fix(api): dont stamp dupes (#1772)

pkg/api/api.go

@@ -329,16 +329,39 @@ func newStamperPutter(s storage.Storer, post postage.Service, signer crypto.Sign
 	return &stamperPutter{Storer: s, stamper: stamper}, nil
 }
 
-func (p *stamperPutter) Put(ctx context.Context, mode storage.ModePut, chs ...swarm.Chunk) (exist []bool, err error) {
+func (p *stamperPutter) Put(ctx context.Context, mode storage.ModePut, chs ...swarm.Chunk) (exists []bool, err error) {
+	var (
+		ctp []swarm.Chunk
+		idx []int
+	)
+	exists = make([]bool, len(chs))
+
 	for i, c := range chs {
+		has, err := p.Storer.Has(ctx, c.Address())
+		if err != nil {
+			return nil, err
+		}
+		if has || containsChunk(c.Address(), chs[:i]...) {
+			exists[i] = true
+			continue
+		}
 		stamp, err := p.stamper.Stamp(c.Address())
 		if err != nil {
 			return nil, err
 		}
 		chs[i] = c.WithStamp(stamp)
+		ctp = append(ctp, chs[i])
+		idx = append(idx, i)
 	}
 
-	return p.Storer.Put(ctx, mode, chs...)
+	exists2, err := p.Storer.Put(ctx, mode, ctp...)
+	if err != nil {
+		return nil, err
+	}
+	for i, v := range idx {
+		exists[v] = exists2[i]
+	}
+	return exists, nil
 }
 
 type pipelineFunc func(context.Context, io.Reader) (swarm.Address, error)
@@ -380,3 +403,14 @@ func requestCalculateNumberOfChunks(r *http.Request) int64 {
 	}
 	return 0
 }
+
+// containsChunk returns true if the chunk with a specific address
+// is present in the provided chunk slice.
+func containsChunk(addr swarm.Address, chs ...swarm.Chunk) bool {
+	for _, c := range chs {
+		if addr.Equal(c.Address()) {
+			return true
+		}
+	}
+	return false
+}