[LEDE-DEV] [PATCH] Added publish/subscribe lua bindings with examples.
Iain Fraser
iainf at netduma.com
Thu May 19 04:01:19 PDT 2016
Signed-off-by: Iain Fraser <iainf at netduma.com>
---
lua/ubus.c | 233 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 232 insertions(+), 1 deletion(-)
diff --git a/lua/ubus.c b/lua/ubus.c
index 86e34b7..9941ef6 100644
--- a/lua/ubus.c
+++ b/lua/ubus.c
@@ -1,6 +1,7 @@
/*
* Copyright (C) 2012 Jo-Philipp Wich <jow at openwrt.org>
* Copyright (C) 2012 John Crispin <blogic at openwrt.org>
+ * Copyright (C) 2016 Iain Fraser <iainf at netduma.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1
@@ -33,6 +34,7 @@ struct ubus_lua_connection {
struct ubus_lua_object {
struct ubus_object o;
int r;
+ int rsubscriber;
};
struct ubus_lua_event {
@@ -40,6 +42,12 @@ struct ubus_lua_event {
int r;
};
+struct ubus_lua_subscriber {
+ struct ubus_subscriber s;
+ int rnotify;
+ int rremove;
+};
+
static int
ubus_lua_parse_blob(lua_State *L, struct blob_attr *attr, bool table);
@@ -412,6 +420,39 @@ static int ubus_lua_load_methods(lua_State *L, struct ubus_method *m)
return 0;
}
+static void
+ubus_new_sub_cb(struct ubus_context *ctx, struct ubus_object *obj){
+ struct ubus_lua_object *luobj;
+
+ luobj = container_of(obj, struct ubus_lua_object, o);
+
+ lua_getglobal(state, "__ubus_cb_publisher");
+ lua_rawgeti(state, -1, luobj->rsubscriber);
+ lua_remove(state, -2);
+
+ if (lua_isfunction(state, -1)) {
+ lua_pushnumber(state, luobj->o.has_subscribers );
+ lua_call(state, 1, 0);
+ } else {
+ lua_pop(state, 1);
+ }
+
+ return;
+}
+
+static void
+ubus_lua_load_newsub_cb( lua_State *L, struct ubus_lua_object *obj ){
+ /* keep ref to func */
+ lua_getglobal(L, "__ubus_cb_publisher");
+ lua_pushvalue(L, -2);
+ obj->rsubscriber = luaL_ref(L, -2);
+ lua_pop(L, 1);
+
+ /* real callback */
+ obj->o.subscribe_cb = ubus_new_sub_cb;
+ return;
+}
+
static struct ubus_object* ubus_lua_load_object(lua_State *L)
{
struct ubus_lua_object *obj = NULL;
@@ -454,6 +495,13 @@ static struct ubus_object* ubus_lua_load_object(lua_State *L)
/* scan each method */
lua_pushnil(L);
while (lua_next(L, -3) != 0) {
+ /* check if its the subscriber notification callback */
+ if( lua_type( L, -2 ) == LUA_TSTRING &&
+ lua_type( L, -1 ) == LUA_TFUNCTION ){
+ if( !strcmp( lua_tostring( L, -2 ), "__subscriber_cb" ) )
+ ubus_lua_load_newsub_cb( L, obj );
+ }
+
/* check if it looks like a method */
if ((lua_type(L, -2) != LUA_TSTRING) ||
(lua_type(L, -1) != LUA_TTABLE) ||
@@ -495,8 +543,14 @@ static int ubus_lua_add(lua_State *L)
if ((lua_type(L, -2) == LUA_TSTRING) && (lua_type(L, -1) == LUA_TTABLE)) {
obj = ubus_lua_load_object(L);
- if (obj)
+ if (obj){
ubus_add_object(c->ctx, obj);
+
+ /* allow future reference of ubus obj */
+ lua_pushstring(state,"__ubusobj");
+ lua_pushlightuserdata(state, obj);
+ lua_settable(state,-3);
+ }
}
lua_pop(L, 1);
}
@@ -504,6 +558,33 @@ static int ubus_lua_add(lua_State *L)
return 0;
}
+static int
+ubus_lua_notify( lua_State *L ){
+ struct ubus_lua_connection *c;
+ struct ubus_object *obj;
+ const char* method;
+
+ c = luaL_checkudata(L, 1, METANAME);
+ method = luaL_checkstring(L, 3);
+ luaL_checktype(L, 4, LUA_TTABLE);
+
+ if( !lua_islightuserdata( L, 2 ) ){
+ lua_pushfstring( L, "Invald 2nd parameter, expected ubus obj ref" );
+ lua_error( L );
+ }
+ obj = lua_touserdata( L, 2 );
+
+ /* create parameters from table */
+ blob_buf_init(&c->buf, 0);
+ if( !ubus_lua_format_blob_array( L, &c->buf, true ) ){
+ lua_pushfstring( L, "Invalid 4th parameter, expected table of arguments" );
+ lua_error( L );
+ }
+
+ ubus_notify( c->ctx, obj, method, c->buf.head, -1 );
+ return 0;
+}
+
static void
ubus_lua_signatures_cb(struct ubus_context *c, struct ubus_object_data *o, void *p)
{
@@ -653,6 +734,147 @@ ubus_lua_listen(lua_State *L) {
return 0;
}
+static void
+ubus_sub_remove_handler(struct ubus_context *ctx, struct ubus_subscriber *s,
+ uint32_t id) {
+ struct ubus_lua_subscriber *sub;
+
+ sub = container_of(s, struct ubus_lua_subscriber, s);
