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commit-slab.h: code split
The struct declaration and implementation macros are moved to commit-slab-hdr.h and commit-slab-impl.h respectively. This right now is not needed for current users but if we make a public commit-slab type, we may want to avoid including the slab implementation in a header file which gets replicated in every c file that includes it. Signed-off-by: Junio C Hamano <[email protected]>
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-109
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3 files changed

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lines changed

‎commit-slab-decl.h

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#ifndef COMMIT_SLAB_HDR_H
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#define COMMIT_SLAB_HDR_H
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/* allocate ~512kB at once, allowing for malloc overhead */
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#ifndef COMMIT_SLAB_SIZE
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#define COMMIT_SLAB_SIZE (512*1024-32)
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#endif
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#define declare_commit_slab(slabname, elemtype) \
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\
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struct slabname { \
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unsigned slab_size; \
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unsigned stride; \
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unsigned slab_count; \
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elemtype **slab; \
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}
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/*
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* Statically initialize a commit slab named "var". Note that this
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* evaluates "stride" multiple times! Example:
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*
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* struct indegree indegrees = COMMIT_SLAB_INIT(1, indegrees);
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*
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*/
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#define COMMIT_SLAB_INIT(stride, var) { \
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COMMIT_SLAB_SIZE / sizeof(**((var).slab)) / (stride), \
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(stride), 0, NULL \
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}
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#endif /* COMMIT_SLAB_HDR_H */

‎commit-slab-impl.h

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

‎commit-slab.h

Lines changed: 6 additions & 109 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,9 @@
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#ifndef COMMIT_SLAB_H
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#define COMMIT_SLAB_H
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#include "commit-slab-decl.h"
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#include "commit-slab-impl.h"
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/*
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* define_commit_slab(slabname, elemtype) creates boilerplate code to define
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* a new struct (struct slabname) that is used to associate a piece of data
@@ -41,114 +44,8 @@
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* leaking memory.
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*/
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/* allocate ~512kB at once, allowing for malloc overhead */
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#ifndef COMMIT_SLAB_SIZE
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#define COMMIT_SLAB_SIZE (512*1024-32)
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#endif
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#define MAYBE_UNUSED __attribute__((__unused__))
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#define define_commit_slab(slabname, elemtype) \
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\
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struct slabname { \
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unsigned slab_size; \
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unsigned stride; \
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unsigned slab_count; \
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elemtype **slab; \
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}; \
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static int stat_ ##slabname## realloc; \
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\
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static MAYBE_UNUSED void init_ ##slabname## _with_stride(struct slabname *s, \
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unsigned stride) \
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{ \
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unsigned int elem_size; \
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if (!stride) \
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stride = 1; \
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s->stride = stride; \
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elem_size = sizeof(elemtype) * stride; \
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s->slab_size = COMMIT_SLAB_SIZE / elem_size; \
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s->slab_count = 0; \
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s->slab = NULL; \
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} \
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\
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static MAYBE_UNUSED void init_ ##slabname(struct slabname *s) \
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{ \
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init_ ##slabname## _with_stride(s, 1); \
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} \
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\
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static MAYBE_UNUSED void clear_ ##slabname(struct slabname *s) \
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{ \
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unsigned int i; \
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for (i = 0; i < s->slab_count; i++) \
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free(s->slab[i]); \
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s->slab_count = 0; \
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FREE_AND_NULL(s->slab); \
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} \
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\
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static MAYBE_UNUSED elemtype *slabname## _at_peek(struct slabname *s, \
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const struct commit *c, \
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int add_if_missing) \
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{ \
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unsigned int nth_slab, nth_slot; \
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\
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nth_slab = c->index / s->slab_size; \
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nth_slot = c->index % s->slab_size; \
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\
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if (s->slab_count <= nth_slab) { \
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unsigned int i; \
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if (!add_if_missing) \
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return NULL; \
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REALLOC_ARRAY(s->slab, nth_slab + 1); \
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stat_ ##slabname## realloc++; \
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for (i = s->slab_count; i <= nth_slab; i++) \
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s->slab[i] = NULL; \
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s->slab_count = nth_slab + 1; \
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} \
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if (!s->slab[nth_slab]) { \
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if (!add_if_missing) \
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return NULL; \
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s->slab[nth_slab] = xcalloc(s->slab_size, \
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sizeof(**s->slab) * s->stride); \
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} \
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return &s->slab[nth_slab][nth_slot * s->stride]; \
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} \
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\
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static MAYBE_UNUSED elemtype *slabname## _at(struct slabname *s, \
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const struct commit *c) \
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{ \
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return slabname##_at_peek(s, c, 1); \
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} \
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\
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static MAYBE_UNUSED elemtype *slabname## _peek(struct slabname *s, \
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const struct commit *c) \
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{ \
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return slabname##_at_peek(s, c, 0); \
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} \
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\
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struct slabname
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/*
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* Note that this redundant forward declaration is required
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* to allow a terminating semicolon, which makes instantiations look
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* like function declarations. I.e., the expansion of
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*
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* define_commit_slab(indegree, int);
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*
137-
* ends in 'struct indegree;'. This would otherwise
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* be a syntax error according (at least) to ISO C. It's hard to
139-
* catch because GCC silently parses it by default.
140-
*/
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142-
/*
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* Statically initialize a commit slab named "var". Note that this
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* evaluates "stride" multiple times! Example:
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*
146-
* struct indegree indegrees = COMMIT_SLAB_INIT(1, indegrees);
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*
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*/
149-
#define COMMIT_SLAB_INIT(stride, var) { \
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COMMIT_SLAB_SIZE / sizeof(**((var).slab)) / (stride), \
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(stride), 0, NULL \
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}
47+
#define define_commit_slab(slabname, elemtype) \
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declare_commit_slab(slabname, elemtype); \
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implement_commit_slab(slabname, elemtype)
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#endif /* COMMIT_SLAB_H */

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