Adding upstream version 2.52.6.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/gopsutil/mem/mem_darwin_nocgo.go

@@ -0,0 +1,93 @@
+//go:build darwin && !cgo
+
+package mem
+
+import (
+	"context"
+	"os/exec"
+	"strconv"
+	"strings"
+
+	"golang.org/x/sys/unix"
+)
+
+// Runs vm_stat and returns Free and inactive pages
+func getVMStat(vms *VirtualMemoryStat) error {
+	vm_stat, err := exec.LookPath("vm_stat")
+	if err != nil {
+		return err
+	}
+	out, err := invoke.Command(vm_stat)
+	if err != nil {
+		return err
+	}
+	return parseVMStat(string(out), vms)
+}
+
+func parseVMStat(out string, vms *VirtualMemoryStat) error {
+	var err error
+
+	lines := strings.Split(out, "\n")
+	pagesize := uint64(unix.Getpagesize())
+	for _, line := range lines {
+		fields := strings.Split(line, ":")
+		if len(fields) < 2 {
+			continue
+		}
+		key := strings.TrimSpace(fields[0])
+		value := strings.Trim(fields[1], " .")
+		switch key {
+		case "Pages free":
+			free, e := strconv.ParseUint(value, 10, 64)
+			if e != nil {
+				err = e
+			}
+			vms.Free = free * pagesize
+		case "Pages inactive":
+			inactive, e := strconv.ParseUint(value, 10, 64)
+			if e != nil {
+				err = e
+			}
+			vms.Inactive = inactive * pagesize
+		case "Pages active":
+			active, e := strconv.ParseUint(value, 10, 64)
+			if e != nil {
+				err = e
+			}
+			vms.Active = active * pagesize
+		case "Pages wired down":
+			wired, e := strconv.ParseUint(value, 10, 64)
+			if e != nil {
+				err = e
+			}
+			vms.Wired = wired * pagesize
+		}
+	}
+	return err
+}
+
+// VirtualMemory returns VirtualmemoryStat.
+func VirtualMemory() (*VirtualMemoryStat, error) {
+	return VirtualMemoryWithContext(context.Background())
+}
+
+func VirtualMemoryWithContext(ctx context.Context) (*VirtualMemoryStat, error) {
+	ret := &VirtualMemoryStat{}
+
+	total, err := getHwMemsize()
+	if err != nil {
+		return nil, err
+	}
+	err = getVMStat(ret)
+	if err != nil {
+		return nil, err
+	}
+
+	ret.Available = ret.Free + ret.Inactive
+	ret.Total = total
+
+	ret.Used = ret.Total - ret.Available
+	ret.UsedPercent = 100 * float64(ret.Used) / float64(ret.Total)
+
+	return ret, nil
+}