1 files changed, 69 insertions, 0 deletions
diff --git a/contrib/btree_gist/btree_common.c b/contrib/btree_gist/btree_common.c
new file mode 100644
index 0000000000..9873af911c
--- /dev/null
+++ b/contrib/btree_gist/btree_common.c
@@ -0,0 +1,69 @@
+#include "btree_gist.h"
+
+PG_FUNCTION_INFO_V1(btree_decompress);
+Datum   btree_decompress(PG_FUNCTION_ARGS);
+
+/*
+** GiST DeCompress methods
+** do not do anything.
+*/
+Datum
+btree_decompress(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_POINTER(PG_GETARG_POINTER(0));
+}
+
+
+/**************************************************
+ * Common btree-function (for all ops)
+ **************************************************/
+
+/*
+** The GiST PickSplit method
+*/
+extern GIST_SPLITVEC *
+btree_picksplit(bytea *entryvec, GIST_SPLITVEC *v, BINARY_UNION bu, CMPFUNC cmp)
+{
+	OffsetNumber i;
+	RIX		   *array;
+	OffsetNumber maxoff;
+	int			nbytes;
+
+	maxoff = ((VARSIZE(entryvec) - VARHDRSZ) / sizeof(GISTENTRY)) - 1;
+	nbytes = (maxoff + 2) * sizeof(OffsetNumber);
+	v->spl_left = (OffsetNumber *) palloc(nbytes);
+	v->spl_right = (OffsetNumber *) palloc(nbytes);
+	v->spl_nleft = 0;
+	v->spl_nright = 0;
+	v->spl_ldatum = PointerGetDatum(0);
+	v->spl_rdatum = PointerGetDatum(0);
+	array = (RIX *) palloc(sizeof(RIX) * (maxoff + 1));
+
+	/* copy the data into RIXes, and sort the RIXes */
+	for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
+	{
+		array[i].index = i;
+		array[i].r = (char *) DatumGetPointer((((GISTENTRY *) (VARDATA(entryvec)))[i].key));
+	}
+	qsort((void *) &array[FirstOffsetNumber], maxoff - FirstOffsetNumber + 1,
+		  sizeof(RIX), cmp);
+
+	for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
+	{
+		if (i <= (maxoff - FirstOffsetNumber + 1) / 2)
+		{
+			v->spl_left[v->spl_nleft] = array[i].index;
+			v->spl_nleft++;
+			(*bu) (&v->spl_ldatum, array[i].r);
+		}
+		else
+		{
+			v->spl_right[v->spl_nright] = array[i].index;
+			v->spl_nright++;
+			(*bu) (&v->spl_rdatum, array[i].r);
+		}
+	}
+	pfree(array);
+
+	return (v);
+}