local multicast support

lualib-src/lua-multicast.c

@@ -0,0 +1,104 @@
+#include "skynet.h"
+
+#include <lua.h>
+#include <lauxlib.h>
+#include <stdint.h>
+
+struct mc_package {
+	int reference;
+	uint32_t size;
+	void *data;
+};
+
+/*
+	lightuserdata
+	integer size
+
+	return lightuserdata, sizeof(struct mc_package *)
+ */
+static int
+mc_packlocal(lua_State *L) {
+	void * data = lua_touserdata(L, 1);
+	size_t size = luaL_checkunsigned(L, 2);
+	if (size != (uint32_t)size) {
+		return luaL_error(L, "Size should be 32bit integer");
+	}
+	struct mc_package * pack = skynet_malloc(sizeof(struct mc_package));
+	pack->reference = 0;
+	pack->size = (uint32_t)size;
+	pack->data = data;
+	struct mc_package ** ret = skynet_malloc(sizeof(*ret));
+	*ret = pack;
+	lua_pushlightuserdata(L, ret);
+	lua_pushinteger(L, sizeof(ret));
+	return 2;
+}
+
+/*
+	lightuserdata struct mc_package **
+	integer size (must be sizeof(struct mc_package *)
+
+	return package, lightuserdata, size
+ */
+static int
+mc_unpacklocal(lua_State *L) {
+	struct mc_package ** pack = lua_touserdata(L,1);
+	int sz = luaL_checkinteger(L,2);
+	if (sz != sizeof(*pack)) {
+		return luaL_error(L, "Invalid multicast package size %d", sz);
+	}
+	lua_settop(L, 1);
+	lua_pushlightuserdata(L, (*pack)->data);
+	lua_pushunsigned(L, (*pack)->size);
+	return 3;
+}
+
+/*
+	lightuserdata struct mc_package **
+	integer reference
+ */
+static int
+mc_bindrefer(lua_State *L) {
+	struct mc_package ** pack = lua_touserdata(L,1);
+	int ref = luaL_checkinteger(L,2);
+	if ((*pack)->reference != 0) {
+		return luaL_error(L, "Can't bind a multicast package more than once");
+	}
+	(*pack)->reference = ref;
+
+	return 0;
+}
+
+/*
+	lightuserdata struct mc_package **
+ */
+static int
+mc_closelocal(lua_State *L) {
+	struct mc_package **ptr = lua_touserdata(L,1);
+	struct mc_package *pack = *ptr;
+
+	int ref = __sync_sub_and_fetch(&pack->reference, 1);
+	if (ref <= 0) {
+		skynet_free(pack->data);
+		skynet_free(pack);
+		if (ref < 0) {
+			return luaL_error(L, "Invalid multicast package reference %d", ref);
+		}
+	}
+
+	return 0;
+}
+
+int
+luaopen_multicast_c(lua_State *L) {
+	luaL_Reg l[] = {
+		{ "pack", mc_packlocal },
+		{ "unpack", mc_unpacklocal },
+		{ "bind", mc_bindrefer },
+		{ "close", mc_closelocal },
+		{ NULL, NULL },
+	};
+	luaL_checkversion(L);
+	luaL_newlib(L,l);
+	return 1;
+}