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diff --git a/src/backend/access/rtree.h b/src/backend/access/rtree.h
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+/*-------------------------------------------------------------------------
+ *
+ * rtree.h--
+ * common declarations for the rtree access method code.
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: rtree.h,v 1.1.1.1 1996/07/09 06:21:08 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef RTREE_H
+#define RTREE_H
+
+/* see rtstrat.c for what all this is about */
+#define RTNStrategies 8
+#define RTLeftStrategyNumber 1
+#define RTOverLeftStrategyNumber 2
+#define RTOverlapStrategyNumber 3
+#define RTOverRightStrategyNumber 4
+#define RTRightStrategyNumber 5
+#define RTSameStrategyNumber 6
+#define RTContainsStrategyNumber 7
+#define RTContainedByStrategyNumber 8
+
+#define RTNProcs 3
+#define RT_UNION_PROC 1
+#define RT_INTER_PROC 2
+#define RT_SIZE_PROC 3
+
+#define F_LEAF (1 << 0)
+
+typedef struct RTreePageOpaqueData {
+ uint32 flags;
+} RTreePageOpaqueData;
+
+typedef RTreePageOpaqueData *RTreePageOpaque;
+
+/*
+ * When we descend a tree, we keep a stack of parent pointers.
+ */
+
+typedef struct RTSTACK {
+ struct RTSTACK *rts_parent;
+ OffsetNumber rts_child;
+ BlockNumber rts_blk;
+} RTSTACK;
+
+/*
+ * When we're doing a scan, we need to keep track of the parent stack
+ * for the marked and current items. Also, rtrees have the following
+ * property: if you're looking for the box (1,1,2,2), on the internal
+ * nodes you have to search for all boxes that *contain* (1,1,2,2), and
+ * not the ones that match it. We have a private scan key for internal
+ * nodes in the opaque structure for rtrees for this reason. See
+ * access/index-rtree/rtscan.c and rtstrat.c for how it gets initialized.
+ */
+
+typedef struct RTreeScanOpaqueData {
+ struct RTSTACK *s_stack;
+ struct RTSTACK *s_markstk;
+ uint16 s_flags;
+ uint16 s_internalNKey;
+ ScanKey s_internalKey;
+} RTreeScanOpaqueData;
+
+typedef RTreeScanOpaqueData *RTreeScanOpaque;
+
+/*
+ * When we're doing a scan and updating a tree at the same time, the
+ * updates may affect the scan. We use the flags entry of the scan's
+ * opaque space to record our actual position in response to updates
+ * that we can't handle simply by adjusting pointers.
+ */
+
+#define RTS_CURBEFORE ((uint16) (1 << 0))
+#define RTS_MRKBEFORE ((uint16) (1 << 1))
+
+/* root page of an rtree */
+#define P_ROOT 0
+
+/*
+ * When we update a relation on which we're doing a scan, we need to
+ * check the scan and fix it if the update affected any of the pages it
+ * touches. Otherwise, we can miss records that we should see. The only
+ * times we need to do this are for deletions and splits. See the code in
+ * rtscan.c for how the scan is fixed. These two contants tell us what sort
+ * of operation changed the index.
+ */
+
+#define RTOP_DEL 0
+#define RTOP_SPLIT 1
+
+/* defined in rtree.c */
+extern void freestack(RTSTACK *s);
+
+#endif /* RTREE_H */