1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _BCACHEFS_DARRAY_H
3#define _BCACHEFS_DARRAY_H
4
5/*
6 * Dynamic arrays:
7 *
8 * Inspired by CCAN's darray
9 */
10
11#include <linux/slab.h>
12
13#define DARRAY_PREALLOCATED(_type, _nr)					\
14struct {								\
15	size_t nr, size;						\
16	_type *data;							\
17	_type preallocated[_nr];					\
18}
19
20#define DARRAY(_type) DARRAY_PREALLOCATED(_type, 0)
21
22typedef DARRAY(char)	darray_char;
23typedef DARRAY(char *) darray_str;
24
25int __bch2_darray_resize(darray_char *, size_t, size_t, gfp_t);
26
27static inline int __darray_resize(darray_char *d, size_t element_size,
28				  size_t new_size, gfp_t gfp)
29{
30	return unlikely(new_size > d->size)
31		? __bch2_darray_resize(d, element_size, new_size, gfp)
32		: 0;
33}
34
35#define darray_resize_gfp(_d, _new_size, _gfp)				\
36	unlikely(__darray_resize((darray_char *) (_d), sizeof((_d)->data[0]), (_new_size), _gfp))
37
38#define darray_resize(_d, _new_size)					\
39	darray_resize_gfp(_d, _new_size, GFP_KERNEL)
40
41static inline int __darray_make_room(darray_char *d, size_t t_size, size_t more, gfp_t gfp)
42{
43	return __darray_resize(d, t_size, d->nr + more, gfp);
44}
45
46#define darray_make_room_gfp(_d, _more, _gfp)				\
47	__darray_make_room((darray_char *) (_d), sizeof((_d)->data[0]), (_more), _gfp)
48
49#define darray_make_room(_d, _more)					\
50	darray_make_room_gfp(_d, _more, GFP_KERNEL)
51
52#define darray_room(_d)		((_d).size - (_d).nr)
53
54#define darray_top(_d)		((_d).data[(_d).nr])
55
56#define darray_push_gfp(_d, _item, _gfp)				\
57({									\
58	int _ret = darray_make_room_gfp((_d), 1, _gfp);			\
59									\
60	if (!_ret)							\
61		(_d)->data[(_d)->nr++] = (_item);			\
62	_ret;								\
63})
64
65#define darray_push(_d, _item)	darray_push_gfp(_d, _item, GFP_KERNEL)
66
67#define darray_pop(_d)		((_d)->data[--(_d)->nr])
68
69#define darray_first(_d)	((_d).data[0])
70#define darray_last(_d)		((_d).data[(_d).nr - 1])
71
72#define darray_insert_item(_d, pos, _item)				\
73({									\
74	size_t _pos = (pos);						\
75	int _ret = darray_make_room((_d), 1);				\
76									\
77	if (!_ret)							\
78		array_insert_item((_d)->data, (_d)->nr, _pos, (_item));	\
79	_ret;								\
80})
81
82#define darray_remove_item(_d, _pos)					\
83	array_remove_item((_d)->data, (_d)->nr, (_pos) - (_d)->data)
84
85#define __darray_for_each(_d, _i)						\
86	for ((_i) = (_d).data; _i < (_d).data + (_d).nr; _i++)
87
88#define darray_for_each(_d, _i)						\
89	for (typeof(&(_d).data[0]) _i = (_d).data; _i < (_d).data + (_d).nr; _i++)
90
91#define darray_for_each_reverse(_d, _i)					\
92	for (typeof(&(_d).data[0]) _i = (_d).data + (_d).nr - 1; _i >= (_d).data; --_i)
93
94#define darray_init(_d)							\
95do {									\
96	(_d)->nr = 0;							\
97	(_d)->size = ARRAY_SIZE((_d)->preallocated);			\
98	(_d)->data = (_d)->size ? (_d)->preallocated : NULL;		\
99} while (0)
100
101#define darray_exit(_d)							\
102do {									\
103	if (!ARRAY_SIZE((_d)->preallocated) ||				\
104	    (_d)->data != (_d)->preallocated)				\
105		kvfree((_d)->data);					\
106	darray_init(_d);						\
107} while (0)
108
109#endif /* _BCACHEFS_DARRAY_H */
110