mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 17:08:10 +00:00
1e20932a23
Conflicts: fs/btrfs/ulist.h Signed-off-by: Chris Mason <chris.mason@oracle.com>
77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/*
|
|
* Copyright (C) 2011 STRATO AG
|
|
* written by Arne Jansen <sensille@gmx.net>
|
|
* Distributed under the GNU GPL license version 2.
|
|
*
|
|
*/
|
|
|
|
#ifndef __ULIST__
|
|
#define __ULIST__
|
|
|
|
/*
|
|
* 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 */
|
|
unsigned long aux; /* auxiliary value saved along with the val */
|
|
};
|
|
|
|
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;
|
|
|
|
/*
|
|
* 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, unsigned long aux,
|
|
gfp_t gfp_mask);
|
|
int ulist_add_merge(struct ulist *ulist, u64 val, unsigned long aux,
|
|
unsigned long *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
|