modules.c

VLC Player Source Code

/*****************************************************************************
 * modules.c : Builtin and plugin modules management functions
 *****************************************************************************
 * Copyright (C) 2001-2007 the VideoLAN team
 * $Id: 9ff601b3a6aa5916a564b14758292fdc99d412df $
 *
 * Authors: Sam Hocevar <[e-mail]>
 *          Ethan C. Baldridge <[e-mail]>
 *          Hans-Peter Jansen <[e-mail]>
 *          Gildas Bazin <[e-mail]>
 *
 * 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 <vlc_common.h>
#include <vlc_plugin.h>
#include "libvlc.h"

/* Some faulty libcs have a broken struct dirent when _FILE_OFFSET_BITS
 * is set to 64. Don't try to be cleverer. */
#ifdef _FILE_OFFSET_BITS
#undef _FILE_OFFSET_BITS
#endif

#include <stdlib.h>                                      /* free(), strtol() */
#include <stdio.h>                                              /* sprintf() */
#include <string.h>                                              /* strdup() */
#include <assert.h>

#ifdef HAVE_DIRENT_H
#   include <dirent.h>
#endif

#ifdef HAVE_SYS_TYPES_H
#   include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#   include <sys/stat.h>
#endif
#ifdef HAVE_UNISTD_H
#   include <unistd.h>
#endif

#if !defined(HAVE_DYNAMIC_PLUGINS)
    /* no support for plugins */
#elif defined(HAVE_DL_DYLD)
#   if defined(HAVE_MACH_O_DYLD_H)
#       include <mach-o/dyld.h>
#   endif
#elif defined(HAVE_DL_BEOS)
#   if defined(HAVE_IMAGE_H)
#       include <image.h>
#   endif
#elif defined(HAVE_DL_WINDOWS)
#   include <windows.h>
#elif defined(HAVE_DL_DLOPEN)
#   if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */
#       include <dlfcn.h>
#   endif
#   if defined(HAVE_SYS_DL_H)
#       include <sys/dl.h>
#   endif
#elif defined(HAVE_DL_SHL_LOAD)
#   if defined(HAVE_DL_H)
#       include <dl.h>
#   endif
#endif

#include "config/configuration.h"

#include "vlc_charset.h"
#include "vlc_arrays.h"

#include "modules/modules.h"
#include "modules/builtin.h"

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
#ifdef HAVE_DYNAMIC_PLUGINS
static void AllocateAllPlugins  ( vlc_object_t * );
static void AllocatePluginDir   ( vlc_object_t *, const char *, int );
static int  AllocatePluginFile  ( vlc_object_t *, char *, int64_t, int64_t );
static module_t * AllocatePlugin( vlc_object_t *, char * );
#endif
static int  AllocateBuiltinModule( vlc_object_t *, int ( * ) ( module_t * ) );
static void DeleteModule ( module_t *, bool );
#ifdef HAVE_DYNAMIC_PLUGINS
static void   DupModule        ( module_t * );
static void   UndupModule      ( module_t * );
#endif

/**
 * Init bank
 *
 * Creates a module bank structure which will be filled later
 * on with all the modules found.
 * \param p_this vlc object structure
 * \return nothing
 */
void __module_InitBank( vlc_object_t *p_this )
{
    module_bank_t *p_bank = NULL;
    libvlc_global_data_t *p_libvlc_global = vlc_global();

    vlc_mutex_t *lock = var_AcquireMutex( "libvlc" );

    if( p_libvlc_global->p_module_bank == NULL )
    {
        p_bank = vlc_custom_create( p_this, sizeof(module_bank_t),
                                    VLC_OBJECT_GENERIC, "module bank");
        p_bank->i_usage = 1;
        p_bank->i_cache = p_bank->i_loaded_cache = 0;
        p_bank->pp_cache = p_bank->pp_loaded_cache = NULL;
        p_bank->b_cache = p_bank->b_cache_dirty =
        p_bank->b_cache_delete = false;

        /* Everything worked, attach the object */
        p_libvlc_global->p_module_bank = p_bank;
        vlc_object_attach( p_bank, p_libvlc_global );

