Change API of LoadBlob to return io.ReadSeeker instead of io.Reader and use ServeContent to serve blob content (#19)

* first test with http.ServeContent

* added debug to help me here

* removed debug messages

* changed LoadBlob to requisre io.ReadSeeker

---------

Co-authored-by: Your Name <you@example.com>

blossom/handlers.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/liamg/magic"
 	"github.com/nbd-wtf/go-nostr"
@@ -190,8 +191,14 @@ func (bs BlossomServer) handleGetBlob(w http.ResponseWriter, r *http.Request) {
 	for _, lb := range bs.LoadBlob {
 		reader, _ := lb(r.Context(), hhash)
 		if reader != nil {
-			w.Header().Add("Content-Type", mime.TypeByExtension(ext))
-			io.Copy(w, reader)
+			// use unix epoch as the time if we can't find the descriptor
+			// as described in the http.ServeContent documentation
+			t := time.Unix(0, 0)
+			descriptor, err := bs.Store.Get(r.Context(), hhash)
+			if err == nil && descriptor != nil {
+				t = descriptor.Uploaded.Time()
+			}
+			http.ServeContent(w, r, hhash+ext, t, reader)
 			return
 		}
 	}

blossom/server.go

@@ -15,7 +15,7 @@ type BlossomServer struct {
 	Store      BlobIndex
 
 	StoreBlob  []func(ctx context.Context, sha256 string, body []byte) error
-	LoadBlob   []func(ctx context.Context, sha256 string) (io.Reader, error)
+	LoadBlob   []func(ctx context.Context, sha256 string) (io.ReadSeeker, error)
 	DeleteBlob []func(ctx context.Context, sha256 string) error
 
 	RejectUpload []func(ctx context.Context, auth *nostr.Event, size int, ext string) (bool, string, int)