DMAC/internal/pkg/logging/logging.go

package logging

import (
    "log"
    "fmt"
    "os"
    "time"
    "strconv"
)

func getVerbosity() int {
    v := os.Getenv("VERBOSE")
    level := 0
    if v != "" {
        var err error
        level, err = strconv.Atoi(v)
        if err != nil {
            log.Fatalf("Invalid Vverboity %v", v)
        }
    }
    return level
}

type logTopic string
const (
    // define 4 character topic abbreviations for coloring
    DError logTopic = "ERRO"
    DClient logTopic = "CLNT"
    DStart logTopic = "STRT"
    DExit logTopic = "EXIT"
    DPing logTopic = "PING"
    DScan logTopic = "SCAN"
    DSpawn logTopic = "SPWN"
)
// the list can grow

var debugStart time.Time
var debugVerbosity int

func init() {
    debugVerbosity = getVerbosity()
    debugStart = time.Now()
    if debugVerbosity > 0 {
        filename := time.Now().Format("01-02T15:04:05")
        filename += ".log"
        f, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0664)
        if err != nil {
            log.Fatal(err)
        }
    log.SetOutput(f)
    }

    log.SetFlags(log.Flags() &^ (log.Ldate | log.Ltime)) // turns off date and time so we can set manually
}

// example call Debug(dClient, "R%d connecting to client %d", r.Id, c.Id)
func Debug(topic logTopic, format string, a ...interface{}) {
    if debugVerbosity >= 1 {
        time := time.Since(debugStart).Microseconds()
        time /= 100
        prefix := fmt.Sprintf("%06d %v ", time, string(topic))
        format = prefix + format
        log.Printf(format, a...)
    }
}