modules/misc/lua/demux.c

   1 /*****************************************************************************
   2  * demux.c :  Lua playlist demux module
   3  *****************************************************************************
   4  * Copyright (C) 2007-2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Antoine Cellerier <dionoea at videolan tod org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <assert.h>
  32
  33 #include <vlc_common.h>
  34 #include <vlc_demux.h>
  35 #include <vlc_url.h>
  36 #include <vlc_strings.h>
  37
  38 #include "vlc.h"
  39 #include "libs.h"
  40 #include "libs/playlist.h"
  41
  42
  43 /*****************************************************************************
  44  * Local prototypes
  45  *****************************************************************************/
  46 static int Demux( demux_t *p_demux );
  47 static int Control( demux_t *p_demux, int i_query, va_list args );
  48
  49 /*****************************************************************************
  50  * Demux specific functions
  51  *****************************************************************************/
  52 struct demux_sys_t
  53 {
  54     lua_State *L;
  55     char *psz_filename;
  56 };
  57
  58 static int vlclua_demux_peek( lua_State *L )
  59 {
  60     demux_t *p_demux = (demux_t *)vlclua_get_this( L );
  61     int n = luaL_checkint( L, 1 );
  62     const uint8_t *p_peek;
  63     int i_peek = stream_Peek( p_demux->s, &p_peek, n );
  64     lua_pushlstring( L, (const char *)p_peek, i_peek );
  65     return 1;
  66 }
  67
  68 static int vlclua_demux_read( lua_State *L )
  69 {
  70     demux_t *p_demux = (demux_t *)vlclua_get_this( L );
  71     const uint8_t *p_read;
  72     int n = luaL_checkint( L, 1 );
  73     int i_read = stream_Peek( p_demux->s, &p_read, n );
  74     lua_pushlstring( L, (const char *)p_read, i_read );
  75     int i_seek = stream_Read( p_demux->s, NULL, i_read );
  76     assert(i_read==i_seek);
  77     return 1;
  78 }
  79
  80 static int vlclua_demux_readline( lua_State *L )
  81 {
  82     demux_t *p_demux = (demux_t *)vlclua_get_this( L );
  83     char *psz_line = stream_ReadLine( p_demux->s );
  84     if( psz_line )
  85     {
  86         lua_pushstring( L, psz_line );
  87         free( psz_line );
  88     }
  89     else
  90     {
  91         lua_pushnil( L );
  92     }
  93     return 1;
  94 }
  95
  96 /*****************************************************************************
  97  *
  98  *****************************************************************************/
  99 /* Functions to register */
 100 static const luaL_Reg p_reg[] =
 101 {
 102     { "peek", vlclua_demux_peek },
 103     { NULL, NULL }
 104 };
 105
 106 /* Functions to register for parse() function call only */
 107 static const luaL_Reg p_reg_parse[] =
 108 {
 109     { "read", vlclua_demux_read },
 110     { "readline", vlclua_demux_readline },
 111     { NULL, NULL }
 112 };
 113
 114 /*****************************************************************************
 115  * Called through lua_scripts_batch_execute to call 'probe' on
 116  * the script pointed by psz_filename.
 117  *****************************************************************************/
 118 static int probe_luascript( vlc_object_t *p_this, const char * psz_filename,
 119                             void * user_data )
 120 {
 121     VLC_UNUSED(user_data);
 122     demux_t * p_demux = (demux_t *)p_this;
 123
 124     p_demux->p_sys->psz_filename = strdup(psz_filename);
 125
 126     /* Initialise Lua state structure */
 127     lua_State *L = luaL_newstate();
 128     if( !L )
 129     {
 130         msg_Err( p_demux, "Could not create new Lua State" );
 131         goto error;
 132     }
 133     p_demux->p_sys->L = L;
 134
 135     /* Load Lua libraries */
 136     luaL_openlibs( L ); /* FIXME: Don't open all the libs? */
 137
 138     vlclua_set_this( L, p_demux );
 139     luaL_register( L, "vlc", p_reg );
 140     luaopen_msg( L );
 141     luaopen_strings( L );
 142     luaopen_stream( L );
 143     luaopen_xml( L );
 144     luaopen_md5( L );
 145     lua_pushstring( L, p_demux->psz_location );
 146     lua_setfield( L, -2, "path" );
 147     lua_pushstring( L, p_demux->psz_access );
 148     lua_setfield( L, -2, "access" );
 149
 150     lua_pop( L, 1 );
 151
 152     /* Setup the module search path */
 153     if( vlclua_add_modules_path( p_demux, L, psz_filename ) )
