implement intel power stats

app/cpu/proc/vendor_intel.go

@@ -2,15 +2,18 @@ package proc
 
 import (
 	"fmt"
+	"math"
 	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 )
 
 type IntelReader struct {
-	hwmonDir string
-	driver   string
+	hwmonDir    string
+	driver      string
+	energyState map[string]EnergyState
 }
 
 func NewIntelReader() (*IntelReader, error) {
@@ -76,5 +79,121 @@ func (r *IntelReader) ReadTemperatureSensors() ([]TempSensor, error) {
 }
 
 func (r *IntelReader) ReadPowerSensors() ([]PowerSensor, error) {
-	return []PowerSensor{}, nil
+	return r.readRaplPower(), nil
+}
+
+func (r *IntelReader) readRaplPower() []PowerSensor {
+	powerSensors := []PowerSensor{}
+
+	patterns := []string{
+		"/sys/class/powercap/intel-rapl*/energy_uj",
+		"/sys/class/powercap/intel-rapl/intel-rapl*/energy_uj",
+		"/sys/class/powercap/intel-rapl/intel-rapl*/*/energy_uj",
+		"/sys/class/powercap/intel-rapl:*/energy_uj",
+		"/sys/class/powercap/intel-rapl:*/*/energy_uj",
+	}
+
+	energyInputs := []string{}
+	seen := make(map[string]bool)
+
+	for _, pattern := range patterns {
+		matches, _ := filepath.Glob(pattern)
+
+		for _, match := range matches {
+			realPath, err := filepath.EvalSymlinks(match)
+			if err != nil {
+				realPath = match
+			}
+			if !seen[realPath] {
+				seen[realPath] = true
+				energyInputs = append(energyInputs, realPath)
+			}
+		}
+	}
+
+	if len(energyInputs) == 0 {
+		return powerSensors
+	}
+
+	getLabel := func(inputPath string) string {
+		dir := filepath.Dir(inputPath)
+		if nameBytes, err := os.ReadFile(filepath.Join(dir, "name")); err == nil {
+			return strings.TrimSpace(string(nameBytes))
+		}
+		return filepath.Base(dir)
+	}
+
+	r.calculateEnergyDelta(energyInputs, getLabel, &powerSensors)
+	return powerSensors
+}
+
+func (r *IntelReader) calculateEnergyDelta(inputs []string, getLabel func(string) string, out *[]PowerSensor) {
+	now := time.Now()
+
+	if r.energyState == nil {
+		r.energyState = make(map[string]EnergyState)
+	}
+
+	for _, rawPath := range inputs {
+		key, err := filepath.EvalSymlinks(rawPath)
+		if err != nil {
+			key = filepath.Clean(rawPath)
+		}
+
+		valBytes, err := os.ReadFile(key)
+		if err != nil {
+			continue
+		}
+
+		microJoules, err := strconv.ParseUint(strings.TrimSpace(string(valBytes)), 10, 64)
+		if err != nil {
+			continue
+		}
+
+		prevState, exists := r.energyState[key]
+
+		if !exists {
+			r.energyState[key] = EnergyState{
+				lastEnergy: microJoules,
+				lastTime:   now,
+			}
+			*out = append(*out, PowerSensor{
+				Name:  getLabel(key),
+				Watts: 0.0,
+			})
+			continue
+		}
+
+		timeDiff := now.Sub(prevState.lastTime).Seconds()
+		if timeDiff < 0.05 {
+			continue
+		}
+
+		maxRange := uint64(math.MaxUint64)
+		rangeBytes, err := os.ReadFile(filepath.Join(filepath.Dir(key), "max_energy_range_uj"))
+		if err == nil {
+			if parsedMax, err := strconv.ParseUint(strings.TrimSpace(string(rangeBytes)), 10, 64); err == nil && parsedMax > 0 {
+				maxRange = parsedMax
+			}
+		}
+
+		var energyDiff uint64
+		if microJoules >= prevState.lastEnergy {
+			energyDiff = microJoules - prevState.lastEnergy
+		} else {
+			energyDiff = (maxRange - prevState.lastEnergy) + microJoules
+		}
+
+		watts := (float64(energyDiff) / 1_000_000.0) / timeDiff
+
+		r.energyState[key] = EnergyState{
+			lastEnergy: microJoules,
+			lastTime:   now,
+		}
+
+		*out = append(*out, PowerSensor{
+			Name:  getLabel(key),
+			Watts: watts,
+		})
+	}
 }