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#pragma once
#include "Assertions.h"
#include "Retainable.h"
#include "RetainPtr.h"
#include "StdLibExtras.h"
#include "kmalloc.h"
namespace AK {
template<typename T>
class Buffer : public Retainable<Buffer<T>> {
public:
static Retained<Buffer> create_uninitialized(ssize_t count);
static Retained<Buffer> copy(const T*, ssize_t count);
static Retained<Buffer> wrap(T*, ssize_t count);
static Retained<Buffer> adopt(T*, ssize_t count);
~Buffer() { clear(); }
void clear()
{
if (!m_elements)
return;
if (m_owned)
kfree(m_elements);
m_elements = nullptr;
}
T& operator[](ssize_t i) { ASSERT(i < m_size); return m_elements[i]; }
const T& operator[](ssize_t i) const { ASSERT(i < m_size); return m_elements[i]; }
bool is_empty() const { return !m_size; }
ssize_t size() const { return m_size; }
T* pointer() { return m_elements; }
const T* pointer() const { return m_elements; }
T* offset_pointer(ssize_t offset) { return m_elements + offset; }
const T* offset_pointer(ssize_t offset) const { return m_elements + offset; }
const void* end_pointer() const { return m_elements + m_size; }
// NOTE: trim() does not reallocate.
void trim(ssize_t size)
{
ASSERT(size <= m_size);
m_size = size;
}
void grow(ssize_t size);
private:
enum ConstructionMode { Uninitialized, Copy, Wrap, Adopt };
explicit Buffer(ssize_t); // For ConstructionMode=Uninitialized
Buffer(const T*, ssize_t, ConstructionMode); // For ConstructionMode=Copy
Buffer(T*, ssize_t, ConstructionMode); // For ConstructionMode=Wrap/Adopt
Buffer() { }
T* m_elements { nullptr };
ssize_t m_size { 0 };
bool m_owned { false };
};
template<typename T>
inline Buffer<T>::Buffer(ssize_t size)
: m_size(size)
{
m_elements = static_cast<T*>(kmalloc(size * sizeof(T)));
m_owned = true;
}
template<typename T>
inline Buffer<T>::Buffer(const T* elements, ssize_t size, ConstructionMode mode)
: m_size(size)
{
ASSERT(mode == Copy);
m_elements = static_cast<T*>(kmalloc(size * sizeof(T)));
memcpy(m_elements, elements, size * sizeof(T));
m_owned = true;
}
template<typename T>
inline Buffer<T>::Buffer(T* elements, ssize_t size, ConstructionMode mode)
: m_elements(elements)
, m_size(size)
{
if (mode == Adopt) {
m_owned = true;
} else if (mode == Wrap) {
m_owned = false;
}
}
template<typename T>
inline void Buffer<T>::grow(ssize_t size)
{
ASSERT(size > m_size);
ASSERT(m_owned);
T* new_elements = static_cast<T*>(kmalloc(size * sizeof(T)));
memcpy(new_elements, m_elements, m_size * sizeof(T));
T* old_elements = m_elements;
m_elements = new_elements;
m_size = size;
kfree(old_elements);
}
template<typename T>
inline Retained<Buffer<T>> Buffer<T>::create_uninitialized(ssize_t size)
{
return ::adopt(*new Buffer<T>(size));
}
template<typename T>
inline Retained<Buffer<T>> Buffer<T>::copy(const T* elements, ssize_t size)
{
return ::adopt(*new Buffer<T>(elements, size, Copy));
}
template<typename T>
inline Retained<Buffer<T>> Buffer<T>::wrap(T* elements, ssize_t size)
{
return ::adopt(*new Buffer<T>(elements, size, Wrap));
}
template<typename T>
inline Retained<Buffer<T>> Buffer<T>::adopt(T* elements, ssize_t size)
{
return ::adopt(*new Buffer<T>(elements, size, Adopt));
}
}
using AK::Buffer;
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