Scott Baker | ed4efab | 2020-01-13 19:12:25 -0800 | [diff] [blame] | 1 | package sarama |
| 2 | |
| 3 | import ( |
| 4 | "encoding/binary" |
| 5 | "sync" |
| 6 | ) |
| 7 | |
| 8 | // LengthField implements the PushEncoder and PushDecoder interfaces for calculating 4-byte lengths. |
| 9 | type lengthField struct { |
| 10 | startOffset int |
| 11 | length int32 |
| 12 | } |
| 13 | |
| 14 | var lengthFieldPool = sync.Pool{} |
| 15 | |
| 16 | func acquireLengthField() *lengthField { |
| 17 | val := lengthFieldPool.Get() |
| 18 | if val != nil { |
| 19 | return val.(*lengthField) |
| 20 | } |
| 21 | return &lengthField{} |
| 22 | } |
| 23 | |
| 24 | func releaseLengthField(m *lengthField) { |
| 25 | lengthFieldPool.Put(m) |
| 26 | } |
| 27 | |
| 28 | func (l *lengthField) decode(pd packetDecoder) error { |
| 29 | var err error |
| 30 | l.length, err = pd.getInt32() |
| 31 | if err != nil { |
| 32 | return err |
| 33 | } |
| 34 | if l.length > int32(pd.remaining()) { |
| 35 | return ErrInsufficientData |
| 36 | } |
| 37 | return nil |
| 38 | } |
| 39 | |
| 40 | func (l *lengthField) saveOffset(in int) { |
| 41 | l.startOffset = in |
| 42 | } |
| 43 | |
| 44 | func (l *lengthField) reserveLength() int { |
| 45 | return 4 |
| 46 | } |
| 47 | |
| 48 | func (l *lengthField) run(curOffset int, buf []byte) error { |
| 49 | binary.BigEndian.PutUint32(buf[l.startOffset:], uint32(curOffset-l.startOffset-4)) |
| 50 | return nil |
| 51 | } |
| 52 | |
| 53 | func (l *lengthField) check(curOffset int, buf []byte) error { |
| 54 | if int32(curOffset-l.startOffset-4) != l.length { |
| 55 | return PacketDecodingError{"length field invalid"} |
| 56 | } |
| 57 | |
| 58 | return nil |
| 59 | } |
| 60 | |
| 61 | type varintLengthField struct { |
| 62 | startOffset int |
| 63 | length int64 |
| 64 | } |
| 65 | |
| 66 | func (l *varintLengthField) decode(pd packetDecoder) error { |
| 67 | var err error |
| 68 | l.length, err = pd.getVarint() |
| 69 | return err |
| 70 | } |
| 71 | |
| 72 | func (l *varintLengthField) saveOffset(in int) { |
| 73 | l.startOffset = in |
| 74 | } |
| 75 | |
| 76 | func (l *varintLengthField) adjustLength(currOffset int) int { |
| 77 | oldFieldSize := l.reserveLength() |
| 78 | l.length = int64(currOffset - l.startOffset - oldFieldSize) |
| 79 | |
| 80 | return l.reserveLength() - oldFieldSize |
| 81 | } |
| 82 | |
| 83 | func (l *varintLengthField) reserveLength() int { |
| 84 | var tmp [binary.MaxVarintLen64]byte |
| 85 | return binary.PutVarint(tmp[:], l.length) |
| 86 | } |
| 87 | |
| 88 | func (l *varintLengthField) run(curOffset int, buf []byte) error { |
| 89 | binary.PutVarint(buf[l.startOffset:], l.length) |
| 90 | return nil |
| 91 | } |
| 92 | |
| 93 | func (l *varintLengthField) check(curOffset int, buf []byte) error { |
| 94 | if int64(curOffset-l.startOffset-l.reserveLength()) != l.length { |
| 95 | return PacketDecodingError{"length field invalid"} |
| 96 | } |
| 97 | |
| 98 | return nil |
| 99 | } |