CPU History, CPU Utilization

3 files changed, 252 insertions, 0 deletions

diff --git a/util/sys/sys_darwin.go b/util/sys/sys_darwin.go
index 3f5b2072..6ecc78c0 100644
--- a/util/sys/sys_darwin.go
+++ b/util/sys/sys_darwin.go
@@ -4,7 +4,12 @@
 package sys
 
 import (
+	"encoding/binary"
+	"fmt"
+	"sync"
+
 	"github.com/shirou/gopsutil/v4/net"
+	"golang.org/x/sys/unix"
 )
 
 func GetTCPCount() (int, error) {
@@ -22,3 +27,69 @@ func GetUDPCount() (int, error) {
 	}
 	return len(stats), nil
 }
+
+// --- CPU Utilization (macOS native) ---
+
+// sysctl kern.cp_time returns an array of 5 longs: user, nice, sys, idle, intr.
+// We compute utilization deltas without cgo.
+var (
+	cpuMu       sync.Mutex
+	lastTotals  [5]uint64
+	hasLastCPUT bool
+)
+
+func CPUPercentRaw() (float64, error) {
+	raw, err := unix.SysctlRaw("kern.cp_time")
+	if err != nil {
+		return 0, err
+	}
+	// Expect either 5*8 bytes (uint64) or 5*4 bytes (uint32)
+	var out [5]uint64
+	switch len(raw) {
+	case 5 * 8:
+		for i := 0; i < 5; i++ {
+			out[i] = binary.LittleEndian.Uint64(raw[i*8 : (i+1)*8])
+		}
+	case 5 * 4:
+		for i := 0; i < 5; i++ {
+			out[i] = uint64(binary.LittleEndian.Uint32(raw[i*4 : (i+1)*4]))
+		}
+	default:
+		return 0, fmt.Errorf("unexpected kern.cp_time size: %d", len(raw))
+	}
+
+	// user, nice, sys, idle, intr
+	user := out[0]
+	nice := out[1]
+	sysv := out[2]
+	idle := out[3]
+	intr := out[4]
+
+	cpuMu.Lock()
+	defer cpuMu.Unlock()
+
+	if !hasLastCPUT {
+		lastTotals = out
+		hasLastCPUT = true
+		return 0, nil
+	}
+
+	dUser := user - lastTotals[0]
+	dNice := nice - lastTotals[1]
+	dSys := sysv - lastTotals[2]
+	dIdle := idle - lastTotals[3]
+	dIntr := intr - lastTotals[4]
+
+	lastTotals = out
+
+	totald := dUser + dNice + dSys + dIdle + dIntr
+	if totald == 0 {
+		return 0, nil
+	}
+	busy := totald - dIdle
+	pct := float64(busy) / float64(totald) * 100.0
+	if pct > 100 {
+		pct = 100
+	}
+	return pct, nil
+}
diff --git a/util/sys/sys_linux.go b/util/sys/sys_linux.go
index d4e6e8ae..8a494d62 100644
--- a/util/sys/sys_linux.go
+++ b/util/sys/sys_linux.go
@@ -4,10 +4,14 @@
 package sys
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
 	"io"
 	"os"
+	"strconv"
+	"strings"
+	"sync"
 )
 
