blob: 9be854c0741df2692ae7756c1b3e733de5d7d254 [file] [log] [blame]
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 {