/* * Copyright (c) 2018 IOTA Stiftung * https://github.com/iotaledger/iota_common * * Refer to the LICENSE file for licensing information */ #include #include #include "common/trinary/trit_byte.h" #include "utils/macros.h" // Since the LUT can be quite heavy for little devices, it is possible to // disable it and recompute values at runtime #ifndef NO_BYTES_TRITS_LUT // Values are ordered like this: 0, 1, ... 120, 121, -121, -120, ... -2, -1 static trit_t const BYTES_TRITS_LUT[BYTE_SPACE_SIZE][NUMBER_OF_TRITS_IN_A_BYTE] = { {0, 0, 0, 0, 0}, {1, 0, 0, 0, 0}, {-1, 1, 0, 0, 0}, {0, 1, 0, 0, 0}, {1, 1, 0, 0, 0}, {-1, -1, 1, 0, 0}, {0, -1, 1, 0, 0}, {1, -1, 1, 0, 0}, {-1, 0, 1, 0, 0}, {0, 0, 1, 0, 0}, {1, 0, 1, 0, 0}, {-1, 1, 1, 0, 0}, {0, 1, 1, 0, 0}, {1, 1, 1, 0, 0}, {-1, -1, -1, 1, 0}, {0, -1, -1, 1, 0}, {1, -1, -1, 1, 0}, {-1, 0, -1, 1, 0}, {0, 0, -1, 1, 0}, {1, 0, -1, 1, 0}, {-1, 1, -1, 1, 0}, {0, 1, -1, 1, 0}, {1, 1, -1, 1, 0}, {-1, -1, 0, 1, 0}, {0, -1, 0, 1, 0}, {1, -1, 0, 1, 0}, {-1, 0, 0, 1, 0}, {0, 0, 0, 1, 0}, {1, 0, 0, 1, 0}, {-1, 1, 0, 1, 0}, {0, 1, 0, 1, 0}, {1, 1, 0, 1, 0}, {-1, -1, 1, 1, 0}, {0, -1, 1, 1, 0}, {1, -1, 1, 1, 0}, {-1, 0, 1, 1, 0}, {0, 0, 1, 1, 0}, {1, 0, 1, 1, 0}, {-1, 1, 1, 1, 0}, {0, 1, 1, 1, 0}, {1, 1, 1, 1, 0}, {-1, -1, -1, -1, 1}, {0, -1, -1, -1, 1}, {1, -1, -1, -1, 1}, {-1, 0, -1, -1, 1}, {0, 0, -1, -1, 1}, {1, 0, -1, -1, 1}, {-1, 1, -1, -1, 1}, {0, 1, -1, -1, 1}, {1, 1, -1, -1, 1}, {-1, -1, 0, -1, 1}, {0, -1, 0, -1, 1}, {1, -1, 0, -1, 1}, {-1, 0, 0, -1, 1}, {0, 0, 0, -1, 1}, {1, 0, 0, -1, 1}, {-1, 1, 0, -1, 1}, {0, 1, 0, -1, 1}, {1, 1, 0, -1, 1}, {-1, -1, 1, -1, 1}, {0, -1, 1, -1, 1}, {1, -1, 1, -1, 1}, {-1, 0, 1, -1, 1}, {0, 0, 1, -1, 1}, {1, 0, 1, -1, 1}, {-1, 1, 1, -1, 1}, {0, 1, 1, -1, 1}, {1, 1, 1, -1, 1}, {-1, -1, -1, 0, 1}, {0, -1, -1, 0, 1}, {1, -1, -1, 0, 1}, {-1, 0, -1, 0, 1}, {0, 0, -1, 0, 1}, {1, 0, -1, 0, 1}, {-1, 1, -1, 0, 1}, {0, 1, -1, 0, 1}, {1, 1, -1, 0, 1}, {-1, -1, 0, 0, 1}, {0, -1, 0, 0, 1}, {1, -1, 0, 0, 1}, {-1, 0, 0, 0, 1}, {0, 0, 0, 0, 1}, {1, 0, 0, 0, 1}, {-1, 1, 0, 0, 1}, {0, 1, 0, 0, 1}, {1, 1, 0, 0, 1}, {-1, -1, 1, 0, 1}, {0, -1, 1, 0, 1}, {1, -1, 1, 0, 1}, {-1, 0, 1, 0, 1}, {0, 0, 1, 0, 1}, {1, 0, 1, 0, 1}, {-1, 1, 1, 0, 1}, {0, 1, 1, 0, 1}, {1, 1, 1, 0, 