modules/misc/lua/services_discovery.c

   1 /*****************************************************************************
   2  * services_discovery.c : Services discovery using lua scripts
   3  *****************************************************************************
   4  * Copyright (C) 2009 VideoLAN and AUTHORS
   5  *
   6  * Authors: Fabio Ritrovato <sephiroth87 at videolan dot org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <vlc_common.h>
  28 #include <vlc_services_discovery.h>
  29
  30 #include "vlc.h"
  31 #include "libs.h"
  32
  33 /*****************************************************************************
  34  * Local prototypes
  35  *****************************************************************************/
  36 static void *Run( void * );
  37
  38 static const char * const ppsz_sd_options[] = { "sd", "longname", NULL };
  39
  40 /*****************************************************************************
  41  * Local structures
  42  *****************************************************************************/
  43 struct services_discovery_sys_t
  44 {
  45     lua_State *L;
  46     char *psz_filename;
  47     vlc_thread_t thread;
  48 };
  49 static const luaL_Reg p_reg[] = { { NULL, NULL } };
  50
  51 /*****************************************************************************
  52  * Open: initialize and create stuff
  53  *****************************************************************************/
  54 int Open_LuaSD( vlc_object_t *p_this )
  55 {
  56     services_discovery_t *p_sd = ( services_discovery_t * )p_this;
  57     services_discovery_sys_t *p_sys;
  58     lua_State *L = NULL;
  59     char *psz_name = NULL;
  60
  61     if( !strcmp(p_sd->psz_name, "lua"))
  62     {
  63         // We want to load the module name "lua"
  64         // This module can be used to load lua script not registered
  65         // as builtin lua SD modules.
  66         config_ChainParse( p_sd, "lua-", ppsz_sd_options, p_sd->p_cfg );
  67         psz_name = var_CreateGetString( p_sd, "lua-sd" );
  68     }
  69     else
  70     {
  71         // We are loading a builtin lua sd module.
  72         psz_name = strdup(p_sd->psz_name);
  73     }
  74
  75     if( !( p_sys = malloc( sizeof( services_discovery_sys_t ) ) ) )
  76     {
  77         free( psz_name );
  78         return VLC_ENOMEM;
  79     }
  80     p_sd->p_sys = p_sys;
  81     p_sys->psz_filename = vlclua_find_file( p_this, "sd", psz_name );
  82     if( !p_sys->psz_filename )
  83     {
  84         msg_Err( p_sd, "Couldn't find lua services discovery script \"%s\".",
  85                  psz_name );
  86         free( psz_name );
  87         goto error;
  88     }
  89     free( psz_name );
  90     L = luaL_newstate();
  91     if( !L )
  92     {
  93         msg_Err( p_sd, "Could not create new Lua State" );
  94         goto error;
  95     }
  96     vlclua_set_this( L, p_sd );
  97     luaL_openlibs( L );
  98     luaL_register( L, "vlc", p_reg );
  99     luaopen_input( L );
 100     luaopen_msg( L );
 101     luaopen_misc( L );
 102     luaopen_net( L );
 103     luaopen_object( L );
 104     luaopen_sd( L );
 105     luaopen_strings( L );
 106     luaopen_variables( L );
 107     luaopen_stream( L );
 108     luaopen_gettext( L );
 109     luaopen_xml( L );
 110     luaopen_md5( L );
 111     lua_pop( L, 1 );
 112
 113     if( vlclua_add_modules_path( p_sd, L, p_sys->psz_filename ) )
 114     {
 115         msg_Warn( p_sd, "Error while setting the module search path for %s",
 116                   p_sys->psz_filename );
 117         goto error;
 118     }
 119     if( luaL_dofile( L, p_sys->psz_filename ) )
 120     {
 121
 122         msg_Err( p_sd, "Error loading script %s: %s", p_sys->psz_filename,
 123                   lua_tostring( L, lua_gettop( L ) ) );
 124         lua_pop( L, 1 );
 125         goto error;
 126     }
 127     p_sys->L = L;
 128     if( vlc_clone (&p_sd->p_sys->thread, Run, p_sd, VLC_THREAD_PRIORITY_LOW) )
 129     {
 130         goto error;
 131     }
 132     return VLC_SUCCESS;
 133 error:
 134     if( L )
 135         lua_close( L );
 136     free( p_sys->psz_filename );
 137     free( p_sys );
 138     return VLC_EGENERIC;
 139 }
 140
 141 /*****************************************************************************
 142  * Close: cleanup
 143  *****************************************************************************/
 144 void Close_LuaSD( vlc_object_t *p_this )
 145 {
 146     services_discovery_t *p_sd = ( services_discovery_t * )p_this;
 147
 148     vlc_join (p_sd->p_sys->thread, NULL);
 149     free( p_sd->p_sys->psz_filename );
 150     lua_close( p_sd->p_sys->L );
 151     free( p_sd->p_sys );
 152 }
 153
 154 /*****************************************************************************
 155  * Run: Thread entry-point
 156  ****************************************************************************/
 157 static void* Run( void *data )
 158 {
 159     services_discovery_t *p_sd = ( services_discovery_t * )data;
 160     services_discovery_sys_t *p_sys = p_sd->p_sys;
 161     lua_State *L = p_sys->L;
 162
 163     lua_getglobal( L, "main" );
 164     if( !lua_isfunction( L, lua_gettop( L ) ) || lua_pcall( L, 0, 1, 0 ) )
 165     {
 166         msg_Err( p_sd, "Error while running script %s, "
 167                   "function main(): %s", p_sys->psz_filename,
 168                   lua_tostring( L, lua_gettop( L ) ) );
 169         lua_pop( L, 1 );
 170         return NULL;
 171     }
 172     msg_Dbg( p_sd, "LuaSD script loaded: %s", p_sys->psz_filename );
 173
 174     /* Force garbage collection, because the core will keep the SD
 175      * open, but lua will never gc until lua_close(). */
 176     lua_gc( L, LUA_GCCOLLECT, 0 );
 177
 178     return NULL;
 179 }