feat: create standalone native fnOS repository

app-src/internal/sysinfo/sysinfo_linux.go

@@ -0,0 +1,76 @@
+//go:build linux
+
+package sysinfo
+
+import (
+	"os"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+func readPlatform() (Stats, CPUSample) {
+	var (
+		stats  Stats
+		sample CPUSample
+	)
+	if raw, err := os.ReadFile("/proc/stat"); err == nil {
+		sample = parseProcStat(string(raw))
+	}
+	if raw, err := os.ReadFile("/proc/meminfo"); err == nil {
+		stats.MemTotalBytes, stats.MemUsedBytes = parseMemInfo(string(raw))
+	}
+	stats.DiskTotalBytes, stats.DiskUsedBytes = diskUsage("/")
+	return stats, sample
+}
+
+// LoadAvg 返回 1 / 5 / 15 分钟平均负载；读取失败返回 nil
+func LoadAvg() []float64 {
+	raw, err := os.ReadFile("/proc/loadavg")
+	if err != nil {
+		return nil
+	}
+	fields := strings.Fields(string(raw))
+	if len(fields) < 3 {
+		return nil
+	}
+	values := make([]float64, 0, 3)
+	for _, field := range fields[:3] {
+		value, err := strconv.ParseFloat(field, 64)
+		if err != nil {
+			return nil
+		}
+		values = append(values, value)
+	}
+	return values
+}
+
+// UptimeSeconds 返回系统运行秒数（/proc/uptime）
+func UptimeSeconds() uint64 {
+	raw, err := os.ReadFile("/proc/uptime")
+	if err != nil {
+		return 0
+	}
+	fields := strings.Fields(string(raw))
+	if len(fields) == 0 {
+		return 0
+	}
+	seconds, err := strconv.ParseFloat(fields[0], 64)
+	if err != nil || seconds < 0 {
+		return 0
+	}
+	return uint64(seconds)
+}
+
+func diskUsage(path string) (total, used uint64) {
+	var stat syscall.Statfs_t
+	if err := syscall.Statfs(path, &stat); err != nil {
+		return 0, 0
+	}
+	total = stat.Blocks * uint64(stat.Bsize)
+	free := stat.Bavail * uint64(stat.Bsize)
+	if free > total {
+		return total, 0
+	}
+	return total, total - free
+}