1 files changed, 84 insertions, 0 deletions
diff --git a/src/backend/access/rmgrdesc/rmgrdesc_utils.c b/src/backend/access/rmgrdesc/rmgrdesc_utils.c
new file mode 100644
index 00000000000..180f64bf84b
--- /dev/null
+++ b/src/backend/access/rmgrdesc/rmgrdesc_utils.c
@@ -0,0 +1,84 @@
+/*-------------------------------------------------------------------------
+ *
+ * rmgrdesc_utils.c
+ *	  Support functions for rmgrdesc routines
+ *
+ * Copyright (c) 2023, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/rmgrdesc/rmgrdesc_utils.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/rmgrdesc_utils.h"
+#include "storage/off.h"
+
+/*
+ * Guidelines for formatting desc functions:
+ *
+ * member1_name: member1_value, member2_name: member2_value
+ *
+ * If the value is a list, please use:
+ *
+ * member3_name: [ member3_list_value1, member3_list_value2 ]
+ *
+ * The first item appended to the string should not be prepended by any spaces
+ * or comma, however all subsequent appends to the string are responsible for
+ * prepending themselves with a comma followed by a space.
+ *
+ * Arrays should have a space between the opening square bracket and first
+ * element and between the last element and closing brace.
+ *
+ * Flags should be in ALL CAPS.
+ *
+ * For lists/arrays of items, the number of those items should be listed at
+ * the beginning with all of the other numbers.
+ *
+ * List punctuation should still be included even if there are 0 items.
+ *
+ * Composite objects in a list should be surrounded with { }.
+ */
+void
+array_desc(StringInfo buf, void *array, size_t elem_size, int count,
+		   void (*elem_desc) (StringInfo buf, void *elem, void *data),
+		   void *data)
+{
+	if (count == 0)
+	{
+		appendStringInfoString(buf, " []");
+		return;
+	}
+	appendStringInfo(buf, " [");
+	for (int i = 0; i < count; i++)
+	{
+		if (i > 0)
+			appendStringInfoString(buf, ",");
+		appendStringInfoString(buf, " ");
+
+		elem_desc(buf, (char *) array + elem_size * i, data);
+	}
+	appendStringInfoString(buf, " ]");
+}
+
+void
+offset_elem_desc(StringInfo buf, void *offset, void *data)
+{
+	appendStringInfo(buf, "%u", *(OffsetNumber *) offset);
+}
+
+void
+redirect_elem_desc(StringInfo buf, void *offset, void *data)
+{
+	OffsetNumber *new_offset = (OffsetNumber *) offset;
+
+	appendStringInfo(buf, "%u->%u", new_offset[0], new_offset[1]);
+}
+
+void
+relid_desc(StringInfo buf, void *relid, void *data)
+{
+	appendStringInfo(buf, "%u", *(Oid *) relid);
+}