector for FreeBsdDataCollector {
-    fn refresh_data(&mut self) -> CollectionResult<()> {
-        Ok(())
-    }
-
-    fn get_temperature_data(&self) -> CollectionResult<Option<Vec<TemperatureData>>> {
-        let mut results = get_temperature_data(&self.temp_type, &self.temp_filters);
-
-        for entry in sysctl_temp_iter(&self.temp_type, &self.temp_filters) {
-            results.push(entry);
-        }
-
-        Ok(Some(results))
-    }
-}

src/new_data_collection/collectors/linux.rs

@@ -2,28 +2,36 @@
 
 use std::time::Instant;
 
-use starship_battery::{Battery, Manager};
-
 use crate::{
     app::filter::Filter,
+    data_collection::Data,
     new_data_collection::{
         error::CollectionResult,
         sources::{
-            common::{
-                disk::DiskHarvest,
-                processes::ProcessHarvest,
-                temperature::{TemperatureData, TemperatureType},
-            },
-            linux::{
-                processes::{linux_process_data, ProcessCollector},
-                temperature::get_temperature_data,
+            cpu::CpuHarvest,
+            disk::DiskHarvest,
+            linux::{get_temperature_data, linux_process_data, ProcessCollector},
+            memory::MemHarvest,
+            processes::ProcessHarvest,
+            sysinfo::{
+                cpu::{get_cpu_data_list, get_load_avg},
+                memory::{get_cache_usage, get_ram_usage, get_swap_usage},
             },
+            temperature::{TemperatureData, TemperatureType},
         },
     },
 };
 
 use super::common::DataCollector;
 
+cfg_if::cfg_if! {
+    if #[cfg(feature = "battery")] {
+        use starship_battery::{Battery, Manager};
+        use crate::new_data_collection::sources::battery::BatteryHarvest;
+    }
+
+}
+
 /// The [`DataCollector`] for Linux.
 pub struct LinuxDataCollector {
     current_collection_time: Instant,
@@ -37,19 +45,30 @@ pub struct LinuxDataCollector {
     system: sysinfo::System,
     network: sysinfo::Networks,
 
+    show_average_cpu: bool,
+
     #[cfg(feature = "battery")]
-    battery_manager: Option<Manager>,
-    #[cfg(feature = "battery")]
-    battery_list: Option<Vec<Battery>>,
+    batteries: Option<(Manager, Vec<Battery>)>,
+
+    #[cfg(feature = "gpu")]
+    nvml: nvml_wrapper::Nvml,
 
     #[cfg(feature = "gpu")]
     gpus_total_mem: Option<u64>,
 }
 
-impl DataCollector for LinuxDataCollector {
+impl LinuxDataCollector {
     fn refresh_data(&mut self) -> CollectionResult<()> {
         Ok(())
     }
+}
+
+impl DataCollector for LinuxDataCollector {
+    fn get_data(&mut self) -> Data {
+        let collection_time = Instant::now();
+
+        todo!()
+    }
 
     fn get_temperature_data(&mut self) -> CollectionResult<Vec<TemperatureData>> {
         Ok(get_temperature_data(&self.temp_type, &self.temp_filters))
@@ -73,4 +92,44 @@ impl DataCollector for LinuxDataCollector {
     fn get_disk_data(&mut self) -> CollectionResult<DiskHarvest> {
         todo!()
     }
+
+    fn get_cpu_data(&mut self) -> CollectionResult<CpuHarvest> {
+        let usages = get_cpu_data_list(&self.system, self.show_average_cpu);
+        let load_average = get_load_avg();
+
+        CollectionResult::Ok(CpuHarvest {
+            usages,
+            load_average,
+        })
+    }
+
+    fn get_memory_data(&mut self) -> CollectionResult<MemHarvest> {
+        let memory = get_ram_usage(&self.system);
+        let swap = get_swap_usage(&self.system);
+        let cache = get_cache_usage(&self.system);
+
+        CollectionResult::Ok(MemHarvest {
+            memory,
+            swap,
+            cache,
+            #[cfg(feature = "zfs")]
+            arc: crate::new_data_collection::sources::linux::get_arc_usage(),
+            #[cfg(feature = "gpu")]
+            gpu: crate::new_data_collection::sources::nvidia::get_gpu_memory_usage(&self.nvml),
+        })
+    }
+
+    #[cfg(feature = "battery")]
+    fn get_battery_data(&mut self) -> CollectionResult<Vec<BatteryHarvest>> {
+        use crate::new_data_collection::{
+            error::CollectionError, sources::starship::refresh_batteries,
+        };
+
+        match &mut self.batteries {
+            Some((battery_manager, battery_list)) => {
+                CollectionResult::Ok(refresh_batteries(battery_manager, battery_list))
+            }
+            None => CollectionResult::Err(CollectionError::NoData),
+        }
+    }
 }

