libs/minisat/Vec.h

   1 /*******************************************************************************************[Vec.h]
   2 Copyright (c) 2003-2007, Niklas Een, Niklas Sorensson
   3 Copyright (c) 2007-2010, Niklas Sorensson
   4
   5 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
   6 associated documentation files (the "Software"), to deal in the Software without restriction,
   7 including without limitation the rights to use, copy, modify, merge, publish, distribute,
   8 sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
   9 furnished to do so, subject to the following conditions:
  10
  11 The above copyright notice and this permission notice shall be included in all copies or
  12 substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
  15 NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  16 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  17 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
  18 OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 **************************************************************************************************/
  20
  21 #ifndef Minisat_Vec_h
  22 #define Minisat_Vec_h
  23
  24 #include <assert.h>
  25 #include <limits>
  26 #include <new>
  27
  28 #include "IntTypes.h"
  29 #include "XAlloc.h"
  30
  31 namespace Minisat {
  32
  33 //=================================================================================================
  34 // Automatically resizable arrays
  35 //
  36 // NOTE! Don't use this vector on datatypes that cannot be re-located in memory (with realloc)
  37
  38 template<class T, class _Size = int>
  39 class vec {
  40 public:
  41     typedef _Size Size;
  42 private:
  43     T*   data;
  44     Size sz;
  45     Size cap;
  46
  47     // Don't allow copying (error prone):
  48     vec<T>&  operator=(vec<T>& other);
  49              vec      (vec<T>& other);
  50
  51     static inline Size max(Size x, Size y){ return (x > y) ? x : y; }
  52
  53 public:
  54     // Constructors:
  55     vec()                        : data(NULL), sz(0), cap(0)    { }
  56     explicit vec(Size size)      : data(NULL), sz(0), cap(0)    { growTo(size); }
  57     vec(Size size, const T& pad) : data(NULL), sz(0), cap(0)    { growTo(size, pad); }
  58    ~vec()                                                       { clear(true); }
  59
  60     // Pointer to first element:
  61     operator T*       (void)           { return data; }
  62
  63     // Size operations:
  64     Size     size     (void) const   { return sz; }
  65     void     shrink   (Size nelems)  { assert(nelems <= sz); for (Size i = 0; i < nelems; i++) sz--, data[sz].~T(); }
  66     void     shrink_  (Size nelems)  { assert(nelems <= sz); sz -= nelems; }
  67     int      capacity (void) const   { return cap; }
  68     void     capacity (Size min_cap);
  69     void     growTo   (Size size);
  70     void     growTo   (Size size, const T& pad);
  71     void     clear    (bool dealloc = false);
  72
  73     // Stack interface:
  74     void     push  (void)              { if (sz == cap) capacity(sz+1); new (&data[sz]) T(); sz++; }
  75     //void     push  (const T& elem)     { if (sz == cap) capacity(sz+1); data[sz++] = elem; }
  76     void     push  (const T& elem)     { if (sz == cap) capacity(sz+1); new (&data[sz++]) T(elem); }
  77     void     push_ (const T& elem)     { assert(sz < cap); data[sz++] = elem; }
  78     void     pop   (void)              { assert(sz > 0); sz--, data[sz].~T(); }
  79     // NOTE: it seems possible that overflow can happen in the 'sz+1' expression of 'push()', but
  80     // in fact it can not since it requires that 'cap' is equal to INT_MAX. This in turn can not
  81     // happen given the way capacities are calculated (below). Essentially, all capacities are
  82     // even, but INT_MAX is odd.
  83
  84     const T& last  (void) const        { return data[sz-1]; }
  85     T&       last  (void)              { return data[sz-1]; }
  86
  87     // Vector interface:
  88     const T& operator [] (Size index) const { return data[index]; }
  89     T&       operator [] (Size index)       { return data[index]; }
  90
  91     // Duplicatation (preferred instead):
  92     void copyTo(vec<T>& copy) const { copy.clear(); copy.growTo(sz); for (Size i = 0; i < sz; i++) copy[i] = data[i]; }
  93     void moveTo(vec<T>& dest) { dest.clear(true); dest.data = data; dest.sz = sz; dest.cap = cap; data = NULL; sz = 0; cap = 0; }
  94 };
  95
  96
  97 template<class T, class _Size>
  98 void vec<T,_Size>::capacity(Size min_cap) {
  99     if (cap >= min_cap) return;
 100     Size add = max((min_cap - cap + 1) & ~1, ((cap >> 1) + 2) & ~1);   // NOTE: grow by approximately 3/2
 101     const Size size_max = std::numeric_limits<Size>::max();
 102     if ( ((size_max <= std::numeric_limits<int>::max()) && (add > size_max - cap))
 103     ||   (((data = (T*)::realloc(data, (cap += add) * sizeof(T))) == NULL) && errno == ENOMEM) )
 104         throw OutOfMemoryException();
 105  }
 106
 107
 108 template<class T, class _Size>
 109 void vec<T,_Size>::growTo(Size size, const T& pad) {
 110     if (sz >= size) return;
 111     capacity(size);
 112     for (Size i = sz; i < size; i++) data[i] = pad;
 113     sz = size; }
 114
 115
 116 template<class T, class _Size>
 117 void vec<T,_Size>::growTo(Size size) {
 118     if (sz >= size) return;
 119     capacity(size);
 120     for (Size i = sz; i < size; i++) new (&data[i]) T();
 121     sz = size; }
 122
 123
 124 template<class T, class _Size>
 125 void vec<T,_Size>::clear(bool dealloc) {
 126     if (data != NULL){
 127         for (Size i = 0; i < sz; i++) data[i].~T();
 128         sz = 0;
 129         if (dealloc) free(data), data = NULL, cap = 0; } }
 130
 131 //=================================================================================================
 132 }
 133
 134 #endif