1 files changed, 91 insertions, 0 deletions
diff --git a/storage/innobase/include/buf0buddy.h b/storage/innobase/include/buf0buddy.h
new file mode 100644
index 00000000..bb999420
--- /dev/null
+++ b/storage/innobase/include/buf0buddy.h
@@ -0,0 +1,91 @@
+/*****************************************************************************
+
+Copyright (c) 2006, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2018, 2020, MariaDB Corporation.
+
+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; version 2 of the License.
+
+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 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file include/buf0buddy.h
+Binary buddy allocator for compressed pages
+
+Created December 2006 by Marko Makela
+*******************************************************/
+
+#ifndef buf0buddy_h
+#define buf0buddy_h
+
+#include "buf0types.h"
+
+/**
+@param[in]	block size in bytes
+@return index of buf_pool.zip_free[], or BUF_BUDDY_SIZES */
+inline
+ulint
+buf_buddy_get_slot(ulint size)
+{
+	ulint	i;
+	ulint	s;
+
+	ut_ad(ut_is_2pow(size));
+	ut_ad(size >= UNIV_ZIP_SIZE_MIN);
+	ut_ad(size <= srv_page_size);
+
+	for (i = 0, s = BUF_BUDDY_LOW; s < size; i++, s <<= 1) {
+	}
+	ut_ad(i <= BUF_BUDDY_SIZES);
+	return i;
+}
+
+/** Allocate a ROW_FORMAT=COMPRESSED block.
+@param i      index of buf_pool.zip_free[] or BUF_BUDDY_SIZES
+@param lru    assigned to true if buf_pool.mutex was temporarily released
+@return allocated block, never NULL */
+byte *buf_buddy_alloc_low(ulint i, bool *lru) MY_ATTRIBUTE((malloc));
+
+/** Allocate a ROW_FORMAT=COMPRESSED block.
+@param size   compressed page size in bytes
+@param lru    assigned to true if buf_pool.mutex was temporarily released
+@return allocated block, never NULL */
+inline byte *buf_buddy_alloc(ulint size, bool *lru= nullptr)
+{
+  return buf_buddy_alloc_low(buf_buddy_get_slot(size), lru);
+}
+
+/** Deallocate a block.
+@param[in]	buf	block to be freed, must not be pointed to
+			by the buffer pool
+@param[in]	i	index of buf_pool.zip_free[], or BUF_BUDDY_SIZES */
+void buf_buddy_free_low(void* buf, ulint i);
+
+/** Deallocate a block.
+@param[in]	buf	block to be freed, must not be pointed to
+			by the buffer pool
+@param[in]	size	block size in bytes */
+inline void buf_buddy_free(void* buf, ulint size)
+{
+	buf_buddy_free_low(buf, buf_buddy_get_slot(size));
+}
+
+/** Try to reallocate a block.
+@param[in]	buf		block to be reallocated, must be pointed
+to by the buffer pool
+@param[in]	size		block size, up to srv_page_size
+@retval false	if failed because of no free blocks. */
+bool buf_buddy_realloc(void* buf, ulint size);
+
+/** Combine all pairs of free buddies. */
+void buf_buddy_condense_free();
+#endif /* buf0buddy_h */