cubefs

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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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	getUVarint() (uint64, error)
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	getFloat64() (float64, error)
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	getArrayLength() (int, error)
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	getCompactArrayLength() (int, error)
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	getBool() (bool, error)
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	getEmptyTaggedFieldArray() (int, error)
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	// Collections
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	getBytes() ([]byte, error)
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	getVarintBytes() ([]byte, error)
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	getCompactBytes() ([]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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	getCompactString() (string, error)
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	getCompactNullableString() (*string, error)
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	getCompactInt32Array() ([]int32, 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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