From 1ab9b012bdf1f106792fc523e21b9ca8299bb8ed Mon Sep 17 00:00:00 2001
From: Tom Lane
Date: Tue, 22 Feb 2011 13:08:22 -0500
Subject: Allow binary I/O of type "void".

void_send is useful for the same reason that void_out doesn't throw error,
namely that someone might do "select void_returning_func(...)"  from a
client that prefers to operate in binary mode.  The void_recv function may
or may not have any practical use, but we provide it for symmetry.

Radosław Smogura
---
 src/backend/utils/adt/pseudotypes.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'src/backend')

diff --git a/src/backend/utils/adt/pseudotypes.c b/src/backend/utils/adt/pseudotypes.c
index d9329f83428..ddb1bd2b71c 100644
--- a/src/backend/utils/adt/pseudotypes.c
+++ b/src/backend/utils/adt/pseudotypes.c
@@ -212,6 +212,34 @@ void_out(PG_FUNCTION_ARGS)
 	PG_RETURN_CSTRING(pstrdup(""));
 }
 
+/*
+ * void_recv	- binary input routine for pseudo-type VOID.
+ *
+ * Note that since we consume no bytes, an attempt to send anything but
+ * an empty string will result in an "invalid message format" error.
+ */
+Datum
+void_recv(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_VOID();
+}
+
+/*
+ * void_send	- binary output routine for pseudo-type VOID.
+ *
+ * We allow this so that "SELECT function_returning_void(...)" works
+ * even when binary output is requested.
+ */
+Datum
+void_send(PG_FUNCTION_ARGS)
+{
+	StringInfoData buf;
+
+	/* send an empty string */
+	pq_begintypsend(&buf);
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
 
 /*
  * trigger_in		- input routine for pseudo-type TRIGGER.
-- 
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