Added External pre allocation

src/memory/ExtPreAlloc.hpp

+/* ExtPreAlloc.hpp
+ *
+ *  Created on: Apr 3, 2015
+ *      Author: Pietro Incardona
+ */
+
+#ifndef EXTPREALLOC_HPP_
+#define EXTPREALLOC_HPP_
+
+/*! Preallocated memory sequence
+ *
+ * External pre-allocated memory, is a class that preallocate memory and than it answer
+ * to a particular allocation pattern
+ *
+ * \tparam Base memory allocation class [Example] HeapMemory or CudaMemory
+ *
+ *
+ */
+
+template<typename Mem>
+class ExtPreAlloc : public memory
+{
+	// Actual allocation pointer
+	size_t a_seq ;
+	// List of allowed allocation
+	std::vector<size_t> sequence;
+	// starting from 0 is the cumulative buffer of sequence
+	// Example sequence   = 2,6,3,6
+	//         sequence_c = 0,2,8,11
+	std::vector<size_t> sequence_c;
+
+	// Main class for memory allocation
+	Mem * mem;
+	//! Reference counter
+	long int ref_cnt;
+
+	ExtPreAlloc(const ExtPreAlloc & ext)
+	{}
+
+public:
+
+	~ExtPreAlloc()
+	{
+		if (ref_cnt != 0)
+			std::cerr << "Error: " << __FILE__ << " " << __LINE__ << " destroying a live object" << "\n";
+	}
+
+	//! Default constructor
+	ExtPreAlloc()
+	:a_seq(0),ref_cnt(0)
+	{
+		int debug = 0;
+		debug++;
+	}
+
+	/*! \brief Preallocated memory sequence
+	 *
+	 * \param sequence of allocation size
+	 * \param mem external memory, used if you want to keep the memory
+	 *
+	 */
+	ExtPreAlloc(std::vector<size_t> & seq, Mem & mem)
+	:a_seq(0),mem(&mem),ref_cnt(0)
+	{
+		size_t total_size = 0;
+
+		// Resize the sequence
+		sequence.resize(seq.size());
+		sequence_c.resize(seq.size());
+		for (size_t i = 0 ; i < seq.size() ; i++)
+		{
+			sequence[i] = seq[i];
+			sequence_c[i] = total_size;
+			total_size += seq[i];
+		}
+
+		// Allocate the total size of memory
+		mem.allocate(total_size);
+	}
+
+	//! Increment the reference counter
+	virtual void incRef()
+	{ref_cnt++;}
+
+	//! Decrement the reference counter
+	virtual void decRef()
+	{ref_cnt--;}
+
+	//! Return the reference counter
+	virtual long int ref()
+	{
+		return ref_cnt;
+	}
+
+	/*! \brief Allocate a chunk of memory
+	 *
+	 * Allocate a chunk of memory
+	 *
+	 * \param sz size of the chunk of memory to allocate in byte
+	 *
+	 */
+	virtual bool allocate(size_t sz)
+	{
+		// Check that the size match
+
+		if (sequence[a_seq] != sz)
+		{
+			std::cerr << "Error: " << __FILE__ << " " << __LINE__ << "expecting: " << sequence[a_seq] << " got: " << sz <<  " allocation failed \n";
+			std::cerr << "NOTE: if you are using this structure with vector remember to use openfpm::vector<...>::calculateMem(...) to get the required allocation sequence\n";
+
+			return false;
+		}
+
+		a_seq++;
+
+		return true;
+	}
+
+	/*! \brief Return a readable pointer with your data
+	 *
+	 * Return a readable pointer with your data
+	 *
+	 */
+	virtual void * getPointer()
+	{
+		if (a_seq == 0)
+			return NULL;
+
+		return (((unsigned char *)mem->getPointer()) +  sequence_c[a_seq-1]);
+	}
+
+	/*! \brief Allocate or resize the allocated memory
+	 *
+	 * Resize the allocated memory, if request is smaller than the allocated, memory
+	 * is not resized
+	 *
+	 * \param sz size
+	 * \return true if the resize operation complete correctly
+	 *
+	 */
+
+	virtual bool resize(size_t sz)
+	{
+		return allocate(sz);
+	}
+
+	/*! \brief Get the size of the allocated memory
+	 *
+	 * Get the size of the allocated memory
+	 *
+	 * \return the size of the allocated memory
+	 *
+	 */
+
+	virtual size_t size()
+	{
+		if (a_seq == 0)
+			return 0;
+
+		return sequence[a_seq-1];
+	}
+
+	/*! \brief Destroy memory
+	 *
+	 */
+
+	void destroy()
+	{
+		mem->destroy();
+	}
+
+	/*! \brief Copy memory
+	 *
+	 */
+
+	virtual bool copy(memory & m)
+	{
+		return mem->copy(m);
+	}
+
+	/*! \brief Allocated Memory is never initialized
+	 *
+	 * \return false
+	 *
+	 */
+	bool isInitialized()
+	{
+		return false;
+	}
+};
+
+#endif /* PREALLOCHEAPMEMORY_HPP_ */