/***************************************************************************** * services_discovery.c : Services discovery using lua scripts ***************************************************************************** * Copyright (C) 2010 VideoLAN and AUTHORS * * Authors: Fabio Ritrovato * Rémi Duraffort * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include "vlc.h" #include "libs.h" /***************************************************************************** * Local prototypes *****************************************************************************/ static void *Run( void * ); static int DoSearch( services_discovery_t *p_sd, const char *psz_query ); static int FillDescriptor( services_discovery_t *, services_discovery_descriptor_t * ); static int Control( services_discovery_t *p_sd, int i_command, va_list args ); static const char * const ppsz_sd_options[] = { "sd", "longname", NULL }; /***************************************************************************** * Local structures *****************************************************************************/ struct services_discovery_sys_t { lua_State *L; char *psz_filename; vlc_thread_t thread; vlc_mutex_t lock; vlc_cond_t cond; char **ppsz_query; int i_query; }; static const luaL_Reg p_reg[] = { { NULL, NULL } }; /***************************************************************************** * Open: initialize and create stuff *****************************************************************************/ int Open_LuaSD( vlc_object_t *p_this ) { services_discovery_t *p_sd = ( services_discovery_t * )p_this; services_discovery_sys_t *p_sys; lua_State *L = NULL; char *psz_name; if( !strcmp( p_sd->psz_name, "lua" ) ) { // We want to load the module name "lua" // This module can be used to load lua script not registered // as builtin lua SD modules. config_ChainParse( p_sd, "lua-", ppsz_sd_options, p_sd->p_cfg ); psz_name = var_GetString( p_sd, "lua-sd" ); } else { // We are loading a builtin lua sd module. psz_name = strdup(p_sd->psz_name); } if( !( p_sys = malloc( sizeof( services_discovery_sys_t ) ) ) ) { free( psz_name ); return VLC_ENOMEM; } p_sd->p_sys = p_sys; p_sd->pf_control = Control; p_sys->psz_filename = vlclua_find_file( "sd", psz_name ); if( !p_sys->psz_filename ) { msg_Err( p_sd, "Couldn't find lua services discovery script \"%s\".", psz_name ); free( psz_name ); goto error; } free( psz_name ); L = luaL_newstate(); if( !L ) { msg_Err( p_sd, "Could not create new Lua State" ); goto error; } vlclua_set_this( L, p_sd ); luaL_openlibs( L ); luaL_register( L, "vlc", p_reg ); luaopen_input( L ); luaopen_msg( L ); luaopen_object( L ); luaopen_sd( L ); luaopen_strings( L ); luaopen_variables( L ); luaopen_stream( L ); luaopen_gettext( L ); luaopen_xml( L ); lua_pop( L, 1 ); if( vlclua_add_modules_path( L, p_sys->psz_filename ) ) { msg_Warn( p_sd, "Error while setting the module search path for %s", p_sys->psz_filename ); goto error; } if( luaL_dofile( L, p_sys->psz_filename ) ) { msg_Err( p_sd, "Error loading script %s: %s", p_sys->psz_filename, lua_tostring( L, lua_gettop( L ) ) ); lua_pop( L, 1 ); goto error; } p_sys->L = L; vlc_mutex_init( &p_sys->lock ); vlc_cond_init( &p_sys->cond ); TAB_INIT( p_sys->i_query, p_sys->ppsz_query ); if( vlc_clone( &p_sys->thread, Run, p_sd, VLC_THREAD_PRIORITY_LOW ) ) { TAB_CLEAN( p_sys->i_query, p_sys->ppsz_query ); vlc_cond_destroy( &p_sys->cond ); vlc_mutex_destroy( &p_sys->lock ); goto error; } return VLC_SUCCESS; error: if( L ) lua_close( L ); free( p_sys->psz_filename ); free( p_sys ); return VLC_EGENERIC; } /***************************************************************************** * Close: cleanup *****************************************************************************/ void Close_LuaSD( vlc_object_t *p_this ) { services_discovery_t *p_sd = ( services_discovery_t * )p_this; services_discovery_sys_t *p_sys = p_sd->p_sys; vlc_cancel( p_sys->thread ); vlc_join( p_sys->thread, NULL ); for( int i = 0; i < p_sys->i_query; i++ ) free( p_sys->ppsz_query[i] ); TAB_CLEAN( p_sys->i_query, p_sys->ppsz_query ); vlc_cond_destroy( &p_sys->cond ); vlc_mutex_destroy( &p_sys->lock ); free( p_sys->psz_filename ); lua_close( p_sys->L ); free( p_sys ); } /***************************************************************************** * Run: Thread entry-point ****************************************************************************/ static void* Run( void *data ) { services_discovery_t *p_sd = ( services_discovery_t * )data; services_discovery_sys_t *p_sys = p_sd->p_sys; lua_State *L = p_sys->L; int cancel = vlc_savecancel(); lua_getglobal( L, "main" ); if( !lua_isfunction( L, lua_gettop( L ) ) || lua_pcall( L, 0, 1, 0 ) ) { msg_Err( p_sd, "Error while running script %s, " "function