ruleset: add aux function for async request processing

Signed-off-by: He Xian <[email protected]>

src/ruleset/base.c

@@ -293,12 +293,23 @@ int aux_resume(lua_State *restrict L, lua_State *restrict from, const int narg)
 	int status, nres;
 #if LUA_VERSION_NUM >= 504
 	status = lua_resume(L, from, narg, &nres);
-#elif LUA_VERSION_NUM == 503
+#else
 	status = lua_resume(L, from, narg);
 #endif
 	return status;
 }
 
+int aux_async(
+	lua_State *restrict L, lua_State *restrict from, const int narg,
+	const int finishidx)
+{
+	lua_pushvalue(from, finishidx);
+	lua_xmove(from, L, 1);
+	lua_pushnil(L);
+	lua_xmove(from, L, 1 + narg);
+	return aux_resume(L, from, 3 + narg);
+}
+
 static bool ruleset_pcallv(
 	lua_State *restrict L, const lua_CFunction func, const int nargs,
 	const int nresults, va_list args)

src/ruleset/base.h

@@ -68,9 +68,12 @@ bool aux_todialreq(lua_State *L, int n);
 
 int aux_traceback(lua_State *L);
 
-/* co stack: finish ? func ...(narg) */
+/* [-narg, +0, -] */
 int aux_resume(lua_State *L, lua_State *from, int narg);
 
+/* [-(narg+1), +(0|1), -] */
+int aux_async(lua_State *L, lua_State *from, int narg, int finishidx);
+
 /* main routine */
 bool ruleset_pcall(
 	struct ruleset *r, lua_CFunction func, int nargs, int nresults, ...);

src/ruleset/cfunc.c

@@ -110,17 +110,14 @@ int cfunc_request(lua_State *restrict L)
 	lua_pushcclosure(L, request_finish, 1);
 	(void)lua_getglobal(L, "ruleset");
 	(void)lua_getfield(L, -1, func);
-	lua_pushnil(L);
-	lua_replace(L, -3);
 	lua_pushstring(L, request);
 	lua_pushstring(L, username);
 	lua_pushstring(L, password);
-	lua_xmove(L, co, 6);
-	/* lua stack: state co; co stack: finish nil func request username password */
+	/* lua stack: state co finish ruleset func request username password */
 
 	state->request = *in_cb;
 	*pstate = state;
-	const int status = aux_resume(co, L, 6);
+	const int status = aux_async(co, L, 3, -6);
 	if (status != LUA_OK && status != LUA_YIELD) {
 		lua_xmove(co, L, 1);
 		return lua_error(L);
@@ -218,7 +215,6 @@ int cfunc_rpcall(lua_State *restrict L)
 	lua_State *restrict co = aux_getthread(L);
 	lua_pushvalue(L, 1);
 	lua_pushcclosure(L, rpcall_finish, 1);
-	lua_pushnil(L);
 	if (lua_load(L, aux_reader, stream, "=(rpc)", "t")) {
 		return lua_error(L);
 	}
@@ -231,12 +227,11 @@ int cfunc_rpcall(lua_State *restrict L)
 	const char *upvalue = lua_setupvalue(L, -2, 1);
 	ASSERT(upvalue != NULL && strcmp(upvalue, "_ENV") == 0);
 	UNUSED(upvalue);
-	lua_xmove(L, co, 3);
-	/* lua stack: state co; co stack: finish nil chunk */
+	/* lua stack: state co finish chunk */
 
 	state->rpcall = *in_cb;
 	*pstate = state;
-	const int status = aux_resume(co, L, 3);
+	const int status = aux_async(co, L, 0, -2);
 	if (status != LUA_OK && status != LUA_YIELD) {
 		lua_xmove(co, L, 1);
 		return lua_error(L);