add btree_disk_structures.h

persistent-data/data-structures/btree_disk_structures.h

@@ -0,0 +1,64 @@
+// Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+//
+// This file is part of the thin-provisioning-tools source.
+//
+// thin-provisioning-tools 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 3 of
+// the License, or (at your option) any later version.
+//
+// thin-provisioning-tools 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 thin-provisioning-tools.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef PERSISTENT_DATA_BTREE_DISK_STRUCTURES_H
+#define PERSISTENT_DATA_BTREE_DISK_STRUCTURES_H
+
+#include "base/endian_utils.h"
+
+//----------------------------------------------------------------
+
+namespace persistent_data {
+	namespace btree_detail {
+		using namespace base;
+
+		uint32_t const BTREE_CSUM_XOR = 121107;
+
+		//------------------------------------------------
+		// On disk data layout for btree nodes
+		enum node_flags {
+			INTERNAL_NODE = 1,
+			LEAF_NODE = 1 << 1
+		};
+
+		struct node_header {
+			le32 csum;
+			le32 flags;
+			le64 blocknr; /* which block this node is supposed to live in */
+
+			le32 nr_entries;
+			le32 max_entries;
+			le32 value_size;
+			le32 padding;
+		} __attribute__((packed));
+
+		struct disk_node {
+			struct node_header header;
+			le64 keys[0];
+		} __attribute__((packed));
+
+		enum node_type {
+			INTERNAL,
+			LEAF
+		};
+	}
+}
+
+//----------------------------------------------------------------
+
+#endif