src/new_data_collection/collectors/macos.rs

@@ -1,33 +0,0 @@
-//! The data collector for macOS.
-
-use crate::{
-    app::filter::Filter,
-    new_data_collection::{
-        error::CollectionResult,
-        sources::{
-            common::temperature::{TemperatureData, TemperatureType},
-            sysinfo::temperature::get_temperature_data,
-        },
-    },
-};
-
-use super::common::DataCollector;
-
-/// The [`DataCollector`] for macOS.
-pub struct MacOsDataCollector {
-    temp_type: TemperatureType,
-    temp_filters: Option<Filter>,
-}
-
-impl DataCollector for MacOsDataCollector {
-    fn refresh_data(&mut self) -> CollectionResult<()> {
-        Ok(())
-    }
-
-    fn get_temperature_data(&self) -> CollectionResult<Option<Vec<TemperatureData>>> {
-        Ok(Some(get_temperature_data(
-            &self.temp_type,
-            &self.temp_filters,
-        )))
-    }
-}

src/new_data_collection/collectors/windows.rs

@@ -1,33 +0,0 @@
-//! The data collector for Windows.
-
-use crate::{
-    app::filter::Filter,
-    new_data_collection::{
-        error::CollectionResult,
-        sources::{
-            common::temperature::{TemperatureData, TemperatureType},
-            sysinfo::temperature::get_temperature_data,
-        },
-    },
-};
-
-use super::common::DataCollector;
-
-/// The [`DataCollector`] for Windows.
-pub struct WindowsDataCollector {
-    temp_type: TemperatureType,
-    temp_filters: Option<Filter>,
-}
-
-impl DataCollector for WindowsDataCollector {
-    fn refresh_data(&mut self) -> CollectionResult<()> {
-        Ok(())
-    }
-
-    fn get_temperature_data(&self) -> CollectionResult<Option<Vec<TemperatureData>>> {
-        Ok(Some(get_temperature_data(
-            &self.temp_type,
-            &self.temp_filters,
-        )))
-    }
-}

src/new_data_collection/error.rs

@@ -6,6 +6,9 @@ pub enum CollectionError {
     /// A general error to propagate back up. A wrapper around [`anyhow::Error`].
     General(anyhow::Error),
 
+    /// No data.
+    NoData,
+
     /// Collection is unsupported.
     Unsupported,
 }
@@ -14,6 +17,9 @@ impl std::fmt::Display for CollectionError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             CollectionError::General(err) => err.fmt(f),
+            CollectionError::NoData => {
+                write!(f, "no data found")
+            }
             CollectionError::Unsupported => {
                 write!(
                     f,

