Function reassembleBytes

cmd/es-utils/utils/optimism_blob_encoder.go:215–225

reassembleBytes takes the 4x6-bit chunks from encodedByte, reassembles them into 3 bytes of output, and places them in their appropriate output positions.

(opos int, encodedByte []byte, output []byte)

// reassembleBytes takes the 4x6-bit chunks from encodedByte, reassembles them into 3 bytes of
// output, and places them in their appropriate output positions.
func reassembleBytes(opos int, encodedByte []byte, output []byte) int {
	opos-- // account for fact that we don't output a 128th byte
	x := (encodedByte[0] & 0b0011_1111) | ((encodedByte[1] & 0b0011_0000) << 2)
	y := (encodedByte[1] & 0b0000_1111) | ((encodedByte[3] & 0b0000_1111) << 4)
	z := (encodedByte[2] & 0b0011_1111) | ((encodedByte[3] & 0b0011_0000) << 2)
	// put the re-assembled bytes in their appropriate output locations
	output[opos-32] = z
	output[opos-(32*2)] = y
	output[opos-(32*3)] = x
	return opos
}