File size: 3,891 Bytes
f6dd1c2 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 | #ifndef _GEODESIC_MEMORY
#define _GEODESIC_MEMORY
//two fast and simple memory allocators
#include "../tools/Types.h"
#include <memory>
namespace geodesic{
template<class T> //quickly allocates multiple elements of a given type; no deallocation
class SimlpeMemoryAllocator
{
public:
typedef T* pointer;
SimlpeMemoryAllocator(unsigned block_size = 0,
unsigned max_number_of_blocks = 0)
{
reset(block_size,
max_number_of_blocks);
};
~SimlpeMemoryAllocator(){};
void reset(unsigned block_size,
unsigned max_number_of_blocks)
{
m_block_size = block_size;
m_max_number_of_blocks = max_number_of_blocks;
m_current_position = 0;
m_storage.reserve(max_number_of_blocks);
m_storage.resize(1);
m_storage[0].resize(block_size);
};
pointer allocate(unsigned const n) //allocate n units
{
assert(n < m_block_size);
if(m_current_position + n >= m_block_size)
{
m_storage.push_back( std::vector<T>() );
m_storage.back().resize(m_block_size);
m_current_position = 0;
}
pointer result = & m_storage.back()[m_current_position];
m_current_position += n;
return result;
};
private:
std::vector<std::vector<T> > m_storage;
unsigned m_block_size; //size of a single block
unsigned m_max_number_of_blocks; //maximum allowed number of blocks
unsigned m_current_position; //first unused element inside the current block
};
template<class T> //quickly allocates and deallocates single elements of a given type
class MemoryAllocator
{
public:
typedef T* pointer;
MemoryAllocator(unsigned block_size = 1024,
unsigned max_number_of_blocks = 1024)
{
reset(block_size,
max_number_of_blocks);
};
~MemoryAllocator(){};
void clear()
{
reset(m_block_size,
m_max_number_of_blocks);
}
void reset(unsigned block_size,
unsigned max_number_of_blocks)
{
m_block_size = block_size;
m_max_number_of_blocks = max_number_of_blocks;
assert(m_block_size > 0);
assert(m_max_number_of_blocks > 0);
m_current_position = 0;
m_storage.reserve(max_number_of_blocks);
m_storage.resize(1);
m_storage[0].resize(block_size);
m_deleted.clear();
m_deleted.reserve(2*block_size);
};
pointer allocate() //allocates single unit of memory
{
pointer result;
if(m_deleted.empty())
{
if(m_current_position + 1 >= m_block_size)
{
m_storage.push_back( std::vector<T>() );
m_storage.back().resize(m_block_size);
m_current_position = 0;
}
result = & m_storage.back()[m_current_position];
++m_current_position;
}
else
{
result = m_deleted.back();
m_deleted.pop_back();
}
return result;
};
void deallocate(pointer p) //allocate n units
{
if(m_deleted.size() < m_deleted.capacity())
{
m_deleted.push_back(p);
}
};
private:
std::vector<std::vector<T> > m_storage;
unsigned m_block_size; //size of a single block
unsigned m_max_number_of_blocks; //maximum allowed number of blocks
unsigned m_current_position; //first unused element inside the current block
std::vector<pointer> m_deleted; //pointers to deleted elemets
};
class OutputBuffer
{
public:
OutputBuffer():
m_num_bytes(0)
{}
void clear()
{
m_num_bytes = 0;
m_buffer = std::auto_ptr<Scalar>();
}
template<class T>
T* allocate(unsigned n)
{
Scalar wanted = n*sizeof(T);
if(wanted > m_num_bytes)
{
unsigned new_size = (unsigned) ceil(wanted / (Scalar)sizeof(Scalar));
m_buffer = std::auto_ptr<Scalar>(new Scalar[new_size]);
m_num_bytes = new_size*sizeof(Scalar);
}
return (T*)m_buffer.get();
}
template <class T>
T* get()
{
return (T*)m_buffer.get();
}
template<class T>
unsigned capacity()
{
return (unsigned)floor((Scalar)m_num_bytes/(Scalar)sizeof(T));
};
private:
std::auto_ptr<Scalar> m_buffer;
unsigned m_num_bytes;
};
} //geodesic
#endif
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