src/new_data_collection/mod.rs

@@ -9,15 +9,15 @@ mod collectors {
         if #[cfg(target_os = "linux")] {
             pub mod linux;
             pub use linux::LinuxDataCollector as DataCollectorImpl;
-        } else if #[cfg(target_os = "macos")] {
-            pub mod macos;
-            pub use macos::MacOsDataCollector as DataCollectorImpl;
-        } else if #[cfg(target_os = "windows")] {
-            pub mod windows;
-            pub use windows::WindowsDataCollector as DataCollectorImpl;
-        } else if #[cfg(target_os = "freebsd")] {
-            pub mod freebsd;
-            pub use freebsd::FreeBsdDataCollector as DataCollectorImpl;
+        // } else if #[cfg(target_os = "macos")] {
+        //     pub mod macos;
+        //     pub use macos::MacOsDataCollector as DataCollectorImpl;
+        // } else if #[cfg(target_os = "windows")] {
+        //     pub mod windows;
+        //     pub use windows::WindowsDataCollector as DataCollectorImpl;
+        // } else if #[cfg(target_os = "freebsd")] {
+        //     pub mod freebsd;
+        //     pub use freebsd::FreeBsdDataCollector as DataCollectorImpl;
         } else {
             pub mod fallback;
             pub use fallback::FallbackDataCollector as DataCollectorImpl;

src/new_data_collection/sources/common/battery.rs

@@ -0,0 +1,20 @@
+//! Common code for retrieving battery data.
+
+#[derive(Debug, Clone)]
+pub enum State {
+    Unknown,
+    Charging,
+    Discharging,
+    Empty,
+    Full,
+}
+
+#[derive(Debug, Clone)]
+pub struct BatteryHarvest {
+    pub charge_percent: f64,
+    pub secs_until_full: Option<i64>,
+    pub secs_until_empty: Option<i64>,
+    pub power_consumption_rate_watts: f64,
+    pub health_percent: f64,
+    pub state: State,
+}

src/new_data_collection/sources/common/cpu.rs

@@ -0,0 +1,21 @@
+//! Common code for retrieving CPU data.
+
+#[derive(Debug, Clone, Copy)]
+pub(crate) enum CpuDataType {
+    Avg,
+    Cpu(usize),
+}
+
+/// Represents a single core/thread and its usage.
+#[derive(Debug, Clone)]
+pub(crate) struct CpuData {
+    pub entry_type: CpuDataType,
+    pub usage: f64,
+}
+
+/// Collected CPU data at an instance.
+#[derive(Debug, Clone)]
+pub(crate) struct CpuHarvest {
+    pub usages: Vec<CpuData>,
+    pub load_average: [f32; 3],
+}

src/new_data_collection/sources/common/disk.rs

@@ -26,6 +26,7 @@ pub struct IoData {
     pub write_bytes: u64,
 }
 
+#[derive(Clone, Debug)]
 pub struct DiskHarvest {
     /// Disk entries.
     pub entries: Vec<DiskEntry>,

src/new_data_collection/sources/common/memory.rs

@@ -0,0 +1,22 @@
+//! Code pertaining to memory data retrieval.
+
+#[derive(Debug)]
+pub(crate) struct MemData {
+    pub used_bytes: u64,
+    pub total_bytes: u64,
+}
+
+#[derive(Debug)]
+pub(crate) struct MemHarvest {
+    pub memory: MemData,
+    pub swap: MemData,
+
+    #[cfg(not(target_os = "windows"))]
+    pub cache: MemData,
+
+    #[cfg(feature = "zfs")]
+    pub arc: MemData,
+
+    #[cfg(feature = "gpu")]
+    pub gpu: Vec<(String, MemData)>,
+}

src/new_data_collection/sources/common/mod.rs

@@ -1,3 +1,7 @@
+#[cfg(feature = "battery")]
+pub mod battery;
+pub mod cpu;
 pub mod disk;
+pub mod memory;
 pub mod processes;
 pub mod temperature;

src/new_data_collection/sources/freebsd/mod.rs

@@ -1 +0,0 @@
-mod temperature;

