/* SPDX-FileCopyrightText: 2008 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

#pragma once

/** \file
 * \ingroup bli
 */

#include "BLI_compiler_attrs.h"

#include <type_traits>

namespace blender {

struct BLI_mempool;
struct BLI_mempool_chunk;

BLI_mempool *BLI_mempool_create(unsigned int esize,
                                unsigned int elem_num,
                                unsigned int pchunk,
                                unsigned int flag)
    ATTR_MALLOC ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL;
void *BLI_mempool_alloc(BLI_mempool *pool) ATTR_MALLOC ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL
    ATTR_NONNULL(1);
void *BLI_mempool_calloc(BLI_mempool *pool)
    ATTR_MALLOC ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL ATTR_NONNULL(1);

/**
 * C++ templates for convenience.
 */
template<typename T>
ATTR_MALLOC ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL
    ATTR_NONNULL(1) T *BLI_mempool_alloc(BLI_mempool *pool)
{
  static_assert(std::is_trivial_v<T>,
                "Only trivial types may be allocated with BLI_mempool_alloc");
  return static_cast<T *>(BLI_mempool_alloc(pool));
}
template<typename T>
ATTR_MALLOC ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL
    ATTR_NONNULL(1) T *BLI_mempool_calloc(BLI_mempool *pool)
{
  static_assert(std::is_trivial_v<T>,
                "Only trivial types may be allocated with BLI_mempool_calloc");
  return static_cast<T *>(BLI_mempool_calloc(pool));
}

/**
 * Free an element from the mempool.
 *
 * \note doesn't protect against double frees, take care!
 */
void BLI_mempool_free(BLI_mempool *pool, void *addr) ATTR_NONNULL(1, 2);
/**
 * Empty the pool, as if it were just created.
 *
 * \param pool: The pool to clear.
 * \param elem_num_reserve: Optionally reserve how many items should be kept from clearing.
 */
void BLI_mempool_clear_ex(BLI_mempool *pool, int elem_num_reserve) ATTR_NONNULL(1);
/**
 * Wrap #BLI_mempool_clear_ex with no reserve set.
 */
void BLI_mempool_clear(BLI_mempool *pool) ATTR_NONNULL(1);
/**
 * Free the mempool itself (and all elements).
 */
void BLI_mempool_destroy(BLI_mempool *pool) ATTR_NONNULL(1);
int BLI_mempool_len(const BLI_mempool *pool) ATTR_NONNULL(1);
void *BLI_mempool_findelem(BLI_mempool *pool, unsigned int index) ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL(1);

/**
 * Fill in \a data with the contents of the mempool.
 */
void BLI_mempool_as_array(BLI_mempool *pool, void *data) ATTR_NONNULL(1, 2);
/**
 * A version of #BLI_mempool_as_array that allocates and returns the data.
 */
void *BLI_mempool_as_arrayN(BLI_mempool *pool,
                            const char *allocstr) ATTR_MALLOC ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL(1, 2);

#ifndef NDEBUG
void BLI_mempool_set_memory_debug();
#endif

/**
 * Iteration stuff.
 * \note this may easy to produce bugs with.
 */

/**  \note Private structure. */
struct BLI_mempool_iter {
  BLI_mempool *pool;
  struct BLI_mempool_chunk *curchunk;
  unsigned int curindex;
};

/** #BLI_mempool.flag */
enum {
  BLI_MEMPOOL_NOP = 0,
  /**
   * Allow iterating on this mempool.
   *
   * \note this requires that the first four bytes of the elements
   * never begin with 'free' (#FREEWORD).
   * \note order of iteration is only assured to be the
   * order of allocation when no chunks have been freed.
   */
  BLI_MEMPOOL_ALLOW_ITER = (1 << 0),
};

/**
 * Initialize a new mempool iterator, #BLI_MEMPOOL_ALLOW_ITER flag must be set.
 */
void BLI_mempool_iternew(BLI_mempool *pool, BLI_mempool_iter *iter) ATTR_NONNULL();
/**
 * Step over the iterator, returning the mempool item or NULL.
 */
void *BLI_mempool_iterstep(BLI_mempool_iter *iter) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();

}  // namespace blender