 154     {
 155         msg_Warn( p_demux, "Error while setting the module search path for %s",
 156                   psz_filename );
 157         goto error;
 158     }
 159
 160     /* Load and run the script(s) */
 161     if( luaL_dofile( L, psz_filename ) )
 162     {
 163         msg_Warn( p_demux, "Error loading script %s: %s", psz_filename,
 164                   lua_tostring( L, lua_gettop( L ) ) );
 165         goto error;
 166     }
 167
 168     lua_getglobal( L, "probe" );
 169
 170     if( !lua_isfunction( L, -1 ) )
 171     {
 172         msg_Warn( p_demux, "Error while running script %s, "
 173                   "function probe() not found", psz_filename );
 174         goto error;
 175     }
 176
 177     if( lua_pcall( L, 0, 1, 0 ) )
 178     {
 179         msg_Warn( p_demux, "Error while running script %s, "
 180                   "function probe(): %s", psz_filename,
 181                   lua_tostring( L, lua_gettop( L ) ) );
 182         goto error;
 183     }
 184
 185     if( lua_gettop( L ) )
 186     {
 187         if( lua_toboolean( L, 1 ) )
 188         {
 189             msg_Dbg( p_demux, "Lua playlist script %s's "
 190                      "probe() function was successful", psz_filename );
 191             lua_pop( L, 1 );
 192             return VLC_SUCCESS;
 193         }
 194     }
 195
 196 error:
 197     lua_pop( L, 1 );
 198     lua_close( p_demux->p_sys->L );
 199     p_demux->p_sys->L = NULL;
 200     FREENULL( p_demux->p_sys->psz_filename );
 201     return VLC_EGENERIC;
 202 }
 203
 204 /*****************************************************************************
 205  * Import_LuaPlaylist: main import function
 206  *****************************************************************************/
 207 int Import_LuaPlaylist( vlc_object_t *p_this )
 208 {
 209     demux_t *p_demux = (demux_t *)p_this;
 210     int ret;
 211
 212     p_demux->p_sys = calloc( 1, sizeof( demux_sys_t ) );
 213     if( !p_demux->p_sys )
 214         return VLC_ENOMEM;
 215
 216     p_demux->pf_control = Control;
 217     p_demux->pf_demux = Demux;
 218
 219     ret = vlclua_scripts_batch_execute( p_this, "playlist",
 220                                         &probe_luascript, NULL );
 221     if( ret )
 222         Close_LuaPlaylist( p_this );
 223     return ret;
 224 }
 225
 226
 227 /*****************************************************************************
 228  * Deactivate: frees unused data
 229  *****************************************************************************/
 230 void Close_LuaPlaylist( vlc_object_t *p_this )
 231 {
 232     demux_t *p_demux = (demux_t *)p_this;
 233     if( p_demux->p_sys->L )
 234         lua_close( p_demux->p_sys->L );
 235     free( p_demux->p_sys->psz_filename );
 236     free( p_demux->p_sys );
 237 }
 238
 239 static int Demux( demux_t *p_demux )
 240 {
 241     lua_State *L = p_demux->p_sys->L;
 242     char *psz_filename = p_demux->p_sys->psz_filename;
 243
 244     input_thread_t *p_input_thread = demux_GetParentInput( p_demux );
 245     input_item_t *p_current_input = input_GetItem( p_input_thread );
 246     playlist_t *p_playlist = pl_Get( p_demux );
 247
 248     luaL_register( L, "vlc", p_reg_parse );
 249
 250     lua_getglobal( L, "parse" );
 251
 252     if( !lua_isfunction( L, -1 ) )
 253     {
 254         msg_Warn( p_demux, "Error while running script %s, "
 255                   "function parse() not found", psz_filename );
 256         vlc_object_release( p_input_thread );
 257         return VLC_EGENERIC;
 258     }
 259
 260     if( lua_pcall( L, 0, 1, 0 ) )
 261     {
 262         msg_Warn( p_demux, "Error while running script %s, "
 263                   "function parse(): %s", psz_filename,
 264                   lua_tostring( L, lua_gettop( L ) ) );
 265         vlc_object_release( p_input_thread );
 266         return VLC_EGENERIC;
 267     }
 268
 269     if( lua_gettop( L ) )
 270         vlclua_playlist_add_internal( p_demux, L, p_playlist,
 271                                       p_current_input, 0 );
 272     else
 273         msg_Err( p_demux, "Script went completely foobar" );
 274
 275     vlc_object_release( p_input_thread );
 276
 277     return -1; /* Needed for correct operation of go back */
 278 }
 279
 280 static int Control( demux_t *p_demux, int i_query, va_list args )
 281 {
 282     VLC_UNUSED(p_demux); VLC_UNUSED(i_query); VLC_UNUSED(args);
 283     return VLC_EGENERIC;
 284 }