| /**************************************************************************** |
| ** |
| ** Copyright (C) 2016 Intel Corporation |
| ** |
| ** Permission is hereby granted, free of charge, to any person obtaining a copy |
| ** of this software and associated documentation files (the "Software"), to deal |
| ** in the Software without restriction, including without limitation the rights |
| ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| ** copies of the Software, and to permit persons to whom the Software is |
| ** furnished to do so, subject to the following conditions: |
| ** |
| ** The above copyright notice and this permission notice shall be included in |
| ** all copies or substantial portions of the Software. |
| ** |
| ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| ** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| ** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| ** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| ** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| ** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| ** THE SOFTWARE. |
| ** |
| ****************************************************************************/ |
| |
| #ifndef _BSD_SOURCE |
| #define _BSD_SOURCE 1 |
| #endif |
| #ifndef _DEFAULT_SOURCE |
| #define _DEFAULT_SOURCE 1 |
| #endif |
| #ifndef __STDC_LIMIT_MACROS |
| # define __STDC_LIMIT_MACROS 1 |
| #endif |
| |
| #include "cbor.h" |
| #include "cborinternal_p.h" |
| #include "compilersupport_p.h" |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| /** |
| * \defgroup CborEncoding Encoding to CBOR |
| * \brief Group of functions used to encode data to CBOR. |
| * |
| * CborEncoder is used to encode data into a CBOR stream. The outermost |
| * CborEncoder is initialized by calling cbor_encoder_init(), with the buffer |
| * where the CBOR stream will be stored. The outermost CborEncoder is usually |
| * used to encode exactly one item, most often an array or map. It is possible |
| * to encode more than one item, but care must then be taken on the decoder |
| * side to ensure the state is reset after each item was decoded. |
| * |
| * Nested CborEncoder objects are created using cbor_encoder_create_array() and |
| * cbor_encoder_create_map(), later closed with cbor_encoder_close_container() |
| * or cbor_encoder_close_container_checked(). The pairs of creation and closing |
| * must be exactly matched and their parameters are always the same. |
| * |
| * CborEncoder writes directly to the user-supplied buffer, without extra |
| * buffering. CborEncoder does not allocate memory and CborEncoder objects are |
| * usually created on the stack of the encoding functions. |
| * |
| * The example below initializes a CborEncoder object with a buffer and encodes |
| * a single integer. |
| * |
| * \code |
| * uint8_t buf[16]; |
| * CborEncoder encoder; |
| * cbor_encoder_init(&encoder, buf, sizeof(buf), 0); |
| * cbor_encode_int(&encoder, some_value); |
| * \endcode |
| * |
| * As explained before, usually the outermost CborEncoder object is used to add |
| * one array or map, which in turn contains multiple elements. The example |
| * below creates a CBOR map with one element: a key "foo" and a boolean value. |
| * |
| * \code |
| * uint8_t buf[16]; |
| * CborEncoder encoder, mapEncoder; |
| * cbor_encoder_init(&encoder, buf, sizeof(buf), 0); |
| * cbor_encoder_create_map(&encoder, &mapEncoder, 1); |
| * cbor_encode_text_stringz(&mapEncoder, "foo"); |
| * cbor_encode_boolean(&mapEncoder, some_value); |
| * cbor_encoder_close_container(&encoder, &mapEncoder); |
| * \endcode |
| * |
| * <h3 class="groupheader">Error checking and buffer size</h3> |
| * |
| * All functions operating on CborEncoder return a condition of type CborError. |
| * If the encoding was successful, they return CborNoError. Some functions do |
| * extra checking on the input provided and may return some other error |
| * conditions (for example, cbor_encode_simple_value() checks that the type is |
