Signed-off-by: Thomas Schoebel-Theuer <t...@schoebel-theuer.de> --- include/linux/brick/lib_pairing_heap.h | 109 +++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 include/linux/brick/lib_pairing_heap.h
diff --git a/include/linux/brick/lib_pairing_heap.h b/include/linux/brick/lib_pairing_heap.h new file mode 100644 index 000000000000..9456e9ea348c --- /dev/null +++ b/include/linux/brick/lib_pairing_heap.h @@ -0,0 +1,109 @@ +/* + * MARS Long Distance Replication Software + * + * Copyright (C) 2010-2014 Thomas Schoebel-Theuer + * Copyright (C) 2011-2014 1&1 Internet AG + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef PAIRING_HEAP_H +#define PAIRING_HEAP_H + +/* Algorithm: see http://en.wikipedia.org/wiki/Pairing_heap + * This is just an efficient translation from recursive to iterative form. + * + * Note: find_min() is so trivial that we don't implement it. + */ + +/* generic version: KEYDEF is kept separate, allowing you to + * embed this structure into other container structures already + * possessing some key (just provide an empty KEYDEF in this case). + */ +#define _PAIRING_HEAP_TYPEDEF(KEYTYPE, KEYDEF) \ + \ +struct pairing_heap_##KEYTYPE { \ + KEYDEF \ + struct pairing_heap_##KEYTYPE *next; \ + struct pairing_heap_##KEYTYPE *subheaps; \ +} + +/* less generic version: define the key inside. + */ +#define PAIRING_HEAP_TYPEDEF(KEYTYPE) \ + _PAIRING_HEAP_TYPEDEF(KEYTYPE, KEYTYPE key;) + +/* generic methods: allow arbitrary CMP() functions. + */ +#define _PAIRING_HEAP_FUNCTIONS(_STATIC, KEYTYPE, CMP) \ + \ +_STATIC \ +struct pairing_heap_##KEYTYPE *_ph_merge_##KEYTYPE( \ +struct pairing_heap_##KEYTYPE *heap1, struct pairing_heap_##KEYTYPE *heap2)\ +{ \ + if (!heap1) \ + return heap2; \ + if (!heap2) \ + return heap1; \ + if (CMP(heap1, heap2) < 0) { \ + heap2->next = heap1->subheaps; \ + heap1->subheaps = heap2; \ + return heap1; \ + } \ + heap1->next = heap2->subheaps; \ + heap2->subheaps = heap1; \ + return heap2; \ +} \ + \ +_STATIC \ +void ph_insert_##KEYTYPE(struct pairing_heap_##KEYTYPE **heap, struct pairing_heap_##KEYTYPE *new)\ +{ \ + new->next = NULL; \ + new->subheaps = NULL; \ + *heap = _ph_merge_##KEYTYPE(*heap, new); \ +} \ + \ +_STATIC \ +void ph_delete_min_##KEYTYPE(struct pairing_heap_##KEYTYPE **heap) \ +{ \ + struct pairing_heap_##KEYTYPE *tmplist = NULL; \ + struct pairing_heap_##KEYTYPE *ptr; \ + struct pairing_heap_##KEYTYPE *next; \ + struct pairing_heap_##KEYTYPE *res; \ + if (!*heap) { \ + return; \ + } \ + for (ptr = (*heap)->subheaps; ptr; ptr = next) { \ + struct pairing_heap_##KEYTYPE *p2 = ptr->next; \ + next = p2; \ + if (p2) { \ + next = p2->next; \ + ptr = _ph_merge_##KEYTYPE(ptr, p2); \ + } \ + ptr->next = tmplist; \ + tmplist = ptr; \ + } \ + res = NULL; \ + for (ptr = tmplist; ptr; ptr = next) { \ + next = ptr->next; \ + res = _ph_merge_##KEYTYPE(res, ptr); \ + } \ + *heap = res; \ +} + +/* some default CMP() function */ +#define PAIRING_HEAP_COMPARE(a, b) ((a)->key < (b)->key ? -1 : ((a)->key > (b)->key ? 1 : 0)) + +/* less generic version: use the default CMP() function */ +#define PAIRING_HEAP_FUNCTIONS(_STATIC, KEYTYPE) \ + _PAIRING_HEAP_FUNCTIONS(_STATIC, KEYTYPE, PAIRING_HEAP_COMPARE) + +#endif -- 2.11.0
