/* SPDX-FileCopyrightText: 2001-2002 NaN Holding BV. All rights reserved.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup bli
 */

#pragma once

#include <cstddef>

#include "BLI_compiler_attrs.h"

#include "MEM_guardedalloc.h"

namespace blender {

/**
 * A reasonable standard buffer size, big enough to not cause much internal fragmentation,
 * small enough not to waste resources
 */
#define BLI_MEMARENA_STD_BUFSIZE MEM_SIZE_OPTIMAL(1 << 14)

struct MemArena;

MemArena *BLI_memarena_new(size_t bufsize,
                           const char *name) ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL
    ATTR_NONNULL(2) ATTR_MALLOC;
void BLI_memarena_free(MemArena *ma) ATTR_NONNULL(1);
void BLI_memarena_use_malloc(MemArena *ma) ATTR_NONNULL(1);
void BLI_memarena_use_calloc(MemArena *ma) ATTR_NONNULL(1);
void BLI_memarena_use_align(MemArena *ma, size_t align) ATTR_NONNULL(1);
void *BLI_memarena_alloc(MemArena *ma, size_t size) ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL(1) ATTR_MALLOC ATTR_ALLOC_SIZE(2);
void *BLI_memarena_calloc(MemArena *ma, size_t size) ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL(1) ATTR_MALLOC ATTR_ALLOC_SIZE(2);

/**
 * C++ templates for convenience.
 */
template<typename T>
ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1) ATTR_MALLOC T *BLI_memarena_alloc(MemArena *ma,
                                                                          const size_t num = 1)
{
  static_assert(std::is_trivial_v<T>,
                "Only trivial types may be allocated with BLI_memarena_alloc");
  return static_cast<T *>(BLI_memarena_alloc(ma, sizeof(T) * num));
}
template<typename T>
ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1) ATTR_MALLOC T *BLI_memarena_calloc(MemArena *ma,
                                                                           const size_t num = 1)
{
  static_assert(std::is_trivial_v<T>,
                "Only trivial types may be allocated with BLI_memarena_calloc");
  return static_cast<T *>(BLI_memarena_calloc(ma, sizeof(T) * num));
}

/**
 * Transfer ownership of allocated blocks from `ma_src` into `ma_dst`,
 * cleaning the contents of `ma_src`.
 *
 * \note Useful for multi-threaded tasks that need a thread-local #MemArena
 * that is kept after the multi-threaded operation is completed.
 *
 * \note Avoid accumulating memory pools where possible
 * as any unused memory in `ma_src` is wasted every merge.
 */
void BLI_memarena_merge(MemArena *ma_dst, MemArena *ma_src) ATTR_NONNULL(1, 2);

/**
 * Clear for reuse, avoids re-allocation when an arena may
 * otherwise be freed and recreated.
 */
void BLI_memarena_clear(MemArena *ma) ATTR_NONNULL(1);

}  // namespace blender