1 files changed, 134 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/BLI_memblock.c b/source/blender/blenlib/intern/BLI_memblock.c
new file mode 100644
index 00000000000..f50aa22a1c0
--- /dev/null
+++ b/source/blender/blenlib/intern/BLI_memblock.c
@@ -0,0 +1,134 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2008 by Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup bli
+ *
+ * Dead simple, fast memory allocator for allocating many elements of the same size.
+ *
+ */
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "atomic_ops.h"
+
+#include "BLI_utildefines.h"
+
+#include "BLI_memblock.h" /* own include */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_strict_flags.h" /* keep last */
+
+#define BLI_MEM_BLOCK_CHUNK_SIZE (1 << 15) /* 32KiB */
+#define CHUNK_LIST_SIZE 16
+
+struct BLI_memblock {
+  void **chunk_list;
+
+  /** Element size in bytes. */
+  uint elem_size;
+  /** First unused element index. */
+  uint elem_next;
+  /** Chunck size in bytes. */
+  uint chunk_size;
+  /** Number of allocated chunck. */
+  uint chunk_len;
+};
+
+BLI_memblock *BLI_memblock_create(uint elem_size)
+{
+  BLI_assert(elem_size < BLI_MEM_BLOCK_CHUNK_SIZE);
+
+  BLI_memblock *mblk = MEM_mallocN(sizeof(BLI_memblock), "BLI_memblock");
+  mblk->elem_size = elem_size;
+  mblk->elem_next = 0;
+  mblk->chunk_size = BLI_MEM_BLOCK_CHUNK_SIZE;
+  mblk->chunk_len = CHUNK_LIST_SIZE;
+  mblk->chunk_list = MEM_callocN(sizeof(void *) * mblk->chunk_len, "BLI_memblock chunk list");
+  return mblk;
+}
+
+void BLI_memblock_destroy(BLI_memblock *mblk)
+{
+  for (uint i = 0; i < mblk->chunk_len; i++) {
+    MEM_SAFE_FREE(mblk->chunk_list[i]);
+  }
+  MEM_SAFE_FREE(mblk->chunk_list);
+  MEM_freeN(mblk);
+}
+
+/* Reset elem count to 0 but keep as much memory allocated needed for at least the previous elem
+ * count. */
+void BLI_memblock_clear(BLI_memblock *mblk)
+{
+  uint elem_per_chunk = mblk->chunk_size / mblk->elem_size;
+  uint last_used_chunk = (mblk->elem_next - 1) / elem_per_chunk;
+
+  for (uint i = last_used_chunk + 1; i < mblk->chunk_len; i++) {
+    MEM_SAFE_FREE(mblk->chunk_list[i]);
+  }
+
+  if (UNLIKELY(last_used_chunk + 1 < mblk->chunk_len - CHUNK_LIST_SIZE)) {
+    mblk->chunk_len -= CHUNK_LIST_SIZE;
+    mblk->chunk_list = MEM_recallocN(mblk->chunk_list, sizeof(void *) * mblk->chunk_len);
+  }
+
+  mblk->elem_next = 0;
+}
+
+void *BLI_memblock_alloc(BLI_memblock *mblk)
+{
+  uint elem_per_chunk = mblk->chunk_size / mblk->elem_size;
+  uint chunk_idx = mblk->elem_next / elem_per_chunk;
+  uint elem_idx = mblk->elem_next - elem_per_chunk * chunk_idx;
+  mblk->elem_next++;
+
+  if (UNLIKELY(chunk_idx >= mblk->chunk_len)) {
+    mblk->chunk_len += CHUNK_LIST_SIZE;
+    mblk->chunk_list = MEM_recallocN(mblk->chunk_list, sizeof(void *) * mblk->chunk_len);
+  }
+
+  if (UNLIKELY(mblk->chunk_list[chunk_idx] == NULL)) {
+    mblk->chunk_list[chunk_idx] = MEM_mallocN(mblk->chunk_size, "BLI_memblock chunk");
+  }
+
+  return (char *)(mblk->chunk_list[chunk_idx]) + mblk->elem_size * elem_idx;
+}
+
+void BLI_memblock_iternew(BLI_memblock *mblk, BLI_memblock_iter *iter)
+{
+  iter->mblk = mblk;
+  iter->current_index = 0;
+  iter->elem_per_chunk = mblk->chunk_size / mblk->elem_size;
+}
+
+void *BLI_memblock_iterstep(BLI_memblock_iter *iter)
+{
+  if (iter->current_index >= iter->mblk->elem_next) {
+    return NULL;
+  }
+
+  uint chunk_idx = iter->current_index / iter->elem_per_chunk;
+  uint elem_idx = iter->current_index - iter->elem_per_chunk * chunk_idx;
+  iter->current_index++;
+
+  return (char *)(iter->mblk->chunk_list[chunk_idx]) + iter->mblk->elem_size * elem_idx;
+}