buffer.cc

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/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

 
#include <cstring>
 
#include "MEM_guardedalloc.h"
 
#include "BLI_buffer.h"
#include "BLI_utildefines.h"
 
#include "BLI_strict_flags.h" /* IWYU pragma: keep. Keep last. */
 
static void *buffer_alloc(const BLI_Buffer *buffer, const size_t len)
{
  return MEM_malloc_arrayN(len, buffer->elem_size, "BLI_Buffer.data");
}
 
static void *buffer_realloc(BLI_Buffer *buffer, const size_t len)
{
  return MEM_reallocN_id(buffer->data, buffer->elem_size * len, "BLI_Buffer.data");
}
 
void BLI_buffer_resize(BLI_Buffer *buffer, const size_t new_count)
{
  if (UNLIKELY(new_count > buffer->alloc_count)) {
    if (buffer->flag & BLI_BUFFER_USE_STATIC) {
      const void *orig = buffer->data;
 
      buffer->data = buffer_alloc(buffer, new_count);
      memcpy(buffer->data, orig, buffer->elem_size * buffer->count);
      buffer->alloc_count = new_count;
      buffer->flag &= ~BLI_BUFFER_USE_STATIC;
    }
    else {
      if (buffer->alloc_count && (new_count < buffer->alloc_count * 2)) {
        buffer->alloc_count *= 2;
      }
      else {
        buffer->alloc_count = new_count;
      }
 
      buffer->data = buffer_realloc(buffer, buffer->alloc_count);
    }
  }
 
  buffer->count = new_count;
}
 
void BLI_buffer_reinit(BLI_Buffer *buffer, const size_t new_count)
{
  if (UNLIKELY(new_count > buffer->alloc_count)) {
    if ((buffer->flag & BLI_BUFFER_USE_STATIC) == 0) {
      if (buffer->data) {
        MEM_freeN(buffer->data);
      }
    }
 
    if (buffer->alloc_count && (new_count < buffer->alloc_count * 2)) {
      buffer->alloc_count *= 2;
    }
    else {
      buffer->alloc_count = new_count;
    }
 
    buffer->flag &= ~BLI_BUFFER_USE_STATIC;
    buffer->data = buffer_alloc(buffer, buffer->alloc_count);
  }
 
  buffer->count = new_count;
}
 
void _bli_buffer_append_array(BLI_Buffer *buffer, void *new_data, size_t count)
{
  size_t size = buffer->count;
  BLI_buffer_resize(buffer, size + count);
 
  uint8_t *bytes = (uint8_t *)buffer->data;
  memcpy(bytes + size * buffer->elem_size, new_data, count * buffer->elem_size);
}
 
void _bli_buffer_free(BLI_Buffer *buffer)
{
  if ((buffer->flag & BLI_BUFFER_USE_STATIC) == 0) {
    if (buffer->data) {
      MEM_freeN(buffer->data);
    }
  }
  memset(buffer, 0, sizeof(*buffer));
}