allocator.hpp

#ifndef BV_ALLOCATOR_HPP
#define BV_ALLOCATOR_HPP
 
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <new>
 
namespace bv {
 
class malloc_alloc {
   protected:
    uint64_t allocations_; 
 
   public:
    malloc_alloc() { allocations_ = 0; }
 
    template <class node_type>
    node_type* allocate_node() {
        allocations_++;
        void* nd = malloc(sizeof(node_type));
        return new (nd) node_type();
    }
 
    template <class node_type>
    void deallocate_node(node_type* node) {
        allocations_--;
        free(node);
    }
 
    template <class leaf_type>
    leaf_type* allocate_leaf(uint64_t size) {
        allocations_++;
        constexpr size_t leaf_bytes = sizeof(leaf_type) + sizeof(leaf_type) % 8;
        void* leaf = malloc(leaf_bytes + size * sizeof(uint64_t));
        uint8_t* data_ptr =
            reinterpret_cast<uint8_t*>(leaf) + leaf_bytes;
        memset(data_ptr, 0, size * sizeof(uint64_t));
        return new (leaf)
            leaf_type(size, reinterpret_cast<uint64_t*>(data_ptr));
    }
 
    template <class leaf_type>
    void deallocate_leaf(leaf_type* leaf) {
        allocations_--;
        free(leaf);
    }
 
    template <class leaf_type>
    leaf_type* reallocate_leaf(leaf_type* leaf, uint64_t old_size,
                               uint64_t new_size) {
        constexpr size_t leaf_bytes = sizeof(leaf_type) + sizeof(leaf_type) % 8;
#pragma GCC diagnostic ignored "-Wclass-memaccess"
        leaf_type* n_leaf = reinterpret_cast<leaf_type*>(
            realloc(leaf, leaf_bytes + new_size * sizeof(uint64_t)));
#pragma GCC diagnostic pop
        uint8_t* data_ptr =
            reinterpret_cast<uint8_t*>(n_leaf) + leaf_bytes;
        memset(data_ptr + sizeof(uint64_t) * old_size, 0,
               sizeof(uint64_t) * (new_size - old_size));
        n_leaf->set_data_ptr(reinterpret_cast<uint64_t*>(data_ptr));
        n_leaf->capacity(new_size);
        return n_leaf;
    }
 
    uint64_t live_allocations() const { return allocations_; }
};
}  // namespace bv
#endif