| * of the correct type). |
| * |
| * In addition, all functions check whether the buffer has enough bytes to |
| * encode the item being appended. If that is not possible, they return |
| * CborErrorOutOfMemory. |
| * |
| * It is possible to continue with the encoding of data past the first function |
| * that returns CborErrorOutOfMemory. CborEncoder functions will not overrun |
| * the buffer, but will instead count how many more bytes are needed to |
| * complete the encoding. At the end, you can obtain that count by calling |
| * cbor_encoder_get_extra_bytes_needed(). |
| * |
| * \section1 Finalizing the encoding |
| * |
| * Once all items have been appended and the containers have all been properly |
| * closed, the user-supplied buffer will contain the CBOR stream and may be |
| * immediately used. To obtain the size of the buffer, call |
| * cbor_encoder_get_buffer_size() with the original buffer pointer. |
| * |
| * The example below illustrates how one can encode an item with error checking |
| * and then pass on the buffer for network sending. |
| * |
| * \code |
| * uint8_t buf[16]; |
| * CborError err; |
| * CborEncoder encoder, mapEncoder; |
| * cbor_encoder_init(&encoder, buf, sizeof(buf), 0); |
| * err = cbor_encoder_create_map(&encoder, &mapEncoder, 1); |
| * if (err) |
| * return err; |
| * err = cbor_encode_text_stringz(&mapEncoder, "foo"); |
| * if (err) |
| * return err; |
| * err = cbor_encode_boolean(&mapEncoder, some_value); |
| * if (err) |
| * return err; |
| * err = cbor_encoder_close_container_checked(&encoder, &mapEncoder); |
| * if (err) |
| * return err; |
| * |
| * size_t len = cbor_encoder_get_buffer_size(&encoder, buf); |
| * send_payload(buf, len); |
| * return CborNoError; |
| * \endcode |
| * |
| * Finally, the example below expands on the one above and also |
| * deals with dynamically growing the buffer if the initial allocation wasn't |
| * big enough. Note the two places where the error checking was replaced with |
| * an cbor_assertion, showing where the author assumes no error can occur. |
| * |
| * \code |
| * uint8_t *encode_string_array(const char **strings, int n, size_t *bufsize) |
| * { |
| * CborError err; |
| * CborEncoder encoder, arrayEncoder; |
| * size_t size = 256; |
| * uint8_t *buf = NULL; |
| * |
| * while (1) { |
| * int i; |
| * size_t more_bytes; |
| * uint8_t *nbuf = realloc(buf, size); |
| * if (nbuf == NULL) |
| * goto error; |
| * buf = nbuf; |
| * |
| * cbor_encoder_init(&encoder, buf, size, 0); |
| * err = cbor_encoder_create_array(&encoder, &arrayEncoder, n); |
| * cbor_assert(!err); // can't fail, the buffer is always big enough |
| * |
| * for (i = 0; i < n; ++i) { |
| * err = cbor_encode_text_stringz(&arrayEncoder, strings[i]); |
| * if (err && err != CborErrorOutOfMemory) |
| * goto error; |
| * } |
| * |
| * err = cbor_encoder_close_container_checked(&encoder, &arrayEncoder); |
| * cbor_assert(!err); // shouldn't fail! |
| * |
| * more_bytes = cbor_encoder_get_extra_bytes_needed(encoder); |
| * if (more_size) { |
| * // buffer wasn't big enough, try again |
| * size += more_bytes; |
| * continue; |
| * } |
| * |
| * *bufsize = cbor_encoder_get_buffer_size(encoder, buf); |
| * return buf; |
| * } |
| * error: |
| * free(buf); |
| * return NULL; |
| * } |
| * \endcode |
| */ |
| |
| /** |
| * \addtogroup CborEncoding |
| * @{ |
| */ |
| |
| /** |
| * \struct CborEncoder |
| * Structure used to encode to CBOR. |
| */ |
| |
| /** |
| * Initializes a CborEncoder structure \a encoder by pointing it to buffer \a |
| * buffer of size \a size. The \a flags field is currently unused and must be |
| * zero. |
| */ |
| void cbor_encoder_init(CborEncoder *encoder, uint8_t *buffer, size_t size, int flags) |
| { |
| encoder->data.ptr = buffer; |
| encoder->end = buffer + size; |
| encoder->remaining = 2; |
| encoder->flags = flags; |
| } |
| |
| static inline void put16(void *where, uint16_t v) |
| { |
| uint16_t v_be = cbor_htons(v); |
| memcpy(where, &v_be, sizeof(v_be)); |
| } |
| |
