Rethink the way walreceiver is linked into the backend. Instead than shoving

walreceiver as whole into a dynamically loaded module, split the
libpq-specific parts of it into dynamically loaded module and keep the rest
in the main backend binary.

Although Tom fixed the Windows compilation problems with the old walreceiver
module already, this is a cleaner division of labour and makes the code
more readable. There's also the prospect of adding new transport methods
as pluggable modules in the future, which this patch makes easier, though for
now the API between libpqwalreceiver and walreceiver process should be
considered private.

The libpq-specific module is now in src/backend/replication/libpqwalreceiver,
and the part linked with postgres binary is in
src/backend/replication/walreceiver.c.

1 files changed, 13 insertions, 1 deletions

diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index f848a9e509..57de368d41 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -5,13 +5,14 @@
  *
  * Portions Copyright (c) 2010-2010, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/replication/walreceiver.h,v 1.2 2010/01/16 00:04:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/replication/walreceiver.h,v 1.3 2010/01/20 09:16:24 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef _WALRECEIVER_H
 #define _WALRECEIVER_H
 
+#include "access/xlogdefs.h"
 #include "storage/spin.h"
 
 /*
@@ -60,6 +61,17 @@ typedef struct
 
 extern PGDLLIMPORT WalRcvData *WalRcv;
 
+/* libpqwalreceiver hooks */
+typedef bool (*walrcv_connect_type) (char *conninfo, XLogRecPtr startpoint);
+extern PGDLLIMPORT walrcv_connect_type walrcv_connect;
+
+typedef bool (*walrcv_receive_type) (int timeout, XLogRecPtr *recptr, char **buffer, int *len);
+extern PGDLLIMPORT walrcv_receive_type walrcv_receive;
+
+typedef void (*walrcv_disconnect_type) (void);
+extern PGDLLIMPORT walrcv_disconnect_type walrcv_disconnect;
+
+extern void WalReceiverMain(void);
 extern Size WalRcvShmemSize(void);
 extern void WalRcvShmemInit(void);
 extern bool WalRcvInProgress(void);