Files
gocommon/metric/common.go

162 lines
3.5 KiB
Go

package metric
import (
"crypto/md5"
"encoding/binary"
"encoding/hex"
"encoding/json"
"fmt"
"math"
"os"
"path"
"sort"
"strings"
"sync/atomic"
"repositories.action2quare.com/ayo/gocommon/logger"
)
const metric_value_line_size = 19
type MetricDescription struct {
Key string
Type MetricType
Name string `json:",omitempty"`
Help string `json:",omitempty"`
ConstLabels map[string]string `json:",omitempty"`
}
type Exporter interface {
RegisterMetric(*MetricDescription)
UpdateMetric(string, float64)
Shutdown()
}
type MetricWriter interface {
Add(int64)
Set(int64)
}
type metric_empty struct{}
func (mw *metric_empty) Set(int64) {}
func (mw *metric_empty) Add(int64) {}
var MetricWriterNil = MetricWriter(&metric_empty{})
type metric_int64 struct {
valptr *int64
buff [metric_value_line_size]byte
}
func (mw *metric_int64) printOut() {
binary.LittleEndian.PutUint64(mw.buff[9:], math.Float64bits(float64(atomic.LoadInt64(mw.valptr))))
os.Stdout.Write(mw.buff[:])
}
func (mw *metric_int64) Set(newval int64) {
atomic.StoreInt64(mw.valptr, newval)
mw.printOut()
}
func (mw *metric_int64) Add(inc int64) {
atomic.AddInt64(mw.valptr, inc)
mw.printOut()
}
func NewMetric(mt MetricType, name string, help string, constLabels map[string]string) (writer MetricWriter) {
if !metricEnabled {
return MetricWriterNil
}
var disorder []struct {
k string
v string
}
for k, v := range constLabels {
disorder = append(disorder, struct {
k string
v string
}{k: strings.ToLower(k), v: strings.ToLower(v)})
}
sort.Slice(disorder, func(i, j int) bool {
return disorder[i].k < disorder[j].k
})
hash := md5.New()
hash.Write([]byte(strings.ToLower(name)))
for _, d := range disorder {
hash.Write([]byte(d.k))
hash.Write([]byte(d.v))
}
key := hex.EncodeToString(hash.Sum(nil))[:metric_key_size]
temp, _ := json.Marshal(MetricDescription{
Key: key,
Type: mt,
Name: name,
Help: help,
ConstLabels: constLabels,
})
impl := &metric_int64{
valptr: new(int64),
}
impl.buff[0] = METRIC_HEAD_INLINE
impl.buff[17] = METRIC_TAIL_INLINE
impl.buff[18] = '\n'
copy(impl.buff[1:], []byte(key))
output := append([]byte{METRIC_HEAD_INLINE}, temp...)
output = append(output, METRIC_TAIL_INLINE, '\n')
os.Stdout.Write(output)
// writer
return impl
}
func ReadMetricValue(line []byte) (string, float64) {
if len(line) < 16 {
return "", 0
}
key := string(line[0:8])
valbits := binary.LittleEndian.Uint64(line[8:])
val := math.Float64frombits(valbits)
return key, val
}
var metricEnabled = false
func init() {
if path.Base(os.Args[0]) == "houston" {
logger.Println("metrics are going to be generated for myself(houston)")
metricEnabled = true
return
}
ppid := os.Getppid()
if parent, _ := os.FindProcess(ppid); parent != nil {
filename := fmt.Sprintf(`/proc/%d/stat`, os.Getppid())
if fn, err := os.ReadFile(filename); err == nil {
stats := strings.SplitN(string(fn), " ", 3)
parentname := strings.Trim(stats[1], "()")
if path.Base(parentname) == "houston" {
logger.Println("metrics are going to be generated for houston")
metricEnabled = true
} else {
logger.Println("metrics are NOT going to be generated. parent is not houston :", filename, string(fn))
}
} else {
logger.Println("metrics are NOT going to be generated. ppid proc is missing :", filename)
}
} else {
logger.Println("metrics are NOT going to be generated. parent process is missing. ppid :", ppid)
}
}