backends/minisat/mtl/Map.h

   1 /*******************************************************************************************[Map.h]
   2 MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
   3
   4 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
   5 associated documentation files (the "Software"), to deal in the Software without restriction,
   6 including without limitation the rights to use, copy, modify, merge, publish, distribute,
   7 sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
   8 furnished to do so, subject to the following conditions:
   9
  10 The above copyright notice and this permission notice shall be included in all copies or
  11 substantial portions of the Software.
  12
  13 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
  14 NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  16 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
  17 OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  18 **************************************************************************************************/
  19
  20 #ifndef Map_h
  21 #define Map_h
  22
  23 #include <stdint.h>
  24
  25 #include "Vec.h"
  26
  27 //=================================================================================================
  28 // Default hash/equals functions
  29 //
  30
  31 template<class K> struct Hash  { uint32_t operator()(const K& k)               const { return hash(k);  } };
  32 template<class K> struct Equal { bool     operator()(const K& k1, const K& k2) const { return k1 == k2; } };
  33
  34 template<class K> struct DeepHash  { uint32_t operator()(const K* k)               const { return hash(*k);  } };
  35 template<class K> struct DeepEqual { bool     operator()(const K* k1, const K* k2) const { return *k1 == *k2; } };
  36
  37 //=================================================================================================
  38 // Some primes
  39 //
  40
  41 static const int nprimes          = 25;
  42 static const int primes [nprimes] = { 31, 73, 151, 313, 643, 1291, 2593, 5233, 10501, 21013, 42073, 84181, 168451, 337219, 674701, 1349473, 2699299, 5398891, 10798093, 21596719, 43193641, 86387383, 172775299, 345550609, 691101253 };
  43
  44 //=================================================================================================
  45 // Hash table implementation of Maps
  46 //
  47
  48 template<class K, class D, class H = Hash<K>, class E = Equal<K> >
  49 class Map {
  50     struct Pair { K key; D data; };
  51
  52     H          hash;
  53     E          equals;
  54
  55     vec<Pair>* table;
  56     int        cap;
  57     int        size;
  58
  59     // Don't allow copying (error prone):
  60     Map<K,D,H,E>&  operator = (Map<K,D,H,E>& other) { assert(0); }
  61                    Map        (Map<K,D,H,E>& other) { assert(0); }
  62
  63     int32_t index  (const K& k) const { return hash(k) % cap; }
  64     void   _insert (const K& k, const D& d) { table[index(k)].push(); table[index(k)].last().key = k; table[index(k)].last().data = d; }
  65     void    rehash () {
  66         const vec<Pair>* old = table;
  67
  68         int newsize = primes[0];
  69         for (int i = 1; newsize <= cap && i < nprimes; i++)
  70            newsize = primes[i];
  71
  72         table = new vec<Pair>[newsize];
  73
  74         for (int i = 0; i < cap; i++){
  75             for (int j = 0; j < old[i].size(); j++){
  76                 _insert(old[i][j].key, old[i][j].data); }}
  77
  78         delete [] old;
  79
  80         cap = newsize;
  81     }
  82
  83
  84     public:
  85
  86      Map () : table(NULL), cap(0), size(0) {}
  87      Map (const H& h, const E& e) : Map(), hash(h), equals(e) {}
  88     ~Map () { delete [] table; }
  89
  90     void insert (const K& k, const D& d) { if (size+1 > cap / 2) rehash(); _insert(k, d); size++; }
  91     bool peek   (const K& k, D& d) {
  92         if (size == 0) return false;
  93         const vec<Pair>& ps = table[index(k)];
  94         for (int i = 0; i < ps.size(); i++)
  95             if (equals(ps[i].key, k)){
  96                 d = ps[i].data;
  97                 return true; }
  98         return false;
  99     }
 100
 101     void remove (const K& k) {
 102         assert(table != NULL);
 103         vec<Pair>& ps = table[index(k)];
 104         int j = 0;
 105         for (; j < ps.size() && !equals(ps[j].key, k); j++);
 106         assert(j < ps.size());
 107         ps[j] = ps.last();
 108         ps.pop();
 109     }
 110
 111     void clear  () {
 112         cap = size = 0;
 113         delete [] table;
 114         table = NULL;
 115     }
 116 };
 117
 118 #endif