初始化提交

mengyamonitor-backend/cpu.go

@@ -0,0 +1,182 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// readCPUUsage 读取CPU整体使用率
+func readCPUUsage() (float64, error) {
+	idle1, total1, err := readCPUTicks()
+	if err != nil {
+		return 0, err
+	}
+	time.Sleep(250 * time.Millisecond)
+	idle2, total2, err := readCPUTicks()
+	if err != nil {
+		return 0, err
+	}
+	if total2 == total1 {
+		return 0, errors.New("cpu totals unchanged")
+	}
+	idleDelta := float64(idle2 - idle1)
+	totalDelta := float64(total2 - total1)
+	usage := (1.0 - idleDelta/totalDelta) * 100
+	if usage < 0 {
+		usage = 0
+	}
+	return usage, nil
+}
+
+// readCPUTicks 读取CPU的idle和total ticks
+func readCPUTicks() (idle, total uint64, err error) {
+	f, err := os.Open("/proc/stat")
+	if err != nil {
+		return 0, 0, err
+	}
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+	if !scanner.Scan() {
+		return 0, 0, errors.New("failed to scan /proc/stat")
+	}
+	fields := strings.Fields(scanner.Text())
+	if len(fields) < 5 {
+		return 0, 0, errors.New("unexpected /proc/stat format")
+	}
+	// fields[0] is "cpu"
+	var vals []uint64
+	for _, f := range fields[1:] {
+		v, err := strconv.ParseUint(f, 10, 64)
+		if err != nil {
+			return 0, 0, err
+		}
+		vals = append(vals, v)
+	}
+	for _, v := range vals {
+		total += v
+	}
+	if len(vals) > 3 {
+		idle = vals[3] // idle time
+		// 注意：不包含 iowait，因为 iowait 不算真正的空闲时间
+		// 如果系统有 iowait，它会在 total 中，但不应该算作 idle
+	}
+	return idle, total, nil
+}
+
+// readPerCoreUsage 读取每个CPU核心的使用率
+func readPerCoreUsage() []CoreUsage {
+	coreUsages := []CoreUsage{}
+
+	// 第一次读取
+	cores1 := readPerCoreTicks()
+	time.Sleep(100 * time.Millisecond) // 减少到100ms
+	// 第二次读取
+	cores2 := readPerCoreTicks()
+
+	for i := 0; i < len(cores1) && i < len(cores2); i++ {
+		idle1, total1 := cores1[i][0], cores1[i][1]
+		idle2, total2 := cores2[i][0], cores2[i][1]
+
+		if total2 == total1 {
+			continue
+		}
+
+		idleDelta := float64(idle2 - idle1)
+		totalDelta := float64(total2 - total1)
+		usage := (1.0 - idleDelta/totalDelta) * 100
+		if usage < 0 {
+			usage = 0
+		}
+
+		coreUsages = append(coreUsages, CoreUsage{
+			Core:    i,
+			Percent: round(usage, 1),
+		})
+	}
+
+	return coreUsages
+}
+
+// readPerCoreTicks 读取每个CPU核心的ticks
+func readPerCoreTicks() [][2]uint64 {
+	var result [][2]uint64
+
+	f, err := os.Open("/proc/stat")
+	if err != nil {
+		return result
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if !strings.HasPrefix(line, "cpu") {
+			continue
+		}
+		if strings.HasPrefix(line, "cpu ") {
+			continue // 跳过总的cpu行
+		}
+
+		fields := strings.Fields(line)
+		if len(fields) < 5 {
+			continue
+		}
+
+		var vals []uint64
+		for _, f := range fields[1:] {
+			v, err := strconv.ParseUint(f, 10, 64)
+			if err != nil {
+				break
+			}
+			vals = append(vals, v)
+		}
+
+		if len(vals) < 5 {
+			continue
+		}
+
+		var total, idle uint64
+		for _, v := range vals {
+			total += v
+		}
+		idle = vals[3] // idle time only, not including iowait
+
+		result = append(result, [2]uint64{idle, total})
+	}
+
+	return result
+}
+
+// readCPUTemperature 读取CPU温度
+func readCPUTemperature() float64 {
+	// 尝试从常见位置读取温度
+	paths := []string{
+		"/sys/class/thermal/thermal_zone0/temp",
+		"/sys/class/hwmon/hwmon0/temp1_input",
+		"/sys/class/hwmon/hwmon1/temp1_input",
+	}
+	for _, path := range paths {
+		if temp := readTempFromFile(path); temp > 0 {
+			return temp
+		}
+	}
+	return 0
+}
+
+// readLoadAverages 读取系统负载平均值
+func readLoadAverages() []float64 {
+	line := readFirstLine("/proc/loadavg")
+	fields := strings.Fields(line)
+	res := make([]float64, 0, 3)
+	for i := 0; i < len(fields) && i < 3; i++ {
+		v, err := strconv.ParseFloat(fields[i], 64)
+		if err == nil {
+			res = append(res, v)
+		}
+	}
+	return res
+}