| /* Note: Since this is currently only used in situations where OOM is the only |
| * valid error, we KNOW this to be true. Thus, this function now returns just 'true', |
| * but if in the future, any function starts returning a non-OOM error, this will need |
| * to be changed to the test. At the moment, this is done to prevent more branches |
| * being created in the tinycbor output */ |
| static inline bool isOomError(CborError err) |
| { |
| (void) err; |
| return true; |
| } |
| |
| static inline void put32(void *where, uint32_t v) |
| { |
| uint32_t v_be = cbor_htonl(v); |
| memcpy(where, &v_be, sizeof(v_be)); |
| } |
| |
| static inline void put64(void *where, uint64_t v) |
| { |
| uint64_t v_be = cbor_htonll(v); |
| memcpy(where, &v_be, sizeof(v_be)); |
| } |
| |
| static inline bool would_overflow(CborEncoder *encoder, size_t len) |
| { |
| ptrdiff_t remaining = (ptrdiff_t)encoder->end; |
| remaining -= remaining ? (ptrdiff_t)encoder->data.ptr : encoder->data.bytes_needed; |
| remaining -= (ptrdiff_t)len; |
| return unlikely(remaining < 0); |
| } |
| |
| static inline void advance_ptr(CborEncoder *encoder, size_t n) |
| { |
| if (encoder->end) |
| encoder->data.ptr += n; |
| else |
| encoder->data.bytes_needed += n; |
| } |
| |
| static inline CborError append_to_buffer(CborEncoder *encoder, const void *data, size_t len) |
| { |
| if (would_overflow(encoder, len)) { |
| if (encoder->end != NULL) { |
| len -= encoder->end - encoder->data.ptr; |
| encoder->end = NULL; |
| encoder->data.bytes_needed = 0; |
| } |
| |
| advance_ptr(encoder, len); |
| return CborErrorOutOfMemory; |
| } |
| |
| memcpy(encoder->data.ptr, data, len); |
| encoder->data.ptr += len; |
| return CborNoError; |
| } |
| |
| static inline CborError append_byte_to_buffer(CborEncoder *encoder, uint8_t byte) |
| { |
| return append_to_buffer(encoder, &byte, 1); |
| } |
| |
| static inline CborError encode_number_no_update(CborEncoder *encoder, uint64_t ui, uint8_t shiftedMajorType) |
| { |
| /* Little-endian would have been so much more convenient here: |
| * We could just write at the beginning of buf but append_to_buffer |
| * only the necessary bytes. |
| * Since it has to be big endian, do it the other way around: |
| * write from the end. */ |
| uint64_t buf[2]; |
| uint8_t *const bufend = (uint8_t *)buf + sizeof(buf); |
| uint8_t *bufstart = bufend - 1; |
| put64(buf + 1, ui); /* we probably have a bunch of zeros in the beginning */ |
| |
| if (ui < Value8Bit) { |
| *bufstart += shiftedMajorType; |
| } else { |
| uint8_t more = 0; |
| if (ui > 0xffU) |
| ++more; |
| if (ui > 0xffffU) |
| ++more; |
| if (ui > 0xffffffffU) |
| ++more; |
| bufstart -= (size_t)1 << more; |
| *bufstart = shiftedMajorType + Value8Bit + more; |
| } |
| |
| return append_to_buffer(encoder, bufstart, bufend - bufstart); |
| } |
| |
| static inline void saturated_decrement(CborEncoder *encoder) |
| { |
| if (encoder->remaining) |
| --encoder->remaining; |
| } |
| |
| static inline CborError encode_number(CborEncoder *encoder, uint64_t ui, uint8_t shiftedMajorType) |
| { |
| saturated_decrement(encoder); |
| return encode_number_no_update(encoder, ui, shiftedMajorType); |
| } |
| |
| /** |
| * Appends the unsigned 64-bit integer \a value to the CBOR stream provided by |
| * \a encoder. |
| * |
| * \sa cbor_encode_negative_int, cbor_encode_int |
| */ |
| CborError cbor_encode_uint(CborEncoder *encoder, uint64_t value) |
| { |
| return encode_number(encoder, value, UnsignedIntegerType << MajorTypeShift); |
| } |
| |
| /** |
| * Appends the negative 64-bit integer whose absolute value is \a |
| * absolute_value to the CBOR stream provided by \a encoder. |
| * |
| * If the value \a absolute_value is zero, this function encodes -2^64. |
| * |
| * \sa cbor_encode_uint, cbor_encode_int |
| */ |
| CborError cbor_encode_negative_int(CborEncoder *encoder, uint64_t absolute_value) |
| { |
| return encode_number(encoder, absolute_value - 1, NegativeIntegerType << MajorTypeShift); |
| } |
| |
| /** |
