Allow extracting machine-readable object identity

Introduce pg_identify_object(oid,oid,int4), which is similar in spirit
to pg_describe_object but instead produces a row of machine-readable
information to uniquely identify the given object, without resorting to
OIDs or other internal representation.  This is intended to be used in
the event trigger implementation, to report objects being operated on;
but it has usefulness of its own.

Catalog version bumped because of the new function.

1 files changed, 46 insertions, 6 deletions

diff --git a/src/backend/utils/adt/regproc.c b/src/backend/utils/adt/regproc.c
index cb11bd0ade6..94599aa44ba 100644
--- a/src/backend/utils/adt/regproc.c
+++ b/src/backend/utils/adt/regproc.c
@@ -41,6 +41,8 @@
 #include "utils/syscache.h"
 #include "utils/tqual.h"
 
+static char *format_operator_internal(Oid operator_oid, bool force_qualify);
+static char *format_procedure_internal(Oid procedure_oid, bool force_qualify);
 static void parseNameAndArgTypes(const char *string, bool allowNone,
 					 List **names, int *nargs, Oid *argtypes);
 
@@ -304,6 +306,25 @@ regprocedurein(PG_FUNCTION_ARGS)
 char *
 format_procedure(Oid procedure_oid)
 {
+	return format_procedure_internal(procedure_oid, false);
+}
+
+char *
+format_procedure_qualified(Oid procedure_oid)
+{
+	return format_procedure_internal(procedure_oid, true);
+}
+
+/*
+ * Routine to produce regprocedure names; see format_procedure above.
+ *
+ * force_qualify says whether to schema-qualify; if true, the name is always
+ * qualified regardless of search_path visibility.  Otherwise the name is only
+ * qualified if the function is not in path.
+ */
+static char *
+format_procedure_internal(Oid procedure_oid, bool force_qualify)
+{
 	char	   *result;
 	HeapTuple	proctup;
 
@@ -326,7 +347,7 @@ format_procedure(Oid procedure_oid)
 		 * Would this proc be found (given the right args) by regprocedurein?
 		 * If not, we need to qualify it.
 		 */
-		if (FunctionIsVisible(procedure_oid))
+		if (!force_qualify && FunctionIsVisible(procedure_oid))
 			nspname = NULL;
 		else
 			nspname = get_namespace_name(procform->pronamespace);
@@ -339,7 +360,10 @@ format_procedure(Oid procedure_oid)
 
 			if (i > 0)
 				appendStringInfoChar(&buf, ',');
-			appendStringInfoString(&buf, format_type_be(thisargtype));
+			appendStringInfoString(&buf,
+								   force_qualify ?
+								   format_type_be_qualified(thisargtype) :
+								   format_type_be(thisargtype));
 		}
 		appendStringInfoChar(&buf, ')');
 
@@ -653,8 +677,8 @@ regoperatorin(PG_FUNCTION_ARGS)
  * This exports the useful functionality of regoperatorout for use
  * in other backend modules.  The result is a palloc'd string.
  */
-char *
-format_operator(Oid operator_oid)
+static char *
+format_operator_internal(Oid operator_oid, bool force_qualify)
 {
 	char	   *result;
 	HeapTuple	opertup;
@@ -674,9 +698,9 @@ format_operator(Oid operator_oid)
 
 		/*
 		 * Would this oper be found (given the right args) by regoperatorin?
-		 * If not, we need to qualify it.
+		 * If not, or if caller explicitely requests it, we need to qualify it.
 		 */
-		if (!OperatorIsVisible(operator_oid))
+		if (force_qualify || !OperatorIsVisible(operator_oid))
 		{
 			nspname = get_namespace_name(operform->oprnamespace);
 			appendStringInfo(&buf, "%s.",
@@ -687,12 +711,16 @@ format_operator(Oid operator_oid)
 
 		if (operform->oprleft)
 			appendStringInfo(&buf, "%s,",
+							 force_qualify ?
+							 format_type_be_qualified(operform->oprleft) :
 							 format_type_be(operform->oprleft));
 		else
 			appendStringInfo(&buf, "NONE,");
 
 		if (operform->oprright)
 			appendStringInfo(&buf, "%s)",
+							 force_qualify ?
+							 format_type_be_qualified(operform->oprright) :
 							 format_type_be(operform->oprright));
 		else
 			appendStringInfo(&buf, "NONE)");
@@ -713,6 +741,18 @@ format_operator(Oid operator_oid)
 	return result;
 }
 
+char *
+format_operator(Oid operator_oid)
+{
+	return format_operator_internal(operator_oid, false);
+}
+
+char *
+format_operator_qualified(Oid operator_oid)
+{
+	return format_operator_internal(operator_oid, true);
+}
+
 /*
  * regoperatorout		- converts operator OID to "opr_name(args)"
  */