1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
// SPDX-License-Identifier: LGPL-3.0-or-later
#include "impl.h"
#include <string.h>
#include <stdlib.h>
static size_t hkvs_slab_size_to_count(size_t elt_size, size_t size) {
size_t block_size = (elt_size + 1) * HKVS_SLAB_BLOCK;
size_t blocks = size / block_size;
size %= block_size;
size_t rest = 0;
if(size > HKVS_SLAB_BLOCK) {
rest = (size - HKVS_SLAB_BLOCK) / elt_size;
}
return blocks * HKVS_SLAB_BLOCK + rest;
}
static size_t hkvs_slab_count_to_size(size_t elt_size, size_t count) {
size_t size;
if(__builtin_mul_overflow(count, elt_size + 1, &size)) return SIZE_MAX;
if(__builtin_add_overflow(size, (-count) % HKVS_SLAB_BLOCK, &size)) return SIZE_MAX;
return size;
}
int hkvs_slab_init(hkvs_slab *s, hkvs_io *io, char *param, size_t elt_size) {
s->param = param;
s->elt_size = elt_size;
uint64_t fi = hkvs_read_u64(param + HKVS_PARAM_SLAB_FI);
if(fi == 0) {
s->addr = NULL;
s->map_size = 0;
return 0;
}
int r = io->open(io, fi, &s->addr, &s->map_size);
if(r < 0) return r;
uint64_t alloc_count = hkvs_read_u64(param + HKVS_PARAM_SLAB_ALLOC);
if(alloc_count > hkvs_slab_size_to_count(elt_size, s->map_size)) {
io->close(io, fi, s->addr, s->map_size);
return -EBADMSG;
}
return 0;
}
int hkvs_slab_alloc(hkvs *c, hkvs_slab *s, size_t *pi) {
size_t alloc_count = hkvs_slab_size(s);
uint64_t at_64 = hkvs_read_u64(s->param + HKVS_PARAM_SLAB_FREE);
if(at_64 < alloc_count) {
size_t at = (size_t)at_64;
char *p = hkvs_slab_at(s, at);
for(size_t i = 1; i < HKVS_SLAB_FREEPTRS; i++) {
uint64_t v = hkvs_read_u64(p + i * 8);
if(v <= at) return -EBADMSG;
if(v < alloc_count) {
size_t id = (size_t)v;
hkvs_write_u64(p + i * 8, UINT64_MAX);
*pi = id;
return 0;
}
}
at_64 = hkvs_read_u64(p);
hkvs_write_u64(s->param + HKVS_PARAM_SLAB_FREE, at_64);
*pi = at;
return 0;
}
if(at_64 != UINT64_MAX) {
hkvs_write_u64(s->param + HKVS_PARAM_SLAB_FREE, UINT64_MAX);
}
size_t cap_count = hkvs_slab_size_to_count(s->elt_size, s->map_size);
hkvs_assume(alloc_count <= cap_count);
if(alloc_count == cap_count) {
size_t grow_count = cap_count + (cap_count >> 3) + 1;
size_t grow_size;
while(true) {
grow_size = hkvs_slab_count_to_size(s->elt_size, grow_count);
if(grow_size != 0) break;
size_t dec = (grow_count - cap_count) / 2;
if(dec == 0) return -EFBIG;
grow_count -= dec;
}
hkvs_io *io = c->io;
uint64_t fi = hkvs_read_u64(s->param + HKVS_PARAM_SLAB_FI);
if(fi == 0) {
int r = io->create(io, &fi, &s->addr, grow_size);
if(r < 0) return r;
hkvs_write_u64(s->param + HKVS_PARAM_SLAB_FI, fi);
} else {
int r = io->resize(io, fi, &s->addr, s->map_size, grow_size);
if(r < 0) return r;
}
s->map_size = grow_size;
}
hkvs_write_u64(s->param + HKVS_PARAM_SLAB_ALLOC, alloc_count + 1);
*pi = alloc_count;
return 0;
}
void hkvs_slab_discard(hkvs_slab *s, size_t id) {
size_t alloc_count = hkvs_slab_size(s);
hkvs_assume(id < alloc_count);
if(id == alloc_count - 1) {
do {
alloc_count--;
} while(alloc_count > 0 && hkvs_slab_mark(s, alloc_count - 1) == 0);
hkvs_write_u64(s->param + HKVS_PARAM_SLAB_ALLOC, alloc_count);
return;
}
hkvs_slab_set_mark(s, id, 0);
uint64_t free_64 = hkvs_read_u64(s->param + HKVS_PARAM_SLAB_FREE);
if(id < free_64) {
hkvs_write_u64(s->param + HKVS_PARAM_SLAB_FREE, id);
char *p = hkvs_slab_at(s, id);
hkvs_write_u64(p, free_64);
for(size_t i = 1; i < HKVS_SLAB_FREEPTRS; i++) {
hkvs_write_u64(p + i * 8, UINT64_MAX);
}
return;
}
char *p = hkvs_slab_at(s, (size_t)free_64);
uint64_t v = hkvs_read_u64(p + 8);
if(v >= alloc_count) {
size_t i = 2;
while(true) {
v = hkvs_read_u64(p + i * 8);
if(v < alloc_count) break;
i++;
if(i == HKVS_SLAB_FREEPTRS) {
hkvs_write_u64(p + 8, id);
return;
}
}
while(v < id) {
hkvs_write_u64(p + (i - 1) * 8, v);
i++;
if(i == HKVS_SLAB_FREEPTRS) break;
v = hkvs_read_u64(p + i * 8);
}
hkvs_write_u64(p + (i - 1) * 8, id);
return;
}
if(hkvs_read_u64(p + (HKVS_SLAB_FREEPTRS - 1) * 8) >= alloc_count) {
size_t i = 1;
while(v < id) {
i++;
v = hkvs_read_u64(p + i * 8);
}
uint64_t v2 = id;
while(true) {
hkvs_write_u64(p + i * 8, v2);
if(v >= alloc_count) break;
v2 = v;
i++;
v = hkvs_read_u64(p + i * 8);
}
return;
}
if(v < id) {
uint64_t v2 = id;
id = (size_t)v;
size_t i = 2;
do {
v = hkvs_read_u64(p + i * 8);
if(v >= v2) break;
hkvs_write_u64(p + (i - 1) * 8, v);
i++;
} while(i < HKVS_SLAB_FREEPTRS);
hkvs_write_u64(p + (i - 1) * 8, v2);
}
char *p2 = hkvs_slab_at(s, id);
memcpy(p2, p, HKVS_SLAB_FREEPTRS * 8);
hkvs_write_u64(p, id);
for(size_t i = 1; i < HKVS_SLAB_FREEPTRS; i++) {
hkvs_write_u64(p + i * 8, UINT64_MAX);
}
return;
}
|