main(): %s", p_sys->psz_filename, lua_tostring( L, lua_gettop( L ) ) ); lua_pop( L, 1 ); vlc_restorecancel( cancel ); return NULL; } msg_Dbg( p_sd, "LuaSD script loaded: %s", p_sys->psz_filename ); /* Force garbage collection, because the core will keep the SD * open, but lua will never gc until lua_close(). */ lua_gc( L, LUA_GCCOLLECT, 0 ); vlc_restorecancel( cancel ); /* Main loop to handle search requests */ vlc_mutex_lock( &p_sys->lock ); mutex_cleanup_push( &p_sys->lock ); for( ;; ) { /* Wait for a request */ if( !p_sys->i_query ) { vlc_cond_wait( &p_sys->cond, &p_sys->lock ); continue; } /* Execute one query (protected against cancellation) */ char *psz_query = p_sys->ppsz_query[p_sys->i_query - 1]; REMOVE_ELEM( p_sys->ppsz_query, p_sys->i_query, p_sys->i_query - 1 ); vlc_mutex_unlock( &p_sys->lock ); cancel = vlc_savecancel(); DoSearch( p_sd, psz_query ); free( psz_query ); /* Force garbage collection, because the core will keep the SD * open, but lua will never gc until lua_close(). */ lua_gc( L, LUA_GCCOLLECT, 0 ); vlc_restorecancel( cancel ); vlc_mutex_lock( &p_sys->lock ); } vlc_cleanup_run(); return NULL; } /***************************************************************************** * Control: services discrovery control ****************************************************************************/ static int Control( services_discovery_t *p_sd, int i_command, va_list args ) { services_discovery_sys_t *p_sys = p_sd->p_sys; switch( i_command ) { case SD_CMD_SEARCH: { const char *psz_query = va_arg( args, const char * ); vlc_mutex_lock( &p_sys->lock ); TAB_APPEND( p_sys->i_query, p_sys->ppsz_query, strdup( psz_query ) ); vlc_cond_signal( &p_sys->cond ); vlc_mutex_unlock( &p_sys->lock ); break; } case SD_CMD_DESCRIPTOR: { services_discovery_descriptor_t *p_desc = va_arg( args, services_discovery_descriptor_t * ); return FillDescriptor( p_sd, p_desc ); } } return VLC_SUCCESS; } /***************************************************************************** * DoSearch: search for a given query ****************************************************************************/ static int DoSearch( services_discovery_t *p_sd, const char *psz_query ) { services_discovery_sys_t *p_sys = p_sd->p_sys; lua_State *L = p_sys->L; /* Lookup for the 'search' function */ lua_getglobal( L, "search" ); if( !lua_isfunction( L, lua_gettop( L ) ) ) { msg_Err( p_sd, "The script '%s' does not define any 'search' function", p_sys->psz_filename ); lua_pop( L, 1 ); return VLC_EGENERIC; } /* Push the query */ lua_pushstring( L, psz_query ); /* Call the 'search' function */ if( lua_pcall( L, 1, 0, 0 ) ) { msg_Err( p_sd, "Error while running the script '%s': %s", p_sys->psz_filename, lua_tostring( L, lua_gettop( L ) ) ); lua_pop( L, 1 ); return VLC_EGENERIC; } return VLC_SUCCESS; } /** List of capabilities */ static const char *const ppsz_capabilities[] = { "search", NULL }; /***************************************************************************** * FillDescriptor: call the descriptor function and fill the structure ****************************************************************************/ static int FillDescriptor( services_discovery_t *p_sd, services_discovery_descriptor_t *p_desc ) { services_discovery_sys_t *p_sys = p_sd->p_sys; int i_ret = VLC_EGENERIC; /* Create a new lua thread */ lua_State *L = luaL_newstate(); if( luaL_dofile( L, p_sys->psz_filename ) ) { msg_Err( p_sd, "Error loading script %s: %s", p_sys->psz_filename, lua_tostring( L, -1 ) ); goto end; } /* Call the "descriptor" function */ lua_getglobal( L, "descriptor" ); if( !lua_isfunction( L, -1 ) || lua_pcall( L, 0, 1, 0 ) ) { msg_Warn( p_sd, "Error getting the descriptor in '%s': %s", p_sys->psz_filename, lua_tostring( L, -1 ) ); goto end; } /* Get the different fields of the returned table */ lua_getfield( L, -1, "short_description" ); p_desc->psz_short_desc = luaL_strdupornull( L, -1 ); lua_pop( L, 1 ); lua_getfield( L, -1, "icon" ); p_desc->psz_icon_url = luaL_strdupornull( L, -1 ); lua_pop( L, 1 ); lua_getfield( L, -1, "url" ); p_desc->psz_url = luaL_strdupornull( L, -1 ); lua_pop( L, 1 ); lua_getfield( L, -1, "capabilities" ); p_desc->i_capabilities = 0; if( lua_istable( L, -1 ) ) { /* List all table entries */ lua_pushnil( L ); while( lua_next( L, -2 ) != 0 ) { /* Key is at index -2 and value at index -1 */ const char *psz_cap = luaL_checkstring( L, -1 ); int i_cap = 0; const char *psz_iter; for( psz_iter = *ppsz_capabilities; psz_iter; psz_iter = ppsz_capabilities[ ++i_cap ] ) { if( !strcmp( psz_iter, psz_cap ) ) { p_desc->i_capabilities |= 1 << i_cap; break; } } lua_pop( L, 1 ); if( !psz_iter ) msg_Warn( p_sd, "Services discovery capability '%s' unknown in " "script '%s'", psz_cap, p_sys->psz_filename ); } } lua_pop( L, 1 ); i_ret = VLC_SUCCESS; end: lua_close( L ); return i_ret; }