The third batch
[git.git] / commit-slab-impl.h
blob5c0eb91a5d175ddb079459a0ba13b9be1f74b1ab
1 #ifndef COMMIT_SLAB_IMPL_H
2 #define COMMIT_SLAB_IMPL_H
4 #include "git-compat-util.h"
6 #define implement_static_commit_slab(slabname, elemtype) \
7 implement_commit_slab(slabname, elemtype, MAYBE_UNUSED static)
9 #define implement_shared_commit_slab(slabname, elemtype) \
10 implement_commit_slab(slabname, elemtype, )
12 #define implement_commit_slab(slabname, elemtype, scope) \
14 scope void init_ ##slabname## _with_stride(struct slabname *s, \
15 unsigned stride) \
16 { \
17 unsigned int elem_size; \
18 if (!stride) \
19 stride = 1; \
20 s->stride = stride; \
21 elem_size = sizeof(elemtype) * stride; \
22 s->slab_size = COMMIT_SLAB_SIZE / elem_size; \
23 s->slab_count = 0; \
24 s->slab = NULL; \
25 } \
27 scope void init_ ##slabname(struct slabname *s) \
28 { \
29 init_ ##slabname## _with_stride(s, 1); \
30 } \
32 scope void clear_ ##slabname(struct slabname *s) \
33 { \
34 unsigned int i; \
35 for (i = 0; i < s->slab_count; i++) \
36 free(s->slab[i]); \
37 s->slab_count = 0; \
38 FREE_AND_NULL(s->slab); \
39 } \
41 scope elemtype *slabname## _at_peek(struct slabname *s, \
42 const struct commit *c, \
43 int add_if_missing) \
44 { \
45 unsigned int nth_slab, nth_slot; \
47 nth_slab = c->index / s->slab_size; \
48 nth_slot = c->index % s->slab_size; \
50 if (s->slab_count <= nth_slab) { \
51 unsigned int i; \
52 if (!add_if_missing) \
53 return NULL; \
54 REALLOC_ARRAY(s->slab, nth_slab + 1); \
55 for (i = s->slab_count; i <= nth_slab; i++) \
56 s->slab[i] = NULL; \
57 s->slab_count = nth_slab + 1; \
58 } \
59 if (!s->slab[nth_slab]) { \
60 if (!add_if_missing) \
61 return NULL; \
62 s->slab[nth_slab] = xcalloc(s->slab_size, \
63 sizeof(**s->slab) * s->stride); \
64 } \
65 return &s->slab[nth_slab][nth_slot * s->stride]; \
66 } \
68 scope elemtype *slabname## _at(struct slabname *s, \
69 const struct commit *c) \
70 { \
71 return slabname##_at_peek(s, c, 1); \
72 } \
74 scope elemtype *slabname## _peek(struct slabname *s, \
75 const struct commit *c) \
76 { \
77 return slabname##_at_peek(s, c, 0); \
78 } \
80 struct slabname
83 * Note that this redundant forward declaration is required
84 * to allow a terminating semicolon, which makes instantiations look
85 * like function declarations. I.e., the expansion of
87 * implement_commit_slab(indegree, int, static);
89 * ends in 'struct indegree;'. This would otherwise
90 * be a syntax error according (at least) to ISO C. It's hard to
91 * catch because GCC silently parses it by default.
94 #endif /* COMMIT_SLAB_IMPL_H */