| * Appends the signed 64-bit integer \a value to the CBOR stream provided by |
| * \a encoder. |
| * |
| * \sa cbor_encode_negative_int, cbor_encode_uint |
| */ |
| CborError cbor_encode_int(CborEncoder *encoder, int64_t value) |
| { |
| /* adapted from code in RFC 7049 appendix C (pseudocode) */ |
| uint64_t ui = value >> 63; /* extend sign to whole length */ |
| uint8_t majorType = ui & 0x20; /* extract major type */ |
| ui ^= value; /* complement negatives */ |
| return encode_number(encoder, ui, majorType); |
| } |
| |
| /** |
| * Appends the CBOR Simple Type of value \a value to the CBOR stream provided by |
| * \a encoder. |
| * |
| * This function may return error CborErrorIllegalSimpleType if the \a value |
| * variable contains a number that is not a valid simple type. |
| */ |
| CborError cbor_encode_simple_value(CborEncoder *encoder, uint8_t value) |
| { |
| #ifndef CBOR_ENCODER_NO_CHECK_USER |
| /* check if this is a valid simple type */ |
| if (value >= HalfPrecisionFloat && value <= Break) |
| return CborErrorIllegalSimpleType; |
| #endif |
| return encode_number(encoder, value, SimpleTypesType << MajorTypeShift); |
| } |
| |
| /** |
| * Appends the floating-point value of type \a fpType and pointed to by \a |
| * value to the CBOR stream provided by \a encoder. The value of \a fpType must |
| * be one of CborHalfFloatType, CborFloatType or CborDoubleType, otherwise the |
| * behavior of this function is undefined. |
| * |
| * This function is useful for code that needs to pass through floating point |
| * values but does not wish to have the actual floating-point code. |
| * |
| * \sa cbor_encode_half_float, cbor_encode_float, cbor_encode_double |
| */ |
| CborError cbor_encode_floating_point(CborEncoder *encoder, CborType fpType, const void *value) |
| { |
| unsigned size; |
| uint8_t buf[1 + sizeof(uint64_t)]; |
| cbor_assert(fpType == CborHalfFloatType || fpType == CborFloatType || fpType == CborDoubleType); |
| buf[0] = fpType; |
| |
| size = 2U << (fpType - CborHalfFloatType); |
| if (size == 8) |
| put64(buf + 1, *(const uint64_t*)value); |
| else if (size == 4) |
| put32(buf + 1, *(const uint32_t*)value); |
| else |
| put16(buf + 1, *(const uint16_t*)value); |
| saturated_decrement(encoder); |
| return append_to_buffer(encoder, buf, size + 1); |
| } |
| |
| /** |
| * Appends the CBOR tag \a tag to the CBOR stream provided by \a encoder. |
| * |
| * \sa CborTag |
| */ |
| CborError cbor_encode_tag(CborEncoder *encoder, CborTag tag) |
| { |
| /* tags don't count towards the number of elements in an array or map */ |
| return encode_number_no_update(encoder, tag, TagType << MajorTypeShift); |
| } |
| |
| static CborError encode_string(CborEncoder *encoder, size_t length, uint8_t shiftedMajorType, const void *string) |
| { |
| CborError err = encode_number(encoder, length, shiftedMajorType); |
| if (err && !isOomError(err)) |
| return err; |
| return append_to_buffer(encoder, string, length); |
| } |
| |
| /** |
| * \fn CborError cbor_encode_text_stringz(CborEncoder *encoder, const char *string) |
| * |
| * Appends the null-terminated text string \a string to the CBOR stream |
| * provided by \a encoder. CBOR requires that \a string be valid UTF-8, but |
| * TinyCBOR makes no verification of correctness. The terminating null is not |
| * included in the stream. |
| * |
| * \sa cbor_encode_text_string, cbor_encode_byte_string |
| */ |
| |
| /** |
| * Appends the byte string \a string of length \a length to the CBOR stream |
| * provided by \a encoder. CBOR byte strings are arbitrary raw data. |
| * |
| * \sa cbor_encode_text_stringz, cbor_encode_text_string |
| */ |
| CborError cbor_encode_byte_string(CborEncoder *encoder, const uint8_t *string, size_t length) |
| { |
| return encode_string(encoder, length, ByteStringType << MajorTypeShift, string); |
| } |
| |
| /** |
| * Appends the text string \a string of length \a length to the CBOR stream |
| * provided by \a encoder. CBOR requires that \a string be valid UTF-8, but |
| * TinyCBOR makes no verification of correctness. |
