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// Copyright (c) 2007, 2008 libmv authors.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
// Get an aligned vector implementation. Must be included before <vector>. The
// Eigen guys went through some trouble to make a portable override for the
// fixed size vector types.
#ifndef LIBMV_BASE_VECTOR_H
#define LIBMV_BASE_VECTOR_H
#include <cstring>
#include <new>
#include <Eigen/Core>
namespace libmv {
// A simple container class, which guarantees 16 byte alignment needed for most
// vectorization. Don't use this container for classes that cannot be copied
// via memcpy.
// FIXME: this class has some issues:
// - doesn't support iterators.
// - impede compatibility with code using STL.
// - the STL already provide support for custom allocators
// it could be replaced with a simple
// template <T> class vector : std::vector<T, aligned_allocator> {} declaration
// provided it doesn't break code relying on libmv::vector specific behavior
template <typename T,
typename Allocator = Eigen::aligned_allocator<T> >
class vector {
public:
~vector() { clear(); }
vector() { init(); }
vector(int size) { init(); resize(size); }
vector(int size, const T & val) {
init();
resize(size);
std::fill(data_, data_+size_, val); }
// Copy constructor and assignment.
vector(const vector<T, Allocator> &rhs) {
init();
copy(rhs);
}
vector<T, Allocator> &operator=(const vector<T, Allocator> &rhs) {
if (&rhs != this) {
copy(rhs);
}
return *this;
}
/// Swaps the contents of two vectors in constant time.
void swap(vector<T, Allocator> &other) {
std::swap(allocator_, other.allocator_);
std::swap(size_, other.size_);
std::swap(capacity_, other.capacity_);
std::swap(data_, other.data_);
}
T *data() const { return data_; }
int size() const { return size_; }
int capacity() const { return capacity_; }
const T& back() const { return data_[size_ - 1]; }
T& back() { return data_[size_ - 1]; }
const T& front() const { return data_[0]; }
T& front() { return data_[0]; }
const T& operator[](int n) const { return data_[n]; }
T& operator[](int n) { return data_[n]; }
const T& at(int n) const { return data_[n]; }
T& at(int n) { return data_[n]; }
const T * begin() const { return data_; }
const T * end() const { return data_+size_; }
T * begin() { return data_; }
T * end() { return data_+size_; }
void resize(size_t size) {
reserve(size);
if (size > size_) {
construct(size_, size);
} else if (size < size_) {
destruct(size, size_);
}
size_ = size;
}
void push_back(const T &value) {
if (size_ == capacity_) {
reserve(size_ ? 2 * size_ : 1);
}
new (&data_[size_++]) T(value);
}
void pop_back() {
resize(size_ - 1);
}
void clear() {
destruct(0, size_);
deallocate();
init();
}
void reserve(unsigned int size) {
if (size > size_) {
T *data = static_cast<T *>(allocate(size));
memcpy(data, data_, sizeof(*data)*size_);
allocator_.deallocate(data_, capacity_);
data_ = data;
capacity_ = size;
}
}
bool empty() {
return size_ == 0;
}
private:
void construct(int start, int end) {
for (int i = start; i < end; ++i) {
new (&data_[i]) T;
}
}
void destruct(int start, int end) {
for (int i = start; i < end; ++i) {
data_[i].~T();
}
}
void init() {
size_ = 0;
data_ = 0;
capacity_ = 0;
}
void *allocate(int size) {
return size ? allocator_.allocate(size) : 0;
}
void deallocate() {
allocator_.deallocate(data_, size_);
data_ = 0;
}
void copy(const vector<T, Allocator> &rhs) {
resize(rhs.size());
for (int i = 0; i < rhs.size(); ++i) {
(*this)[i] = rhs[i];
}
}
Allocator allocator_;
size_t size_;
size_t capacity_;
T *data_;
};
} // namespace libmv
#endif // LIBMV_BASE_VECTOR_H
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