Add CPUFreqCollectorCpuinfo

a metric collector to measure the current frequency of the CPUs
as obtained from /proc/cpuinfo
Only measure on the first hyperthread

collectors/cpufreqCpuinfoMetric.go

@@ -0,0 +1,176 @@
+package collectors
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	lp "github.com/influxdata/line-protocol"
+)
+
+//
+// CPUFreqCollector
+// a metric collector to measure the current frequency of the CPUs
+// as obtained from /proc/cpuinfo
+// Only measure on the first hyperthread
+//
+type CPUFreqCpuInfoCollectorTopology struct {
+	processor     string // logical processor number (continuous, starting at 0)
+	coreID        string // socket local core ID
+	physicalID    string // socket / package ID
+	numPhysicalID string // number of  sockets / packages
+	isHT          bool
+	numNonHT      string // number of non hyperthreading processors
+	tagSet        map[string]string
+}
+
+type CPUFreqCpuInfoCollector struct {
+	MetricCollector
+	topology []CPUFreqCpuInfoCollectorTopology
+}
+
+func (m *CPUFreqCpuInfoCollector) Init(config []byte) error {
+	m.name = "CPUFreqCpuInfoCollector"
+
+	const cpuInfoFile = "/proc/cpuinfo"
+	file, err := os.Open(cpuInfoFile)
+	if err != nil {
+		return fmt.Errorf("Failed to open '%s': %v", cpuInfoFile, err)
+	}
+	defer file.Close()
+
+	// Collect topology information from file cpuinfo
+	foundFreq := false
+	processor := ""
+	numNonHT := 0
+	coreID := ""
+	physicalID := ""
+	maxPhysicalID := 0
+	m.topology = make([]CPUFreqCpuInfoCollectorTopology, 0)
+	coreSeenBefore := make(map[string]bool)
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		lineSplit := strings.Split(scanner.Text(), ":")
+		if len(lineSplit) == 2 {
+			key := strings.TrimSpace(lineSplit[0])
+			value := strings.TrimSpace(lineSplit[1])
+			switch key {
+			case "cpu MHz":
+				// frequency
+				foundFreq = true
+			case "processor":
+				processor = value
+			case "core id":
+				coreID = value
+			case "physical id":
+				physicalID = value
+			}
+		}
+
+		// were all topology information collected?
+		if foundFreq &&
+			len(processor) > 0 &&
+			len(coreID) > 0 &&
+			len(physicalID) > 0 {
+
+			globalID := physicalID + ":" + coreID
+			isHT := coreSeenBefore[globalID]
+			coreSeenBefore[globalID] = true
+			if !isHT {
+				// increase number on non hyper thread cores
+				numNonHT++
+
+				// increase maximun socket / package ID, when required
+				physicalIDInt, err := strconv.Atoi(physicalID)
+				if err != nil {
+					return fmt.Errorf("Failed to convert physical id to int: %v", err)
+				}
+				if physicalIDInt > maxPhysicalID {
+					maxPhysicalID = physicalIDInt
+				}
+			}
+
+			// store collected topology information
+			m.topology = append(
+				m.topology,
+				CPUFreqCpuInfoCollectorTopology{
+					processor:  processor,
+					coreID:     coreID,
+					physicalID: physicalID,
+					isHT:       isHT,
+				})
+
+			// reset topology information
+			foundFreq = false
+			processor = ""
+			coreID = ""
+			physicalID = ""
+		}
+	}
+
+	numPhysicalID := fmt.Sprint(maxPhysicalID + 1)
+	numNonHTString := fmt.Sprint(numNonHT)
+	for i := range m.topology {
+		t := &m.topology[i]
+		t.numPhysicalID = numPhysicalID
+		t.numNonHT = numNonHTString
+		t.tagSet = map[string]string{
+			"type":        "cpu",
+			"type-id":     t.processor,
+			"num_core":    t.numNonHT,
+			"package_id":  t.physicalID,
+			"num_package": t.numPhysicalID,
+		}
+	}
+
+	m.init = true
+	return nil
+}
+
+func (m *CPUFreqCpuInfoCollector) Read(interval time.Duration, out *[]lp.MutableMetric) {
+	if !m.init {
+		return
+	}
+	const cpuInfoFile = "/proc/cpuinfo"
+	file, err := os.Open(cpuInfoFile)
+	if err != nil {
+		log.Printf("Failed to open '%s': %v", cpuInfoFile, err)
+		return
+	}
+	defer file.Close()
+
+	processorCounter := 0
+	now := time.Now()
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		lineSplit := strings.Split(scanner.Text(), ":")
+		if len(lineSplit) == 2 {
+			key := strings.TrimSpace(lineSplit[0])
+
+			// frequency
+			if key == "cpu MHz" {
+				t := &m.topology[processorCounter]
+				if !t.isHT {
+					value, err := strconv.ParseFloat(strings.TrimSpace(lineSplit[1]), 64)
+					if err != nil {
+						log.Printf("Failed to convert cpu MHz to float: %v", err)
+						return
+					}
+					y, err := lp.New("cpufreq", t.tagSet, map[string]interface{}{"value": value}, now)
+					if err == nil {
+						*out = append(*out, y)
+					}
+				}
+				processorCounter++
+			}
+		}
+	}
+}
+
+func (m *CPUFreqCpuInfoCollector) Close() {
+	m.init = false
+}