Merge pull request #251 from xbjfk/free-windows

free: add Windows support

Cargo.toml

@@ -60,6 +60,7 @@ chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
 walkdir = "2.5.0"
 prettytable-rs = "0.10.0"
 nix = { version = "0.29", default-features = false, features = ["process"] }
+windows = { version = "0.58.0" }
 
 [dependencies]
 clap = { workspace = true }

src/uu/free/Cargo.toml

@@ -18,6 +18,7 @@ clap = { workspace = true }
 bytesize = { workspace = true }
 
 sysinfo = { workspace = true }
+windows = { workspace = true, features = ["Wdk_System_SystemInformation", "Win32_System_ProcessStatus", "Win32_System_SystemInformation"] }
 
 [lib]
 path = "src/free.rs"

src/uu/free/src/free.rs

@@ -3,6 +3,9 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
+#[cfg(target_os = "windows")]
+mod windows_util;
+
 use bytesize::{ByteSize, GB, GIB, KB, KIB, MB, MIB, PB, PIB, TB, TIB};
 use clap::{arg, crate_version, ArgAction, ArgGroup, ArgMatches, Command};
 use std::env;
@@ -118,10 +121,42 @@ fn parse_meminfo() -> Result<MemInfo, Box<dyn std::error::Error>> {
     Ok(mem_info)
 }
 
-// TODO: implement function
 #[cfg(target_os = "windows")]
 fn parse_meminfo() -> Result<MemInfo, Box<dyn std::error::Error>> {
-    Ok(MemInfo::default())
+    use std::mem::size_of;
+    use windows::Win32::System::{
+        ProcessStatus::{GetPerformanceInfo, PERFORMANCE_INFORMATION},
+        SystemInformation::{GlobalMemoryStatusEx, MEMORYSTATUSEX},
+    };
+
+    let (pagefile_used, pagefile_total) = windows_util::get_pagefile_usage()?;
+
+    let mut status = MEMORYSTATUSEX {
+        dwLength: size_of::<MEMORYSTATUSEX>() as u32,
+        ..Default::default()
+    };
+    unsafe { GlobalMemoryStatusEx(&mut status)? }
+
+    let mut perf_info = PERFORMANCE_INFORMATION {
+        cb: size_of::<PERFORMANCE_INFORMATION>() as u32,
+        ..Default::default()
+    };
+    unsafe { GetPerformanceInfo(&mut perf_info, perf_info.cb)? }
+
+    let mem_info = MemInfo {
+        total: status.ullTotalPhys / 1024,
+        free: (status.ullAvailPhys - (perf_info.SystemCache * perf_info.PageSize) as u64) / 1024,
+        available: status.ullAvailPhys / 1024,
+        cached: (perf_info.SystemCache * perf_info.PageSize) as u64 / 1024,
+        swap_total: (pagefile_total as u64 * perf_info.PageSize as u64) / 1024,
+        swap_free: ((pagefile_total - pagefile_used) as u64 * perf_info.PageSize as u64) / 1024,
+        swap_used: (pagefile_used as u64 * perf_info.PageSize as u64) / 1024,
+        commit_limit: (perf_info.CommitLimit * perf_info.PageSize) as u64 / 1024,
+        committed: (perf_info.CommitTotal * perf_info.PageSize) as u64 / 1024,
+        ..Default::default()
+    };
+
+    Ok(mem_info)
 }
 
 // print total - used - free combo that is used for everything except memory for now

src/uu/free/src/windows_util.rs

@@ -0,0 +1,74 @@
+use std::ffi::c_void;
+
+use windows::{
+    core::Result,
+    Wdk::System::SystemInformation::{NtQuerySystemInformation, SYSTEM_INFORMATION_CLASS},
+    Win32::Foundation::{STATUS_INFO_LENGTH_MISMATCH, STATUS_SUCCESS, UNICODE_STRING},
+};
+
+#[repr(C)]
+#[derive(Default, Debug)]
+#[allow(non_snake_case)]
+struct SYSTEM_PAGEFILE_INFORMATION {
+    NextEntryOffset: u32,
+    TotalSize: u32,
+    TotalInUse: u32,
+    PeakUsage: u32,
+    PageFileName: UNICODE_STRING,
+}
+
+/// Get the usage and total size of all page files.
+pub(crate) fn get_pagefile_usage() -> Result<(u32, u32)> {
+    let mut buf: Vec<u8> = Vec::new();
+
+    let mut return_len: u32 = 0;
+
+    loop {
+        let status = unsafe {
+            NtQuerySystemInformation(
+                // SystemPageFileInformation
+                SYSTEM_INFORMATION_CLASS(0x12),
+                buf.as_mut_ptr() as *mut c_void,
+                buf.len() as u32,
+                &mut return_len,
+            )
+        };
+
+        debug_assert!(buf.len() <= return_len as usize);
+
+        if status == STATUS_INFO_LENGTH_MISMATCH {
+            debug_assert!(return_len > buf.len() as u32);
+            buf.resize(return_len as usize, 0);
+            continue;
+        } else if status == STATUS_SUCCESS {
+            debug_assert!(return_len == buf.len() as u32);
+            break;
+        } else {
+            return Err(status.into());
+        }
+    }
+
+    let mut usage = 0;
+    let mut total = 0;
+
+    if return_len > 0 {
+        let ptr = buf.as_ptr();
+        let mut offset = 0;
+        loop {
+            let ptr_offset =
+                unsafe { ptr.byte_offset(offset) } as *const SYSTEM_PAGEFILE_INFORMATION;
+            let record = unsafe { std::ptr::read(ptr_offset) };
+
+            usage += record.TotalInUse;
+            total += record.TotalSize;
+
+            offset = record.NextEntryOffset as isize;
+
+            if offset == 0 {
+                break;
+            }
+        }
+    }
+
+    Ok((usage, total))
+}