tomato-testing/toxcore/bin_pack.h
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git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 67badf69416a74e74f6d7eb51dd96f37282b8455
2023-07-25 11:53:09 +02:00

124 lines
4.6 KiB
C

/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2022 The TokTok team.
*/
#ifndef C_TOXCORE_TOXCORE_BIN_PACK_H
#define C_TOXCORE_TOXCORE_BIN_PACK_H
#include <stdbool.h>
#include <stdint.h>
#include "attributes.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Binary serialisation object.
*/
typedef struct Bin_Pack Bin_Pack;
/** @brief Function used to pack an object.
*
* This function would typically cast the `void *` to the actual object pointer type and then call
* more appropriately typed packing functions.
*/
typedef bool bin_pack_cb(Bin_Pack *bp, const void *obj);
/** @brief Determine the serialised size of an object.
*
* @param callback The function called on the created packer and packed object.
* @param obj The object to be packed, passed as `obj` to the callback.
*
* @return The packed size of the passed object according to the callback. UINT32_MAX in case of
* errors such as buffer overflow.
*/
non_null(1) nullable(2)
uint32_t bin_pack_obj_size(bin_pack_cb *callback, const void *obj);
/** @brief Pack an object into a buffer of a given size.
*
* This function creates and initialises a `Bin_Pack` packer object, calls the callback with the
* packer object and the to-be-packed object, and then cleans up the packer object.
*
* You can use `bin_pack_obj_size` to determine the minimum required size of `buf`. If packing
* overflows `uint32_t`, this function returns `false`.
*
* @param callback The function called on the created packer and packed object.
* @param obj The object to be packed, passed as `obj` to the callback.
* @param buf A byte array large enough to hold the serialised representation of `obj`.
* @param buf_size The size of the byte array. Can be `UINT32_MAX` to disable bounds checking.
*
* @retval false if an error occurred (e.g. buffer overflow).
*/
non_null(1, 3) nullable(2)
bool bin_pack_obj(bin_pack_cb *callback, const void *obj, uint8_t *buf, uint32_t buf_size);
/** @brief Allocate a new packer object.
*
* This is the only function that allocates memory in this module.
*
* @param buf A byte array large enough to hold the serialised representation of `obj`.
* @param buf_size The size of the byte array. Can be `UINT32_MAX` to disable bounds checking.
*
* @retval nullptr on allocation failure.
*/
non_null()
Bin_Pack *bin_pack_new(uint8_t *buf, uint32_t buf_size);
/** @brief Deallocates a packer object.
*
* Does not deallocate the buffer inside.
*/
nullable(1)
void bin_pack_free(Bin_Pack *bp);
/** @brief Start packing a MessagePack array.
*
* A call to this function must be followed by exactly `size` calls to other functions below.
*/
non_null()
bool bin_pack_array(Bin_Pack *bp, uint32_t size);
/** @brief Pack a MessagePack bool. */
non_null() bool bin_pack_bool(Bin_Pack *bp, bool val);
/** @brief Pack a `uint8_t` as MessagePack positive integer. */
non_null() bool bin_pack_u08(Bin_Pack *bp, uint8_t val);
/** @brief Pack a `uint16_t` as MessagePack positive integer. */
non_null() bool bin_pack_u16(Bin_Pack *bp, uint16_t val);
/** @brief Pack a `uint32_t` as MessagePack positive integer. */
non_null() bool bin_pack_u32(Bin_Pack *bp, uint32_t val);
/** @brief Pack a `uint64_t` as MessagePack positive integer. */
non_null() bool bin_pack_u64(Bin_Pack *bp, uint64_t val);
/** @brief Pack an empty array member as a MessagePack nil value. */
non_null() bool bin_pack_nil(Bin_Pack *bp);
/** @brief Pack a byte array as MessagePack bin. */
non_null() bool bin_pack_bin(Bin_Pack *bp, const uint8_t *data, uint32_t length);
/** @brief Start packing a custom binary representation.
*
* A call to this function must be followed by exactly `size` bytes packed by functions below.
*/
non_null() bool bin_pack_bin_marker(Bin_Pack *bp, uint32_t size);
/** @brief Write a `uint8_t` directly to the packer in 1 byte. */
non_null() bool bin_pack_u08_b(Bin_Pack *bp, uint8_t val);
/** @brief Write a `uint16_t` as big endian 16 bit int in 2 bytes. */
non_null() bool bin_pack_u16_b(Bin_Pack *bp, uint16_t val);
/** @brief Write a `uint32_t` as big endian 32 bit int in 4 bytes. */
non_null() bool bin_pack_u32_b(Bin_Pack *bp, uint32_t val);
/** @brief Write a `uint64_t` as big endian 64 bit int in 8 bytes. */
non_null() bool bin_pack_u64_b(Bin_Pack *bp, uint64_t val);
/** @brief Write a byte array directly to the packer in `length` bytes.
*
* Note that unless you prepend the array length manually, there is no record of it in the resulting
* serialised representation.
*/
non_null() bool bin_pack_bin_b(Bin_Pack *bp, const uint8_t *data, uint32_t length);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // C_TOXCORE_TOXCORE_BIN_PACK_H