tvl-depot/third_party/git/commit-slab-impl.h
Vincent Ambo f4609b896f merge(3p/git): Merge git subtree at v2.29.2
This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb
2020-11-21 19:45:56 +01:00

107 lines
3.1 KiB
C

#ifndef COMMIT_SLAB_IMPL_H
#define COMMIT_SLAB_IMPL_H
#include "git-compat-util.h"
#define implement_static_commit_slab(slabname, elemtype) \
implement_commit_slab(slabname, elemtype, MAYBE_UNUSED static)
#define implement_shared_commit_slab(slabname, elemtype) \
implement_commit_slab(slabname, elemtype, )
#define implement_commit_slab(slabname, elemtype, scope) \
\
scope void init_ ##slabname## _with_stride(struct slabname *s, \
unsigned stride) \
{ \
unsigned int elem_size; \
if (!stride) \
stride = 1; \
s->stride = stride; \
elem_size = sizeof(elemtype) * stride; \
s->slab_size = COMMIT_SLAB_SIZE / elem_size; \
s->slab_count = 0; \
s->slab = NULL; \
} \
\
scope void init_ ##slabname(struct slabname *s) \
{ \
init_ ##slabname## _with_stride(s, 1); \
} \
\
scope void clear_ ##slabname(struct slabname *s) \
{ \
unsigned int i; \
for (i = 0; i < s->slab_count; i++) \
free(s->slab[i]); \
s->slab_count = 0; \
FREE_AND_NULL(s->slab); \
} \
\
scope void deep_clear_ ##slabname(struct slabname *s, void (*free_fn)(elemtype *)) \
{ \
unsigned int i; \
for (i = 0; i < s->slab_count; i++) { \
unsigned int j; \
if (!s->slab[i]) \
continue; \
for (j = 0; j < s->slab_size; j++) \
free_fn(&s->slab[i][j * s->stride]); \
} \
clear_ ##slabname(s); \
} \
\
scope elemtype *slabname## _at_peek(struct slabname *s, \
const struct commit *c, \
int add_if_missing) \
{ \
unsigned int nth_slab, nth_slot; \
\
nth_slab = c->index / s->slab_size; \
nth_slot = c->index % s->slab_size; \
\
if (s->slab_count <= nth_slab) { \
unsigned int i; \
if (!add_if_missing) \
return NULL; \
REALLOC_ARRAY(s->slab, nth_slab + 1); \
for (i = s->slab_count; i <= nth_slab; i++) \
s->slab[i] = NULL; \
s->slab_count = nth_slab + 1; \
} \
if (!s->slab[nth_slab]) { \
if (!add_if_missing) \
return NULL; \
s->slab[nth_slab] = xcalloc(s->slab_size, \
sizeof(**s->slab) * s->stride); \
} \
return &s->slab[nth_slab][nth_slot * s->stride]; \
} \
\
scope elemtype *slabname## _at(struct slabname *s, \
const struct commit *c) \
{ \
return slabname##_at_peek(s, c, 1); \
} \
\
scope elemtype *slabname## _peek(struct slabname *s, \
const struct commit *c) \
{ \
return slabname##_at_peek(s, c, 0); \
} \
\
struct slabname
/*
* Note that this redundant forward declaration is required
* to allow a terminating semicolon, which makes instantiations look
* like function declarations. I.e., the expansion of
*
* implement_commit_slab(indegree, int, static);
*
* ends in 'struct indegree;'. This would otherwise
* be a syntax error according (at least) to ISO C. It's hard to
* catch because GCC silently parses it by default.
*/
#endif /* COMMIT_SLAB_IMPL_H */