Luna/kernel/include/utils/Dynamic.h

#pragma once
#include "log/Log.h"
#include "std/ensure.h"
#include "std/stdlib.h"
#include "std/string.h"
#include "utils/new.h"

#define __noinline __attribute__((noinline))

template <typename T> struct Dynamic
{
    Dynamic()
    {
        set_expand_rate(16);
        ensure(expand_fixed());
    }

    Dynamic(size_t capacity)
    {
        set_expand_rate(16);
        ensure(expand_fixed());
    }

    Dynamic(const Dynamic<T>& other)
    {
        set_expand_rate(other.m_expand_rate);
        ensure_capacity(other.capacity());
        m_size = other.size();
        memcpy(m_buf, other.data(), m_capacity * sizeof(T));
    }

    Dynamic(Dynamic<T>&& other)
    {
        set_expand_rate(other.m_expand_rate);
        m_buf = other.release_data();
        m_capacity = other.capacity();
        m_size = other.size();
    }

    Dynamic<T>& operator=(const Dynamic<T>& other)
    {
        if (this == &other) return *this;

        if (m_buf)
        {
            while (m_size) pop(); // destroy all objects
            kfree(m_buf);
        }

        set_expand_rate(other.m_expand_rate);
        ensure_capacity(other.capacity());
        m_size = other.size();
        memcpy(m_buf, other.data(), m_capacity * sizeof(T));

        return *this;
    }

    ~Dynamic()
    {
        if (m_buf)
        {
            while (m_size) pop(); // destroy all objects
            kfree(m_buf);
        }
    }

    T& at(size_t index)
    {
        ensure(index < m_size);
        return m_buf[index];
    }

    const T& at(size_t index) const
    {
        ensure(index < m_size);
        return m_buf[index];
    }

    T& operator[](size_t index)
    {
        return at(index);
    }

    const T& operator[](size_t index) const
    {
        return at(index);
    }

    bool expand_capacity(size_t capacity)
    {
        return expand(capacity);
    }

    void ensure_capacity(size_t capacity)
    {
        ensure(expand(capacity));
    }

    void set_expand_rate(size_t rate)
    {
        if (!rate) return;
        m_expand_rate = rate;
    }

    __noinline bool push(const T& item)
    {
        if (m_size == m_capacity)
            if (!expand_fixed()) return false;
        m_size++;
        T* loc = ptr_at(m_size - 1);
        new (loc) T(item);
        return true;
    }

    void pop()
    {
        at(m_size - 1).~T();
        m_size--;
    }

    size_t capacity() const
    {
        return m_capacity;
    }

    size_t size() const
    {
        return m_size;
    }

    const T* data() const
    {
        return m_buf;
    }

    T* release_data()
    {
        T* result = m_buf;
        m_buf = nullptr;
        return result;
    }

  private:
    T* m_buf = nullptr;
    size_t m_capacity = 0;
    size_t m_size = 0;
    size_t m_expand_rate = 16;

    bool expand(size_t new_capacity)
    {
        m_buf = (T*)krealloc(m_buf, new_capacity * sizeof(T));
        if (!m_buf) return false;
        m_capacity = new_capacity;
        return true;
    }

    bool expand_fixed()
    {
        ensure(m_expand_rate != 0);
        return expand(m_capacity + m_expand_rate);
    }

    T* ptr_at(size_t index)
    {
        return (T*)((char*)m_buf + index * sizeof(T));
    }
};