/*
* Copyright © 2018 Christian Persch
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <cstdint>
#include <list>
#include <memory>
#include <stack>
namespace bte {
namespace base {
class Chunk {
private:
class Recycler {
public:
void operator()(Chunk* chunk) {
if (chunk == nullptr)
return;
chunk->recycle();
}
};
void recycle() noexcept;
static unsigned int const k_max_free_chunks = 16;
enum class Flags : uint8_t {
eSEALED = 1u << 0,
eEOS = 1u << 1,
};
public:
using unique_type = std::unique_ptr<Chunk, Recycler>;
static unsigned int const k_chunk_size = 0x2000;
unsigned int len{0};
uint8_t m_flags{0};
uint8_t dataminusone; /* Hack: Keep it right before data, so that data[-1] is valid and usable */
uint8_t data[k_chunk_size - 2 * sizeof(void*) - 2 - sizeof(unsigned int)];
Chunk() = default;<--- Member variable 'Chunk::dataminusone' is not initialized in the constructor. [+]Member variable 'Chunk::dataminusone' is not initialized in the constructor. Member variables of native types, pointers, or references are left uninitialized when the class is instantiated. That may cause bugs or undefined behavior.
<--- Member variable 'Chunk::data' is not initialized in the constructor. [+]Member variable 'Chunk::data' is not initialized in the constructor. Member variables of native types, pointers, or references are left uninitialized when the class is instantiated. That may cause bugs or undefined behavior.
Chunk(Chunk const&) = delete;
Chunk(Chunk&&) = delete;
~Chunk() = default;
Chunk& operator= (Chunk const&) = delete;
Chunk& operator= (Chunk&&) = delete;
void reset() noexcept
{
len = 0;
m_flags = 0;
}
inline constexpr size_t capacity() const noexcept { return sizeof(data); }
inline constexpr size_t remaining_capacity() const noexcept { return capacity() - len; }
static unique_type get() noexcept;
static void prune(unsigned int max_size = k_max_free_chunks) noexcept;
inline constexpr bool sealed() const noexcept { return m_flags & (uint8_t)Flags::eSEALED; }
inline void set_sealed() noexcept { m_flags |= (uint8_t)Flags::eSEALED; }
inline constexpr bool eos() const noexcept { return m_flags & (uint8_t)Flags::eEOS; }
inline void set_eos() noexcept { m_flags |= (uint8_t)Flags::eEOS; }
private:
/* Note that this is using the standard deleter, not Recycler */
static std::stack<std::unique_ptr<Chunk>, std::list<std::unique_ptr<Chunk>>> g_free_chunks;
};
} // namespace base
} // namespace bte