/*

 * Buffer handling functions

 *

 * Copyright (C) 2003, Olaf Kirch <okir@suse.de>

 */

#include <config.h>

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#include <openct/buffer.h>

void

ct_buf_init(ct_buf_t *bp, void *mem, size_t len)

{

	memset(bp, 0, sizeof(*bp));

	bp->base = (unsigned char *) mem;

	bp->size = len;

}

void

ct_buf_set(ct_buf_t *bp, void *mem, size_t len)

{

	ct_buf_init(bp, mem, len);

	bp->tail = len;

}

int

ct_buf_get(ct_buf_t *bp, void *mem, size_t len)

{

	if (len > bp->tail - bp->head)

		return -1;

	if (mem)

		memcpy(mem, bp->base + bp->head, len);

	bp->head += len;

	return len;

}

int

ct_buf_put(ct_buf_t *bp, const void *mem, size_t len)

{

	if (len > bp->size - bp->tail) {

		bp->overrun = 1;

		return -1;

	}

	if (mem)

		memcpy(bp->base + bp->tail, mem, len);

	bp->tail += len;

	return len;

}

int

ct_buf_putc(ct_buf_t *bp, int byte)

{

	unsigned char	c = byte;

	return ct_buf_put(bp, &c, 1);

}

unsigned int

ct_buf_avail(ct_buf_t *bp)

{

	return bp->tail - bp->head;

}

void *

ct_buf_head(ct_buf_t *bp)

{

	return bp->base + bp->head;

}