modules/client/sync: Add flush high-watermark conf item.

modules/client/sync.cc

@@ -89,6 +89,13 @@ sync_timeout_default
 	{ "default",  10 * 1000L                        },
 };
 
+conf::item<size_t>
+sync_flush_hiwat
+{
+	{ "name",     "ircd.client.sync.flush.hiwat" },
+	{ "default",  long(24_KiB)                   },
+};
+
 syncargs::syncargs(const resource::request &request)
 :filter_id
 {

modules/client/sync.int.h

@@ -10,6 +10,8 @@
 
 using namespace ircd;
 
+extern conf::item<size_t> sync_flush_hiwat;
+
 /// Argument parser for the client's /sync request
 struct syncargs
 {
@@ -85,7 +87,8 @@ struct shortpoll
 
 			response->write(buf);
 			return buf;
-		}
+		},
+		size_t(sync_flush_hiwat)
 	};
 
 	shortpoll(ircd::client &client,