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 */