blender/intern/cycles/util/util_vector.h

/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __UTIL_VECTOR_H__
#define __UTIL_VECTOR_H__

/* Vector */

#include <cassert>
#include <cstring>
#include <vector>

#include "util_aligned_malloc.h"
#include "util_guarded_allocator.h"
#include "util_types.h"

CCL_NAMESPACE_BEGIN

/* Vector
 *
 * Own subclass-ed vestion of std::vector. Subclass is needed because:
 *
 * - Use own allocator which keeps track of used/peak memory.
 *
 * - Have method to ensure capacity is re-set to 0.
 */
template<typename value_type,
         typename allocator_type = GuardedAllocator<value_type> >
class vector : public std::vector<value_type, allocator_type>
{
public:
	/* Default constructor. */
	explicit vector() : std::vector<value_type, allocator_type>() {  }

	/* Fill constructor. */
	explicit vector(size_t n, const value_type& val = value_type())
		: std::vector<value_type, allocator_type>(n, val) {  }

	/* Range constructor. */
	template <class InputIterator>
	vector(InputIterator first, InputIterator last)
		: std::vector<value_type, allocator_type>(first, last) {  }

	/* Copy constructor. */
	vector(const vector &x) : std::vector<value_type, allocator_type>(x) {  }

	void shrink_to_fit(void)
	{
#if __cplusplus < 201103L
		vector<value_type>().swap(*this);
#else
		std::vector<value_type, allocator_type>::shrink_to_fit();
#endif
	}

	void free_memory(void)
	{
		std::vector<value_type, allocator_type>::resize(0);
		shrink_to_fit();
	}

	/* Some external API might demand working with std::vector. */
	operator std::vector<value_type>()
	{
		return std::vector<value_type>(*this);
	}
};

/* Array
 *
 * Simplified version of vector, serving multiple purposes:
 * - somewhat faster in that it does not clear memory on resize/alloc,
 *   this was actually showing up in profiles quite significantly. it
 *   also does not run any constructors/destructors
 * - if this is used, we are not tempted to use inefficient operations
 * - aligned allocation for SSE data types */

template<typename T, size_t alignment = 16>
class array
{
public:
	array()
	{
		data = NULL;
		datasize = 0;
		capacity = 0;
	}

	array(size_t newsize)
	{
		if(newsize == 0) {
			data = NULL;
			datasize = 0;
			capacity = 0;
		}
		else {
			data = (T*)util_aligned_malloc(sizeof(T)*newsize, alignment);
			datasize = newsize;
			capacity = datasize;
		}
	}

	array(const array& from)
	{
		*this = from;
	}

	array& operator=(const array& from)
	{
		if(from.datasize == 0) {
			data = NULL;
			datasize = 0;
			capacity = 0;
		}
		else {
			data = (T*)util_aligned_malloc(sizeof(T)*from.datasize, alignment);
			memcpy(data, from.data, from.datasize*sizeof(T));
			datasize = from.datasize;
			capacity = datasize;
		}

		return *this;
	}

	array& operator=(const vector<T>& from)
	{
		datasize = from.size();
		capacity = datasize;
		data = NULL;

		if(datasize > 0) {
			data = (T*)util_aligned_malloc(sizeof(T)*datasize, alignment);
			memcpy(data, &from[0], datasize*sizeof(T));
		}

		return *this;
	}

	~array()
	{
		util_aligned_free(data);
	}

	T* resize(size_t newsize)
	{
		if(newsize == 0) {
			clear();
		}
		else if(newsize != datasize) {
			if(newsize > capacity) {
				T *newdata = (T*)util_aligned_malloc(sizeof(T)*newsize, alignment);
				if(newdata == NULL) {
					/* Allocation failed, likely out of memory. */
					clear();
					return NULL;
				}
				else if(data) {
					memcpy(newdata, data, ((datasize < newsize)? datasize: newsize)*sizeof(T));
					util_aligned_free(data);
				}
				data = newdata;
				capacity = newsize;
			}
			datasize = newsize;
		}
		return data;
	}

	void clear()
	{
		if(data != NULL) {
			util_aligned_free(data);
			data = NULL;
		}
		datasize = 0;
		capacity = 0;
	}

	size_t size() const
	{
		return datasize;
	}

	T& operator[](size_t i) const
	{
		assert(i < datasize);
		return data[i];
	}

	void reserve(size_t newcapacity) {
		if(newcapacity > capacity) {
			T *newdata = (T*)util_aligned_malloc(sizeof(T)*newcapacity, alignment);
			if(data) {
				memcpy(newdata, data, ((datasize < newcapacity)? datasize: newcapacity)*sizeof(T));
				util_aligned_free(data);
			}
			data = newdata;
			capacity = newcapacity;
		}
	}

protected:
	T *data;
	size_t datasize;
	size_t capacity;
};

CCL_NAMESPACE_END

#endif /* __UTIL_VECTOR_H__ */