Moved from backend/access to include/access

1 files changed, 152 insertions, 0 deletions

diff --git a/src/include/access/gist.h b/src/include/access/gist.h
new file mode 100644
index 00000000000..e2d59c2f9fb
--- /dev/null
+++ b/src/include/access/gist.h
@@ -0,0 +1,152 @@
+/*-------------------------------------------------------------------------
+ *
+ * gist.h--
+ *    common declarations for the GiST access method code.
+ *
+ *
+ *
+ * 
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef GIST_H
+#define GIST_H
+
+#include "utils/rel.h"
+#include "storage/off.h"
+#include "storage/block.h"
+#include "storage/bufpage.h"
+#include "access/skey.h"
+
+/* 
+** You can have as many strategies as you please in GiSTs, as
+** long as your consistent method can handle them
+*/
+#define GISTNStrategies			100
+
+/*
+** Helper routines
+*/
+#define GISTNProcs			8
+#define GIST_CONSISTENT_PROC		1
+#define GIST_UNION_PROC			2
+#define GIST_COMPRESS_PROC		3
+#define GIST_DECOMPRESS_PROC		4
+#define GIST_PENALTY_PROC		5
+#define GIST_PICKSPLIT_PROC		6
+#define GIST_EQUAL_PROC 		7
+#define GIST_INFO_PROC			8
+
+#define F_LEAF		(1 << 0)
+
+typedef struct GISTPageOpaqueData {
+	uint32		flags;
+} GISTPageOpaqueData;
+
+typedef GISTPageOpaqueData	*GISTPageOpaque;
+
+#define GIST_LEAF(entry) (((GISTPageOpaque) PageGetSpecialPointer((entry)->page))->flags & F_LEAF)
+
+/*
+ *  When we descend a tree, we keep a stack of parent pointers.
+ */
+
+typedef struct GISTSTACK {
+	struct GISTSTACK *gs_parent;
+	OffsetNumber	gs_child;
+	BlockNumber	gs_blk;
+} GISTSTACK;
+
+typedef struct GISTSTATE {
+    func_ptr consistentFn;
+    func_ptr unionFn;
+    func_ptr compressFn;
+    func_ptr decompressFn;
+    func_ptr penaltyFn;
+    func_ptr picksplitFn;
+    func_ptr equalFn;
+    bool     haskeytype;
+    bool     keytypbyval;
+} GISTSTATE;
+
+
+/*
+**  When we're doing a scan, we need to keep track of the parent stack
+**  for the marked and current items.  
+*/
+
+typedef struct GISTScanOpaqueData {
+	struct GISTSTACK	*s_stack;
+	struct GISTSTACK	*s_markstk;
+	uint16		s_flags;
+	struct GISTSTATE        *giststate;
+} GISTScanOpaqueData;
+
+typedef GISTScanOpaqueData	*GISTScanOpaque;
+
+/*
+**  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 GS_CURBEFORE	((uint16) (1 << 0))
+#define GS_MRKBEFORE	((uint16) (1 << 1))
+
+/* root page of a gist */
+#define GISTP_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
+**  gistscan.c for how the scan is fixed. These two constants tell us what sort
+**  of operation changed the index.
+*/
+
+#define	GISTOP_DEL	0
+#define	GISTOP_SPLIT	1
+
+/*
+** This is the Split Vector to be returned by the PickSplit method.
+*/
+typedef struct GIST_SPLITVEC {
+    OffsetNumber	*spl_left;    /* array of entries that go left */
+    int			spl_nleft;    /* size of this array */
+    char		*spl_ldatum;  /* Union of keys in spl_left */
+    OffsetNumber	*spl_right;   /* array of entries that go right */
+    int			spl_nright;   /* size of the array */
+    char		*spl_rdatum;  /* Union of keys in spl_right */
+} GIST_SPLITVEC;
+
+/*
+** An entry on a GiST node.  Contains the key (pred), as well as 
+** its own location (rel,page,offset) which can supply the matching
+** pointer.  The size of the pred is in bytes, and leafkey is a flag to
+** tell us if the entry is in a leaf node.
+*/
+typedef struct GISTENTRY {
+    char *pred;
+    Relation rel;
+    Page page;
+    OffsetNumber offset;
+    int bytes;
+    bool leafkey;
+} GISTENTRY;
+
+/*
+** macro to initialize a GISTENTRY
+*/
+#define gistentryinit(e, pr, r, pg, o, b, l)\
+   {(e).pred = pr; (e).rel = r; (e).page = pg; (e).offset = o; (e).bytes = b; (e).leafkey = l;}
+
+/* defined in gist.c */
+extern void gistfreestack(GISTSTACK *s);
+extern void initGISTstate(GISTSTATE *giststate, Relation index);
+extern void gistdentryinit(GISTSTATE *giststate, GISTENTRY *e, char *pr, 
+			   Relation r, Page pg, OffsetNumber o, int b, bool l) ;
+extern void gistcentryinit(GISTSTATE *giststate, GISTENTRY *e, char *pr, 
+			   Relation r, Page pg, OffsetNumber o, int b, bool l) ;
+#endif /* GIST_H */