95 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
| #ifndef COMMIT_SLAB_IMPL_H
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| #define COMMIT_SLAB_IMPL_H
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| 
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| #include "git-compat-util.h"
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| 
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| #define implement_static_commit_slab(slabname, elemtype) \
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| 	implement_commit_slab(slabname, elemtype, MAYBE_UNUSED static)
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| 
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| #define implement_shared_commit_slab(slabname, elemtype) \
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| 	implement_commit_slab(slabname, elemtype, )
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| 
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| #define implement_commit_slab(slabname, elemtype, scope)		\
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| 									\
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| scope 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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| scope 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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| scope 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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| scope 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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| 		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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| scope 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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| scope 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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| /*
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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, static);
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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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| 
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| #endif	/* COMMIT_SLAB_IMPL_H */
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