luaevent/src/luaevent.c

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