Implement support for FreeBSD (#766)

* WIP FreeBSD support

* Implement get_cpu_data_list for FreeBSD

* Implement disks for FreeBSD

It doesn't work though as sysinfo doesn't make the device name available.

* Use libxo to read process cpu info on FreeBSD

* Populate get_io_usage with libxo too

Actual I/O stats still aren't populated though as there's not an
easy source for them.

* Share more processes code between macos and freebsd

* Extract function for deserializing libxo output on FreeBSD

* Implement filtering of disks in FreeBSD

* Clean up memory data collection

* Update module docs

1 files changed, 9 insertions, 154 deletions

diff --git a/src/app/data_harvester/memory/general.rs b/src/app/data_harvester/memory/general.rs
index 2afe119f..45fb5fdd 100644
--- a/src/app/data_harvester/memory/general.rs
+++ b/src/app/data_harvester/memory/general.rs
@@ -1,4 +1,12 @@
-//! Data collection for memory via heim.
+cfg_if::cfg_if! {
+    if #[cfg(any(target_os = "linux", target_os = "macos", target_os = "windows"))] {
+        pub mod heim;
+        pub use self::heim::*;
+    } else if #[cfg(target_os = "freebsd")] {
+        pub mod sysinfo;
+        pub use self::sysinfo::*;
+    }
+}
 
 #[derive(Debug, Clone, Default)]
 pub struct MemHarvest {
@@ -6,156 +14,3 @@ pub struct MemHarvest {
     pub mem_used_in_kib: u64,
     pub use_percent: Option<f64>,
 }
-
-pub async fn get_mem_data(
-    actually_get: bool,
-) -> (
-    crate::utils::error::Result<Option<MemHarvest>>,
-    crate::utils::error::Result<Option<MemHarvest>>,
-) {
-    use futures::join;
-
-    if !actually_get {
-        (Ok(None), Ok(None))
-    } else {
-        join!(get_ram_data(), get_swap_data())
-    }
-}
-
-pub async fn get_ram_data() -> crate::utils::error::Result<Option<MemHarvest>> {
-    let (mem_total_in_kib, mem_used_in_kib) = {
-        #[cfg(target_os = "linux")]
-        {
-            use smol::fs::read_to_string;
-            let meminfo = read_to_string("/proc/meminfo").await?;
-
-            // All values are in KiB by default.
-            let mut mem_total = 0;
-            let mut cached = 0;
-            let mut s_reclaimable = 0;
-            let mut shmem = 0;
-            let mut buffers = 0;
-            let mut mem_free = 0;
-
-            let mut keys_read: u8 = 0;
-            const TOTAL_KEYS_NEEDED: u8 = 6;
-
-            for line in meminfo.lines() {
-                if let Some((label, value)) = line.split_once(':') {
-                    let to_write = match label {
-                        "MemTotal" => &mut mem_total,
-                        "MemFree" => &mut mem_free,
-                        "Buffers" => &mut buffers,
-                        "Cached" => &mut cached,
-                        "Shmem" => &mut shmem,
-                        "SReclaimable" => &mut s_reclaimable,
-                        _ => {
-                            continue;
-                        }
-                    };
-
-                    if let Some((number, _unit)) = value.trim_start().split_once(' ') {
-                        // Parse the value, remember it's in KiB!
-                        if let Ok(number) = number.parse::<u64>() {
-                            *to_write = number;
-
-                            // We only need a few keys, so we can bail early.
-                            keys_read += 1;
-                            if keys_read == TOTAL_KEYS_NEEDED {
-                                break;
-                            }
-                        }
-                    }
-                }
-            }
-
-            // Let's preface this by saying that memory usage calculations are... not straightforward.
-            // There are conflicting implementations everywhere.
-            //
-            // Now that we've added this preface (mainly for future reference), the current implementation below for usage
-            // is based on htop's calculation formula. See
-            // https://github.com/htop-dev/htop/blob/976c6123f41492aaf613b9d172eef1842fb7b0a3/linux/LinuxProcessList.c#L1584
-            // for implementation details as of writing.
-            //
-            // Another implementation, commonly used in other things, is to skip the shmem part of the calculation,
-            // which matches gopsutil and stuff like free.
-
-            let total = mem_total;
-            let cached_mem = cached + s_reclaimable - shmem;
-            let used_diff = mem_free + cached_mem + buffers;
-            let used = if total >= used_diff {
-                total - used_diff
-            } else {
-                total - mem_free
-            };
-
-            (total, used)
-        }
-        #[cfg(target_os = "macos")]
-        {
-            let memory = heim::memory::memory().await?;
-
-            use heim::memory::os::macos::MemoryExt;
-            use heim::units::information::kibibyte;
-            (
-                memory.total().get::<kibibyte>(),
-                memory.active().get::<kibibyte>() + memory.wire().get::<kibibyte>(),
-            )
-        }
-        #[cfg(target_os = "windows")]
-        {
-            let memory = heim::memory::memory().await?;
-
-            use heim::units::information::kibibyte;
-            let mem_total_in_kib = memory.total().get::<kibibyte>();
-            (
-                mem_total_in_kib,
-                mem_total_in_kib - memory.available().get::<kibibyte>(),
-            )
-        }
-    };
-
-    Ok(Some(MemHarvest {
-        mem_total_in_kib,
-        mem_used_in_kib,
-        use_percent: if mem_total_in_kib == 0 {
-            None
-        } else {
-            Some(mem_used_in_kib as f64 / mem_total_in_kib as f64 * 100.0)
-        },
-    }))
-}
-
-pub async fn get_swap_data() -> crate::utils::error::Result<Option<MemHarvest>> {
-    let memory = heim::memory::swap().await?;
-
-    let (mem_total_in_kib, mem_used_in_kib) = {
-        #[cfg(target_os = "linux")]
-        {
-            // Similar story to above - heim parses this information incorrectly as far as I can tell, so kilobytes = kibibytes here.
-            use heim::units::information::kilobyte;
-            (
-                memory.total().get::<kilobyte>(),
-                memory.used().get::<kilobyte>(),
-            )
-        }
-        #[cfg(any(target_os = "windows", target_os = "macos"))]
-        {
-            use heim::units::information::kibibyte;
-            (
-                memory.total().get::<kibibyte>(),
-                memory.used().get::<kibibyte>(),
-            )
-        }
-    };
-
-    Ok(Some(MemHarvest {
-        mem_total_in_kib,
-        mem_used_in_kib,
-        use_percent: if mem_total_in_kib == 0 {
-            None
-        } else {
-            Some(mem_used_in_kib as f64 / mem_total_in_kib as f64 * 100.0)
-        },
-    }))
-}