[176] | 1 | // -*- C++ -*- |
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| 2 | |
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| 3 | /* |
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| 4 | |
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| 5 | Heap Layers: An Extensible Memory Allocation Infrastructure |
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| 6 | |
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| 7 | Copyright (C) 2000-2003 by Emery Berger |
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| 8 | http://www.cs.umass.edu/~emery |
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| 9 | emery@cs.umass.edu |
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| 10 | |
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| 11 | This program is free software; you can redistribute it and/or modify |
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| 12 | it under the terms of the GNU General Public License as published by |
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| 13 | the Free Software Foundation; either version 2 of the License, or |
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| 14 | (at your option) any later version. |
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| 15 | |
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| 16 | This program is distributed in the hope that it will be useful, |
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| 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 19 | GNU General Public License for more details. |
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| 20 | |
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| 21 | You should have received a copy of the GNU General Public License |
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| 22 | along with this program; if not, write to the Free Software |
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| 23 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 24 | |
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| 25 | */ |
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| 26 | |
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| 27 | #ifndef _DLLIST_H_ |
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| 28 | #define _DLLIST_H_ |
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| 29 | |
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| 30 | #include <assert.h> |
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| 31 | |
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| 32 | /** |
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| 33 | * |
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| 34 | * @class DLList |
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| 35 | * @brief A "memory neutral" doubly-linked list. |
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| 36 | * @author Emery Berger |
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| 37 | */ |
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| 38 | |
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| 39 | namespace HL { |
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| 40 | |
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| 41 | class DLList { |
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| 42 | public: |
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| 43 | |
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| 44 | inline DLList (void) { |
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| 45 | clear(); |
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| 46 | } |
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| 47 | |
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| 48 | class Entry; |
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| 49 | |
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| 50 | /// Clear the list. |
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| 51 | inline void clear (void) { |
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| 52 | head.setPrev (&head); |
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| 53 | head.setNext (&head); |
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| 54 | } |
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| 55 | |
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| 56 | /// Is the list empty? |
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| 57 | inline bool isEmpty (void) const { |
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| 58 | return (head.getNext() == &head); |
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| 59 | } |
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| 60 | |
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| 61 | /// Get the head of the list. |
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| 62 | inline Entry * get (void) { |
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| 63 | const Entry * e = head.next; |
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| 64 | if (e == &head) { |
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| 65 | return NULL; |
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| 66 | } |
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| 67 | head.next = e->next; |
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| 68 | head.next->prev = &head; |
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| 69 | return (Entry *) e; |
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| 70 | } |
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| 71 | |
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| 72 | /// Remove one item from the list. |
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| 73 | inline void remove (Entry * e) { |
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| 74 | e->remove(); |
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| 75 | } |
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| 76 | |
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| 77 | /// Insert an entry into the head of the list. |
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| 78 | inline void insert (Entry * e) { |
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| 79 | e->insert (&head, head.next); |
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| 80 | } |
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| 81 | |
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| 82 | /// An entry in the list. |
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| 83 | class Entry { |
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| 84 | public: |
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| 85 | // private: |
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| 86 | inline void setPrev (Entry * p) { assert (p != NULL); prev = p; } |
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| 87 | inline void setNext (Entry * p) { assert (p != NULL); next = p; } |
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| 88 | inline Entry * getPrev (void) const { return prev; } |
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| 89 | inline Entry * getNext (void) const { return next; } |
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| 90 | inline void remove (void) const { |
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| 91 | prev->setNext(next); |
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| 92 | next->setPrev(prev); |
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| 93 | } |
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| 94 | inline void insert (Entry * p, Entry * n) { |
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| 95 | prev = p; |
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| 96 | next = n; |
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| 97 | p->setNext (this); |
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| 98 | n->setPrev (this); |
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| 99 | } |
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| 100 | Entry * prev; |
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| 101 | Entry * next; |
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| 102 | }; |
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| 103 | |
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| 104 | |
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| 105 | private: |
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| 106 | |
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| 107 | /// The head of the list. |
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| 108 | Entry head; |
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| 109 | |
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| 110 | }; |
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| 111 | |
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| 112 | }; |
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| 113 | |
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| 114 | #endif |
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