+
+ lua_getglobal(state, "__ubus_cb_subscribe");
+ lua_rawgeti(state, -1, sub->rremove);
+ lua_remove(state, -2);
+
+ if (lua_isfunction(state, -1)) {
+ lua_call(state, 0, 0);
+ } else {
+ lua_pop(state, 1);
+ }
+
+ return;
+}
+
+static int
+ubus_sub_notify_handler(struct ubus_context *ctx, struct ubus_object *obj,
+ struct ubus_request_data *req, const char *method,
+ struct blob_attr *msg){
+
+ struct ubus_subscriber *s;
+ struct ubus_lua_subscriber *sub;
+
+ s = container_of(obj, struct ubus_subscriber, obj);
+ sub = container_of(s, struct ubus_lua_subscriber, s);
+
+ lua_getglobal(state, "__ubus_cb_subscribe");
+ lua_rawgeti(state, -1, sub->rnotify);
+ lua_remove(state, -2);
+
+ if (lua_isfunction(state, -1)) {
+ if( msg ){
+ ubus_lua_parse_blob_array(state, blob_data(msg), blob_len(msg), true);
+ lua_call(state, 1, 0);
+ } else {
+ lua_call(state, 0, 0);
+ }
+ } else {
+ lua_pop(state, 1);
+ }
+
+ return 0;
+}
+
+
+
+static void
+ubus_lua_do_subscribe( struct ubus_context *ctx, lua_State *L, const char* target,
+ int idxnotify, int idxremove ){
+ uint32_t id;
+ int status;
+ struct ubus_lua_subscriber *sub;
+
+ if( ( status = ubus_lookup_id( ctx, target, &id ) ) ){
+ lua_pushfstring( L, "Unable find target, status=%d", status );
+ lua_error( L );
+ }
+
+ sub = malloc( sizeof( struct ubus_lua_subscriber ) );
+ memset( sub, 0, sizeof( struct ubus_lua_subscriber ) );
+ if( !sub ){
+ lua_pushstring( L, "Out of memory" );
+ lua_error( L );
+ }
+
+ if( idxnotify ){
+ /* update the he callback lookup table */
+ lua_getglobal(L, "__ubus_cb_subscribe");
+ lua_pushvalue(L, idxnotify);
+ sub->rnotify = luaL_ref(L, -2);
+ lua_pop(L, 1);
+ sub->s.cb = ubus_sub_notify_handler;
+
+ }
+
+ if( idxremove ){
+ lua_getglobal(L, "__ubus_cb_subscribe");
+ lua_pushvalue(L, idxnotify);
+ sub->rnotify = luaL_ref(L, -2);
+ lua_pop(L, 1);
+ sub->s.remove_cb = ubus_sub_remove_handler;
+ }
+
+ if( ( status = ubus_register_subscriber( ctx, &sub->s ) ) ){
+ lua_pushfstring( L, "Failed to register subscriber, status=%d", status );
+ lua_error( L );
+ }
+
+ if( ( status = ubus_subscribe( ctx, &sub->s, id) ) ){
+ lua_pushfstring( L, "Failed to register subscriber, status=%d", status );
+ lua_error( L );
+ }
+
+ return;
+}
+
+static int
+ubus_lua_subscribe(lua_State *L) {
+ int idxnotify, idxremove, stackstart;
+ struct ubus_lua_connection *c;
+ const char* target;
+
+ idxnotify = idxremove = 0;
+ stackstart = lua_gettop( L );
+
+
+ c = luaL_checkudata(L, 1, METANAME);
+ target = luaL_checkstring(L, 2);
+ luaL_checktype(L, 3, LUA_TTABLE);
+
+
+ lua_pushstring( L, "notify");
+ lua_gettable( L, 3 );
+ if( lua_type( L, -1 ) == LUA_TFUNCTION ){
+ idxnotify = lua_gettop( L );
+ } else {
+ lua_pop( L, 1 );
+ }
+
+ lua_pushstring( L, "remove");
+ lua_gettable( L, 3 );
+ if( lua_type( L, -1 ) == LUA_TFUNCTION ){
+ idxremove = lua_gettop( L );
+ } else {
+ lua_pop( L, 1 );
+ }
+
+ if( idxnotify )
+ ubus_lua_do_subscribe( c->ctx, L, target, idxnotify, idxremove );
+
+ if( lua_gettop( L ) > stackstart )
+ lua_pop( L, lua_gettop( L ) - stackstart );
+
+ return 0;
+}
+
static int
ubus_lua_send(lua_State *L)
{
@@ -699,12 +921,14 @@ static const luaL_Reg ubus[] = {
{ "connect", ubus_lua_connect },
{ "objects", ubus_lua_objects },
{ "add", ubus_lua_add },
+ { "notify", ubus_lua_notify },
{ "reply", ubus_lua_reply },
{ "signatures", ubus_lua_signatures },
{ "call", ubus_lua_call },
{ "close", ubus_lua__gc },
{ "listen", ubus_lua_listen },
{ "send", ubus_lua_send },
+ { "subscribe", ubus_lua_subscribe },
{ "__gc", ubus_lua__gc },
{ NULL, NULL },
};
@@ -758,5 +982,12 @@ luaopen_ubus(lua_State *L)
lua_createtable(L, 1, 0);
lua_setglobal(L, "__ubus_cb_event");
+ /* create the subscriber table */
+ lua_createtable(L, 1, 0);
+ lua_setglobal(L, "__ubus_cb_subscribe");
+
+ /* create the publisher table - notifications of new subs */
+ lua_createtable(L, 1, 0);
+ lua_setglobal(L, "__ubus_cb_publisher");
return 0;
}
--
1.7.9.5
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