block alloc: add lifecycle APIs for cache_entry structs
[git/git.git] / mem-pool.c
CommitLineData
065feab4
JM
1/*
2 * Memory Pool implementation logic.
3 */
4
5#include "cache.h"
6#include "mem-pool.h"
7
8static struct mp_block *mem_pool_alloc_block(struct mem_pool *mem_pool, size_t block_alloc)
9{
10 struct mp_block *p;
11
12 mem_pool->pool_alloc += sizeof(struct mp_block) + block_alloc;
13 p = xmalloc(st_add(sizeof(struct mp_block), block_alloc));
14 p->next_block = mem_pool->mp_block;
15 p->next_free = (char *)p->space;
16 p->end = p->next_free + block_alloc;
17 mem_pool->mp_block = p;
18
19 return p;
20}
21
22void *mem_pool_alloc(struct mem_pool *mem_pool, size_t len)
23{
24 struct mp_block *p;
25 void *r;
26
27 /* round up to a 'uintmax_t' alignment */
28 if (len & (sizeof(uintmax_t) - 1))
29 len += sizeof(uintmax_t) - (len & (sizeof(uintmax_t) - 1));
30
31 for (p = mem_pool->mp_block; p; p = p->next_block)
32 if (p->end - p->next_free >= len)
33 break;
34
35 if (!p) {
36 if (len >= (mem_pool->block_alloc / 2)) {
37 mem_pool->pool_alloc += len;
38 return xmalloc(len);
39 }
40
41 p = mem_pool_alloc_block(mem_pool, mem_pool->block_alloc);
42 }
43
44 r = p->next_free;
45 p->next_free += len;
46 return r;
47}
48
49void *mem_pool_calloc(struct mem_pool *mem_pool, size_t count, size_t size)
50{
51 size_t len = st_mult(count, size);
52 void *r = mem_pool_alloc(mem_pool, len);
53 memset(r, 0, len);
54 return r;
55}