33 lines
563 B
Go
33 lines
563 B
Go
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package crc16
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var Crc16Table = make([]uint16, 256)
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const GeneratorPolynomial = 0x1021
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func init() {
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calculateTable()
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}
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func calculateTable() {
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for dividend := 0; dividend < 256; dividend++ {
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crc := uint16(dividend << 8)
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for bit := 0; bit < 8; bit++ {
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if (crc & 0x8000) != 0 {
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crc = (crc << 1) ^ GeneratorPolynomial
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} else {
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crc <<= 1
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}
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}
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Crc16Table[dividend] = crc
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}
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}
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func Calculate(data []byte) uint16 {
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crc := uint16(0)
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for _, b := range data {
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pos := byte(crc>>8) ^ b
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crc = (crc << 8) ^ Crc16Table[pos]
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}
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return crc
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}
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