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