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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.
*
* The implementation is preliminary and can probably be sped up
* significantly. A first step would be to store the values in an rbtree
* as soon as ULIST_SIZE is exceeded.
*/
/*
* number of elements statically allocated inside struct ulist
*/
#define ULIST_SIZE 16
struct ulist_iterator {
int i;
};
/*
* element of the list
*/
struct ulist_node {
u64 val; /* value to store */
u64 aux; /* auxiliary value saved along with the val */
struct rb_node rb_node; /* used to speed up search */
};
struct ulist {
/*
* number of elements stored in list
*/
unsigned long nnodes;
/*
* number of nodes we already have room for
*/
unsigned long nodes_alloced;
/*
* pointer to the array storing the elements. The first ULIST_SIZE
* elements are stored inline. In this case the it points to int_nodes.
* After exceeding ULIST_SIZE, dynamic memory is allocated.
*/
struct ulist_node *nodes;
struct rb_root root;
/*
* inline storage space for the first ULIST_SIZE entries
*/
struct ulist_node int_nodes[ULIST_SIZE];
};
void ulist_init(struct ulist *ulist);
void ulist_fini(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);
struct ulist_node *ulist_next(struct ulist *ulist,
struct ulist_iterator *uiter);
#define ULIST_ITER_INIT(uiter) ((uiter)->i = 0)
#endif
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