Introduce multipart argument

src/tus_servers.h

@@ -49,6 +49,7 @@ struct VPFX(tus_server) {
 	char					*basedir;
 	char					*schemeauth;
 	VCL_BYTES				max;
+	VCL_BYTES				multipart;
 	VCL_DURATION				expires;
 	int					basefd;
 	struct tus_files			files[1];

src/vmod_tus.c

@@ -263,6 +263,7 @@ tus_server__init(VRT_CTX, struct VPFX(tus_server) **tussrvp,
 		return;
 
 	tussrv->max = args->max;
+	tussrv->multipart = args->multipart;
 	tussrv->expires = args->expires;
 	tussrv->digest = d;
 

src/vmod_tus.vcc

@@ -113,7 +113,8 @@ $Object server(
     BYTES max=1073741824,
     DURATION expires=86400,
     [STRING basedir],
-    [STRING name_hash])
+    [STRING name_hash],
+    BYTES multipart=5242880)
 
 Declare a tus server at the given ``schemeauth``, which is the
 protocol and servername, like ``https://tus.io``.
@@ -153,6 +154,10 @@ as the last part of the url when constructing the backend ``PUT``. For
 ``Upload-Concat: final`` uploads, this name is also used as the
 ``Location`` returned to the client.
 
+The ``multipart`` argument specifies the size of multipart uploads:
+For each chunk of this size, a separate backend request will be
+issued.
+
 $Method BOOL .recv([STRING url], [STRING id])
 
 Process a tus request.