src/new_data_collection/sources/freebsd/temperature.rs

@@ -1,35 +0,0 @@
-//! FreeBSD-specific temperature extraction code.
-
-// For RockPro64 boards on FreeBSD, they apparently use "hw.temperature" for
-// sensors.
-use sysctl::Sysctl;
-
-/// Return an iterator of temperature data pulled from sysctl.
-pub(crate) fn sysctl_temp_iter(
-    temp_type: &TemperatureType, filter: &Option<Filter>,
-) -> impl Iterator<Item = TemperatureData> {
-    const KEY: &str = "hw.temperature";
-
-    if let Ok(root) = sysctl::Ctl::new(KEY) {
-        sysctl::CtlIter::below(root).flatten().filter_map(|ctl| {
-            if let (Ok(name), Ok(temp)) = (ctl.name(), ctl.value()) {
-                if let Some(temp) = temp.as_temperature() {
-                    if Filter::optional_should_keep(filter, &name) {
-                        return Some(TemperatureData {
-                            name,
-                            temperature: Some(match temp_type {
-                                TemperatureType::Celsius => temp.celsius(),
-                                TemperatureType::Kelvin => temp.kelvin(),
-                                TemperatureType::Fahrenheit => temp.fahrenheit(),
-                            }),
-                        });
-                    }
-                }
-            }
-
-            None
-        })
-    } else {
-        std::iter::empty()
-    }
-}

src/new_data_collection/sources/linux/memory.rs

@@ -0,0 +1,46 @@
+use crate::new_data_collection::sources::memory::MemData;
+
+pub(crate) fn get_arc_usage() -> MemData {
+    // TODO: [OPT] is this efficient?
+    use std::fs::read_to_string;
+
+    let (total_bytes, used_bytes) =
+        if let Ok(arc_stats) = read_to_string("/proc/spl/kstat/zfs/arcstats") {
+            let mut mem_arc = 0;
+            let mut mem_total = 0;
+            let mut zfs_keys_read: u8 = 0;
+            const ZFS_KEYS_NEEDED: u8 = 2;
+
+            for line in arc_stats.lines() {
+                if let Some((label, value)) = line.split_once(' ') {
+                    let to_write = match label {
+                        "size" => &mut mem_arc,
+                        "c_max" => &mut mem_total,
+                        _ => {
+                            continue;
+                        }
+                    };
+
+                    if let Some((_type, number)) = value.trim_start().rsplit_once(' ') {
+                        // Parse the value, remember it's in bytes!
+                        if let Ok(number) = number.parse::<u64>() {
+                            *to_write = number;
+                            // We only need a few keys, so we can bail early.
+                            zfs_keys_read += 1;
+                            if zfs_keys_read == ZFS_KEYS_NEEDED {
+                                break;
+                            }
+                        }
+                    }
+                }
+            }
+            (mem_total, mem_arc)
+        } else {
+            (0, 0)
+        };
+
+    MemData {
+        used_bytes,
+        total_bytes,
+    }
+}

src/new_data_collection/sources/linux/mod.rs

@@ -1,2 +1,13 @@
-pub mod processes;
-pub mod temperature;
+mod processes;
+mod temperature;
+
+pub(crate) use processes::*;
+pub(crate) use temperature::*;
+
+// For now we only use a Linux-specific implementation for zfs ARC usage.
+cfg_if::cfg_if! {
+    if #[cfg(feature = "zfs")] {
+        mod memory;
+        pub(crate) use memory::*;
+    }
+}

src/new_data_collection/sources/linux/processes/mod.rs

@@ -272,13 +272,13 @@ fn read_proc(
     ))
 }
 
-pub(crate) struct PrevProc {
+pub struct PrevProc {
     pub prev_idle: f64,
     pub prev_non_idle: f64,
 }
 
 #[derive(Clone, Copy)]
-pub(crate) struct ProcHarvestOptions {
+pub struct ProcHarvestOptions {
     pub use_current_cpu_total: bool,
     pub unnormalized_cpu: bool,
 }
@@ -289,13 +289,13 @@ fn is_str_numeric(s: &str) -> bool {
 
