v1-0001-Remove-list_slots-command.patch

From f7bc02999302c5c714672c8b904a21982e597483 Mon Sep 17 00:00:00 2001
From: Shveta Malik <shveta.malik@gmail.com>
Date: Thu, 20 Jul 2023 14:24:25 +0530
Subject: [PATCH v1] Remove list_slots command

Now list_sots has been replaced by a select query.
---
 .../libpqwalreceiver/libpqwalreceiver.c       |  20 +-
 src/backend/replication/logical/launcher.c    |   2 +-
 src/backend/replication/repl_gram.y           |  32 +--
 src/backend/replication/repl_scanner.l        |   2 -
 src/backend/replication/walsender.c           | 195 ------------------
 src/include/nodes/replnodes.h                 |  10 -
 6 files changed, 16 insertions(+), 245 deletions(-)

diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 0e13cc2417..6580b3ef5b 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -425,7 +425,11 @@ libpqrcv_list_slots(WalReceiverConn *conn, const char *slot_names)
 	WalRecvReplicationSlotData *slot_data;
 
 	initStringInfo(&s);
-	appendStringInfoString(&s, "LIST_SLOTS");
+	appendStringInfo(&s,
+					 "SELECT slot_name, plugin, slot_type, "
+					 "datoid, database, temporary, xmin, "
+					 "catalog_xmin, restart_lsn, confirmed_flush_lsn "
+					 "FROM pg_catalog.pg_replication_slots");
 
 	if (strcmp(slot_names, "") != 0 && strcmp(slot_names, "*") != 0)
 	{
@@ -433,16 +437,18 @@ libpqrcv_list_slots(WalReceiverConn *conn, const char *slot_names)
 		List	   *namelist;
 		ListCell   *lc;
 
-		appendStringInfoChar(&s, ' ');
 		rawname = pstrdup(slot_names);
 		SplitIdentifierString(rawname, ',', &namelist);
-		foreach (lc, namelist)
+
+		appendStringInfoString(&s, " AND slot_name IN (");
+		foreach(lc, namelist)
 		{
 			if (lc != list_head(namelist))
 				appendStringInfoChar(&s, ',');
 			appendStringInfo(&s, "%s",
-							 quote_identifier(lfirst(lc)));
+							 quote_literal_cstr(lfirst(lc)));
 		}
+		appendStringInfoChar(&s, ')');
 	}
 
 	res = libpqrcv_PQexec(conn->streamConn, s.data);
@@ -482,10 +488,12 @@ libpqrcv_list_slots(WalReceiverConn *conn, const char *slot_names)
 			if (OidIsValid(slot_data->persistent_data.database))
 				elog(ERROR, "unexpected physical replication slot with database set");
 		}
-		if (pg_strtoint32(PQgetvalue(res, i, 5)) == 1)
+
+		if (strcmp(PQgetvalue(res, i, 5), "t") == 0)
 			slot_data->persistent_data.persistency = RS_TEMPORARY;
-		else
+		else if (strcmp(PQgetvalue(res, i, 5), "f") == 0)
 			slot_data->persistent_data.persistency = RS_PERSISTENT;
+
 		if (!PQgetisnull(res, i, 6))
 			slot_data->persistent_data.xmin = atooid(PQgetvalue(res, i, 6));
 		if (!PQgetisnull(res, i, 7))
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 640f7647cc..0bf9ed8504 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -1117,7 +1117,7 @@ ApplyLauncherStartSlotSync(long *wait_time)
 	if (strcmp(synchronize_slot_names, "") == 0)
 		return;
 
-	wrconn = walrcv_connect(PrimaryConnInfo, false, false,
+	wrconn = walrcv_connect(PrimaryConnInfo, true, false,
 							"Logical Replication Launcher", &err);
 	if (!wrconn)
 		ereport(ERROR,
diff --git a/src/backend/replication/repl_gram.y b/src/backend/replication/repl_gram.y
index 12a4b74368..0c874e33cf 100644
--- a/src/backend/replication/repl_gram.y
+++ b/src/backend/replication/repl_gram.y
@@ -76,12 +76,11 @@ Node *replication_parse_result;
 %token K_EXPORT_SNAPSHOT
 %token K_NOEXPORT_SNAPSHOT
 %token K_USE_SNAPSHOT
-%token K_LIST_SLOTS
 
 %type <node>	command
 %type <node>	base_backup start_replication start_logical_replication
 				create_replication_slot drop_replication_slot identify_system
-				read_replication_slot timeline_history show list_slots
+				read_replication_slot timeline_history show
 %type <list>	generic_option_list
 %type <defelt>	generic_option
 %type <uintval>	opt_timeline
@@ -92,7 +91,6 @@ Node *replication_parse_result;
 %type <boolval>	opt_temporary
 %type <list>	create_slot_options create_slot_legacy_opt_list
 %type <defelt>	create_slot_legacy_opt
-%type <list>	slot_name_list slot_name_list_opt
 
 %%
 
@@ -116,7 +114,6 @@ command:
 			| read_replication_slot
 			| timeline_history
 			| show
-			| list_slots
 			;
 
