1 files changed, 133 insertions, 0 deletions
diff --git a/src/backend/access/gist/gistvalidate.c b/src/backend/access/gist/gistvalidate.c
new file mode 100644
index 00000000000..86b5aeaec5c
--- /dev/null
+++ b/src/backend/access/gist/gistvalidate.c
@@ -0,0 +1,133 @@
+/*-------------------------------------------------------------------------
+ *
+ * gistvalidate.c
+ *	  Opclass validator for GiST.
+ *
+ * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/gist/gistvalidate.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/gist_private.h"
+#include "access/htup_details.h"
+#include "catalog/pg_amop.h"
+#include "catalog/pg_amproc.h"
+#include "catalog/pg_opclass.h"
+#include "utils/catcache.h"
+#include "utils/syscache.h"
+
+
+/*
+ * Validator for a GiST opclass.
+ */
+bool
+gistvalidate(Oid opclassoid)
+{
+	HeapTuple	classtup;
+	Form_pg_opclass classform;
+	Oid			opfamilyoid;
+	Oid			opcintype;
+	int			numclassops;
+	int32		classfuncbits;
+	CatCList   *proclist,
+			   *oprlist;
+	int			i;
+
+	/* Fetch opclass information */
+	classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
+	if (!HeapTupleIsValid(classtup))
+		elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
+	classform = (Form_pg_opclass) GETSTRUCT(classtup);
+
+	opfamilyoid = classform->opcfamily;
+	opcintype = classform->opcintype;
+
+	ReleaseSysCache(classtup);
+
+	/* Fetch all operators and support functions of the opfamily */
+	oprlist = SearchSysCacheList1(AMOPSTRATEGY, ObjectIdGetDatum(opfamilyoid));
+	proclist = SearchSysCacheList1(AMPROCNUM, ObjectIdGetDatum(opfamilyoid));
+
+	/* We'll track the ops and functions belonging to the named opclass */
+	numclassops = 0;
+	classfuncbits = 0;
+
+	/* Check support functions */
+	for (i = 0; i < proclist->n_members; i++)
+	{
+		HeapTuple	proctup = &proclist->members[i]->tuple;
+		Form_pg_amproc procform = (Form_pg_amproc) GETSTRUCT(proctup);
+
+		/* Check that only allowed procedure numbers exist */
+		if (procform->amprocnum < 1 ||
+			procform->amprocnum > GISTNProcs)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("gist opfamily %u contains invalid support number %d for procedure %u",
+							opfamilyoid,
+							procform->amprocnum, procform->amproc)));
+
+		/* Remember functions that are specifically for the named opclass */
+		if (procform->amproclefttype == opcintype &&
+			procform->amprocrighttype == opcintype)
+			classfuncbits |= (1 << procform->amprocnum);
+	}
+
+	/* Check operators */
+	for (i = 0; i < oprlist->n_members; i++)
+	{
+		HeapTuple	oprtup = &oprlist->members[i]->tuple;
+		Form_pg_amop oprform = (Form_pg_amop) GETSTRUCT(oprtup);
+
+		/* TODO: Check that only allowed strategy numbers exist */
+		if (oprform->amopstrategy < 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("gist opfamily %u contains invalid strategy number %d for operator %u",
+							opfamilyoid,
+							oprform->amopstrategy, oprform->amopopr)));
+
+		/* GiST supports ORDER BY operators, but must have distance proc */
+		if (oprform->amoppurpose != AMOP_SEARCH &&
+			oprform->amoplefttype == opcintype &&
+			oprform->amoprighttype == opcintype &&
+			(classfuncbits & (1 << GIST_DISTANCE_PROC)) == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("gist opfamily %u contains unsupported ORDER BY specification for operator %u",
+							opfamilyoid, oprform->amopopr)));
+
+		/* Count operators that are specifically for the named opclass */
+		/* XXX we consider only lefttype here */
+		if (oprform->amoplefttype == opcintype)
+			numclassops++;
+	}
+
+	/* Check that the named opclass is complete */
+	if (numclassops == 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("gist opclass %u is missing operator(s)",
+						opclassoid)));
+	for (i = 1; i <= GISTNProcs; i++)
+	{
+		if ((classfuncbits & (1 << i)) != 0)
+			continue;			/* got it */
+		if (i == GIST_DISTANCE_PROC || i == GIST_FETCH_PROC)
+			continue;			/* optional methods */
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+			errmsg("gist opclass %u is missing required support function %d",
+				   opclassoid, i)));
+	}
+
+	ReleaseCatCacheList(proclist);
+	ReleaseCatCacheList(oprlist);
+
+	return true;
+}