 /// General args to keep around for reading proc data.
 #[derive(Copy, Clone)]
-pub(crate) struct ReadProcArgs {
-    pub(crate) use_current_cpu_total: bool,
-    pub(crate) cpu_usage: f64,
-    pub(crate) cpu_fraction: f64,
-    pub(crate) total_memory: u64,
-    pub(crate) time_difference_in_secs: u64,
-    pub(crate) uptime: u64,
+pub struct ReadProcArgs {
+    pub use_current_cpu_total: bool,
+    pub cpu_usage: f64,
+    pub cpu_fraction: f64,
+    pub total_memory: u64,
+    pub time_difference_in_secs: u64,
+    pub uptime: u64,
 }
 
 pub struct ProcessCollector {

src/new_data_collection/sources/mod.rs

@@ -1,16 +1,20 @@
 pub mod common;
 pub mod linux;
-pub mod macos;
+// pub mod macos;
 #[cfg(feature = "gpu")]
 pub mod nvidia;
+pub mod starship;
 pub mod sysinfo;
 pub mod unix;
-pub mod windows;
+// pub mod windows;
+
+pub use common::*;
 
 cfg_if::cfg_if! {
-    if #[cfg(target_family = "windows")] {
-        pub use windows::processes::Pid as Pid;
-    } else if #[cfg(target_family = "unix")] {
+    if #[cfg(target_family = "unix")] {
         pub use unix::processes::Pid as Pid;
     }
+    // else if #[cfg(target_family = "windows")] {
+    //     pub use windows::processes::Pid as Pid;
+    // }
 }

src/new_data_collection/sources/nvidia/memory.rs

@@ -0,0 +1,32 @@
+use nvml_wrapper::Nvml;
+
+use crate::new_data_collection::sources::memory::MemData;
+
+/// Returns GPU memory usage per device name.
+pub(crate) fn get_gpu_memory_usage(nvml: &Nvml) -> Vec<(String, MemData)> {
+    let Ok(num_gpu) = nvml.device_count() else {
+        return vec![];
+    };
+
+    (0..num_gpu)
+        .filter_map(|i| nvml.device_by_index(i).ok())
+        .filter_map(|device| match device.name() {
+            Ok(name) => {
+                match device.memory_info() {
+                    Ok(mem_info) => Some((
+                        name,
+                        MemData {
+                            used_bytes: mem_info.used,
+                            total_bytes: mem_info.total,
+                        },
+                    )),
+                    Err(_) => {
+                        // TODO: Maybe we should still return something here if it errors out.
+                        None
+                    }
+                }
+            }
+            Err(_) => None,
+        })
+        .collect()
+}

src/new_data_collection/sources/nvidia/mod.rs

@@ -0,0 +1,2 @@
+mod memory;
+pub(crate) use memory::*;

src/new_data_collection/sources/starship.rs

@@ -10,17 +10,21 @@
 
 use starship_battery::{
     units::{power::watt, ratio::percent, time::second},
-    Battery, Manager, State,
+    Battery, Manager,
 };
 
-#[derive(Debug, Clone)]
-pub struct BatteryHarvest {
-    pub charge_percent: f64,
-    pub secs_until_full: Option<i64>,
-    pub secs_until_empty: Option<i64>,
-    pub power_consumption_rate_watts: f64,
-    pub health_percent: f64,
-    pub state: State,
+use super::battery::{BatteryHarvest, State};
+
+impl From<starship_battery::State> for State {
+    fn from(value: starship_battery::State) -> Self {
+        match value {
+            starship_battery::State::Unknown => State::Unknown,
+            starship_battery::State::Charging => State::Charging,
+            starship_battery::State::Discharging => State::Discharging,
+            starship_battery::State::Empty => State::Empty,
+            starship_battery::State::Full => State::Full,
+        }
+    }
 }
 
 pub fn refresh_batteries(manager: &Manager, batteries: &mut [Battery]) -> Vec<BatteryHarvest> {
@@ -40,7 +44,7 @@ pub fn refresh_batteries(manager: &Manager, batteries: &mut [Battery]) -> Vec<Ba
                     charge_percent: f64::from(battery.state_of_charge().get::<percent>()),
                     power_consumption_rate_watts: f64::from(battery.energy_rate().get::<watt>()),
                     health_percent: f64::from(battery.state_of_health().get::<percent>()),
-                    state: battery.state(),
+                    state: battery.state().into(),
                 })
             } else {
                 None

