xref: /linux-6.15/fs/bcachefs/darray.h (revision acc65769)
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)					\
14 struct {								\
15 	size_t nr, size;						\
16 	_type *data;							\
17 	_type preallocated[_nr];					\
18 }
19 
20 #define DARRAY(_type) DARRAY_PREALLOCATED(_type, 0)
21 
22 typedef DARRAY(char)	darray_char;
23 
24 int __bch2_darray_resize(darray_char *, size_t, size_t, gfp_t);
25 
26 static inline int __darray_resize(darray_char *d, size_t element_size,
27 				  size_t new_size, gfp_t gfp)
28 {
29 	return unlikely(new_size > d->size)
30 		? __bch2_darray_resize(d, element_size, new_size, gfp)
31 		: 0;
32 }
33 
34 #define darray_resize_gfp(_d, _new_size, _gfp)				\
35 	unlikely(__darray_resize((darray_char *) (_d), sizeof((_d)->data[0]), (_new_size), _gfp))
36 
37 #define darray_resize(_d, _new_size)					\
38 	darray_resize_gfp(_d, _new_size, GFP_KERNEL)
39 
40 static inline int __darray_make_room(darray_char *d, size_t t_size, size_t more, gfp_t gfp)
41 {
42 	return __darray_resize(d, t_size, d->nr + more, gfp);
43 }
44 
45 #define darray_make_room_gfp(_d, _more, _gfp)				\
46 	__darray_make_room((darray_char *) (_d), sizeof((_d)->data[0]), (_more), _gfp)
47 
48 #define darray_make_room(_d, _more)					\
49 	darray_make_room_gfp(_d, _more, GFP_KERNEL)
50 
51 #define darray_room(_d)		((_d).size - (_d).nr)
52 
53 #define darray_top(_d)		((_d).data[(_d).nr])
54 
55 #define darray_push_gfp(_d, _item, _gfp)				\
56 ({									\
57 	int _ret = darray_make_room_gfp((_d), 1, _gfp);			\
58 									\
59 	if (!_ret)							\
60 		(_d)->data[(_d)->nr++] = (_item);			\
61 	_ret;								\
62 })
63 
64 #define darray_push(_d, _item)	darray_push_gfp(_d, _item, GFP_KERNEL)
65 
66 #define darray_pop(_d)		((_d)->data[--(_d)->nr])
67 
68 #define darray_first(_d)	((_d).data[0])
69 #define darray_last(_d)		((_d).data[(_d).nr - 1])
70 
71 #define darray_insert_item(_d, pos, _item)				\
72 ({									\
73 	size_t _pos = (pos);						\
74 	int _ret = darray_make_room((_d), 1);				\
75 									\
76 	if (!_ret)							\
77 		array_insert_item((_d)->data, (_d)->nr, _pos, (_item));	\
78 	_ret;								\
79 })
80 
81 #define darray_remove_item(_d, _pos)					\
82 	array_remove_item((_d)->data, (_d)->nr, (_pos) - (_d)->data)
83 
84 #define darray_for_each(_d, _i)						\
85 	for (_i = (_d).data; _i < (_d).data + (_d).nr; _i++)
86 
87 #define darray_for_each_reverse(_d, _i)					\
88 	for (_i = (_d).data + (_d).nr - 1; _i >= (_d).data; --_i)
89 
90 #define darray_init(_d)							\
91 do {									\
92 	(_d)->nr = 0;							\
93 	(_d)->size = ARRAY_SIZE((_d)->preallocated);			\
94 	(_d)->data = (_d)->size ? (_d)->preallocated : NULL;		\
95 } while (0)
96 
97 #define darray_exit(_d)							\
98 do {									\
99 	if (!ARRAY_SIZE((_d)->preallocated) ||				\
100 	    (_d)->data != (_d)->preallocated)				\
101 		kvfree((_d)->data);					\
102 	darray_init(_d);						\
103 } while (0)
104 
105 #endif /* _BCACHEFS_DARRAY_H */
106