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, 5 insertions, 10 deletions

diff --git a/src/pl/plpython/plpy_util.c b/src/pl/plpython/plpy_util.c
index 95cbba5cdc5..88670e66d0a 100644
--- a/src/pl/plpython/plpy_util.c
+++ b/src/pl/plpython/plpy_util.c
@@ -90,11 +90,9 @@ PLyUnicode_Bytes(PyObject *unicode)
 	{
 		PG_TRY();
 		{
-			encoded = (char *) pg_do_encoding_conversion(
-												(unsigned char *) utf8string,
-														 strlen(utf8string),
-														 PG_UTF8,
-													  GetDatabaseEncoding());
+			encoded = pg_any_to_server(utf8string,
+									   strlen(utf8string),
+									   PG_UTF8);
 		}
 		PG_CATCH();
 		{
@@ -109,7 +107,7 @@ PLyUnicode_Bytes(PyObject *unicode)
 	/* finally, build a bytes object in the server encoding */
 	rv = PyBytes_FromStringAndSize(encoded, strlen(encoded));
 
-	/* if pg_do_encoding_conversion allocated memory, free it now */
+	/* if pg_any_to_server allocated memory, free it now */
 	if (utf8string != encoded)
 		pfree(encoded);
 
@@ -149,10 +147,7 @@ PLyUnicode_FromString(const char *s)
 	char	   *utf8string;
 	PyObject   *o;
 
-	utf8string = (char *) pg_do_encoding_conversion((unsigned char *) s,
-													strlen(s),
-													GetDatabaseEncoding(),
-													PG_UTF8);
+	utf8string = pg_server_to_any(s, strlen(s), PG_UTF8);
 
 	o = PyUnicode_FromString(utf8string);