        /* Fills the module bank structure with the main module infos.
         * This is very useful as it will allow us to consider the main
         * library just as another module, and for instance the configuration
         * options of main will be available in the module bank structure just
         * as for every other module. */
        AllocateBuiltinModule( p_this, vlc_entry__main );
    }
    else
        p_libvlc_global->p_module_bank->i_usage++;

    vlc_mutex_unlock( lock );
}


/**
 * End bank
 *
 * Unloads all unused plugin modules and empties the module
 * bank in case of success.
 * \param p_this vlc object structure
 * \return nothing
 */
void __module_EndBank( vlc_object_t *p_this )
{
    module_t * p_next = NULL;
    libvlc_global_data_t *p_libvlc_global = vlc_global();

    vlc_mutex_t *lock = var_AcquireMutex( "libvlc" );
    if( !p_libvlc_global->p_module_bank )
    {
        vlc_mutex_unlock( lock );
        return;
    }
    if( --p_libvlc_global->p_module_bank->i_usage )
    {
        vlc_mutex_unlock( lock );
        return;
    }
    vlc_mutex_unlock( lock );

    /* Save the configuration */
    config_AutoSaveConfigFile( p_this );

#ifdef HAVE_DYNAMIC_PLUGINS
# define p_bank p_libvlc_global->p_module_bank
    if( p_bank->b_cache ) CacheSave( p_this );
    while( p_bank->i_loaded_cache-- )
    {
        if( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] )
        {
            DeleteModule(
                    p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->p_module,
                    p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->b_used );
            free( p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->psz_file );
            free( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] );
            p_bank->pp_loaded_cache[p_bank->i_loaded_cache] = NULL;
        }
    }
    if( p_bank->pp_loaded_cache )
    {
        free( p_bank->pp_loaded_cache );
        p_bank->pp_loaded_cache = NULL;
    }
    while( p_bank->i_cache-- )
    {
        free( p_bank->pp_cache[p_bank->i_cache]->psz_file );
        free( p_bank->pp_cache[p_bank->i_cache] );
        p_bank->pp_cache[p_bank->i_cache] = NULL;
    }
    if( p_bank->pp_cache )
    {
        free( p_bank->pp_cache );
        p_bank->pp_cache = NULL;
    }
# undef p_bank
#endif

    vlc_object_detach( p_libvlc_global->p_module_bank );

    while( vlc_internals( p_libvlc_global->p_module_bank )->i_children )
    {
        p_next = (module_t *)vlc_internals( p_libvlc_global->p_module_bank )->pp_children[0];
        DeleteModule( p_next, true );
    }

    vlc_object_release( p_libvlc_global->p_module_bank );
    p_libvlc_global->p_module_bank = NULL;
}

/**
 * Load all modules which we built with.
 *
 * Fills the module bank structure with the builtin modules.
 * \param p_this vlc object structure
 * \return nothing
 */
void __module_LoadBuiltins( vlc_object_t * p_this )
{
    libvlc_global_data_t *p_libvlc_global = vlc_global();

    vlc_mutex_t *lock = var_AcquireMutex( "libvlc" );
    if( p_libvlc_global->p_module_bank->b_builtins )
    {
        vlc_mutex_unlock( lock );
        return;
    }
    p_libvlc_global->p_module_bank->b_builtins = true;
    vlc_mutex_unlock( lock );

    msg_Dbg( p_this, "checking builtin modules" );
    ALLOCATE_ALL_BUILTINS();
}

/**
 * Load all plugins
 *
 * Load all plugin modules we can find.
 * Fills the module bank structure with the plugin modules.
 * \param p_this vlc object structure
 * \return nothing
 */
void __module_LoadPlugins( vlc_object_t * p_this )
{
#ifdef HAVE_DYNAMIC_PLUGINS
    libvlc_global_data_t *p_libvlc_global = vlc_global();

    vlc_mutex_t *lock = var_AcquireMutex( "libvlc" );
    if( p_libvlc_global->p_module_bank->b_plugins )
    {
        vlc_mutex_unlock( lock );
        return;
    }
    p_libvlc_global->p_module_bank->b_plugins = true;
    vlc_mutex_unlock( lock );

    msg_Dbg( p_this, "checking plugin modules" );

    if( config_GetInt( p_this, "plugins-cache" ) )
        p_libvlc_global->p_module_bank->b_cache = true;

    if( p_libvlc_global->p_module_bank->b_cache ||
        p_libvlc_global->p_module_bank->b_cache_delete ) CacheLoad( p_this );

    AllocateAllPlugins( p_this );
#endif
}

/**
 * Checks whether a module implements a capability.
 *
 * \param m the module
 * \param cap the capability to check
 * \return TRUE if the module have the capability
 */
bool module_IsCapable( const module_t *m, const char *cap )
{
    return !strcmp( m->psz_capability, cap );
}

/**
 * Get the internal name of a module
 *
 * \param m the module
 * \return the module name
 */
const char *module_GetObjName( const module_t *m )
{
    return m->psz_object_name;
}

