Code cleanup

This commit is contained in:
Christopher Ramey 2020-08-20 04:34:22 -08:00
parent 90325e9dd5
commit 87c53831a2
2 changed files with 237 additions and 229 deletions

231
config.go
View File

@ -1,13 +1,5 @@
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
type AlrmConfig struct {
Groups []*AlrmGroup
Interval int
@ -19,10 +11,6 @@ func (ac *AlrmConfig) NewGroup() *AlrmGroup {
return group
}
func (ac *AlrmConfig) LastGroup() *AlrmGroup {
return ac.Groups[len(ac.Groups)-1]
}
type AlrmGroup struct {
Name string
Hosts []*AlrmHost
@ -34,231 +22,16 @@ func (ag *AlrmGroup) NewHost() *AlrmHost {
return host
}
func (ag *AlrmGroup) LastHost() *AlrmHost {
return ag.Hosts[len(ag.Hosts)-1]
}
type AlrmHost struct {
Name string
Address string
}
const (
TK_NONE = iota
TK_SET
TK_MONITOR
TK_GROUP
TK_HOST
)
func stateName(s int) string {
switch s {
case TK_NONE:
return "TK_NONE"
case TK_SET:
return "TK_SET"
case TK_MONITOR:
return "TK_MONTIOR"
case TK_GROUP:
return "TK_GROUP"
case TK_HOST:
return "TK_HOST"
default:
return "UNKNOWN"
}
}
func ReadConfig(fn string) (*AlrmConfig, error) {
file, err := os.Open(fn)
if err != nil {
return nil, fmt.Errorf("cannot open config \"%s\": %s", fn, err.Error())
}
defer file.Close()
config := &AlrmConfig{}
parser := &Parser{}
scan := bufio.NewScanner(file)
scan.Split(parser.Split)
for scan.Scan() {
tk := scan.Text()
stateswitch:
switch parser.GetState() {
case TK_NONE:
switch strings.ToLower(tk) {
case "monitor":
parser.SetState(TK_MONITOR)
case "set":
parser.SetState(TK_SET)
default:
return nil, fmt.Errorf("invalid token in %s, line %d: \"%s\"",
fn, parser.Line+1, tk)
}
case TK_SET:
key := strings.ToLower(tk)
if scan.Scan() {
value := scan.Text()
switch key {
case "interval":
config.Interval, err = strconv.Atoi(value)
if err != nil {
return nil, fmt.Errorf(
"invalid number for interval, line %d: \"%s\"",
parser.Line+1, value,
)
}
default:
return nil, fmt.Errorf("invalid key for set, line %d: \"%s\"",
parser.Line+1, tk,
)
}
}
parser.PrevState()
case TK_MONITOR:
switch strings.ToLower(tk) {
case "host":
config.NewGroup().NewHost()
parser.SetState(TK_HOST)
case "group":
config.NewGroup()
parser.SetState(TK_GROUP)
default:
parser.PrevState()
goto stateswitch
}
case TK_GROUP:
group := config.LastGroup()
switch strings.ToLower(tk) {
case "host":
group.NewHost()
parser.SetState(TK_HOST)
continue
default:
if group.Name == "" {
group.Name = tk
continue
}
parser.PrevState()
goto stateswitch
}
case TK_HOST:
host := config.LastGroup().LastHost()
if host.Name == "" {
host.Name = tk
continue
}
switch strings.ToLower(tk) {
case "address":
if scan.Scan() {
host.Address = scan.Text()
}
default:
parser.PrevState()
goto stateswitch
}
default:
return nil, fmt.Errorf("unknown parser state: %d", parser.GetState())
}
}
if err := scan.Err(); err != nil {
config, err := parser.Parse(fn)
if err != nil {
return nil, err
}
return config, nil
}
type Parser struct {
Line int
states []int
}
func (pr *Parser) GetState() int {
if len(pr.states) < 1 {
return TK_NONE
}
return pr.states[len(pr.states)-1]
}
func (pr *Parser) SetState(state int) {
//fmt.Printf("%s -> %s\n", stateName(pr.GetState()), stateName(state))
pr.states = append(pr.states, state)
}
func (pr *Parser) PrevState() int {
if len(pr.states) > 0 {
pr.states = pr.states[:len(pr.states)-1]
}
return pr.GetState()
}
func (pr *Parser) Split(data []byte, atEOF bool) (int, []byte, error) {
if atEOF && len(data) == 0 {
return 0, nil, nil
}
var ignoreline bool
var started bool
var startidx int
var quote byte
for i := 0; i < len(data); i++ {
c := data[i]
switch c {
case '\f', '\n', '\r':
pr.Line++
if ignoreline {
ignoreline = false
continue
}
fallthrough
case ' ', '\t', '\v':
if started && quote == 0 {
return i + 1, data[startidx:i], nil
}
case '\'', '"', '`':
if started && quote == c {
return i + 1, data[startidx:i], nil
}
if quote == 0 {
quote = c
}
case '#':
if !started {
ignoreline = true
}
default:
if !ignoreline && !started {
started = true
startidx = i
}
}
}
if atEOF {
if ignoreline {
return len(data), nil, nil
}
if started {
return len(data), data[startidx:], nil
}
}
return 0, nil, nil
}