 func getLinesNum(filename string) (int, error) {
@@ -79,3 +83,99 @@ func safeGetLinesNum(path string) (int, error) {
 	}
 	return getLinesNum(path)
 }
+
+// --- CPU Utilization (Linux native) ---
+
+var (
+	cpuMu       sync.Mutex
+	lastTotal   uint64
+	lastIdleAll uint64
+	hasLast     bool
+)
+
+// CPUPercentRaw returns instantaneous total CPU utilization by reading /proc/stat.
+// First call initializes and returns 0; subsequent calls return busy/total * 100.
+func CPUPercentRaw() (float64, error) {
+	f, err := os.Open("/proc/stat")
+	if err != nil {
+		return 0, err
+	}
+	defer f.Close()
+
+	rd := bufio.NewReader(f)
+	line, err := rd.ReadString('\n')
+	if err != nil && err != io.EOF {
+		return 0, err
+	}
+	// Expect line like: cpu  user nice system idle iowait irq softirq steal guest guest_nice
+	fields := strings.Fields(line)
+	if len(fields) < 5 || fields[0] != "cpu" {
+		return 0, fmt.Errorf("unexpected /proc/stat format")
+	}
+
+	var nums []uint64
+	for i := 1; i < len(fields); i++ {
+		v, err := strconv.ParseUint(fields[i], 10, 64)
+		if err != nil {
+			break
+		}
+		nums = append(nums, v)
+	}
+	if len(nums) < 4 { // need at least user,nice,system,idle
+		return 0, fmt.Errorf("insufficient cpu fields")
+	}
+
+	// Conform with standard Linux CPU accounting
+	var user, nice, system, idle, iowait, irq, softirq, steal uint64
+	user = nums[0]
+	if len(nums) > 1 {
+		nice = nums[1]
+	}
+	if len(nums) > 2 {
+		system = nums[2]
+	}
+	if len(nums) > 3 {
+		idle = nums[3]
+	}
+	if len(nums) > 4 {
+		iowait = nums[4]
+	}
+	if len(nums) > 5 {
+		irq = nums[5]
+	}
+	if len(nums) > 6 {
+		softirq = nums[6]
+	}
+	if len(nums) > 7 {
+		steal = nums[7]
+	}
+
+	idleAll := idle + iowait
+	nonIdle := user + nice + system + irq + softirq + steal
+	total := idleAll + nonIdle
+
+	cpuMu.Lock()
+	defer cpuMu.Unlock()
+
+	if !hasLast {
+		lastTotal = total
+		lastIdleAll = idleAll
+		hasLast = true
+		return 0, nil
+	}
+
+	totald := total - lastTotal
+	idled := idleAll - lastIdleAll
+	lastTotal = total
+	lastIdleAll = idleAll
+
+	if totald == 0 {
+		return 0, nil
+	}
+	busy := totald - idled
+	pct := float64(busy) / float64(totald) * 100.0
+	if pct > 100 {
+		pct = 100
+	}
+	return pct, nil
+}
diff --git a/util/sys/sys_windows.go b/util/sys/sys_windows.go
index fd51d470..f3eae076 100644
--- a/util/sys/sys_windows.go
+++ b/util/sys/sys_windows.go
@@ -5,6 +5,9 @@ package sys
 
 import (
 	"errors"
+	"sync"
+	"syscall"
+	"unsafe"
 
 	"github.com/shirou/gopsutil/v4/net"
 )
@@ -28,3 +31,81 @@ func GetTCPCount() (int, error) {
 func GetUDPCount() (int, error) {
 	return GetConnectionCount("udp")
 }
+
+// --- CPU Utilization (Windows native) ---
+
+var (
+	modKernel32        = syscall.NewLazyDLL("kernel32.dll")
+	procGetSystemTimes = modKernel32.NewProc("GetSystemTimes")
+
+	cpuMu      sync.Mutex
+	lastIdle   uint64
+	lastKernel uint64
+	lastUser   uint64
+	hasLast    bool
+)
+
+type filetime struct {
+	LowDateTime  uint32
+	HighDateTime uint32
+}
+
+func ftToUint64(ft filetime) uint64 {
+	return (uint64(ft.HighDateTime) << 32) | uint64(ft.LowDateTime)
+}
+
+// CPUPercentRaw returns the instantaneous total CPU utilization percentage using
+// Windows GetSystemTimes across all logical processors. The first call returns 0
+// as it initializes the baseline. Subsequent calls compute deltas.
+func CPUPercentRaw() (float64, error) {
+	var idleFT, kernelFT, userFT filetime
+	r1, _, e1 := procGetSystemTimes.Call(
+		uintptr(unsafe.Pointer(&idleFT)),
+		uintptr(unsafe.Pointer(&kernelFT)),
+		uintptr(unsafe.Pointer(&userFT)),
+	)
+	if r1 == 0 { // failure
+		if e1 != nil {
+			return 0, e1
+		}
+		return 0, syscall.GetLastError()
+	}
+
+	idle := ftToUint64(idleFT)
+	kernel := ftToUint64(kernelFT)
+	user := ftToUint64(userFT)
+
+	cpuMu.Lock()
+	defer cpuMu.Unlock()
+
+	if !hasLast {
+		lastIdle = idle
+		lastKernel = kernel
+		lastUser = user
+		hasLast = true
+		return 0, nil
+	}
+
+	idleDelta := idle - lastIdle
+	kernelDelta := kernel - lastKernel
+	userDelta := user - lastUser
+
+	// Update for next call
+	lastIdle = idle
+	lastKernel = kernel
+	lastUser = user
+
+	total := kernelDelta + userDelta
+	if total == 0 {
+		return 0, nil
+	}
+	// On Windows, kernel time includes idle time; busy = total - idle
+	busy := total - idleDelta
+
+	pct := float64(busy) / float64(total) * 100.0
+	// lower bound not needed; ratios of uint64 are non-negative
+	if pct > 100 {
+		pct = 100
+	}
+	return pct, nil
+}