linux/fs/btrfs/ulist.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2011 STRATO AG
 * written by Arne Jansen <[email protected]>
 */

#ifndef BTRFS_ULIST_H
#define BTRFS_ULIST_H

#include <linux/types.h>
#include <linux/list.h>
#include <linux/rbtree.h>

/*
 * ulist is a generic data structure to hold a collection of unique u64
 * values. The only operations it supports is adding to the list and
 * enumerating it.
 * It is possible to store an auxiliary value along with the key.
 *
 */
struct ulist_iterator { … };

/*
 * element of the list
 */
struct ulist_node { … };

struct ulist { … };

void ulist_init(struct ulist *ulist);
void ulist_release(struct ulist *ulist);
void ulist_reinit(struct ulist *ulist);
struct ulist *ulist_alloc(gfp_t gfp_mask);
void ulist_prealloc(struct ulist *ulist, gfp_t mask);
void ulist_free(struct ulist *ulist);
int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
		    u64 *old_aux, gfp_t gfp_mask);
int ulist_del(struct ulist *ulist, u64 val, u64 aux);

/* just like ulist_add_merge() but take a pointer for the aux data */
static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,
				      void **old_aux, gfp_t gfp_mask)
{ … }

struct ulist_node *ulist_next(const struct ulist *ulist,
			      struct ulist_iterator *uiter);

#define ULIST_ITER_INIT(uiter) …

#endif