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/*
Copyright (C) 2015-2020, Dirk Krause
SPDX-License-Identifier: BSD-3-Clause
*/

/*
	WARNING: This file was generated by the dkct program (see
	http://dktools.sourceforge.net/ for details).
	Changes you make here will be lost if dkct is run again!
	You should modify the original source and run dkct on it.
	Original source: dk4membuf.ctr
*/

#ifndef DK4MEMBUF_H_INCLUDED
/** Avoid multiple inclusions. */
#define DK4MEMBUF_H_INCLUDED 1


#line 9 "dk4membuf.ctr"

/**	@file	dk4membuf.h	Memory buffer.
*/

#ifndef	DK4CONF_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4conf.h"
#else
#include <dktools-4/dk4conf.h>
#endif
#endif

#ifndef DK4ERROR_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4error.h"
#else
#include <dktools-4/dk4error.h>
#endif
#endif

/**	One cell of a memory buffer.
*/
typedef struct _dk4_membuf_cell_t_ {
  struct _dk4_membuf_cell_t_	*next;	/**< Next element in linked list. */
  char				*buf;	/**< Buffer for data storage. */
  size_t			 max;	/**< Number of bytes available. */
  size_t			 used;	/**< Number of bytes used. */
} dk4_membuf_cell_t;

/**	Memory buffer object.
*/
typedef struct {
  dk4_membuf_cell_t	*first;		/**< First cell (head of list). */
  dk4_membuf_cell_t	*last;		/**< Last cell (end of list). */
  int			 he;		/**< Flag: Had allocation error. */
} dk4_membuf_t;

#ifdef __cplusplus
extern "C" {
#endif

/**	Create new buffer, allocate initial memory.
	@param	erp	Error report, may be NULL.
	@return	Pointer on success, NULL on error.

	Error codes:
	- DK4_E_MATH_OVERFLOW<br>
	  on numeric overflow when calculating the product of elsize and nelem,
	- DK4_E_MEMORY_ALLOCATION_FAILED<br>
	  with mem.elsize and mem.nelem set if there is not enough memory
	  available.
*/
dk4_membuf_t *
dk4membuf_open(dk4_er_t *erp);

/**	Destroy buffer, release memory.
	@param	mbptr	Buffer to destroy.
*/
void
dk4membuf_close(dk4_membuf_t *mbptr);

/**	Store data in buffer.
	@param	mbptr	Buffer object.
	@param	src	Address of data to store.
	@param	sz	Number of bytes to store.
	@param	erp	Error report, may be NULL.
	@return	1 on success, 0 on error.
	
	Error code:
	- DK4_E_INVALID_ARGUMENTS<br>
	  if mbptr or src is NULL or sz is 0,
	- DK4_E_MATH_OVERFLOW<br>
	  if a mathematical overflow occured in size calculation,
	- DK4_E_MEMORY_ALLOCATION_FAILED<br>
	  with mem.elsize and mem.nelem set
	  if there is not enough memory available.
*/
int
dk4membuf_store(dk4_membuf_t *mbptr, const void *src, size_t sz, dk4_er_t *erp);

/**	Retrieve size of data stored in memory buffer.
	@param	szptr	Address of result variable.
	@param	mbptr	Buffer to find size for.
	@param	erp	Error report, may be NULL.
	@return	1 on success, 0 on error.

	Error code:
	- DK4_E_INVALID_ARGUMENTS<br>
	  if szptr or mbptr is NULL.
	- DK4_E_MATH_OVERFLOW<br>
	  if a mathematical overflow occured in size calculation.
*/
int
dk4membuf_size(size_t *szptr, dk4_membuf_t const *mbptr, dk4_er_t *erp);

#ifdef __cplusplus
}
#endif

/**	Default chunk size.
*/
#define	DK4MEMBUF_CHUNK_SIZE	4096U


#endif