Support scraping from HTTP trackers

[btrtrc.git] / tracker / http / scrape.go

diff --git a/tracker/http/scrape.go b/tracker/http/scrape.go
new file mode 100644 (file)
index 0000000..6940370
--- /dev/null
+++ b/tracker/http/scrape.go
@@ -0,0 +1,47 @@
+package httpTracker
+
+import (
+       "context"
+       "log"
+       "net/http"
+       "net/url"
+
+       "github.com/anacrolix/torrent/bencode"
+       "github.com/anacrolix/torrent/tracker/udp"
+       "github.com/anacrolix/torrent/types/infohash"
+)
+
+type scrapeResponse struct {
+       Files files `bencode:"files"`
+}
+
+// Bencode should support bencode.Unmarshalers from a string in the dict key position.
+type files = map[string]udp.ScrapeInfohashResult
+
+func (cl Client) Scrape(ctx context.Context, ihs []infohash.T) (out udp.ScrapeResponse, err error) {
+       _url := cl.url_.JoinPath("..", "scrape")
+       query, err := url.ParseQuery(_url.RawQuery)
+       if err != nil {
+               return
+       }
+       for _, ih := range ihs {
+               query.Add("info_hash", ih.AsString())
+       }
+       _url.RawQuery = query.Encode()
+       log.Printf("%q", _url.String())
+       req, err := http.NewRequestWithContext(ctx, http.MethodGet, _url.String(), nil)
+       if err != nil {
+               return
+       }
+       resp, err := cl.hc.Do(req)
+       if err != nil {
+               return
+       }
+       defer resp.Body.Close()
+       var decodedResp scrapeResponse
+       err = bencode.NewDecoder(resp.Body).Decode(&decodedResp)
+       for _, ih := range ihs {
+               out = append(out, decodedResp.Files[ih.AsString()])
+       }
+       return
+}