235
parser.go Normal file
View File

@ -0,0 +1,235 @@
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
const (
TK_NONE = iota
TK_SET
TK_MONITOR
TK_GROUP
TK_HOST
)
type Parser struct {
Line int
states []int
}
func (p *Parser) Parse(fn string) (*AlrmConfig, error) {
file, err := os.Open(fn)
if err != nil {
return nil, fmt.Errorf("cannot open config \"%s\": %s", fn, err.Error())
}
defer file.Close()
config := &AlrmConfig{}
var group *AlrmGroup
var host *AlrmHost
scan := bufio.NewScanner(file)
scan.Split(p.Split)
for scan.Scan() {
tk := scan.Text()
stateswitch:
switch p.state() {
case TK_NONE:
switch strings.ToLower(tk) {
case "monitor":
p.setState(TK_MONITOR)
case "set":
p.setState(TK_SET)
default:
return nil, fmt.Errorf("invalid token in %s, line %d: \"%s\"",
fn, p.Line+1, tk)
}
case TK_SET:
key := strings.ToLower(tk)
if scan.Scan() {
value := scan.Text()
switch key {
case "interval":
config.Interval, err = strconv.Atoi(value)
if err != nil {
return nil, fmt.Errorf(
"invalid number for interval, line %d: \"%s\"",
p.Line+1, value,
)
}
default:
return nil, fmt.Errorf("invalid key for set, line %d: \"%s\"",
p.Line+1, tk,
)
}
}
p.prevState()
case TK_MONITOR:
switch strings.ToLower(tk) {
case "host":
host = config.NewGroup().NewHost()
p.setState(TK_HOST)
case "group":
group = config.NewGroup()
p.setState(TK_GROUP)
default:
p.prevState()
goto stateswitch
}
case TK_GROUP:
if group == nil {
return nil, fmt.Errorf("Group token without initialization")
}
switch strings.ToLower(tk) {
case "host":
host = group.NewHost()
p.setState(TK_HOST)
continue
default:
if group.Name == "" {
group.Name = tk
continue
}
p.prevState()
goto stateswitch
}
case TK_HOST:
if host == nil {
return nil, fmt.Errorf("Host token without initialization")
}
if host.Name == "" {
host.Name = tk
continue
}
switch strings.ToLower(tk) {
case "address":
if scan.Scan() {
host.Address = scan.Text()
}
default:
p.prevState()
goto stateswitch
}
default:
return nil, fmt.Errorf("unknown parser state: %d", p.state())
}
}
if err := scan.Err(); err != nil {
return nil, err
}
return config, nil
}
func (p *Parser) state() int {
if len(p.states) < 1 {
return TK_NONE
}
return p.states[len(p.states)-1]
}
func (p *Parser) setState(state int) {
// fmt.Printf("%s", p.stateName())
p.states = append(p.states, state)
// fmt.Printf(" -> %s\n", p.stateName())
}
func (p *Parser) prevState() int {
if len(p.states) > 0 {
p.states = p.states[:len(p.states)-1]
}
return p.state()
}
func (p *Parser) stateName() string {
switch p.state() {
case TK_NONE:
return "TK_NONE"
case TK_SET:
return "TK_SET"
case TK_MONITOR:
return "TK_MONTIOR"
case TK_GROUP:
return "TK_GROUP"
case TK_HOST:
return "TK_HOST"
default:
return "UNKNOWN"
}
}
func (p *Parser) Split(data []byte, atEOF bool) (int, []byte, error) {
if atEOF && len(data) == 0 {
return 0, nil, nil
}
var ignoreline bool
var started bool
var startidx int
var quote byte
for i := 0; i < len(data); i++ {
c := data[i]
switch c {
case '\f', '\n', '\r':
p.Line++
if ignoreline {
ignoreline = false
continue
}
fallthrough
case ' ', '\t', '\v':
if started && quote == 0 {
return i + 1, data[startidx:i], nil
}
case '\'', '"', '`':
if started && quote == c {
return i + 1, data[startidx:i], nil
}
if quote == 0 {
quote = c
}
case '#':
if !started {
ignoreline = true
}
default:
if !ignoreline && !started {
started = true
startidx = i
}
}
}
if atEOF {
if ignoreline {
return len(data), nil, nil
}
if started {
return len(data), data[startidx:], nil
}
}
return 0, nil, nil
}