/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright (c) 2022 Red Hat GmbH
 * Author: Stefano Brivio <sbrivio@redhat.com>
 */

#ifndef PACKET_H
#define PACKET_H

#include <stdbool.h>

/**
 * struct pool - Generic pool of packets stored in nmemory
 * @size:	Number of usable descriptors for the pool
 * @count:	Number of used descriptors for the pool
 * @pkt:	Descriptors: see macros below
 */
struct pool {
	size_t size;
	size_t count;
	struct iovec pkt[];
};

void packet_add_do(struct pool *p, size_t len, const char *start,
		   const char *func, int line);
void *packet_get_do(const struct pool *p, const size_t idx,
		    size_t offset, size_t len, size_t *left,
		    const char *func, int line);
bool pool_full(const struct pool *p);
void pool_flush(struct pool *p);

#define packet_add(p, len, start)					\
	packet_add_do(p, len, start, __func__, __LINE__)

#define packet_get(p, idx, offset, len, left)				\
	packet_get_do(p, idx, offset, len, left, __func__, __LINE__)

#define packet_get_try(p, idx, offset, len, left)			\
	packet_get_do(p, idx, offset, len, left, NULL, 0)

#define PACKET_POOL_DECL(_name, _size)					\
struct _name ## _t {							\
	size_t size;							\
	size_t count;							\
	struct iovec pkt[_size];					\
}

#define PACKET_POOL_INIT_NOCAST(_size)					\
{									\
	.size = _size,							\
}

#define PACKET_POOL(name, size)						\
	PACKET_POOL_DECL(name, size) name =				\
		PACKET_POOL_INIT_NOCAST(size)

#define PACKET_INIT(name, size)						\
	(struct name ## _t) PACKET_POOL_INIT_NOCAST(size)

#define PACKET_POOL_P(name, size)					\
	PACKET_POOL(name ## _storage, size);				\
	struct pool *name = (struct pool *)&name ## _storage

#endif /* PACKET_H */