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
|
/*
* Memory Pool implementation logic.
*/
#include "cache.h"
#include "mem-pool.h"
#define BLOCK_GROWTH_SIZE (1024 * 1024 - sizeof(struct mp_block))
/*
* The inner union is an approximation for C11's max_align_t, and the
* struct + offsetof computes _Alignof. This can all just be replaced
* with _Alignof(max_align_t) if/when C11 is part of the baseline.
* Note that _Alignof(X) need not be the same as sizeof(X); it's only
* required to be a (possibly trivial) factor. They are the same for
* most architectures, but m68k for example has only 2-byte alignment
* for its 4-byte and 8-byte types, so using sizeof would waste space.
*
* Add more types to the union if the current set is insufficient.
*/
struct git_max_alignment {
char unalign;
union {
uintmax_t max_align_uintmax;
void *max_align_pointer;
} aligned;
};
#define GIT_MAX_ALIGNMENT offsetof(struct git_max_alignment, aligned)
/*
* Allocate a new mp_block and insert it after the block specified in
* `insert_after`. If `insert_after` is NULL, then insert block at the
* head of the linked list.
*/
static struct mp_block *mem_pool_alloc_block(struct mem_pool *pool,
size_t block_alloc,
struct mp_block *insert_after)
{
struct mp_block *p;
pool->pool_alloc += sizeof(struct mp_block) + block_alloc;
p = xmalloc(st_add(sizeof(struct mp_block), block_alloc));
p->next_free = (char *)p->space;
p->end = p->next_free + block_alloc;
if (insert_after) {
p->next_block = insert_after->next_block;
insert_after->next_block = p;
} else {
p->next_block = pool->mp_block;
pool->mp_block = p;
}
return p;
}
void mem_pool_init(struct mem_pool *pool, size_t initial_size)
{
memset(pool, 0, sizeof(*pool));
pool->block_alloc = BLOCK_GROWTH_SIZE;
if (initial_size > 0)
mem_pool_alloc_block(pool, initial_size, NULL);
}
void mem_pool_discard(struct mem_pool *pool, int invalidate_memory)
{
struct mp_block *block, *block_to_free;
block = pool->mp_block;
while (block)
{
block_to_free = block;
block = block->next_block;
if (invalidate_memory)
memset(block_to_free->space, 0xDD, ((char *)block_to_free->end) - ((char *)block_to_free->space));
free(block_to_free);
}
pool->mp_block = NULL;
pool->pool_alloc = 0;
}
void *mem_pool_alloc(struct mem_pool *pool, size_t len)
{
struct mp_block *p = NULL;
void *r;
/* round up to a 'GIT_MAX_ALIGNMENT' alignment */
if (len & (GIT_MAX_ALIGNMENT - 1))
len += GIT_MAX_ALIGNMENT - (len & (GIT_MAX_ALIGNMENT - 1));
if (pool->mp_block &&
pool->mp_block->end - pool->mp_block->next_free >= len)
p = pool->mp_block;
if (!p) {
if (len >= (pool->block_alloc / 2))
return mem_pool_alloc_block(pool, len, pool->mp_block);
p = mem_pool_alloc_block(pool, pool->block_alloc, NULL);
}
r = p->next_free;
p->next_free += len;
return r;
}
void *mem_pool_calloc(struct mem_pool *pool, size_t count, size_t size)
{
size_t len = st_mult(count, size);
void *r = mem_pool_alloc(pool, len);
memset(r, 0, len);
return r;
}
char *mem_pool_strdup(struct mem_pool *pool, const char *str)
{
size_t len = strlen(str) + 1;
char *ret = mem_pool_alloc(pool, len);
return memcpy(ret, str, len);
}
char *mem_pool_strndup(struct mem_pool *pool, const char *str, size_t len)
{
char *p = memchr(str, '\0', len);
size_t actual_len = (p ? p - str : len);
char *ret = mem_pool_alloc(pool, actual_len+1);
ret[actual_len] = '\0';
return memcpy(ret, str, actual_len);
}
int mem_pool_contains(struct mem_pool *pool, void *mem)
{
struct mp_block *p;
/* Check if memory is allocated in a block */
for (p = pool->mp_block; p; p = p->next_block)
if ((mem >= ((void *)p->space)) &&
(mem < ((void *)p->end)))
return 1;
return 0;
}
void mem_pool_combine(struct mem_pool *dst, struct mem_pool *src)
{
struct mp_block *p;
/* Append the blocks from src to dst */
if (dst->mp_block && src->mp_block) {
/*
* src and dst have blocks, append
* blocks from src to dst.
*/
p = dst->mp_block;
while (p->next_block)
p = p->next_block;
p->next_block = src->mp_block;
} else if (src->mp_block) {
/*
* src has blocks, dst is empty.
*/
dst->mp_block = src->mp_block;
} else {
/* src is empty, nothing to do. */
}
dst->pool_alloc += src->pool_alloc;
src->pool_alloc = 0;
src->mp_block = NULL;
}
|