| * |
| * \sa CborError cbor_encode_text_stringz, cbor_encode_byte_string |
| */ |
| CborError cbor_encode_text_string(CborEncoder *encoder, const char *string, size_t length) |
| { |
| return encode_string(encoder, length, TextStringType << MajorTypeShift, string); |
| } |
| |
| #ifdef __GNUC__ |
| __attribute__((noinline)) |
| #endif |
| static CborError create_container(CborEncoder *encoder, CborEncoder *container, size_t length, uint8_t shiftedMajorType) |
| { |
| CborError err; |
| container->data.ptr = encoder->data.ptr; |
| container->end = encoder->end; |
| saturated_decrement(encoder); |
| container->remaining = length + 1; /* overflow ok on CborIndefiniteLength */ |
| |
| cbor_static_assert(((MapType << MajorTypeShift) & CborIteratorFlag_ContainerIsMap) == CborIteratorFlag_ContainerIsMap); |
| cbor_static_assert(((ArrayType << MajorTypeShift) & CborIteratorFlag_ContainerIsMap) == 0); |
| container->flags = shiftedMajorType & CborIteratorFlag_ContainerIsMap; |
| |
| if (length == CborIndefiniteLength) { |
| container->flags |= CborIteratorFlag_UnknownLength; |
| err = append_byte_to_buffer(container, shiftedMajorType + IndefiniteLength); |
| } else { |
| if (shiftedMajorType & CborIteratorFlag_ContainerIsMap) |
| container->remaining += length; |
| err = encode_number_no_update(container, length, shiftedMajorType); |
| } |
| return err; |
| } |
| |
| /** |
| * Creates a CBOR array in the CBOR stream provided by \a encoder and |
| * initializes \a arrayEncoder so that items can be added to the array using |
| * the CborEncoder functions. The array must be terminated by calling either |
| * cbor_encoder_close_container() or cbor_encoder_close_container_checked() |
| * with the same \a encoder and \a arrayEncoder parameters. |
| * |
| * The number of items inserted into the array must be exactly \a length items, |
| * otherwise the stream is invalid. If the number of items is not known when |
| * creating the array, the constant \ref CborIndefiniteLength may be passed as |
| * length instead. |
| * |
| * \sa cbor_encoder_create_map |
| */ |
| CborError cbor_encoder_create_array(CborEncoder *encoder, CborEncoder *arrayEncoder, size_t length) |
| { |
| return create_container(encoder, arrayEncoder, length, ArrayType << MajorTypeShift); |
| } |
| |
| /** |
| * Creates a CBOR map in the CBOR stream provided by \a encoder and |
| * initializes \a mapEncoder so that items can be added to the map using |
| * the CborEncoder functions. The map must be terminated by calling either |
| * cbor_encoder_close_container() or cbor_encoder_close_container_checked() |
| * with the same \a encoder and \a mapEncoder parameters. |
| * |
| * The number of pair of items inserted into the map must be exactly \a length |
| * items, otherwise the stream is invalid. If the number is not known |
| * when creating the map, the constant \ref CborIndefiniteLength may be passed as |
| * length instead. |
| * |
| * \b{Implementation limitation:} TinyCBOR cannot encode more than SIZE_MAX/2 |
| * key-value pairs in the stream. If the length \a length is larger than this |
| * value (and is not \ref CborIndefiniteLength), this function returns error |
| * CborErrorDataTooLarge. |
| * |
| * \sa cbor_encoder_create_array |
| */ |
| CborError cbor_encoder_create_map(CborEncoder *encoder, CborEncoder *mapEncoder, size_t length) |
| { |
| if (length != CborIndefiniteLength && length > SIZE_MAX / 2) |
| return CborErrorDataTooLarge; |
| return create_container(encoder, mapEncoder, length, MapType << MajorTypeShift); |
| } |
| |
| /** |
| * Closes the CBOR container (array or map) provided by \a containerEncoder and |
| * updates the CBOR stream provided by \a encoder. Both parameters must be the |
| * same as were passed to cbor_encoder_create_array() or |
| * cbor_encoder_create_map(). |
| * |
| * Since version 0.5, this function verifies that the number of items (or pairs |
| * of items, in the case of a map) was correct. It is no longer necessary to call |
