box-o-sand/sltcpsrv/message.go

package sltcpsrv

import (
	"fmt"
	"log"
	"strconv"
	"strings"
)

type message struct {
	pri       uint8
	version   int
	timestamp string
	hostname  string
	appName   string
	pid       int
	body      string
}

func newMessage(line []byte) *message {
	if len(line) == 0 {
		return nil
	}

	msg := &message{
		version: -1,
		pid:     -1,
	}

	in := ""
	accum := []byte{}
	everythingElse := ""

	n := len(line)
	for i, b := range line {
		if *isDebug {
			log.Printf("in = %q, accum = %q\n", in, string(accum))
		}

		if i == 0 && b == '<' {
			in = "pri"
			continue
		}

		if in == "pri" {
			if b == '>' {
				in = "pridone"

				pri, err := strconv.ParseUint(string(accum), 10, 8)
				if err != nil {
					if *isDebug {
						log.Println("ERROR:", err)
					}
					return msg
				}

				msg.pri = uint8(pri)
				accum = []byte{}
				continue
			} else {
				accum = append(accum, b)
				continue
			}
		}

		if in == "pridone" {
			in = "everything_else"
			accum = append(accum, b)
			continue
		}

		if in == "everything_else" {
			if i == n-1 {
				accum = append(accum, b)
				everythingElse = string(accum)
				break
			}

			accum = append(accum, b)
			continue
		}
	}

	dateParts := []string{}

	broken := strings.SplitN(everythingElse, ":", 4)
	if len(broken) != 4 {
		if *isDebug {
			log.Printf("ERROR: got back unexpected parts for %q: %+v\n", everythingElse, broken)
		}
		return msg
	}

	verMonthDateHour := strings.Split(broken[0], " ")
	minutes := broken[1]
	secsHostProc := strings.Split(broken[2], " ")
	msg.body = string(broken[3])

	hour := ""

	switch len(verMonthDateHour) {
	case 4:
		v, err := strconv.ParseUint(verMonthDateHour[0], 10, 8)
		if err != nil {
			if *isDebug {
				log.Println("ERROR:", err)
			}
		} else {
			msg.version = int(v)
		}

		dateParts = append(dateParts, verMonthDateHour[1:3]...)
		hour = verMonthDateHour[3]
	case 3:
		dateParts = append(dateParts, verMonthDateHour[:2]...)
		hour = verMonthDateHour[2]
	}

	dateParts = append(dateParts, fmt.Sprintf("%s:%s:%s", hour, minutes, secsHostProc[0]))
	msg.timestamp = strings.Join(dateParts, " ")
	msg.hostname = string(secsHostProc[1])

	procParts := strings.Split(secsHostProc[2], "[")
	if len(procParts) > 1 {
		msg.appName = string(procParts[0])

		p, err := strconv.ParseUint(strings.Trim(procParts[1], "[]"), 10, 16)
		if err != nil {
			if *isDebug {
				log.Println("ERROR:", err)
			}
		} else {
			msg.pid = int(p)
		}
	} else {
		msg.appName = string(procParts[0])
	}

	return msg
}