1 /* 2 * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com> 3 * 4 * libcbor is free software; you can redistribute it and/or modify 5 * it under the terms of the MIT license. See LICENSE for details. 6 */ 7 8 #ifndef LIBCBOR_ENCODING_H 9 #define LIBCBOR_ENCODING_H 10 11 #include "cbor/cbor_export.h" 12 #include "cbor/common.h" 13 14 #ifdef __cplusplus 15 extern "C" { 16 #endif 17 18 /* 19 * All cbor_encode_* methods take 2 or 3 arguments: 20 * - a logical `value` to encode (except for trivial items such as NULLs) 21 * - an output `buffer` pointer 22 * - a `buffer_size` specification 23 * 24 * They serialize the `value` into one or more bytes and write the bytes to the 25 * output `buffer` and return either the number of bytes written, or 0 if the 26 * `buffer_size` was too small to small to fit the serialized value (in which 27 * case it is not modified). 28 */ 29 30 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_uint8(uint8_t, unsigned char *, 31 size_t); 32 33 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_uint16(uint16_t, unsigned char *, 34 size_t); 35 36 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_uint32(uint32_t, unsigned char *, 37 size_t); 38 39 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_uint64(uint64_t, unsigned char *, 40 size_t); 41 42 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_uint(uint64_t, unsigned char *, 43 size_t); 44 45 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_negint8(uint8_t, unsigned char *, 46 size_t); 47 48 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_negint16(uint16_t, 49 unsigned char *, 50 size_t); 51 52 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_negint32(uint32_t, 53 unsigned char *, 54 size_t); 55 56 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_negint64(uint64_t, 57 unsigned char *, 58 size_t); 59 60 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_negint(uint64_t, unsigned char *, 61 size_t); 62 63 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_bytestring_start(size_t, 64 unsigned char *, 65 size_t); 66 67 _CBOR_NODISCARD CBOR_EXPORT size_t 68 cbor_encode_indef_bytestring_start(unsigned char *, size_t); 69 70 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_string_start(size_t, 71 unsigned char *, 72 size_t); 73 74 _CBOR_NODISCARD CBOR_EXPORT size_t 75 cbor_encode_indef_string_start(unsigned char *, size_t); 76 77 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_array_start(size_t, 78 unsigned char *, 79 size_t); 80 81 _CBOR_NODISCARD CBOR_EXPORT size_t 82 cbor_encode_indef_array_start(unsigned char *, size_t); 83 84 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_map_start(size_t, 85 unsigned char *, 86 size_t); 87 88 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_indef_map_start(unsigned char *, 89 size_t); 90 91 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_tag(uint64_t, unsigned char *, 92 size_t); 93 94 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_bool(bool, unsigned char *, 95 size_t); 96 97 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_null(unsigned char *, size_t); 98 99 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_undef(unsigned char *, size_t); 100 101 /** Encodes a half-precision float 102 * 103 * Since there is no native representation or semantics for half floats 104 * in the language, we use single-precision floats, as every value that 105 * can be expressed as a half-float can also be expressed as a float. 106 * 107 * This however means that not all floats passed to this function can be 108 * unambiguously encoded. The behavior is as follows: 109 * - Infinity, NaN are preserved 110 * - Zero is preserved 111 * - Denormalized numbers keep their sign bit and 10 most significant bit of 112 * the significand 113 * - All other numbers 114 * - If the logical value of the exponent is < -24, the output is zero 115 * - If the logical value of the exponent is between -23 and -14, the output 116 * is cut off to represent the 'magnitude' of the input, by which we 117 * mean (-1)^{signbit} x 1.0e{exponent}. The value in the significand is 118 * lost. 119 * - In all other cases, the sign bit, the exponent, and 10 most significant 120 * bits of the significand are kept 121 */ 122 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_half(float, unsigned char *, 123 size_t); 124 125 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_single(float, unsigned char *, 126 size_t); 127 128 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_double(double, unsigned char *, 129 size_t); 130 131 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_break(unsigned char *, size_t); 132 133 _CBOR_NODISCARD CBOR_EXPORT size_t cbor_encode_ctrl(uint8_t, unsigned char *, 134 size_t); 135 136 #ifdef __cplusplus 137 } 138 #endif 139 140 #endif // LIBCBOR_ENCODING_H 141