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cobs.h
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cobs.h
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/*****************************************************************************
*
* cobs.h
*
* Consistent Overhead Byte Stuffing
*
*
----------------------------------------------------------------------------
Copyright (c) 2010 Craig McQueen
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 COBS_H_
#define COBS_H_
/*****************************************************************************
* Includes
****************************************************************************/
#include <stdint.h>
#include <stdlib.h>
/*****************************************************************************
* Defines
****************************************************************************/
#define COBS_ENCODE_DST_BUF_LEN_MAX(SRC_LEN) ((SRC_LEN) + (((SRC_LEN) + 253u)/254u))
#define COBS_DECODE_DST_BUF_LEN_MAX(SRC_LEN) (((SRC_LEN) == 0) ? 0u : ((SRC_LEN) - 1u))
/*
* For in-place encoding, the source data must be offset in the buffer by
* the following amount (or more).
*/
#define COBS_ENCODE_SRC_OFFSET(SRC_LEN) (((SRC_LEN) + 253u)/254u)
/*****************************************************************************
* Typedefs
****************************************************************************/
typedef enum
{
COBS_ENCODE_OK = 0x00,
COBS_ENCODE_NULL_POINTER = 0x01,
COBS_ENCODE_OUT_BUFFER_OVERFLOW = 0x02
} cobs_encode_status;
typedef struct
{
size_t out_len;
cobs_encode_status status;
} cobs_encode_result;
typedef enum
{
COBS_DECODE_OK = 0x00,
COBS_DECODE_NULL_POINTER = 0x01,
COBS_DECODE_OUT_BUFFER_OVERFLOW = 0x02,
COBS_DECODE_ZERO_BYTE_IN_INPUT = 0x04,
COBS_DECODE_INPUT_TOO_SHORT = 0x08
} cobs_decode_status;
typedef struct
{
size_t out_len;
cobs_decode_status status;
} cobs_decode_result;
/*****************************************************************************
* Function prototypes
****************************************************************************/
#ifdef __cplusplus
extern "C" {
#endif
/* COBS-encode a string of input bytes.
*
* dst_buf_ptr: The buffer into which the result will be written
* dst_buf_len: Length of the buffer into which the result will be written
* src_ptr: The byte string to be encoded
* src_len Length of the byte string to be encoded
*
* returns: A struct containing the success status of the encoding
* operation and the length of the result (that was written to
* dst_buf_ptr)
*/
cobs_encode_result cobs_encode(void * dst_buf_ptr, size_t dst_buf_len,
const void * src_ptr, size_t src_len);
/* Decode a COBS byte string.
*
* dst_buf_ptr: The buffer into which the result will be written
* dst_buf_len: Length of the buffer into which the result will be written
* src_ptr: The byte string to be decoded
* src_len Length of the byte string to be decoded
*
* returns: A struct containing the success status of the decoding
* operation and the length of the result (that was written to
* dst_buf_ptr)
*/
cobs_decode_result cobs_decode(void * dst_buf_ptr, size_t dst_buf_len,
const void * src_ptr, size_t src_len);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* COBS_H_ */