blob: 9be854c0741df2692ae7756c1b3e733de5d7d254 [file] [log] [blame]
William Kurkianea869482019-04-09 15:16:11 -04001package sarama
3// PacketDecoder is the interface providing helpers for reading with Kafka's encoding rules.
4// Types implementing Decoder only need to worry about calling methods like GetString,
5// not about how a string is represented in Kafka.
6type packetDecoder interface {
7 // Primitives
8 getInt8() (int8, error)
9 getInt16() (int16, error)
10 getInt32() (int32, error)
11 getInt64() (int64, error)
12 getVarint() (int64, error)
13 getArrayLength() (int, error)
14 getBool() (bool, error)
16 // Collections
17 getBytes() ([]byte, error)
18 getVarintBytes() ([]byte, error)
19 getRawBytes(length int) ([]byte, error)
20 getString() (string, error)
21 getNullableString() (*string, error)
22 getInt32Array() ([]int32, error)
23 getInt64Array() ([]int64, error)
24 getStringArray() ([]string, error)
26 // Subsets
27 remaining() int
28 getSubset(length int) (packetDecoder, error)
29 peek(offset, length int) (packetDecoder, error) // similar to getSubset, but it doesn't advance the offset
Abhilash S.L3b494632019-07-16 15:51:09 +053030 peekInt8(offset int) (int8, error) // similar to peek, but just one byte
William Kurkianea869482019-04-09 15:16:11 -040031
32 // Stacks, see PushDecoder
33 push(in pushDecoder) error
34 pop() error
37// PushDecoder is the interface for decoding fields like CRCs and lengths where the validity
38// of the field depends on what is after it in the packet. Start them with PacketDecoder.Push() where
39// the actual value is located in the packet, then PacketDecoder.Pop() them when all the bytes they
40// depend upon have been decoded.
41type pushDecoder interface {
42 // Saves the offset into the input buffer as the location to actually read the calculated value when able.
43 saveOffset(in int)
45 // Returns the length of data to reserve for the input of this encoder (eg 4 bytes for a CRC32).
46 reserveLength() int
48 // Indicates that all required data is now available to calculate and check the field.
49 // SaveOffset is guaranteed to have been called first. The implementation should read ReserveLength() bytes
50 // of data from the saved offset, and verify it based on the data between the saved offset and curOffset.
51 check(curOffset int, buf []byte) error
54// dynamicPushDecoder extends the interface of pushDecoder for uses cases where the length of the
55// fields itself is unknown until its value was decoded (for instance varint encoded length
56// fields).
57// During push, dynamicPushDecoder.decode() method will be called instead of reserveLength()
58type dynamicPushDecoder interface {
59 pushDecoder
60 decoder