Refactor function parse_output_parameters.

Instead of using multiple parameters in parse_ouput_parameters function
signature, use the struct PGOutputData that encapsulates all pgoutput
options. It will be useful for future work where we need to add other
options in pgoutput.

Author: Euler Taveira
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CADK3HHJ-+9SO7KuRLH=9Wa1rAo60Yreq1GFNkH_kd0=CdaWM+A@mail.gmail.com

src/backend/replication/pgoutput/pgoutput.c

@@ -156,9 +156,7 @@ _PG_output_plugin_init(OutputPluginCallbacks *cb)
 }
 
 static void
-parse_output_parameters(List *options, uint32 *protocol_version,
-						List **publication_names, bool *binary,
-						bool *enable_streaming)
+parse_output_parameters(List *options, PGOutputData *data)
 {
 	ListCell   *lc;
 	bool		protocol_version_given = false;
@@ -166,7 +164,8 @@ parse_output_parameters(List *options, uint32 *protocol_version,
 	bool		binary_option_given = false;
 	bool		streaming_given = false;
 
-	*binary = false;
+	data->binary = false;
+	data->streaming = false;
 
 	foreach(lc, options)
 	{
@@ -196,7 +195,7 @@ parse_output_parameters(List *options, uint32 *protocol_version,
 						 errmsg("proto_version \"%s\" out of range",
 								strVal(defel->arg))));
 
-			*protocol_version = (uint32) parsed;
+			data->protocol_version = (uint32) parsed;
 		}
 		else if (strcmp(defel->defname, "publication_names") == 0)
 		{
@@ -207,7 +206,7 @@ parse_output_parameters(List *options, uint32 *protocol_version,
 			publication_names_given = true;
 
 			if (!SplitIdentifierString(strVal(defel->arg), ',',
-									   publication_names))
+									   &data->publication_names))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_NAME),
 						 errmsg("invalid publication_names syntax")));
@@ -220,7 +219,7 @@ parse_output_parameters(List *options, uint32 *protocol_version,
 						 errmsg("conflicting or redundant options")));
 			binary_option_given = true;
 
-			*binary = defGetBoolean(defel);
+			data->binary = defGetBoolean(defel);
 		}
 		else if (strcmp(defel->defname, "streaming") == 0)
 		{
@@ -230,7 +229,7 @@ parse_output_parameters(List *options, uint32 *protocol_version,
 						 errmsg("conflicting or redundant options")));
 			streaming_given = true;
 
-			*enable_streaming = defGetBoolean(defel);
+			data->streaming = defGetBoolean(defel);
 		}
 		else
 			elog(ERROR, "unrecognized pgoutput option: %s", defel->defname);
@@ -244,7 +243,6 @@ static void
 pgoutput_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
 				 bool is_init)
 {
-	bool		enable_streaming = false;
 	PGOutputData *data = palloc0(sizeof(PGOutputData));
 
 	/* Create our memory context for private allocations. */
@@ -265,11 +263,7 @@ pgoutput_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
 	if (!is_init)
 	{
 		/* Parse the params and ERROR if we see any we don't recognize */
-		parse_output_parameters(ctx->output_plugin_options,
-								&data->protocol_version,
-								&data->publication_names,
-								&data->binary,
-								&enable_streaming);
+		parse_output_parameters(ctx->output_plugin_options, data);
 
 		/* Check if we support requested protocol */
 		if (data->protocol_version > LOGICALREP_PROTO_MAX_VERSION_NUM)
@@ -295,7 +289,7 @@ pgoutput_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
 		 * we only allow it with sufficient version of the protocol, and when
 		 * the output plugin supports it.
 		 */
-		if (!enable_streaming)
+		if (!data->streaming)
 			ctx->streaming = false;
 		else if (data->protocol_version < LOGICALREP_PROTO_STREAM_VERSION_NUM)
 			ereport(ERROR,

src/include/replication/pgoutput.h

@@ -25,6 +25,7 @@ typedef struct PGOutputData
 	List	   *publication_names;
 	List	   *publications;
 	bool		binary;
+	bool		streaming;
 } PGOutputData;
 
 #endif							/* PGOUTPUT_H */