Files
bt/tracker/get_peers.go
2023-03-01 22:50:46 +08:00

97 lines
2.2 KiB
Go

// Copyright 2020~2023 xgfone
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tracker
import (
"context"
"net/url"
"sync"
"github.com/xgfone/bt/metainfo"
)
// GetPeersResult represents the result of getting the peers from the tracker.
type GetPeersResult struct {
Error error // nil stands for success. Or, for failure.
Tracker string
Resp AnnounceResponse
}
// GetPeers gets the peers from the trackers.
//
// Notice: the returned chan will be closed when all the requests end.
func GetPeers(ctx context.Context, nodeid, infohash metainfo.Hash, trackers []string) []GetPeersResult {
if len(trackers) == 0 {
return nil
}
for i, t := range trackers {
if u, err := url.Parse(t); err == nil && u.Path == "" {
u.Path = "/announce"
trackers[i] = u.String()
}
}
_len := len(trackers)
wlen := _len
if wlen > 10 {
wlen = 10
}
reqs := make(chan string, wlen)
go func() {
for i := 0; i < _len; i++ {
reqs <- trackers[i]
}
}()
wg := new(sync.WaitGroup)
wg.Add(_len)
var lock sync.Mutex
results := make([]GetPeersResult, 0, _len)
for i := 0; i < wlen; i++ {
go func() {
for tracker := range reqs {
resp, err := getPeers(ctx, wg, tracker, nodeid, infohash)
lock.Lock()
results = append(results, GetPeersResult{
Tracker: tracker,
Error: err,
Resp: resp,
})
lock.Unlock()
}
}()
}
wg.Wait()
close(reqs)
return results
}
func getPeers(ctx context.Context, wg *sync.WaitGroup, tracker string,
nodeID, infoHash metainfo.Hash) (resp AnnounceResponse, err error) {
defer wg.Done()
client, err := NewClient(tracker, nodeID, nil)
if err == nil {
resp, err = client.Announce(ctx, AnnounceRequest{InfoHash: infoHash})
}
return
}