Add KNNGIST support to contrib/btree_gist.

This extends GiST's support for nearest-neighbor searches to many of the
standard data types.

Teodor Sigaev

1 files changed, 33 insertions, 6 deletions

diff --git a/contrib/btree_gist/btree_utils_num.h b/contrib/btree_gist/btree_utils_num.h
index 091784bd5a1..243d3b5cb99 100644
--- a/contrib/btree_gist/btree_utils_num.h
+++ b/contrib/btree_gist/btree_utils_num.h
@@ -40,24 +40,25 @@ typedef struct
 
 	/* Methods */
 
-	bool		(*f_gt) (const void *, const void *);	/* greater then */
-	bool		(*f_ge) (const void *, const void *);	/* greater equal */
+	bool		(*f_gt) (const void *, const void *);	/* greater than */
+	bool		(*f_ge) (const void *, const void *);	/* greater or equal */
 	bool		(*f_eq) (const void *, const void *);	/* equal */
-	bool		(*f_le) (const void *, const void *);	/* less equal */
-	bool		(*f_lt) (const void *, const void *);	/* less then */
+	bool		(*f_le) (const void *, const void *);	/* less or equal */
+	bool		(*f_lt) (const void *, const void *);	/* less than */
 	int			(*f_cmp) (const void *, const void *);	/* key compare function */
+	float8		(*f_dist) (const void *, const void *);	/* key distance function */
 } gbtree_ninfo;
 
 
 /*
  *	Numeric btree functions
-*/
+ */
 
 
 
 /*
  * Note: The factor 0.49 in following macro avoids floating point overflows
-*/
+ */
 #define penalty_num(result,olower,oupper,nlower,nupper) do { \
   double	tmp = 0.0F; \
   (*(result))	= 0.0F; \
@@ -91,11 +92,37 @@ typedef struct
 	 (ivp)->month * (30.0 * SECS_PER_DAY))
 #endif
 
+#define GET_FLOAT_DISTANCE(t, arg1, arg2)	Abs( ((float8) *((const t *) (arg1))) - ((float8) *((const t *) (arg2))) )
+
+#define SAMESIGN(a,b)   (((a) < 0) == ((b) < 0))
+
+/*
+ * check to see if a float4/8 val has underflowed or overflowed
+ * borrowed from src/backend/utils/adt/float.c
+ */
+#define CHECKFLOATVAL(val, inf_is_valid, zero_is_valid)			\
+do {															\
+	if (isinf(val) && !(inf_is_valid))							\
+		ereport(ERROR,											\
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),	\
+		  errmsg("value out of range: overflow")));				\
+																\
+	if ((val) == 0.0 && !(zero_is_valid))						\
+		ereport(ERROR,											\
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),	\
+		 errmsg("value out of range: underflow")));				\
+} while(0)
+
+
+extern Interval *abs_interval(Interval *a);
 
 extern bool gbt_num_consistent(const GBT_NUMKEY_R *key, const void *query,
 				   const StrategyNumber *strategy, bool is_leaf,
 				   const gbtree_ninfo *tinfo);
 
+extern float8 gbt_num_distance(const GBT_NUMKEY_R *key, const void *query,
+				   bool is_leaf, const gbtree_ninfo *tinfo);
+
 extern GIST_SPLITVEC *gbt_num_picksplit(const GistEntryVector *entryvec, GIST_SPLITVEC *v,
 				  const gbtree_ninfo *tinfo);