Function EncodeLogRecord

engine/data/log_record.go:54–79

EncodeLogRecord encodes a LogRecord and returns the byte array and length. +-------------+------------+------------+--------------+-------+---------+---------+---------+---------+ | crc checksum | record type | key size | value size | key | value | +-------------+----

(logrecord *LogRecord)

// |   4 bytes     |  1 byte       | variable (max 5)  |  variable (max 5)   |  variable  |  variable |
// +-------------+------------+------------+--------------+-------+---------+---------+---------+---------+
func EncodeLogRecord(logrecord *LogRecord) ([]byte, int64) {
	header := make([]byte, maxLogRecordHeaderSize)

	// Store the record type at the fifth byte
	header[4] = logrecord.Type
	var headerIndex = 5

	// Store the lengths of key and value after the fifth byte
	// Use variable-length encoding to save space
	headerIndex += binary.PutVarint(header[headerIndex:], int64(len(logrecord.Key)))
	headerIndex += binary.PutVarint(header[headerIndex:], int64(len(logrecord.Value)))

	var size = headerIndex + len(logrecord.Key) + len(logrecord.Value)
	encBytes := make([]byte, size)

	// Copy the header content and key/value data
	copy(encBytes[:headerIndex], header[:headerIndex])
	copy(encBytes[headerIndex:], logrecord.Key)
	copy(encBytes[headerIndex+len(logrecord.Key):], logrecord.Value)

	// Calculate the CRC checksum for the entire LogRecord data
	crc := crc32.ChecksumIEEE(encBytes[4:])
	binary.LittleEndian.PutUint32(encBytes[:4], crc)

	return encBytes, int64(size)
}

// EncodeLogRecordPst encodes the position information of a log record.
func EncodeLogRecordPst(pst *LogRecordPst) []byte {