src/new_data_collection/sources/sysinfo/cpu.rs

@@ -0,0 +1,40 @@
+use std::collections::VecDeque;
+
+use sysinfo::{LoadAvg, System};
+
+use crate::{
+    data_collection::cpu::LoadAvgHarvest,
+    new_data_collection::sources::cpu::{CpuData, CpuDataType},
+};
+
+pub(crate) fn get_cpu_data_list(sys: &System, show_average_cpu: bool) -> Vec<CpuData> {
+    let mut cpu_deque: VecDeque<_> = sys
+        .cpus()
+        .iter()
+        .enumerate()
+        .map(|(i, cpu)| CpuData {
+            entry_type: CpuDataType::Cpu(i),
+            usage: cpu.cpu_usage() as f64,
+        })
+        .collect();
+
+    if show_average_cpu {
+        let cpu = sys.global_cpu_info();
+
+        cpu_deque.push_front(CpuData {
+            entry_type: CpuDataType::Avg,
+            usage: cpu.cpu_usage() as f64,
+        })
+    }
+
+    Vec::from(cpu_deque)
+}
+
+#[cfg(not(target_os = "windows"))]
+pub(crate) fn get_load_avg() -> LoadAvgHarvest {
+    // The API for sysinfo apparently wants you to call it like this, rather than
+    // using a &System.
+    let LoadAvg { one, five, fifteen } = sysinfo::System::load_average();
+
+    [one as f32, five as f32, fifteen as f32]
+}

src/new_data_collection/sources/sysinfo/memory.rs

@@ -0,0 +1,47 @@
+//! Collecting memory data using sysinfo.
+
+use sysinfo::System;
+
+use crate::new_data_collection::sources::memory::MemData;
+
+/// Returns RAM usage.
+pub(crate) fn get_ram_usage(sys: &System) -> MemData {
+    let mem_used = sys.used_memory();
+    let mem_total = sys.total_memory();
+
+    MemData {
+        used_bytes: mem_used,
+        total_bytes: mem_total,
+    }
+}
+
+/// Returns SWAP usage.
+pub(crate) fn get_swap_usage(sys: &System) -> MemData {
+    let mem_used = sys.used_swap();
+    let mem_total = sys.total_swap();
+
+    MemData {
+        used_bytes: mem_used,
+        total_bytes: mem_total,
+    }
+}
+
+/// Returns cache usage. sysinfo has no way to do this directly but it should
+/// equal the difference between the available and free memory. Free memory is
+/// defined as memory not containing any data, which means cache and buffer
+/// memory are not "free". Available memory is defined as memory able
+/// to be allocated by processes, which includes cache and buffer memory. On
+/// Windows, this will always be 0 - as such, we do not use this on Windows.
+///
+/// For more information, see [docs](https://docs.rs/sysinfo/latest/sysinfo/struct.System.html#method.available_memory)
+/// and [memory explanation](https://askubuntu.com/questions/867068/what-is-available-memory-while-using-free-command)
+#[cfg(not(target_os = "windows"))]
+pub(crate) fn get_cache_usage(sys: &System) -> MemData {
+    let mem_used = sys.available_memory().saturating_sub(sys.free_memory());
+    let mem_total = sys.total_memory();
+
+    MemData {
+        total_bytes: mem_total,
+        used_bytes: mem_used,
+    }
+}

src/new_data_collection/sources/sysinfo/mod.rs

@@ -1 +1,4 @@
 pub mod temperature;
+pub mod cpu;
+pub mod disk;
+pub mod memory;

src/new_data_collection/sources/windows/mod.rs

@@ -1 +0,0 @@
-pub mod processes;

src/new_data_collection/sources/windows/processes.rs

@@ -1,3 +0,0 @@
-/// A Windows process ID.
-#[cfg(target_family = "windows")]
-pub type Pid = usize;