mmap_vector.h

Go to the documentation of this file.

 
#ifndef GRAPHSCOPE_UTILS_MMAP_VECTOR_H_
#define GRAPHSCOPE_UTILS_MMAP_VECTOR_H_
#include "flex/utils/mmap_array.h"
 
namespace gs {
template <typename T>
class mmap_vector {
 public:
 mmap_vector() : size_(0) {}
 
 void open(const std::string& filename, bool sync_to_file = true) {
 array_.open(filename, sync_to_file);
 }
 
 void reserve(size_t size) { array_.resize(size); }
 
 void unlink() { array_.unlink(); }
 
 ~mmap_vector() {}
 
 mmap_vector(mmap_vector&& other) {
 array_.swap(other.array_);
 size_ = other.size_;
 }
 
 void push_back(const T& val) {
 size_t cap = array_.size();
 if (size_ == cap) {
 array_.resize(std::max(cap * 2, 1ul));
 }
 array_.set(size_, val);
 ++size_;
 }
 
 void emplace_back(T&& val) {
 size_t cap = array_.size();
 if (size_ == cap) {
 array_.resize(std::max(cap * 2, 1ul));
 }
 array_.set(size_, val);
 ++size_;
 }
 
 void resize(size_t size) {
 size_t cap = std::max(array_.size(), 1ul);
 while (size > cap) {
 cap *= 2;
 }
 array_.resize(cap);
 size_ = size;
 }
 
 size_t size() const { return size_; }
 
 const T& operator[](size_t index) const { return array_[index]; }
 T& operator[](size_t index) { return array_[index]; }
 const T* begin() const { return array_.data(); }
 const T* end() const { return array_.data() + size_; }
 
 void clear() { size_ = 0; }
 
 private:
 mmap_array<T> array_;
 size_t size_;
};
}; // namespace gs
#endif // GRAPHSCOPE_UTILS_MMAP_VECTOR_H_