diff options
Diffstat (limited to 'commit-slab.h')
| -rw-r--r-- | commit-slab.h | 57 |
1 files changed, 46 insertions, 11 deletions
diff --git a/commit-slab.h b/commit-slab.h index cc114b53b0..42d16dcded 100644 --- a/commit-slab.h +++ b/commit-slab.h @@ -8,14 +8,20 @@ * * After including this header file, using: * - * define_commit_slab(indegee, int); + * define_commit_slab(indegree, int); * * will let you call the following functions: * * - int *indegree_at(struct indegree *, struct commit *); * * This function locates the data associated with the given commit in - * the indegree slab, and returns the pointer to it. + * the indegree slab, and returns the pointer to it. The location to + * store the data is allocated as necessary. + * + * - int *indegree_peek(struct indegree *, struct commit *); + * + * This function is similar to indegree_at(), but it will return NULL + * until a call to indegree_at() was made for the commit. * * - void init_indegree(struct indegree *); * void init_indegree_with_stride(struct indegree *, int); @@ -80,8 +86,9 @@ static MAYBE_UNUSED void clear_ ##slabname(struct slabname *s) \ s->slab = NULL; \ } \ \ -static MAYBE_UNUSED elemtype *slabname## _at(struct slabname *s, \ - const struct commit *c) \ +static MAYBE_UNUSED elemtype *slabname## _at_peek(struct slabname *s, \ + const struct commit *c, \ + int add_if_missing) \ { \ int nth_slab, nth_slot; \ \ @@ -90,31 +97,59 @@ static MAYBE_UNUSED elemtype *slabname## _at(struct slabname *s, \ \ if (s->slab_count <= nth_slab) { \ int i; \ - s->slab = xrealloc(s->slab, \ - (nth_slab + 1) * sizeof(*s->slab)); \ + if (!add_if_missing) \ + return NULL; \ + REALLOC_ARRAY(s->slab, nth_slab + 1); \ stat_ ##slabname## realloc++; \ 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 (!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]; \ + } \ + return &s->slab[nth_slab][nth_slot * s->stride]; \ +} \ + \ +static MAYBE_UNUSED elemtype *slabname## _at(struct slabname *s, \ + const struct commit *c) \ +{ \ + return slabname##_at_peek(s, c, 1); \ } \ \ -static int stat_ ##slabname## realloc +static MAYBE_UNUSED elemtype *slabname## _peek(struct slabname *s, \ + const struct commit *c) \ +{ \ + return slabname##_at_peek(s, c, 0); \ +} \ + \ +struct slabname /* - * Note that this seemingly redundant second declaration is required + * 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 * * define_commit_slab(indegree, int); * - * ends in 'static int stat_indegreerealloc;'. This would otherwise + * 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. */ +/* + * Statically initialize a commit slab named "var". Note that this + * evaluates "stride" multiple times! Example: + * + * struct indegree indegrees = COMMIT_SLAB_INIT(1, indegrees); + * + */ +#define COMMIT_SLAB_INIT(stride, var) { \ + COMMIT_SLAB_SIZE / sizeof(**((var).slab)) / (stride), \ + (stride), 0, NULL \ +} + #endif /* COMMIT_SLAB_H */ |