torrent/sources.go

81 lines
1.8 KiB
Go

package torrent
import (
"context"
"errors"
"fmt"
"net/http"
"github.com/anacrolix/log"
"github.com/anacrolix/torrent/bencode"
"github.com/anacrolix/torrent/metainfo"
)
// Add HTTP endpoints that serve the metainfo. They will be used if the torrent info isn't obtained
// yet. The Client HTTP client is used.
func (t *Torrent) UseSources(sources []string) {
select {
case <-t.Closed():
return
case <-t.GotInfo():
return
default:
}
for _, s := range sources {
_, loaded := t.activeSources.LoadOrStore(s, struct{}{})
if loaded {
continue
}
s := s
go func() {
err := t.useActiveTorrentSource(s)
_, loaded := t.activeSources.LoadAndDelete(s)
if !loaded {
panic(s)
}
level := log.Debug
if err != nil && !errors.Is(err, context.Canceled) {
level = log.Warning
}
t.logger.Levelf(level, "used torrent source %q [err=%v]", s, err)
}()
}
}
func (t *Torrent) useActiveTorrentSource(source string) error {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
go func() {
select {
case <-t.GotInfo():
case <-t.Closed():
case <-ctx.Done():
}
cancel()
}()
mi, err := getTorrentSource(ctx, source, t.cl.httpClient)
if err != nil {
return err
}
return t.MergeSpec(TorrentSpecFromMetaInfo(&mi))
}
func getTorrentSource(ctx context.Context, source string, hc *http.Client) (mi metainfo.MetaInfo, err error) {
var req *http.Request
if req, err = http.NewRequestWithContext(ctx, http.MethodGet, source, nil); err != nil {
return
}
var resp *http.Response
if resp, err = hc.Do(req); err != nil {
return
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
err = fmt.Errorf("unexpected response status code: %v", resp.StatusCode)
return
}
err = bencode.NewDecoder(resp.Body).Decode(&mi)
return
}