| package sarama |
| |
| // PacketDecoder is the interface providing helpers for reading with Kafka's encoding rules. |
| // Types implementing Decoder only need to worry about calling methods like GetString, |
| // not about how a string is represented in Kafka. |
| type packetDecoder interface { |
| // Primitives |
| getInt8() (int8, error) |
| getInt16() (int16, error) |
| getInt32() (int32, error) |
| getInt64() (int64, error) |
| getVarint() (int64, error) |
| getArrayLength() (int, error) |
| getBool() (bool, error) |
| |
| // Collections |
| getBytes() ([]byte, error) |
| getVarintBytes() ([]byte, error) |
| getRawBytes(length int) ([]byte, error) |
| getString() (string, error) |
| getNullableString() (*string, error) |
| getInt32Array() ([]int32, error) |
| getInt64Array() ([]int64, error) |
| getStringArray() ([]string, error) |
| |
| // Subsets |
| remaining() int |
| getSubset(length int) (packetDecoder, error) |
| peek(offset, length int) (packetDecoder, error) // similar to getSubset, but it doesn't advance the offset |
| peekInt8(offset int) (int8, error) // similar to peek, but just one byte |
| |
| // Stacks, see PushDecoder |
| push(in pushDecoder) error |
| pop() error |
| } |
| |
| // PushDecoder is the interface for decoding fields like CRCs and lengths where the validity |
| // of the field depends on what is after it in the packet. Start them with PacketDecoder.Push() where |
| // the actual value is located in the packet, then PacketDecoder.Pop() them when all the bytes they |
| // depend upon have been decoded. |
| type pushDecoder interface { |
| // Saves the offset into the input buffer as the location to actually read the calculated value when able. |
| saveOffset(in int) |
| |
| // Returns the length of data to reserve for the input of this encoder (eg 4 bytes for a CRC32). |
| reserveLength() int |
| |
| // Indicates that all required data is now available to calculate and check the field. |
| // SaveOffset is guaranteed to have been called first. The implementation should read ReserveLength() bytes |
| // of data from the saved offset, and verify it based on the data between the saved offset and curOffset. |
| check(curOffset int, buf []byte) error |
| } |
| |
| // dynamicPushDecoder extends the interface of pushDecoder for uses cases where the length of the |
| // fields itself is unknown until its value was decoded (for instance varint encoded length |
| // fields). |
| // During push, dynamicPushDecoder.decode() method will be called instead of reserveLength() |
| type dynamicPushDecoder interface { |
| pushDecoder |
| decoder |
| } |