1}, {-1, -1, -1, 1, 1}, {0, -1, -1, 1, 1}, {1, -1, -1, 1, 1}, {-1, 0, -1, 1, 1}, {0, 0, -1, 1, 1}, {1, 0, -1, 1, 1}, {-1, 1, -1, 1, 1}, {0, 1, -1, 1, 1}, {1, 1, -1, 1, 1}, {-1, -1, 0, 1, 1}, {0, -1, 0, 1, 1}, {1, -1, 0, 1, 1}, {-1, 0, 0, 1, 1}, {0, 0, 0, 1, 1}, {1, 0, 0, 1, 1}, {-1, 1, 0, 1, 1}, {0, 1, 0, 1, 1}, {1, 1, 0, 1, 1}, {-1, -1, 1, 1, 1}, {0, -1, 1, 1, 1}, {1, -1, 1, 1, 1}, {-1, 0, 1, 1, 1}, {0, 0, 1, 1, 1}, {1, 0, 1, 1, 1}, {-1, 1, 1, 1, 1}, {0, 1, 1, 1, 1}, {1, 1, 1, 1, 1}, {-1, -1, -1, -1, -1}, {0, -1, -1, -1, -1}, {1, -1, -1, -1, -1}, {-1, 0, -1, -1, -1}, {0, 0, -1, -1, -1}, {1, 0, -1, -1, -1}, {-1, 1, -1, -1, -1}, {0, 1, -1, -1, -1}, {1, 1, -1, -1, -1}, {-1, -1, 0, -1, -1}, {0, -1, 0, -1, -1}, {1, -1, 0, -1, -1}, {-1, 0, 0, -1, -1}, {0, 0, 0, -1, -1}, {1, 0, 0, -1, -1}, {-1, 1, 0, -1, -1}, {0, 1, 0, -1, -1}, {1, 1, 0, -1, -1}, {-1, -1, 1, -1, -1}, {0, -1, 1, -1, -1}, {1, -1, 1, -1, -1}, {-1, 0, 1, -1, -1}, {0, 0, 1, -1, -1}, {1, 0, 1, -1, -1}, {-1, 1, 1, -1, -1}, {0, 1, 1, -1, -1}, {1, 1, 1, -1, -1}, {-1, -1, -1, 0, -1}, {0, -1, -1, 0, -1}, {1, -1, -1, 0, -1}, {-1, 0, -1, 0, -1}, {0, 0, -1, 0, -1}, {1, 0, -1, 0, -1}, {-1, 1, -1, 0, -1}, {0, 1, -1, 0, -1}, {1, 1, -1, 0, -1}, {-1, -1, 0, 0, -1}, {0, -1, 0, 0, -1}, {1, -1, 0, 0, -1}, {-1, 0, 0, 0, -1}, {0, 0, 0, 0, -1}, {1, 0, 0, 0, -1}, {-1, 1, 0, 0, -1}, {0, 1, 0, 0, -1}, {1, 1, 0, 0, -1}, {-1, -1, 1, 0, -1}, {0, -1, 1, 0, -1}, {1, -1, 1, 0, -1}, {-1, 0, 1, 0, -1}, {0, 0, 1, 0, -1}, {1, 0, 1, 0, -1}, {-1, 1, 1, 0, -1}, {0, 1, 1, 0, -1}, {1, 1, 1, 0, -1}, {-1, -1, -1, 1, -1}, {0, -1, -1, 1, -1}, {1, -1, -1, 1, -1}, {-1, 0, -1, 1, -1}, {0, 0, -1, 1, -1}, {1, 0, -1, 1, -1}, {-1, 1, -1, 1, -1}, {0, 1, -1, 1, -1}, {1, 1, -1, 1, -1}, {-1, -1, 0, 1, -1}, {0, -1, 0, 1, -1}, {1, -1, 0, 1, -1}, {-1, 0, 0, 1, -1}, {0, 0, 0, 1, -1}, {1, 0, 0, 1, -1}, {-1, 1, 0, 1, -1}, {0, 1, 0, 1, -1}, {1, 1, 0, 1, -1}, {-1, -1, 1, 1, -1}, {0, -1, 1, 1, -1}, {1, -1, 1, 1, -1}, {-1, 0, 1, 1, -1}, {0, 0, 1, 1, -1}, {1, 0, 1, 1, -1}, {-1, 1, 1, 1, -1}, {0, 1, 1, 1, -1}, {1, 1, 1, 1, -1}, {-1, -1, -1, -1, 0}, {0, -1, -1, -1, 0}, {1, -1, -1, -1, 0}, {-1, 0, -1, -1, 0}, {0, 0, -1, -1, 0}, {1, 0, -1, -1, 0}, {-1, 1, -1, -1, 0}, {0, 1, -1, -1, 0}, {1, 1, -1, -1, 0}, {-1, -1, 0, -1, 