/*-
 * Copyright (c) 2019 Taylor R. Campbell
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef	CRADIX_H
#define	CRADIX_H

#ifdef _KERNEL
#include <sys/types.h>
#else
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#endif

#define	CRADIX_CHUNK_SIZE	5
#define	CRADIX_MAX_FANOUT	(1u << CRADIX_CHUNK_SIZE)
#define	CRADIX_CHUNK_MASK	(CRADIX_MAX_FANOUT - 1)
#define	CRADIX_NCHUNKS							      \
	((64 + CRADIX_CHUNK_SIZE - 1)/CRADIX_CHUNK_SIZE)
typedef uint32_t cradix_bitmap_t;

struct cradix_ops;

struct cradix {
	const struct cradix_ops	*ops;
	uintptr_t		root;
	unsigned		keylen;
};

/*
 * Should be treated as opaque; used only for alignment and
 * type-checking.
 */
struct cradix_node {
} __aligned(2);

/* Opaque; allocated via the allocator.  */
struct cradix_branch;

struct cradix_ops {
	uint64_t	(*key)(const struct cradix *,
			    const struct cradix_node *);
	void *		(*alloc)(struct cradix *, size_t);
	void		(*free)(struct cradix *, void *, size_t);
	void		(*recycle)(struct cradix *, void *, size_t);
};

void	cradix_init(struct cradix *, const struct cradix_ops *);
void	cradix_destroy(struct cradix *);

struct cradix_node *
	cradix_lookup(const struct cradix *, uint64_t);

struct cradix_insert {
	struct cradix_branch	*alloc[CRADIX_CHUNK_SIZE];
	struct cradix_branch	*recycle;
};

bool	cradix_insert_begin(struct cradix *, struct cradix_insert *);
void	cradix_insert_end(struct cradix *, struct cradix_insert *);
struct cradix_node *
	cradix_insert(struct cradix *, struct cradix_node *,
	    struct cradix_insert *);

struct cradix_delete {
	struct cradix_branch	*recycle;
};

void	cradix_delete_begin(struct cradix *, struct cradix_delete *);
void	cradix_delete_end(struct cradix *, struct cradix_delete *);
void	cradix_delete(struct cradix *, struct cradix_node *,
	    struct cradix_delete *);
struct cradix_node *
	cradix_delete_key(struct cradix *, uint64_t, struct cradix_delete *);

void	cradix_dump(const struct cradix *);

#endif	/* CRADIX_H */