bird/lib/hash.h
Ondrej Zajicek (work) c8cafc8ebb Minor code cleanups
2016-11-08 17:46:29 +01:00

191 lines
5.5 KiB
C

/*
* BIRD Library -- Generic Hash Table
*
* (c) 2013 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2013 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_HASH_H_
#define _BIRD_HASH_H_
#define HASH(type) struct { type **data; uint count, order; }
#define HASH_TYPE(v) typeof(** (v).data)
#define HASH_SIZE(v) (1U << (v).order)
#define HASH_EQ(v,id,k1,k2...) (id##_EQ(k1, k2))
#define HASH_FN(v,id,key...) ((u32) (id##_FN(key)) >> (32 - (v).order))
#define HASH_INIT(v,pool,init_order) \
({ \
(v).count = 0; \
(v).order = (init_order); \
(v).data = mb_allocz(pool, HASH_SIZE(v) * sizeof(* (v).data)); \
})
#define HASH_FIND(v,id,key...) \
({ \
u32 _h = HASH_FN(v, id, key); \
HASH_TYPE(v) *_n = (v).data[_h]; \
while (_n && !HASH_EQ(v, id, id##_KEY(_n), key)) \
_n = id##_NEXT(_n); \
_n; \
})
#define HASH_INSERT(v,id,node) \
({ \
u32 _h = HASH_FN(v, id, id##_KEY((node))); \
HASH_TYPE(v) **_nn = (v).data + _h; \
id##_NEXT(node) = *_nn; \
*_nn = node; \
(v).count++; \
})
#define HASH_DO_REMOVE(v,id,_nn) \
({ \
*_nn = id##_NEXT((*_nn)); \
(v).count--; \
})
#define HASH_DELETE(v,id,key...) \
({ \
u32 _h = HASH_FN(v, id, key); \
HASH_TYPE(v) *_n, **_nn = (v).data + _h; \
\
while ((*_nn) && !HASH_EQ(v, id, id##_KEY((*_nn)), key)) \
_nn = &(id##_NEXT((*_nn))); \
\
if (_n = *_nn) \
HASH_DO_REMOVE(v,id,_nn); \
_n; \
})
#define HASH_REMOVE(v,id,node) \
({ \
u32 _h = HASH_FN(v, id, id##_KEY((node))); \
HASH_TYPE(v) *_n, **_nn = (v).data + _h; \
\
while ((*_nn) && (*_nn != (node))) \
_nn = &(id##_NEXT((*_nn))); \
\
if (_n = *_nn) \
HASH_DO_REMOVE(v,id,_nn); \
_n; \
})
#define HASH_REHASH(v,id,pool,step) \
({ \
HASH_TYPE(v) *_n, *_n2, **_od; \
uint _i, _os; \
\
_os = HASH_SIZE(v); \
_od = (v).data; \
(v).count = 0; \
(v).order += (step); \
(v).data = mb_allocz(pool, HASH_SIZE(v) * sizeof(* (v).data)); \
\
for (_i = 0; _i < _os; _i++) \
for (_n = _od[_i]; _n && (_n2 = id##_NEXT(_n), 1); _n = _n2) \
HASH_INSERT(v, id, _n); \
\
mb_free(_od); \
})
#define REHASH_LO_MARK(a,b,c,d,e,f) a
#define REHASH_HI_MARK(a,b,c,d,e,f) b
#define REHASH_LO_STEP(a,b,c,d,e,f) c
#define REHASH_HI_STEP(a,b,c,d,e,f) d
#define REHASH_LO_BOUND(a,b,c,d,e,f) e
#define REHASH_HI_BOUND(a,b,c,d,e,f) f
#define HASH_DEFINE_REHASH_FN(id,type) \
static void id##_REHASH(void *v, pool *p, int step) \
{ HASH_REHASH(* (HASH(type) *) v, id, p, step); }
#define HASH_MAY_STEP_UP(v,id,pool) HASH_MAY_STEP_UP_(v,pool, id##_REHASH, id##_PARAMS)
#define HASH_MAY_STEP_DOWN(v,id,pool) HASH_MAY_STEP_DOWN_(v,pool, id##_REHASH, id##_PARAMS)
#define HASH_MAY_RESIZE_DOWN(v,id,pool) HASH_MAY_RESIZE_DOWN_(v,pool, id##_REHASH, id##_PARAMS)
#define HASH_MAY_STEP_UP_(v,pool,rehash_fn,args) \
({ \
if (((v).count > (HASH_SIZE(v) REHASH_HI_MARK(args))) && \
((v).order < (REHASH_HI_BOUND(args)))) \
rehash_fn(&(v), pool, REHASH_HI_STEP(args)); \
})
#define HASH_MAY_STEP_DOWN_(v,pool,rehash_fn,args) \
({ \
if (((v).count < (HASH_SIZE(v) REHASH_LO_MARK(args))) && \
((v).order > (REHASH_LO_BOUND(args)))) \
rehash_fn(&(v), pool, -(REHASH_LO_STEP(args))); \
})
#define HASH_MAY_RESIZE_DOWN_(v,pool,rehash_fn,args) \
({ \
uint _o = (v).order; \
while (((v).count < ((1U << _o) REHASH_LO_MARK(args))) && \
(_o > (REHASH_LO_BOUND(args)))) \
_o -= (REHASH_LO_STEP(args)); \
if (_o < (v).order) \
rehash_fn(&(v), pool, _o - (v).order); \
})
#define HASH_INSERT2(v,id,pool,node) \
({ \
HASH_INSERT(v, id, node); \
HASH_MAY_STEP_UP(v, id, pool); \
})
#define HASH_DELETE2(v,id,pool,key...) \
({ \
HASH_TYPE(v) *_n = HASH_DELETE(v, id, key); \
if (_n) HASH_MAY_STEP_DOWN(v, id, pool); \
_n; \
})
#define HASH_REMOVE2(v,id,pool,node) \
({ \
HASH_TYPE(v) *_n = HASH_REMOVE(v, id, node); \
if (_n) HASH_MAY_STEP_DOWN(v, id, pool); \
_n; \
})
#define HASH_WALK(v,next,n) \
do { \
HASH_TYPE(v) *n; \
uint _i; \
uint _s = HASH_SIZE(v); \
for (_i = 0; _i < _s; _i++) \
for (n = (v).data[_i]; n; n = n->next)
#define HASH_WALK_END } while (0)
#define HASH_WALK_DELSAFE(v,next,n) \
do { \
HASH_TYPE(v) *n, *_next; \
uint _i; \
uint _s = HASH_SIZE(v); \
for (_i = 0; _i < _s; _i++) \
for (n = (v).data[_i]; n && (_next = n->next, 1); n = _next)
#define HASH_WALK_DELSAFE_END } while (0)
#define HASH_WALK_FILTER(v,next,n,nn) \
do { \
HASH_TYPE(v) *n, **nn; \
uint _i; \
uint _s = HASH_SIZE(v); \
for (_i = 0; _i < _s; _i++) \
for (nn = (v).data + _i; n = *nn; (*nn == n) ? (nn = &n->next) : NULL)
#define HASH_WALK_FILTER_END } while (0)
#endif