Add required database and origin filtering for logical messages.

Logical messages, added in 3fe3511d05, during decoding failed to filter
messages emitted in other databases and messages emitted "under" a
replication origin the output plugin isn't interested in.

Add tests to verify that both types of filtering actually work. While
touching message.sql remove hunk obsoleted by d25379e.

Bump XLOG_PAGE_MAGIC because xl_logical_message changed and because
3fe3511d05 had omitted doing so. 3fe3511d05 additionally didn't bump
catversion, but 7a542700d has done so since.

Author: Petr Jelinek
Reported-By: Andres Freund
Discussion: 20160406142513.wotqy3ba3kanr423@alap3.anarazel.de

contrib/test_decoding/expected/messages.out

@@ -1,6 +1,5 @@
 -- predictability
 SET synchronous_commit = on;
-SET client_encoding = 'utf8';
 SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding');
  ?column? 
 ----------
@@ -71,9 +70,30 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'for
  message: transactional: 1 prefix: test, sz: 11 content:czechtastic
 (7 rows)
 
-SELECT 'init' FROM pg_drop_replication_slot('regression_slot');
+-- test db filtering
+\set prevdb :DBNAME
+\c template1
+SELECT 'otherdb1' FROM pg_logical_emit_message(false, 'test', 'otherdb1');
  ?column? 
 ----------
- init
+ otherdb1
+(1 row)
+
+SELECT 'otherdb2' FROM pg_logical_emit_message(true, 'test', 'otherdb2');
+ ?column? 
+----------
+ otherdb2
+(1 row)
+
+\c :prevdb
+SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'force-binary', '0', 'skip-empty-xacts', '1');
+ data 
+------
+(0 rows)
+
+SELECT 'cleanup' FROM pg_drop_replication_slot('regression_slot');
+ ?column? 
+----------
+ cleanup
 (1 row)
 

contrib/test_decoding/expected/replorigin.out

@@ -59,6 +59,12 @@ SELECT pg_replication_origin_session_setup('test_decoding: regression_slot');
 -- ensure we prevent duplicate setup
 SELECT pg_replication_origin_session_setup('test_decoding: regression_slot');
 ERROR:  cannot setup replication origin when one is already setup
+SELECT '' FROM pg_logical_emit_message(false, 'test', 'this message will not be decoded');
+ ?column? 
+----------
+ 
+(1 row)
+
 BEGIN;
 -- setup transaction origin
 SELECT pg_replication_origin_xact_setup('0/aabbccdd', '2013-01-01 00:00');

contrib/test_decoding/sql/messages.sql

@@ -1,6 +1,5 @@
 -- predictability
 SET synchronous_commit = on;
-SET client_encoding = 'utf8';
 
 SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding');
 
@@ -22,4 +21,14 @@ SELECT 'ignorethis' FROM pg_logical_emit_message(true, 'test', 'czechtastic');
 
 SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'force-binary', '0', 'skip-empty-xacts', '1');
 
-SELECT 'init' FROM pg_drop_replication_slot('regression_slot');
+-- test db filtering
+\set prevdb :DBNAME
+\c template1
+
+SELECT 'otherdb1' FROM pg_logical_emit_message(false, 'test', 'otherdb1');
+SELECT 'otherdb2' FROM pg_logical_emit_message(true, 'test', 'otherdb2');
+
+\c :prevdb
+SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'force-binary', '0', 'skip-empty-xacts', '1');
+
+SELECT 'cleanup' FROM pg_drop_replication_slot('regression_slot');

contrib/test_decoding/sql/replorigin.sql

@@ -31,6 +31,8 @@ SELECT pg_replication_origin_session_setup('test_decoding: regression_slot');
 -- ensure we prevent duplicate setup
 SELECT pg_replication_origin_session_setup('test_decoding: regression_slot');
 
+SELECT '' FROM pg_logical_emit_message(false, 'test', 'this message will not be decoded');
+
 BEGIN;
 -- setup transaction origin
 SELECT pg_replication_origin_xact_setup('0/aabbccdd', '2013-01-01 00:00');

src/backend/replication/logical/decode.c

@@ -464,6 +464,15 @@ DecodeHeapOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 	}
 }
 
+static inline bool
+FilterByOrigin(LogicalDecodingContext *ctx, RepOriginId origin_id)
+{
+	if (ctx->callbacks.filter_by_origin_cb == NULL)
+		return false;
+
+	return filter_by_origin_cb_wrapper(ctx, origin_id);
+}
+
 /*
  * Handle rmgr LOGICALMSG_ID records for DecodeRecordIntoReorderBuffer().
  */
@@ -474,6 +483,7 @@ DecodeLogicalMsgOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 	XLogReaderState *r = buf->record;
 	TransactionId	xid = XLogRecGetXid(r);
 	uint8			info = XLogRecGetInfo(r) & ~XLR_INFO_MASK;
+	RepOriginId		origin_id = XLogRecGetOrigin(r);
 	Snapshot		snapshot;
 	xl_logical_message *message;
 
@@ -488,6 +498,10 @@ DecodeLogicalMsgOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
 	message = (xl_logical_message *) XLogRecGetData(r);
 
+	if (message->dbId != ctx->slot->data.database ||
+		FilterByOrigin(ctx, origin_id))
+		return;
+
 	if (message->transactional &&
 		!SnapBuildProcessChange(builder, xid, buf->origptr))
 		return;
@@ -504,15 +518,6 @@ DecodeLogicalMsgOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 							  message->message + message->prefix_size);
 }
 
-static inline bool
-FilterByOrigin(LogicalDecodingContext *ctx, RepOriginId origin_id)
-{
-	if (ctx->callbacks.filter_by_origin_cb == NULL)
-		return false;
-
-	return filter_by_origin_cb_wrapper(ctx, origin_id);
-}
-
 /*
  * Consolidated commit record handling between the different form of commit
  * records.

src/backend/replication/logical/message.c

@@ -31,6 +31,8 @@
 
 #include "postgres.h"
 
+#include "miscadmin.h"
+
 #include "access/xact.h"
 
 #include "catalog/indexing.h"
@@ -60,6 +62,7 @@ LogLogicalMessage(const char *prefix, const char *message, size_t size,
 		GetCurrentTransactionId();
 	}
 
+	xlrec.dbId = MyDatabaseId;
 	xlrec.transactional = transactional;
 	xlrec.prefix_size = strlen(prefix) + 1;
 	xlrec.message_size = size;
@@ -69,6 +72,9 @@ LogLogicalMessage(const char *prefix, const char *message, size_t size,
 	XLogRegisterData((char *) prefix, xlrec.prefix_size);
 	XLogRegisterData((char *) message, size);
 
+	/* allow origin filtering */
+	XLogIncludeOrigin();
+
 	return XLogInsert(RM_LOGICALMSG_ID, XLOG_LOGICAL_MESSAGE);
 }
 

src/include/access/xlog_internal.h

@@ -31,7 +31,7 @@
 /*
  * Each page of XLOG file has a header like this:
  */
-#define XLOG_PAGE_MAGIC 0xD090	/* can be used as WAL version indicator */
+#define XLOG_PAGE_MAGIC 0xD091	/* can be used as WAL version indicator */
 
 typedef struct XLogPageHeaderData
 {

src/include/replication/message.h

@@ -19,6 +19,7 @@
  */
 typedef struct xl_logical_message
 {
+	Oid         dbId;							/* database Oid emitted from */
 	bool		transactional;					/* is message transactional? */
 	Size		prefix_size;					/* length of prefix */
 	Size		message_size;					/* size of the message */