clash/adapter/provider/fetcher.go
2022-03-16 12:10:13 +08:00

185 lines
3.2 KiB
Go

package provider
import (
"bytes"
"crypto/md5"
"os"
"path/filepath"
"time"
types "github.com/Dreamacro/clash/constant/provider"
"github.com/Dreamacro/clash/log"
)
var (
fileMode os.FileMode = 0o666
dirMode os.FileMode = 0o755
)
type parser = func([]byte) (any, error)
type fetcher struct {
name string
vehicle types.Vehicle
updatedAt *time.Time
ticker *time.Ticker
done chan struct{}
hash [16]byte
parser parser
onUpdate func(any)
}
func (f *fetcher) Name() string {
return f.name
}
func (f *fetcher) VehicleType() types.VehicleType {
return f.vehicle.Type()
}
func (f *fetcher) Initial() (any, error) {
var (
buf []byte
err error
isLocal bool
)
if stat, fErr := os.Stat(f.vehicle.Path()); fErr == nil {
buf, err = os.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
}
isLocal = false
}
if f.vehicle.Type() != types.File && !isLocal {
if err := safeWrite(f.vehicle.Path(), buf); 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() (any, 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
os.Chtimes(f.vehicle.Path(), now, now)
return nil, true, nil
}
proxies, err := f.parser(buf)
if err != nil {
return nil, false, err
}
if f.vehicle.Type() != types.File {
if err := safeWrite(f.vehicle.Path(), buf); 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.done <- struct{}{}
}
return nil
}
func (f *fetcher) pullLoop() {
for {
select {
case <-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)
}
case <-f.done:
f.ticker.Stop()
return
}
}
}
func safeWrite(path string, buf []byte) error {
dir := filepath.Dir(path)
if _, err := os.Stat(dir); os.IsNotExist(err) {
if err := os.MkdirAll(dir, dirMode); err != nil {
return err
}
}
return os.WriteFile(path, buf, fileMode)
}
func newFetcher(name string, interval time.Duration, vehicle types.Vehicle, parser parser, onUpdate func(any)) *fetcher {
var ticker *time.Ticker
if interval != 0 {
ticker = time.NewTicker(interval)
}
return &fetcher{
name: name,
ticker: ticker,
vehicle: vehicle,
parser: parser,
done: make(chan struct{}, 1),
onUpdate: onUpdate,
}
}