Add a new function "pg_client_encoding" which returns the current client

side encoding name. This is necessary for client API's such as JDBC
to perform correct encoding conversions. See my email "[HACKERS]
pg_client_encoding" 10 Sep 2001.

doc/src/sgml/func.sgml

-<!-- $Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.77 2001/10/10 00:02:42 petere Exp $ -->
+<!-- $Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.78 2001/10/12 02:08:34 ishii Exp $ -->
 
 <chapter id="functions">
  <title>Functions and Operators</title>
@@ -1008,6 +1008,16 @@
       <entry><literal>trim</literal></entry>
      </row>
 
+     <row>
+      <entry><function>pg_client_encoding</function>()</entry>
+      <entry><type>name</type></entry>
+      <entry>
+       Returns current client encoding name.
+      </entry>
+      <entry><literal>pg_client_encoding()</literal></entry>
+      <entry><literal>SQL_ASCII</literal></entry>
+     </row>
+
      <row>
       <entry><function>repeat</function>(<type>text</type>, <type>integer</type>)</entry>
       <entry><type>text</type></entry>

src/backend/utils/init/miscinit.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/init/miscinit.c,v 1.77 2001/09/08 15:24:00 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/init/miscinit.c,v 1.78 2001/10/12 02:08:34 ishii Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -197,6 +197,12 @@ getdatabaseencoding(PG_FUNCTION_ARGS)
 	return DirectFunctionCall1(namein, CStringGetDatum("SQL_ASCII"));
 }
 
+Datum
+pg_client_encoding(PG_FUNCTION_ARGS)
+{
+	return DirectFunctionCall1(namein, CStringGetDatum("SQL_ASCII"));
+}
+
 Datum
 PG_encoding_to_char(PG_FUNCTION_ARGS)
 {

src/backend/utils/mb/mbutils.c

@@ -3,7 +3,7 @@
  * client encoding and server internal encoding.
  * (currently mule internal code (mic) is used)
  * Tatsuo Ishii
- * $Id: mbutils.c,v 1.23 2001/09/21 15:27:38 tgl Exp $
+ * $Id: mbutils.c,v 1.24 2001/10/12 02:08:34 ishii Exp $
  */
 #include "postgres.h"
 
@@ -471,3 +471,10 @@ getdatabaseencoding(PG_FUNCTION_ARGS)
 	Assert(DatabaseEncoding);
 	return DirectFunctionCall1(namein, CStringGetDatum(DatabaseEncoding->name));
 }
+
+Datum
+pg_client_encoding(PG_FUNCTION_ARGS)
+{
+	Assert(ClientEncoding);
+	return DirectFunctionCall1(namein, CStringGetDatum(ClientEncoding->name));
+}

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_proc.h,v 1.215 2001/10/03 17:22:05 tgl Exp $
+ * $Id: pg_proc.h,v 1.216 2001/10/12 02:08:34 ishii Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -2140,10 +2140,14 @@ DESCR("return portion of string");
 
 /* for multi-byte support */
 
-/* old encoding names - back compatibility only */
+/* return database encoding name */
 DATA(insert OID = 1039 (  getdatabaseencoding	   PGUID 12 f t f t 0 f 19 "0" 100 0 0 100  getdatabaseencoding - ));
 DESCR("encoding name of current database");
 
+/* return client encoding name i.e. session encoding */
+DATA(insert OID = 810 (  pg_client_encoding	   PGUID 12 f t f t 0 f 19 "0" 100 0 0 100  pg_client_encoding - ));
+DESCR("encoding name of current database");
+
 DATA(insert OID = 1717 (  convert		   PGUID 12 f t f t 2 f 25 "25 19" 100 0 0 100  pg_convert - ));
 DESCR("convert string with specified destination encoding name");