src/luaevent.c

   1 /* LuaEvent - Copyright (C) 2007 Thomas Harning <harningt@gmail.com>
   2  * Licensed as LGPL - See doc/COPYING for details */
   3
   4 #include "luaevent.h"
   5
   6 #include <lua.h>
   7 #include <lauxlib.h>
   8 #include <assert.h>
   9
  10 #define EVENT_BASE_MT "EVENT_BASE_MT"
  11 #define EVENT_CALLBACK_ARG_MT "EVENT_CALLBACK_ARG_MT"
  12
  13 int luaevent_newbase(lua_State* L) {
  14         le_base *base = (le_base*)lua_newuserdata(L, sizeof(le_base));
  15         base->loop_L = NULL; /* No running loop */
  16         base->base = event_init();
  17         luaL_getmetatable(L, EVENT_BASE_MT);
  18         lua_setmetatable(L, -2);
  19         return 1;
  20 }
  21
  22 void freeCallbackArgs(le_callback* arg, lua_State* L) {
  23         if(arg->base) {
  24                 arg->base = NULL;
  25                 event_del(&arg->ev);
  26                 luaL_unref(L, LUA_REGISTRYINDEX, arg->callbackRef);
  27         }
  28 }
  29 /* le_callback is allocated at the beginning of the coroutine in which it
  30 is used, no need to manually de-allocate */
  31
  32 /* Index for coroutine is fd as integer for *nix, as lightuserdata for Win */
  33 static void luaevent_callback(int fd, short event, void* p) {
  34         le_callback* arg = p;
  35         lua_State* L;
  36         int ret;
  37         assert(arg && arg->base && arg->base->loop_L);
  38         L = arg->base->loop_L;
  39         lua_rawgeti(L, LUA_REGISTRYINDEX, arg->callbackRef);
  40         lua_pushinteger(L, event);
  41         lua_call(L, 1, 1);
  42         ret = lua_tointeger(L, -1);
  43         lua_pop(L, 1);
  44         if(ret == -1) {
  45                 freeCallbackArgs(arg, L);
  46         } else {
  47                 struct event *ev = &arg->ev;
  48                 int newEvent = ret;
  49                 if(newEvent != event) { // Need to hook up new event...
  50                         event_del(ev);
  51                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, arg);
  52                         event_add(ev, NULL);
  53                 }
  54         }
  55 }
  56
  57 static int luaevent_base_gc(lua_State* L) {
  58         le_base *base = luaL_checkudata(L, 1, EVENT_BASE_MT);
  59         if(base->base) {
  60                 event_base_free(base->base);
  61                 base->base = NULL;
  62         }
  63         return 0;
  64 }
  65
  66 static int luaevent_cb_gc(lua_State* L) {
  67         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  68         freeCallbackArgs(arg, L);
  69         return 0;
  70 }
  71
  72 int getSocketFd(lua_State* L, int idx) {
  73         int fd;
  74         luaL_checktype(L, idx, LUA_TUSERDATA);
  75         lua_getfield(L, idx, "getfd");
  76         if(lua_isnil(L, -1))
  77                 return luaL_error(L, "Socket type missing 'getfd' method");
  78         lua_pushvalue(L, idx);
  79         lua_call(L, 1, 1);
  80         fd = lua_tointeger(L, -1);
  81         lua_pop(L, 1);
  82         return fd;
  83 }
  84
  85 /* sock, event, callback */
  86 static int luaevent_addevent(lua_State* L) {
  87         int fd, event, callbackRef;
  88         le_callback* arg;
  89         le_base *base = luaL_checkudata(L, 1, EVENT_BASE_MT);
  90         fd = getSocketFd(L, 2);
  91         event = luaL_checkinteger(L, 3);
  92         luaL_checktype(L, 4, LUA_TFUNCTION);
  93         lua_pushvalue(L, 4);
  94         callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
  95         arg = lua_newuserdata(L, sizeof(*arg));
  96         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
  97         lua_setmetatable(L, -2);
  98
  99         arg->base = base;
 100         arg->callbackRef = callbackRef;
 101         /* Setup event... */
 102         event_set(&arg->ev, fd, event | EV_PERSIST, luaevent_callback, arg);
 103         event_base_set(base->base, &arg->ev);
 104         event_add(&arg->ev, NULL);
 105         return 1;
 106 }
 107
 108 static int luaevent_loop(lua_State* L) {
 109         le_base *base = luaL_checkudata(L, 1, EVENT_BASE_MT);
 110         base->loop_L = L;
 111         int ret = event_base_loop(base->base, 0);
 112         lua_pushinteger(L, ret);
 113         return 1;
 114 }
 115
 116 static luaL_Reg base_funcs[] = {
 117         { "addevent", luaevent_addevent },
 118         { "loop", luaevent_loop },
 119         { NULL, NULL }
 120 };
 121
 122 static luaL_Reg funcs[] = {
 123         { "new", luaevent_newbase },
 124         { NULL, NULL }
 125 };
 126
 127 typedef struct {
 128         const char* name;
 129         int value;
 130 } namedInteger;
 131
 132 static namedInteger consts[] = {
 133         {"LEAVE", -1},
 134         {"EV_READ", EV_READ},
 135         {"EV_WRITE", EV_WRITE},
 136         {NULL, 0}
 137 };
 138
 139 void setNamedIntegers(lua_State* L, namedInteger* p) {
 140         while(p->name) {
 141                 lua_pushinteger(L, p->value);
 142                 lua_setfield(L, -2, p->name);
 143                 p++;
 144         }
 145 }
 146
 147 /* Verified ok */
 148 int luaopen_luaevent_core(lua_State* L) {
 149         /* Setup metatable */
 150         luaL_newmetatable(L, EVENT_BASE_MT);
 151         lua_newtable(L);
 152         luaL_register(L, NULL, base_funcs);
 153         lua_setfield(L, -2, "__index");
 154         lua_pushcfunction(L, luaevent_base_gc);
 155         lua_setfield(L, -2, "__gc");
 156         lua_pop(L, 1);
 157         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
 158         lua_pushcfunction(L, luaevent_cb_gc);
 159         lua_setfield(L, -2, "__gc");
 160         lua_newtable(L);
 161         lua_pushcfunction(L, luaevent_cb_gc);
 162         lua_setfield(L, -2, "close");
 163         lua_setfield(L, -2, "__index");
 164         lua_pop(L, 1);
 165
 166         luaL_register(L, "luaevent.core", funcs);
 167         setNamedIntegers(L, consts);
 168         return 1;
 169 }