mihomo/adapters/provider/fetcher.go
2020-04-26 22:38:15 +08:00

154 lines
2.6 KiB
Go

package provider
import (
"bytes"
"crypto/md5"
"io/ioutil"
"os"
"time"
"github.com/Dreamacro/clash/log"
)
var (
fileMode os.FileMode = 0666
)
type parser = func([]byte) (interface{}, error)
type fetcher struct {
name string
vehicle Vehicle
updatedAt *time.Time
ticker *time.Ticker
hash [16]byte
parser parser
onUpdate func(interface{})
}
func (f *fetcher) Name() string {
return f.name
}
func (f *fetcher) VehicleType() VehicleType {
return f.vehicle.Type()
}
func (f *fetcher) Initial() (interface{}, error) {
var buf []byte
var err error
var isLocal bool
if stat, err := os.Stat(f.vehicle.Path()); err == nil {
buf, err = ioutil.ReadFile(f.vehicle.Path())
modTime := stat.ModTime()
f.updatedAt = &modTime
isLocal = true
} else {
buf, err = f.vehicle.Read()
}
if err != nil {
return nil, err
}
proxies, err := f.parser(buf)
if err != nil {
if !isLocal {
return nil, err
}
// parse local file error, fallback to remote
buf, err = f.vehicle.Read()
if err != nil {
return nil, err
}
proxies, err = f.parser(buf)
if err != nil {
return nil, err
}
}
if err := ioutil.WriteFile(f.vehicle.Path(), buf, fileMode); err != nil {
return nil, err
}
f.hash = md5.Sum(buf)
// pull proxies automatically
if f.ticker != nil {
go f.pullLoop()
}
return proxies, nil
}
func (f *fetcher) Update() (interface{}, bool, error) {
buf, err := f.vehicle.Read()
if err != nil {
return nil, false, err
}
now := time.Now()
hash := md5.Sum(buf)
if bytes.Equal(f.hash[:], hash[:]) {
f.updatedAt = &now
return nil, true, nil
}
proxies, err := f.parser(buf)
if err != nil {
return nil, false, err
}
if err := ioutil.WriteFile(f.vehicle.Path(), buf, fileMode); err != nil {
return nil, false, err
}
f.updatedAt = &now
f.hash = hash
return proxies, false, nil
}
func (f *fetcher) Destroy() error {
if f.ticker != nil {
f.ticker.Stop()
}
return nil
}
func (f *fetcher) pullLoop() {
for range f.ticker.C {
elm, same, err := f.Update()
if err != nil {
log.Warnln("[Provider] %s pull error: %s", f.Name(), err.Error())
continue
}
if same {
log.Debugln("[Provider] %s's proxies doesn't change", f.Name())
continue
}
log.Infoln("[Provider] %s's proxies update", f.Name())
if f.onUpdate != nil {
f.onUpdate(elm)
}
}
}
func newFetcher(name string, interval time.Duration, vehicle Vehicle, parser parser, onUpdate func(interface{})) *fetcher {
var ticker *time.Ticker
if interval != 0 {
ticker = time.NewTicker(interval)
}
return &fetcher{
name: name,
ticker: ticker,
vehicle: vehicle,
parser: parser,
onUpdate: onUpdate,
}
}