From 4e662561c23819a33267e85a64940ed9c3e3b47e Mon Sep 17 00:00:00 2001
From: Justin Yang <linuxjustin@gmail.com>
Date: Sat, 2 Sep 2023 22:57:30 +0800
Subject: [PATCH] mem: Add support for NetBSD

---
 mem/mem_netbsd.go | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 mem/mem_netbsd.go

diff --git a/mem/mem_netbsd.go b/mem/mem_netbsd.go
new file mode 100644
index 0000000..fb6fafe
--- /dev/null
+++ b/mem/mem_netbsd.go
@@ -0,0 +1,87 @@
+//go:build netbsd
+// +build netbsd
+
+package mem
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"errors"
+	"fmt"
+
+	"github.com/shirou/gopsutil/v3/internal/common"
+	"golang.org/x/sys/unix"
+)
+
+func GetPageSize() (uint64, error) {
+	return GetPageSizeWithContext(context.Background())
+}
+
+func GetPageSizeWithContext(ctx context.Context) (uint64, error) {
+	uvmexp, err := unix.SysctlUvmexp("vm.uvmexp2")
+	if err != nil {
+		return 0, err
+	}
+	return uint64(uvmexp.Pagesize), nil
+}
+
+func VirtualMemory() (*VirtualMemoryStat, error) {
+	return VirtualMemoryWithContext(context.Background())
+}
+
+func VirtualMemoryWithContext(ctx context.Context) (*VirtualMemoryStat, error) {
+	uvmexp, err := unix.SysctlUvmexp("vm.uvmexp2")
+	if err != nil {
+		return nil, err
+	}
+	p := uint64(uvmexp.Pagesize)
+
+	ret := &VirtualMemoryStat{
+		Total:    uint64(uvmexp.Npages) * p,
+		Free:     uint64(uvmexp.Free) * p,
+		Active:   uint64(uvmexp.Active) * p,
+		Inactive: uint64(uvmexp.Inactive) * p,
+		Cached:   0, // not available
+		Wired:    uint64(uvmexp.Wired) * p,
+	}
+
+	ret.Available = ret.Inactive + ret.Cached + ret.Free
+	ret.Used = ret.Total - ret.Available
+	ret.UsedPercent = float64(ret.Used) / float64(ret.Total) * 100.0
+
+    // Get buffers from vm.bufmem sysctl
+	ret.Buffers = unix.SysctlUint64("vm.bufmem")
+
+	return ret, nil
+}
+
+// Return swapctl summary info
+func SwapMemory() (*SwapMemoryStat, error) {
+	return SwapMemoryWithContext(context.Background())
+}
+
+func SwapMemoryWithContext(ctx context.Context) (*SwapMemoryStat, error) {
+	out, err := invoke.CommandWithContext(ctx, "swapctl", "-sk")
+	if err != nil {
+		return &SwapMemoryStat{}, nil
+	}
+
+	line := string(out)
+	var total, used, free uint64
+
+	_, err = fmt.Sscanf(line,
+		"total: %d 1K-blocks allocated, %d used, %d available",
+		&total, &used, &free)
+	if err != nil {
+		return nil, errors.New("failed to parse swapctl output")
+	}
+
+	percent := float64(used) / float64(total) * 100
+	return &SwapMemoryStat{
+		Total:       total * 1024,
+		Used:        used * 1024,
+		Free:        free * 1024,
+		UsedPercent: percent,
+	}, nil
+}