 /*
@@ -129,33 +126,6 @@ identify_system:
 				}
 			;
 
-slot_name_list:
-			IDENT
-				{
-					$$ = list_make1($1);
-				}
-			| slot_name_list ',' IDENT
-				{
-					$$ = lappend($1, $3);
-				}
-
-slot_name_list_opt:
-			slot_name_list			{ $$ = $1; }
-			| /* EMPTY */			{ $$ = NIL; }
-		;
-
-/*
- * LIST_SLOTS
- */
-list_slots:
-			K_LIST_SLOTS slot_name_list_opt
-				{
-					ListSlotsCmd *cmd = makeNode(ListSlotsCmd);
-					cmd->slot_names = $2;
-					$$ = (Node *) cmd;
-				}
-			;
-
 /*
  * READ_REPLICATION_SLOT %s
  */
diff --git a/src/backend/replication/repl_scanner.l b/src/backend/replication/repl_scanner.l
index 11064feb86..1cc7fb858c 100644
--- a/src/backend/replication/repl_scanner.l
+++ b/src/backend/replication/repl_scanner.l
@@ -128,7 +128,6 @@ DROP_REPLICATION_SLOT		{ return K_DROP_REPLICATION_SLOT; }
 TIMELINE_HISTORY	{ return K_TIMELINE_HISTORY; }
 PHYSICAL			{ return K_PHYSICAL; }
 RESERVE_WAL			{ return K_RESERVE_WAL; }
-LIST_SLOTS			{ return K_LIST_SLOTS; }
 LOGICAL				{ return K_LOGICAL; }
 SLOT				{ return K_SLOT; }
 TEMPORARY			{ return K_TEMPORARY; }
@@ -305,7 +304,6 @@ replication_scanner_is_replication_command(void)
 		case K_READ_REPLICATION_SLOT:
 		case K_TIMELINE_HISTORY:
 		case K_SHOW:
-		case K_LIST_SLOTS:
 			/* Yes; push back the first token so we can parse later. */
 			repl_pushed_back_token = first_token;
 			return true;
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 26d07ae549..d27ef2985d 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -473,194 +473,6 @@ IdentifySystem(void)
 	end_tup_output(tstate);
 }
 