0}, {0, -1, 0, -1, 0}, {1, -1, 0, -1, 0}, {-1, 0, 0, -1, 0}, {0, 0, 0, -1, 0}, {1, 0, 0, -1, 0}, {-1, 1, 0, -1, 0}, {0, 1, 0, -1, 0}, {1, 1, 0, -1, 0}, {-1, -1, 1, -1, 0}, {0, -1, 1, -1, 0}, {1, -1, 1, -1, 0}, {-1, 0, 1, -1, 0}, {0, 0, 1, -1, 0}, {1, 0, 1, -1, 0}, {-1, 1, 1, -1, 0}, {0, 1, 1, -1, 0}, {1, 1, 1, -1, 0}, {-1, -1, -1, 0, 0}, {0, -1, -1, 0, 0}, {1, -1, -1, 0, 0}, {-1, 0, -1, 0, 0}, {0, 0, -1, 0, 0}, {1, 0, -1, 0, 0}, {-1, 1, -1, 0, 0}, {0, 1, -1, 0, 0}, {1, 1, -1, 0, 0}, {-1, -1, 0, 0, 0}, {0, -1, 0, 0, 0}, {1, -1, 0, 0, 0}, {-1, 0, 0, 0, 0}}; #else static const byte_t byte_radix[] = {1, 3, 9, 27, 81}; #endif // NO_BYTES_TRITS_LUT byte_t trits_to_byte(trit_t const *const trits, size_t const num_trits) { byte_t byte = 0; assert(num_trits <= NUMBER_OF_TRITS_IN_A_BYTE); if (num_trits == 0) { return 0; } for (int i = num_trits - 1; i >= 0; i--) { byte = byte * RADIX + trits[i]; } return byte; } void trits_to_bytes(trit_t const *const trits, byte_t *const bytes, size_t const num_trits) { if (num_trits == 0) { return; } for (size_t i = 0, j = 0; i < num_trits; i += NUMBER_OF_TRITS_IN_A_BYTE, j++) { bytes[j] = trits_to_byte(trits + i, MIN(num_trits - i, NUMBER_OF_TRITS_IN_A_BYTE)); } } void byte_to_trits(byte_t const byte, trit_t *const trits, size_t const num_trits) { assert(num_trits <= NUMBER_OF_TRITS_IN_A_BYTE); if (num_trits == 0) { return; } #ifndef NO_BYTES_TRITS_LUT memcpy(trits, BYTES_TRITS_LUT[byte < 0 ? BYTE_SPACE_SIZE + byte : byte], num_trits); #else size_t j = NUMBER_OF_TRITS_IN_A_BYTE - 1; size_t i = num_trits - 1; byte_t value = byte; while (j < -1) { trit_t trit = 0; if (value > (byte_radix[j] >> 1)) { value -= byte_radix[j]; trit = 1; } else if (value < -(byte_radix[j] >> 1)) { value += byte_radix[j]; trit = -1; } if (j == i) { trits[i] = trit; i -= 1; } j -= 1; } #endif // NO_BYTES_TRITS_LUT } void bytes_to_trits(byte_t const *const bytes, size_t const num_bytes, trit_t *const trits, size_t const num_trits) { assert(num_trits <= NUMBER_OF_TRITS_IN_A_BYTE * num_bytes); if (num_bytes == 0 || num_trits == 0) { return; } for (size_t i = 0, j = 0; i < num_trits && j < num_bytes; i += NUMBER_OF_TRITS_IN_A_BYTE, j++) { byte_to_trits(bytes[j], &trits[i], MIN(num_trits - i, NUMBER_OF_TRITS_IN_A_BYTE)); } }