ulist.h
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/*
* Copyright (C) 2011 STRATO AG
* written by Arne Jansen <sensille@gmx.net>
* Distributed under the GNU GPL license version 2.
*
*/
#ifndef __ULIST__
#define __ULIST__
#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 {
#ifdef CONFIG_BTRFS_DEBUG
int i;
#endif
struct list_head *cur_list; /* hint to start search */
};
/*
* element of the list
*/
struct ulist_node {
u64 val; /* value to store */
u64 aux; /* auxiliary value saved along with the val */
#ifdef CONFIG_BTRFS_DEBUG
int seqnum; /* sequence number this node is added */
#endif
struct list_head list; /* used to link node */
struct rb_node rb_node; /* used to speed up search */
};
struct ulist {
/*
* number of elements stored in list
*/
unsigned long nnodes;
struct list_head nodes;
struct rb_root root;
};
void ulist_init(struct ulist *ulist);
void ulist_reinit(struct ulist *ulist);
struct ulist *ulist_alloc(gfp_t gfp_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)
{
#if BITS_PER_LONG == 32
u64 old64 = (uintptr_t)*old_aux;
int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);
*old_aux = (void *)((uintptr_t)old64);
return ret;
#else
return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask);
#endif
}
struct ulist_node *ulist_next(struct ulist *ulist,
struct ulist_iterator *uiter);
#define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)
#endif