Make the _cmp and _eq methods use the same equality conditions so that

indexed and unindexed answers will be the same. (#292)

git-svn-id: http://svn.osgeo.org/postgis/trunk@4814 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/postgis/geography_btree.c b/postgis/geography_btree.c
index a6d24fae49c571a81b81e8398546410089d71165..f806f3cfc08d14ff04826f82933dc69464fd26aa 100644 (file)
--- a/postgis/geography_btree.c
+++ b/postgis/geography_btree.c
@@ -26,14 +26,6 @@ Datum geography_gt(PG_FUNCTION_ARGS);
 Datum geography_cmp(PG_FUNCTION_ARGS);
 
 
-/*
-** Calculate a hash code based on the geometry data alone
-*/
-static uint32 geography_hash(GSERIALIZED *g)
-{
-       return DatumGetUInt32(hash_any((void*)g, VARSIZE(g)));
-}
-
 /*
 ** Utility function to return the center point of a 
 ** geocentric bounding box. We don't divide by two 
@@ -166,16 +158,27 @@ Datum geography_ge(PG_FUNCTION_ARGS)
        PG_RETURN_BOOL(FALSE);  
 }
 
+
+#if 0
+/*
+** Calculate a hash code based on the geometry data alone
+*/
+static uint32 geography_hash(GSERIALIZED *g)
+{
+       return DatumGetUInt32(hash_any((void*)g, VARSIZE(g)));
+}
 /*
 ** BTree support function. Based on two geographies return true if
-** they are "equal" and false otherwise.
+** they are "equal" and false otherwise. This version uses a hash
+** function to try and shoot for a more exact equality test.
 */
 PG_FUNCTION_INFO_V1(geography_eq);
 Datum geography_eq(PG_FUNCTION_ARGS)
 {
-       /* Put aside some stack memory and use it for GIDX pointers. */
+       /* Perfect equals test based on hash */
        GSERIALIZED *g1 = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
        GSERIALIZED *g2 = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
+
        uint32 h1 = geography_hash(g1);
        uint32 h2 = geography_hash(g2);
 
@@ -185,7 +188,39 @@ Datum geography_eq(PG_FUNCTION_ARGS)
        if( h1 == h2 )
                PG_RETURN_BOOL(TRUE);   
                
+       PG_RETURN_BOOL(FALSE); 
+}
+#endif
+
+/*
+** BTree support function. Based on two geographies return true if
+** they are "equal" and false otherwise.
+*/
+PG_FUNCTION_INFO_V1(geography_eq);
+Datum geography_eq(PG_FUNCTION_ARGS)
+{
+       /* Put aside some stack memory and use it for GIDX pointers. */
+       char gboxmem1[GIDX_MAX_SIZE];
+       char gboxmem2[GIDX_MAX_SIZE];
+       GIDX *gbox1 = (GIDX*)gboxmem1;
+       GIDX *gbox2 = (GIDX*)gboxmem2;
+       POINT3D p1, p2;
+
+       /* Must be able to build box for each argument (ie, not empty geometry) */
+       if( ! geography_datum_gidx(PG_GETARG_DATUM(0), gbox1) ||
+           ! geography_datum_gidx(PG_GETARG_DATUM(1), gbox2) )
+       {
+               PG_RETURN_BOOL(FALSE);
+       }
+       
+       geography_gidx_center(gbox1, &p1);
+       geography_gidx_center(gbox2, &p2);
+       
+       if( FP_EQUALS(p1.x, p2.x) && FP_EQUALS(p1.y, p2.y) && FP_EQUALS(p1.z, p2.z) ) 
+               PG_RETURN_BOOL(TRUE);   
+       
        PG_RETURN_BOOL(FALSE);  
+
 }
 
 /*