Prefer pg_any_to_server/pg_server_to_any over pg_do_encoding_conversion.

A large majority of the callers of pg_do_encoding_conversion were
specifying the database encoding as either source or target of the
conversion, meaning that we can use the less general functions
pg_any_to_server/pg_server_to_any instead.

The main advantage of using the latter functions is that they can make use
of a cached conversion-function lookup in the common case that the other
encoding is the current client_encoding.  It's notationally cleaner too in
most cases, not least because of the historical artifact that the latter
functions use "char *" rather than "unsigned char *" in their APIs.

Note that pg_any_to_server will apply an encoding verification step in
some cases where pg_do_encoding_conversion would have just done nothing.
This seems to me to be a good idea at most of these call sites, though
it partially negates the performance benefit.

Per discussion of bug #9210.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 05380389821..b3bf65ec885 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -63,13 +63,17 @@
 static unsigned char *
 utf_u2e(unsigned char *src)
 {
-	return pg_do_encoding_conversion(src, strlen(src), PG_UTF8, GetDatabaseEncoding());
+	return (unsigned char *) pg_any_to_server((char *) src,
+											  strlen(src),
+											  PG_UTF8);
 }
 
 static unsigned char *
 utf_e2u(unsigned char *src)
 {
-	return pg_do_encoding_conversion(src, strlen(src), GetDatabaseEncoding(), PG_UTF8);
+	return (unsigned char *) pg_server_to_any((char *) src,
+											  strlen(src),
+											  PG_UTF8);
 }
 
 #define PLTCL_UTF