-static int
-pg_qsort_namecmp(const void *a, const void *b)
-{
-	return strncmp(NameStr(*(Name) a), NameStr(*(Name) b), NAMEDATALEN);
-}
-
-/*
- * Handle the LIST_SLOTS command.
- */
-static void
-ListSlots(ListSlotsCmd *cmd)
-{
-	DestReceiver *dest;
-	TupOutputState *tstate;
-	TupleDesc	tupdesc;
-	NameData   *slot_names;
-	int			numslot_names;
-
-	numslot_names = list_length(cmd->slot_names);
-	if (numslot_names)
-	{
-		ListCell   *lc;
-		int			i = 0;
-
-		slot_names = palloc(numslot_names * sizeof(NameData));
-		foreach(lc, cmd->slot_names)
-		{
-			char	   *slot_name = lfirst(lc);
-
-			ReplicationSlotValidateName(slot_name, ERROR);
-			namestrcpy(&slot_names[i++], slot_name);
-		}
-
-		qsort(slot_names, numslot_names, sizeof(NameData), pg_qsort_namecmp);
-	}
-
-	dest = CreateDestReceiver(DestRemoteSimple);
-
-	/* need a tuple descriptor representing four columns */
-	tupdesc = CreateTemplateTupleDesc(10);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 1, "slot_name",
-							  TEXTOID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 2, "plugin",
-							  TEXTOID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 3, "slot_type",
-							  TEXTOID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 4, "datoid",
-							  INT8OID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 5, "database",
-							  TEXTOID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 6, "temporary",
-							  INT4OID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 7, "xmin",
-							  INT8OID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 8, "catalog_xmin",
-							  INT8OID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 9, "restart_lsn",
-							  TEXTOID, -1, 0);
-	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 10, "confirmed_flush",
-							  TEXTOID, -1, 0);
-
-	/* prepare for projection of tuples */
-	tstate = begin_tup_output_tupdesc(dest, tupdesc, &TTSOpsVirtual);
-
-	LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
-	for (int slotno = 0; slotno < max_replication_slots; slotno++)
-	{
-		ReplicationSlot *slot = &ReplicationSlotCtl->replication_slots[slotno];
-		char		restart_lsn_str[MAXFNAMELEN];
-		char		confirmed_flush_lsn_str[MAXFNAMELEN];
-		Datum		values[10];
-		bool		nulls[10];
-
-		ReplicationSlotPersistency persistency;
-		TransactionId xmin;
-		TransactionId catalog_xmin;
-		XLogRecPtr	restart_lsn;
-		XLogRecPtr	confirmed_flush_lsn;
-		Oid			datoid;
-		NameData	slot_name;
-		NameData	plugin;
-		int			i;
-		int64		tmpbigint;
-
-		if (!slot->in_use)
-			continue;
-
-		SpinLockAcquire(&slot->mutex);
-
-		xmin = slot->data.xmin;
-		catalog_xmin = slot->data.catalog_xmin;
-		datoid = slot->data.database;
-		restart_lsn = slot->data.restart_lsn;
-		confirmed_flush_lsn = slot->data.confirmed_flush;
-		namestrcpy(&slot_name, NameStr(slot->data.name));
-		namestrcpy(&plugin, NameStr(slot->data.plugin));
-		persistency = slot->data.persistency;
-
-		SpinLockRelease(&slot->mutex);
-
-		if (numslot_names &&
-			!bsearch((void *) &slot_name, (void *) slot_names,
-					 numslot_names, sizeof(NameData), pg_qsort_namecmp))
-			continue;
-
-		memset(nulls, 0, sizeof(nulls));
-
-		i = 0;
-		values[i++] = CStringGetTextDatum(NameStr(slot_name));
-
-		if (datoid == InvalidOid)
-			nulls[i++] = true;
-		else
-			values[i++] = CStringGetTextDatum(NameStr(plugin));
-
-		if (datoid == InvalidOid)
-			values[i++] = CStringGetTextDatum("physical");
-		else
-			values[i++] = CStringGetTextDatum("logical");
-
-		if (datoid == InvalidOid)
-			nulls[i++] = true;
-		else
-		{
-			tmpbigint = datoid;
-			values[i++] = Int64GetDatum(tmpbigint);
-		}
-
-		if (datoid == InvalidOid)
-			nulls[i++] = true;
-		else
-		{
-			MemoryContext cur = CurrentMemoryContext;
-
-			/* syscache access needs a transaction env. */
-			StartTransactionCommand();
-			/* make dbname live outside TX context */
-			MemoryContextSwitchTo(cur);
-			values[i++] = CStringGetTextDatum(get_database_name(datoid));
-			CommitTransactionCommand();
-			/* CommitTransactionCommand switches to TopMemoryContext */
-			MemoryContextSwitchTo(cur);
-		}
-
-		values[i++] = Int32GetDatum(persistency == RS_TEMPORARY ? 1 : 0);
-
-		if (xmin != InvalidTransactionId)
-		{
-			tmpbigint = xmin;
-			values[i++] = Int64GetDatum(tmpbigint);
-		}
-		else
-			nulls[i++] = true;
-
-		if (catalog_xmin != InvalidTransactionId)
-		{
-			tmpbigint = catalog_xmin;
-			values[i++] = Int64GetDatum(tmpbigint);
-		}
-		else
-			nulls[i++] = true;
-
-		if (restart_lsn != InvalidXLogRecPtr)
-		{
-			snprintf(restart_lsn_str, sizeof(restart_lsn_str), "%X/%X",
-					 LSN_FORMAT_ARGS(restart_lsn));
-			values[i++] = CStringGetTextDatum(restart_lsn_str);
-		}
-		else
-			nulls[i++] = true;
-
-		if (confirmed_flush_lsn != InvalidXLogRecPtr)
-		{
-			snprintf(confirmed_flush_lsn_str, sizeof(confirmed_flush_lsn_str),
-					 "%X/%X", LSN_FORMAT_ARGS(confirmed_flush_lsn));
-			values[i++] = CStringGetTextDatum(confirmed_flush_lsn_str);
-		}
-		else
-			nulls[i++] = true;
-
-		/* send it to dest */
-		do_tup_output(tstate, values, nulls);
-	}
-	LWLockRelease(ReplicationSlotControlLock);
-
-	end_tup_output(tstate);
-}
-
 /* Handle READ_REPLICATION_SLOT command */
 static void
 ReadReplicationSlot(ReadReplicationSlotCmd *cmd)
@@ -2007,13 +1819,6 @@ exec_replication_command(const char *cmd_string)
 			EndReplicationCommand(cmdtag);
 			break;
 
-		case T_ListSlotsCmd:
-			cmdtag = "LIST_SLOTS";
-			set_ps_display(cmdtag);
-			ListSlots((ListSlotsCmd *) cmd_node);
-			EndReplicationCommand(cmdtag);
-			break;
-
 		case T_StartReplicationCmd:
 			{
 				StartReplicationCmd *cmd = (StartReplicationCmd *) cmd_node;
diff --git a/src/include/nodes/replnodes.h b/src/include/nodes/replnodes.h
index 980e0b2ee2..b9c7ed61c6 100644
--- a/src/include/nodes/replnodes.h
+++ b/src/include/nodes/replnodes.h
@@ -33,16 +33,6 @@ typedef struct IdentifySystemCmd
 	NodeTag		type;
 } IdentifySystemCmd;
 
-/* ----------------------
- *		LIST_SLOTS command
- * ----------------------
- */
-typedef struct ListSlotsCmd
-{
-	NodeTag		type;
-	List	   *slot_names;
-} ListSlotsCmd;
-
 /* ----------------------
  *		BASE_BACKUP command
  * ----------------------
-- 
2.34.1