/*

 * Copyright (c) 2020-2023, Andreas Kling <kling@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include <AK/Badge.h>

#include <LibJS/Heap/BlockAllocator.h>

#include <LibJS/Heap/CellAllocator.h>

#include <LibJS/Heap/Heap.h>

#include <LibJS/Heap/HeapBlock.h>

namespace JS {

CellAllocator::CellAllocator(size_t cell_size, char const* class_name)

    : m_class_name(class_name)

    , m_cell_size(cell_size)

{

}

Cell* CellAllocator::allocate_cell(Heap& heap)

{

    if (!m_list_node.is_in_list())

        heap.register_cell_allocator({}, *this);

    if (m_usable_blocks.is_empty()) {

        auto block = HeapBlock::create_with_cell_size(heap, *this, m_cell_size, m_class_name);

        auto block_ptr = reinterpret_cast<FlatPtr>(block.ptr());

        if (m_min_block_address > block_ptr)

            m_min_block_address = block_ptr;

        if (m_max_block_address < block_ptr)

            m_max_block_address = block_ptr;

        m_usable_blocks.append(*block.leak_ptr());

    }

    auto& block = *m_usable_blocks.last();

    auto* cell = block.allocate();

    VERIFY(cell);

    if (block.is_full())

        m_full_blocks.append(*m_usable_blocks.last());

    return cell;

}

void CellAllocator::block_did_become_empty(Badge<Heap>, HeapBlock& block)

{

    block.m_list_node.remove();

    // NOTE: HeapBlocks are managed by the BlockAllocator, so we don't want to `delete` the block here.

    block.~HeapBlock();

    m_block_allocator.deallocate_block(&block);

}

void CellAllocator::block_did_become_usable(Badge<Heap>, HeapBlock& block)

{

    VERIFY(!block.is_full());

    m_usable_blocks.append(block);

}

}