include/AD/contain/varptrarray.h

   1 //////////////////////////////////////////////////////////////////////////////
   2 // NOTICE:
   3 //
   4 // ADLib, Prop and their related set of tools and documentation are in the
   5 // public domain.   The author(s) of this software reserve no copyrights on
   6 // the source code and any code generated using the tools.  You are encouraged
   7 // to use ADLib and Prop to develop software, in both academic and commercial
   8 // settings, and are free to incorporate any part of ADLib and Prop into
   9 // your programs.
  10 //
  11 // Although you are under no obligation to do so, we strongly recommend that
  12 // you give away all software developed using our tools.
  13 //
  14 // We also ask that credit be given to us when ADLib and/or Prop are used in
  15 // your programs, and that this notice be preserved intact in all the source
  16 // code.
  17 //
  18 // This software is still under development and we welcome any suggestions
  19 // and help from the users.
  20 //
  21 // Allen Leung
  22 // 1994
  23 //////////////////////////////////////////////////////////////////////////////
  24
  25 #ifndef variable_sized_pointer_array_h
  26 #define variable_sized_pointer_array_h
  27
  28 ///////////////////////////////////////////////////////////////////////////
  29 //  Class VarPtrArray<T> provides an abstraction for
  30 //  an dense mapping from integers to type T.
  31 //  The array will grow in size when necessary.
  32 //  Both positive and negative indices are allowed.
  33 //  The indices should be centered around 0.
  34 ///////////////////////////////////////////////////////////////////////////
  35
  36 #include <new.h>
  37 #include <string.h>
  38 #include <AD/generic/generic.h>   // Generic definitions
  39
  40 template<class T>
  41    class VarPtrArray {
  42       T ** array;      // array of elements; displaced by offset
  43       int low, high;   // upper and lower bound on array
  44       int growthRate;  // minimal number of elements for expansion
  45
  46       void grow(int i);
  47
  48    public:
  49
  50       //////////////////////////////////////////////////////////////////
  51       // Constructor and destructors
  52       //////////////////////////////////////////////////////////////////
  53       VarPtrArray(int lowerBound = 0,
  54                int upperBound = 9, int growthFactor = 32);
  55       VarPtrArray(const VarPtrArray& A) : array(0), low(0) { *this = A; }
  56       VarPtrArray(size_t size, T * const []);
  57      ~VarPtrArray()
  58       {  // memset(array + low, 0, sizeof(T*) * (high - low + 1));
  59          free(array + low);
  60       }
  61
  62       ////////////////////////////////////////////////////////////////////
  63       // Assignment
  64       ////////////////////////////////////////////////////////////////////
  65       VarPtrArray& operator = (const VarPtrArray&);
  66
  67       ////////////////////////////////////////////////////////////////////
  68       // Conversion
  69       ////////////////////////////////////////////////////////////////////
  70       inline operator const T ** () const { return array; }
  71       inline operator T ** ()             { return array; }
  72
  73       ////////////////////////////////////////////////////////////////////
  74       // Selectors
  75       ////////////////////////////////////////////////////////////////////
  76       inline int hi() const             { return high; }
  77       inline int lo() const             { return low; }
  78       inline int size() const           { return high - low + 1; }
  79       inline int capacity() const       { return size(); }
  80       inline Bool hasKey(int i) const   { return i >= low && i <= high; }
  81       inline const T * operator [] (int i) const { return array[i]; }
  82       inline T *& operator [] (int i)
  83          { if (! hasKey(i)) grow(i); return array[i]; }
  84
  85       ////////////////////////////////////////////////////////////////////
  86       // Iteration
  87       ////////////////////////////////////////////////////////////////////
  88       inline Ix first()    const { return low > high ? 0 : (Ix)&array[lo()]; }
  89       inline Ix last()     const { return low > high ? 0 : (Ix)&array[hi()]; }
  90       inline Ix next(Ix i) const { return i >= (Ix)(array + hi()) ? 0 : (((T**)i)+1); }
  91       inline Ix prev(Ix i) const { return i <= (Ix)(array + lo()) ? 0 : (((T**)i)-1); }
  92       inline const T * operator() (Ix i) const { return *(T**)i; }
  93       inline T * operator() (Ix i) { return *(T**)i; }
  94    };
  95
  96 ////////////////////////////////////////////////////////////////////
  97 // Implementation comes here
  98 ////////////////////////////////////////////////////////////////////
  99 template<class T>
 100    VarPtrArray<T>::VarPtrArray(int lowerBound, int upperBound, int growthFactor)
 101    {  size_t size = upperBound - lowerBound + 1;
 102       high = upperBound; low = lowerBound;
 103       array = (T**)calloc(size, sizeof(T *)) - low;
 104       growthRate = growthFactor;
 105    }
 106
 107 template<class T>
 108    VarPtrArray<T>::VarPtrArray(size_t size, T * const A[])
 109    {  array = (T**)malloc(size * sizeof(T*));
 110       low = 0; high = size - 1;
 111       growthRate = 32;
 112       memcpy(array, A, size * sizeof(T*));
 113    }
 114
 115 template<class T>
 116    VarPtrArray<T>& VarPtrArray<T>::operator = (const VarPtrArray<T>& A)
 117    {  if (this != &A) {
 118          // memset(array + low, 0, sizeof(T*) * (high - low + 1));
 119          free (array + low);
 120          high = A.high; low = A.low;
 121          array = (T**)malloc((high - low + 1) * sizeof(T*)) - A.low;
 122          memcpy(array, A.array, sizeof(T*) * (high - low + 1));
 123       }
 124       return *this;
 125    }
 126
 127 template<class T>
 128    void VarPtrArray<T>::grow(int i)
 129    {  int newHigh, newLow;
 130       int growth = growthRate <= 0 ? (size() * 3 / 2 + 32) : growthRate;
 131       if (i > high)
 132          if (i < high + growth) newHigh = high + growth;
 133          else newHigh = i;
 134       else newHigh = high;
 135       if (i < low)
 136          if (i > low - growth) newLow = low - growth;
 137          else newLow = i;
 138       else newLow = low;
 139       register T ** newArray =
 140         (T**) calloc(newHigh - newLow + 1,sizeof(T*)) - newLow;
 141       memcpy(newArray, array, sizeof(T*) * (high - low + 1));
 142       // memset(array + low, 0, sizeof(T*) * (high - low + 1));
 143       free(array + low);
 144       array = newArray;
 145       low = newLow; high = newHigh;
 146    }
 147
 148 #endif