/**
 * Get the human-friendly name of a module.
 *
 * \param m the module
 * \param long_name TRUE to have the long name of the module
 * \return the short or long name of the module
 */
const char *module_GetName( const module_t *m, bool long_name )
{
    if( long_name && ( m->psz_longname != NULL) )
        return m->psz_longname;

    return m->psz_shortname ?: m->psz_object_name;
}

/**
 * Get the help for a module
 *
 * \param m the module
 * \return the help
 */
const char *module_GetHelp( const module_t *m )
{
    return m->psz_help;
}

/**
 * module Need
 *
 * Return the best module function, given a capability list.
 * \param p_this the vlc object
 * \param psz_capability list of capabilities needed
 * \param psz_name name of the module asked
 * \param b_strict TRUE yto use the strict mode
 * \return the module or NULL in case of a failure
 */
module_t * __module_Need( vlc_object_t *p_this, const char *psz_capability,
                          const char *psz_name, bool b_strict )
{
    typedef struct module_list_t module_list_t;

    stats_TimerStart( p_this, "module_Need()", STATS_TIMER_MODULE_NEED );

    struct module_list_t
    {
        module_t *p_module;
        int i_score;
        bool b_force;
        module_list_t *p_next;
    };

    module_list_t *p_list, *p_first, *p_tmp;
    vlc_list_t *p_all;

    int i_which_module, i_index = 0;

    module_t *p_module;

    int   i_shortcuts = 0;
    char *psz_shortcuts = NULL, *psz_var = NULL, *psz_alias = NULL;
    bool b_force_backup = p_this->b_force;


    /* Deal with variables */
    if( psz_name && psz_name[0] == '$' )
    {
        psz_name = psz_var = var_CreateGetString( p_this, psz_name + 1 );
    }

    /* Count how many different shortcuts were asked for */
    if( psz_name && *psz_name )
    {
        char *psz_parser, *psz_last_shortcut;

        /* If the user wants none, give him none. */
        if( !strcmp( psz_name, "none" ) )
        {
            free( psz_var );
            stats_TimerStop( p_this, STATS_TIMER_MODULE_NEED );
            stats_TimerDump( p_this, STATS_TIMER_MODULE_NEED );
            stats_TimerClean( p_this, STATS_TIMER_MODULE_NEED );
            return NULL;
        }

        i_shortcuts++;
        psz_shortcuts = psz_last_shortcut = strdup( psz_name );

        for( psz_parser = psz_shortcuts; *psz_parser; psz_parser++ )
        {
            if( *psz_parser == ',' )
            {
                 *psz_parser = '\0';
                 i_shortcuts++;
                 psz_last_shortcut = psz_parser + 1;
            }
        }

        /* Check if the user wants to override the "strict" mode */
        if( psz_last_shortcut )
        {
            if( !strcmp(psz_last_shortcut, "none") )
            {
                b_strict = true;
                i_shortcuts--;
            }
            else if( !strcmp(psz_last_shortcut, "any") )
            {
                b_strict = false;
                i_shortcuts--;
            }
        }
    }

    /* Sort the modules and test them */
    p_all = vlc_list_find( p_this, VLC_OBJECT_MODULE, FIND_ANYWHERE );
    p_list = malloc( p_all->i_count * sizeof( module_list_t ) );
    p_first = NULL;
    unsigned i_cpu = vlc_CPU();

    /* Parse the module list for capabilities and probe each of them */
    for( i_which_module = 0; i_which_module < p_all->i_count; i_which_module++ )
    {
        int i_shortcut_bonus = 0;

        p_module = (module_t *)p_all->p_values[i_which_module].p_object;

        /* Test that this module can do what we need */
        if( !module_IsCapable( p_module, psz_capability ) )
        {
            /* Don't recurse through the sub-modules because vlc_list_find()
             * will list them anyway. */
            continue;
        }

        /* Test if we have the required CPU */
        if( (p_module->i_cpu & i_cpu) != p_module->i_cpu )
        {
            continue;
        }

        /* If we required a shortcut, check this plugin provides it. */
        if( i_shortcuts > 0 )
        {
            bool b_trash;
            const char *psz_name = psz_shortcuts;

            /* Let's drop modules with a <= 0 score (unless they are
             * explicitly requested) */
            b_trash = p_module->i_score <= 0;

            for( unsigned i_short = i_shortcuts; i_short > 0; i_short-- )
            {
                for( unsigned i = 0; p_module->pp_shortcuts[i]; i++ )
                {
                    char *c;
                    if( ( c = strchr( psz_name, '@' ) )
                        ? !strncasecmp( psz_name, p_module->pp_shortcuts[i],
                                        c-psz_name )
                        : !strcasecmp( psz_name, p_module->pp_shortcuts[i] ) )
                    {
                        /* Found it */
                        if( c && c[1] )