storage/ec: fix some Get socket leaks (#308)

* storage/ec: fix some Get socket leaks

* fix linters

pkg/eestream/pad.go

@@ -33,7 +33,7 @@ func makePadding(dataLen int64, blockSize int) []byte {
 // Pad takes a Ranger and returns another Ranger that is a multiple of
 // blockSize in length. The return value padding is a convenience to report how
 // much padding was added.
-func Pad(data ranger.Ranger, blockSize int) (
+func Pad(data ranger.RangeCloser, blockSize int) (
 	rr ranger.Ranger, padding int) {
 	paddingBytes := makePadding(data.Size(), blockSize)
 	return ranger.Concat(data, ranger.ByteRanger(paddingBytes)), len(paddingBytes)

pkg/ranger/reader.go

@@ -59,14 +59,17 @@ func (b ByteRanger) Range(ctx context.Context, offset, length int64) (io.ReadClo
 	return ioutil.NopCloser(bytes.NewReader(b[offset : offset+length])), nil
 }
 
+// Close is a no-op
+func (b ByteRanger) Close() error { return nil }
+
 // ByteRangeCloser turns a byte slice into a RangeCloser
 func ByteRangeCloser(data []byte) RangeCloser {
 	return NopCloser(ByteRanger(data))
 }
 
 type concatReader struct {
-	r1 Ranger
-	r2 Ranger
+	r1 RangeCloser
+	r2 RangeCloser
 }
 
 func (c *concatReader) Size() int64 {
@@ -92,12 +95,21 @@ func (c *concatReader) Range(ctx context.Context, offset, length int64) (io.Read
 		})), nil
 }
 
-func concat2(r1, r2 Ranger) Ranger {
+func (c *concatReader) Close() error {
+	err1 := c.r1.Close()
+	err2 := c.r2.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func concat2(r1, r2 RangeCloser) RangeCloser {
 	return &concatReader{r1: r1, r2: r2}
 }
 
 // Concat concatenates Rangers
-func Concat(r ...Ranger) Ranger {
+func Concat(r ...RangeCloser) RangeCloser {
 	switch len(r) {
 	case 0:
 		return ByteRanger(nil)

pkg/ranger/reader_test.go

@@ -76,7 +76,7 @@ func TestConcatReader(t *testing.T) {
 		{[]string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l"},
 			12, 7, 3, "hij"},
 	} {
-		var readers []Ranger
+		var readers []RangeCloser
 		for _, data := range example.data {
 			readers = append(readers, ByteRanger([]byte(data)))
 		}

pkg/storage/ec/client.go

@@ -152,8 +152,10 @@ func (ec *ecClient) Get(ctx context.Context, nodes []*proto.Node, es eestream.Er
 			if err != nil {
 				zap.S().Errorf("Failed getting piece %s -> %s from node %s: %v",
 					pieceID, derivedPieceID, n.GetId(), err)
+				ch <- rangerInfo{i: i, rr: nil, err: err}
+				return
 			}
-			ch <- rangerInfo{i: i, rr: rr, err: err}
+			ch <- rangerInfo{i: i, rr: rr, err: nil}
 		}(i, n)
 	}
 	for range nodes {
@@ -164,9 +166,17 @@ func (ec *ecClient) Get(ctx context.Context, nodes []*proto.Node, es eestream.Er
 	}
 	rr, err = eestream.Decode(rrs, es, ec.mbm)
 	if err != nil {
+		for _, rr := range rrs {
+			_ = rr.Close()
+		}
 		return nil, err
 	}
-	return eestream.Unpad(rr, int(paddedSize-size))
+	uprr, err := eestream.Unpad(rr, int(paddedSize-size))
+	if err != nil {
+		_ = rr.Close()
+		return nil, err
+	}
+	return uprr, nil
 }
 
 func (ec *ecClient) Delete(ctx context.Context, nodes []*proto.Node, pieceID client.PieceID) (err error) {

pkg/storage/streams/store.go

@@ -144,20 +144,26 @@ func (s *streamStore) Get(ctx context.Context, path paths.Path) (
 	msi := streamspb.MetaStreamInfo{}
 	err = proto.Unmarshal(lastSegmentMeta.Data, &msi)
 	if err != nil {
+		_ = lastRangerCloser.Close()
 		return nil, Meta{}, err
 	}
 
 	newMeta, err := convertMeta(lastSegmentMeta)
 	if err != nil {
+		_ = lastRangerCloser.Close()
 		return nil, Meta{}, err
 	}
 
-	var rangers []ranger.Ranger
+	var rangers []ranger.RangeCloser
 
 	for i := 0; i < int(msi.NumberOfSegments); i++ {
 		currentPath := fmt.Sprintf("s%d", i)
 		rangeCloser, _, err := s.segments.Get(ctx, path.Prepend(currentPath))
 		if err != nil {
+			for _, ranger := range rangers {
+				_ = ranger.Close()
+			}
+			_ = lastRangerCloser.Close()
 			return nil, Meta{}, err
 		}
 
@@ -168,7 +174,7 @@ func (s *streamStore) Get(ctx context.Context, path paths.Path) (
 
 	catRangers := ranger.Concat(rangers...)
 
-	return ranger.NopCloser(catRangers), newMeta, nil
+	return catRangers, newMeta, nil
 }
 
 // Meta implements Store.Meta