#include <foundation/buffer.h>

#include "slab.h"

//------------------------------------------------------------------------------
Buffer::~Buffer()
{
    dec_ref();
}

//------------------------------------------------------------------------------
Buffer::Buffer(Buffer&& rhs)
{
    move(std::move(rhs));
}

//------------------------------------------------------------------------------
void Buffer::operator = (Buffer&& rhs)
{
    move(std::move(rhs));
}

//------------------------------------------------------------------------------
const uint8* Buffer::get_pointer() const
{ 
    return _slab->get_pointer() + _offset;
}

//------------------------------------------------------------------------------
uint32 Buffer::get_size() const
{ 
    return _size;
}

//------------------------------------------------------------------------------
BufferStream Buffer::create_stream() const
{ 
    return BufferStream(_slab, get_pointer(), get_size());
}

//------------------------------------------------------------------------------
BufferRef Buffer::create_ref() const
{ 
    return BufferRef(_slab, get_pointer());
}

//------------------------------------------------------------------------------
void Buffer::inc_ref()
{ 
    if (_slab != nullptr)
        _slab->inc_ref();
}

//------------------------------------------------------------------------------
void Buffer::dec_ref()
{ 
    if (_slab != nullptr)
        _slab->dec_ref();
    _slab = nullptr;
}

//------------------------------------------------------------------------------
Buffer Buffer::create_sub_buffer(uint32 left, uint32 right) const
{
    right = std::min<uint32>(right, _size);
    return create_sub_buffer(get_pointer() + left, right - left);
}

//------------------------------------------------------------------------------
Buffer Buffer::create_sub_buffer(const uint8* ptr, uint32 size) const
{
    uint32 offset = uint32(ptrdiff_t(ptr - get_pointer()));
    if (offset >= _size)
        return Buffer();

    Buffer buffer = clone();
    buffer._offset += offset;
    buffer._size = size;
    return buffer;
}

//------------------------------------------------------------------------------
void Buffer::move(Buffer&& rhs)
{
    dec_ref();
    std::swap(_slab, rhs._slab);
    std::swap(_offset, rhs._offset);
    std::swap(_size, rhs._size);
}

//------------------------------------------------------------------------------
Buffer Buffer::clone() const
{
    Buffer buffer;
    buffer._slab = _slab;
    buffer._offset = _offset;
    buffer._size = _size;
    buffer.inc_ref();
    return buffer;
}



//------------------------------------------------------------------------------
uint8* MutableBuffer::get_pointer()
{
    return _slab->get_pointer() + _offset;
}

//------------------------------------------------------------------------------
MutableBuffer::MutableBuffer(Slab* slab, uint32 size, uint32 offset)
{
    _slab = slab;
    _offset = offset;
    _size = size;
    inc_ref();
}