| * cbor_encoder_close_container_checked() instead. |
| * |
| * \sa cbor_encoder_create_array(), cbor_encoder_create_map() |
| */ |
| CborError cbor_encoder_close_container(CborEncoder *encoder, const CborEncoder *containerEncoder) |
| { |
| // synchronise buffer state with that of the container |
| encoder->end = containerEncoder->end; |
| encoder->data = containerEncoder->data; |
| |
| if (containerEncoder->flags & CborIteratorFlag_UnknownLength) |
| return append_byte_to_buffer(encoder, BreakByte); |
| |
| if (containerEncoder->remaining != 1) |
| return containerEncoder->remaining == 0 ? CborErrorTooManyItems : CborErrorTooFewItems; |
| |
| if (!encoder->end) |
| return CborErrorOutOfMemory; /* keep the state */ |
| |
| return CborNoError; |
| } |
| |
| /** |
| * \fn CborError cbor_encode_boolean(CborEncoder *encoder, bool value) |
| * |
| * Appends the boolean value \a value to the CBOR stream provided by \a encoder. |
| */ |
| |
| /** |
| * \fn CborError cbor_encode_null(CborEncoder *encoder) |
| * |
| * Appends the CBOR type representing a null value to the CBOR stream provided |
| * by \a encoder. |
| * |
| * \sa cbor_encode_undefined() |
| */ |
| |
| /** |
| * \fn CborError cbor_encode_undefined(CborEncoder *encoder) |
| * |
| * Appends the CBOR type representing an undefined value to the CBOR stream |
| * provided by \a encoder. |
| * |
| * \sa cbor_encode_null() |
| */ |
| |
| /** |
| * \fn CborError cbor_encode_half_float(CborEncoder *encoder, const void *value) |
| * |
| * Appends the IEEE 754 half-precision (16-bit) floating point value pointed to |
| * by \a value to the CBOR stream provided by \a encoder. |
| * |
| * \sa cbor_encode_floating_point(), cbor_encode_float(), cbor_encode_double() |
| */ |
| |
| /** |
| * \fn CborError cbor_encode_float(CborEncoder *encoder, float value) |
| * |
| * Appends the IEEE 754 single-precision (32-bit) floating point value \a value |
| * to the CBOR stream provided by \a encoder. |
| * |
| * \sa cbor_encode_floating_point(), cbor_encode_half_float(), cbor_encode_double() |
| */ |
| |
| /** |
| * \fn CborError cbor_encode_double(CborEncoder *encoder, double value) |
| * |
| * Appends the IEEE 754 double-precision (64-bit) floating point value \a value |
| * to the CBOR stream provided by \a encoder. |
| * |
| * \sa cbor_encode_floating_point(), cbor_encode_half_float(), cbor_encode_float() |
| */ |
| |
| /** |
| * \fn size_t cbor_encoder_get_buffer_size(const CborEncoder *encoder, const uint8_t *buffer) |
| * |
| * Returns the total size of the buffer starting at \a buffer after the |
| * encoding finished without errors. The \a encoder and \a buffer arguments |
| * must be the same as supplied to cbor_encoder_init(). |
| * |
| * If the encoding process had errors, the return value of this function is |
| * meaningless. If the only errors were CborErrorOutOfMemory, instead use |
| * cbor_encoder_get_extra_bytes_needed() to find out by how much to grow the |
| * buffer before encoding again. |
| * |
| * See \ref CborEncoding for an example of using this function. |
| * |
| * \sa cbor_encoder_init(), cbor_encoder_get_extra_bytes_needed(), CborEncoding |
| */ |
| |
| /** |
| * \fn size_t cbor_encoder_get_extra_bytes_needed(const CborEncoder *encoder) |
| * |
| * Returns how many more bytes the original buffer supplied to |
| * cbor_encoder_init() needs to be extended by so that no CborErrorOutOfMemory |
| * condition will happen for the encoding. If the buffer was big enough, this |
| * function returns 0. The \a encoder must be the original argument as passed |
| * to cbor_encoder_init(). |
| * |
| * This function is usually called after an encoding sequence ended with one or |
| * more CborErrorOutOfMemory errors, but no other error. If any other error |
| * happened, the return value of this function is meaningless. |
| * |
| * See \ref CborEncoding for an example of using this function. |
| * |
| * \sa cbor_encoder_init(), cbor_encoder_get_buffer_size(), CborEncoding |
| */ |
| |
| /** @} */ |