1// This may look like C code, but it is really -*- C++ -*- 2/* 3Copyright (C) 1988 Free Software Foundation 4 written by Doug Lea (dl@rocky.oswego.edu) 5 6This file is part of GNU CC. 7 8GNU CC is distributed in the hope that it will be useful, 9but WITHOUT ANY WARRANTY. No author or distributor 10accepts responsibility to anyone for the consequences of using it 11or for whether it serves any particular purpose or works at all, 12unless he says so in writing. Refer to the GNU CC General Public 13License for full details. 14 15Everyone is granted permission to copy, modify and redistribute 16GNU CC, but only under the conditions described in the 17GNU CC General Public License. A copy of this license is 18supposed to have been given to you along with GNU CC so you 19can know your rights and responsibilities. It should be in a 20file named COPYING. Among other things, the copyright notice 21and this notice must be preserved on all copies. 22*/ 23 24#ifdef __GNUG__ 25#pragma implementation 26#endif 27#include "<T>.<C>.CHMap.h" 28 29// The nodes are linked together serially via a version 30// of a trick used in some vtables: odd pointers are 31// actually links to the next table entry. 32// Not terrible, but not wonderful either 33 34static inline int goodCHptr(<T><C>CHNode* t) 35{ 36 return ((((unsigned)t) & 1) == 0); 37} 38 39static inline <T><C>CHNode* index_to_CHptr(int i) 40{ 41 return (<T><C>CHNode*)((i << 1) + 1); 42} 43 44static inline int CHptr_to_index(<T><C>CHNode* t) 45{ 46 return ( ((unsigned) t) >> 1); 47} 48 49<T><C>CHMap::<T><C>CHMap(<C&> dflt, unsigned int sz) 50 :<T><C>Map(dflt) 51{ 52 tab = (<T><C>CHNode**)(new <T><C>CHNodePtr[size = sz]); 53 for (unsigned int i = 0; i < size; ++i) tab[i] = index_to_CHptr(i+1); 54 count = 0; 55} 56 57<T><C>CHMap::<T><C>CHMap(<T><C>CHMap& a) :<T><C>Map(a.def) 58{ 59 tab = (<T><C>CHNode**)(new <T><C>CHNodePtr[size = a.size]); 60 for (unsigned int i = 0; i < size; ++i) tab[i] = index_to_CHptr(i+1); 61 count = 0; 62 for (Pix p = a.first(); p; a.next(p)) (*this)[a.key(p)] = a.contents(p); 63} 64 65 66Pix <T><C>CHMap::seek(<T&> key) 67{ 68 unsigned int h = <T>HASH(key) % size; 69 70 for (<T><C>CHNode* t = tab[h]; goodCHptr(t); t = t->tl) 71 if (<T>EQ(key, t->hd)) 72 return Pix(t); 73 74 return 0; 75} 76 77 78<C>& <T><C>CHMap::operator [](<T&> item) 79{ 80 unsigned int h = <T>HASH(item) % size; 81 82 for (<T><C>CHNode* t = tab[h]; goodCHptr(t); t = t->tl) 83 if (<T>EQ(item, t->hd)) 84 return t->cont; 85 86 t = new <T><C>CHNode(item, def, tab[h]); 87 tab[h] = t; 88 ++count; 89 return t->cont; 90} 91 92 93void <T><C>CHMap::del(<T&> key) 94{ 95 unsigned int h = <T>HASH(key) % size; 96 97 <T><C>CHNode* t = tab[h]; 98 <T><C>CHNode* trail = t; 99 while (goodCHptr(t)) 100 { 101 if (<T>EQ(key, t->hd)) 102 { 103 if (trail == t) 104 tab[h] = t->tl; 105 else 106 trail->tl = t->tl; 107 delete t; 108 --count; 109 return; 110 } 111 trail = t; 112 t = t->tl; 113 } 114} 115 116 117void <T><C>CHMap::clear() 118{ 119 for (unsigned int i = 0; i < size; ++i) 120 { 121 <T><C>CHNode* p = tab[i]; 122 tab[i] = index_to_CHptr(i+1); 123 while (goodCHptr(p)) 124 { 125 <T><C>CHNode* nxt = p->tl; 126 delete(p); 127 p = nxt; 128 } 129 } 130 count = 0; 131} 132 133Pix <T><C>CHMap::first() 134{ 135 for (unsigned int i = 0; i < size; ++i) if (goodCHptr(tab[i])) return Pix(tab[i]); 136 return 0; 137} 138 139void <T><C>CHMap::next(Pix& p) 140{ 141 <T><C>CHNode* t = ((<T><C>CHNode*)p)->tl; 142 if (goodCHptr(t)) 143 p = Pix(t); 144 else 145 { 146 for (unsigned int i = CHptr_to_index(t); i < size; ++i) 147 { 148 if (goodCHptr(tab[i])) 149 { 150 p = Pix(tab[i]); 151 return; 152 } 153 } 154 p = 0; 155 } 156} 157 158 159int <T><C>CHMap::OK() 160{ 161 int v = tab != 0; 162 int n = 0; 163 for (unsigned int i = 0; i < size; ++i) 164 { 165 for (<T><C>CHNode* p = tab[i]; goodCHptr(p); p = p->tl) ++n; 166 v &= CHptr_to_index(p) == i + 1; 167 } 168 v &= count == n; 169 if (!v) error("invariant failure"); 170 return v; 171} 172