khenaidoo | ac63710 | 2019-01-14 15:44:34 -0500 | [diff] [blame] | 1 | package sarama |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | |
| 6 | "github.com/rcrowley/go-metrics" |
| 7 | ) |
| 8 | |
| 9 | // Encoder is the interface that wraps the basic Encode method. |
| 10 | // Anything implementing Encoder can be turned into bytes using Kafka's encoding rules. |
| 11 | type encoder interface { |
| 12 | encode(pe packetEncoder) error |
| 13 | } |
| 14 | |
| 15 | // Encode takes an Encoder and turns it into bytes while potentially recording metrics. |
| 16 | func encode(e encoder, metricRegistry metrics.Registry) ([]byte, error) { |
| 17 | if e == nil { |
| 18 | return nil, nil |
| 19 | } |
| 20 | |
| 21 | var prepEnc prepEncoder |
| 22 | var realEnc realEncoder |
| 23 | |
| 24 | err := e.encode(&prepEnc) |
| 25 | if err != nil { |
| 26 | return nil, err |
| 27 | } |
| 28 | |
| 29 | if prepEnc.length < 0 || prepEnc.length > int(MaxRequestSize) { |
| 30 | return nil, PacketEncodingError{fmt.Sprintf("invalid request size (%d)", prepEnc.length)} |
| 31 | } |
| 32 | |
| 33 | realEnc.raw = make([]byte, prepEnc.length) |
| 34 | realEnc.registry = metricRegistry |
| 35 | err = e.encode(&realEnc) |
| 36 | if err != nil { |
| 37 | return nil, err |
| 38 | } |
| 39 | |
| 40 | return realEnc.raw, nil |
| 41 | } |
| 42 | |
| 43 | // Decoder is the interface that wraps the basic Decode method. |
| 44 | // Anything implementing Decoder can be extracted from bytes using Kafka's encoding rules. |
| 45 | type decoder interface { |
| 46 | decode(pd packetDecoder) error |
| 47 | } |
| 48 | |
| 49 | type versionedDecoder interface { |
| 50 | decode(pd packetDecoder, version int16) error |
| 51 | } |
| 52 | |
| 53 | // Decode takes bytes and a Decoder and fills the fields of the decoder from the bytes, |
| 54 | // interpreted using Kafka's encoding rules. |
| 55 | func decode(buf []byte, in decoder) error { |
| 56 | if buf == nil { |
| 57 | return nil |
| 58 | } |
| 59 | |
| 60 | helper := realDecoder{raw: buf} |
| 61 | err := in.decode(&helper) |
| 62 | if err != nil { |
| 63 | return err |
| 64 | } |
| 65 | |
| 66 | if helper.off != len(buf) { |
| 67 | return PacketDecodingError{"invalid length"} |
| 68 | } |
| 69 | |
| 70 | return nil |
| 71 | } |
| 72 | |
| 73 | func versionedDecode(buf []byte, in versionedDecoder, version int16) error { |
| 74 | if buf == nil { |
| 75 | return nil |
| 76 | } |
| 77 | |
| 78 | helper := realDecoder{raw: buf} |
| 79 | err := in.decode(&helper, version) |
| 80 | if err != nil { |
| 81 | return err |
| 82 | } |
| 83 | |
| 84 | if helper.off != len(buf) { |
| 85 | return PacketDecodingError{"invalid length"} |
| 86 | } |
| 87 | |
| 88 | return nil |
| 89 | } |