research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_repository.c

   1 /*
   2  * repository.c -- provides a map between service and shared objects
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "mlt_repository.h"
  22 #include "mlt_properties.h"
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <dlfcn.h>
  27 #include <string.h>
  28
  29 struct mlt_repository_s
  30 {
  31         struct mlt_properties_s parent; // a list of object files
  32         mlt_properties consumers; // lists of entry points
  33         mlt_properties filters;
  34         mlt_properties producers;
  35         mlt_properties transitions;
  36 };
  37
  38 /** Construct a new repository
  39 */
  40
  41 mlt_repository mlt_repository_init( const char *directory )
  42 {
  43         // Safety check
  44         if ( directory == NULL || strcmp( directory, "" ) == 0 )
  45                 return NULL;
  46
  47         // Construct the repository
  48         mlt_repository this = calloc( sizeof( struct mlt_repository_s ), 1 );
  49         mlt_properties_init( &this->parent, this );
  50         this->consumers = mlt_properties_new();
  51         this->filters = mlt_properties_new();
  52         this->producers = mlt_properties_new();
  53         this->transitions = mlt_properties_new();
  54
  55         // Get the directory list
  56         mlt_properties dir = mlt_properties_new();
  57         int count = mlt_properties_dir_list( dir, directory, NULL, 0 );
  58         int i;
  59
  60         // Iterate over files
  61         for ( i = 0; i < count; i++ )
  62         {
  63                 int flags = RTLD_NOW;
  64                 const char *object_name = mlt_properties_get_value( dir, i);
  65
  66                 // Very temporary hack to allow the quicktime plugins to work
  67                 // TODO: extend repository to allow this to be used on a case by case basis
  68                 if ( strstr( object_name, "libmltkino" ) )
  69                         flags |= RTLD_GLOBAL;
  70
  71                 // Open the shared object
  72                 void *object = dlopen( object_name, flags );
  73                 if ( object != NULL )
  74                 {
  75                         // Get the registration function
  76                         int ( *symbol_ptr )( mlt_repository ) = dlsym( object, "mlt_register" );
  77
  78                         // Call the registration function
  79                         if ( symbol_ptr != NULL )
  80                         {
  81                                 symbol_ptr( this );
  82
  83                                 // Register the object file for closure
  84                                 mlt_properties_set_data( &this->parent, object_name, object, 0, ( mlt_destructor )dlclose, NULL );
  85                         }
  86                         else
  87                         {
  88                                 dlclose( object );
  89                         }
  90                 }
  91                 else if ( strstr( object_name, "libmlt" ) )
  92                 {
  93                         fprintf( stderr, "%s:%s: failed to dlopen %s\n", __FILE__, __FUNCTION__, object_name );
  94                 }
  95         }
  96
  97         return this;
  98 }
  99
 100 static mlt_properties new_service( void *symbol )
 101 {
 102         mlt_properties properties = mlt_properties_new();
 103         mlt_properties_set_data( properties, "symbol", symbol, 0, NULL, NULL );
 104         return properties;
 105 }
 106
 107 /** Register a service with the repository
 108     Typically, this is invoked by a module within its mlt_register().
 109 */
 110
 111 void mlt_repository_register( mlt_repository this, mlt_service_type service_type, const char *service, void *symbol )
 112 {
 113         // Add the entry point to the corresponding service list
 114         switch ( service_type )
 115         {
 116                 case consumer_type:
 117                         mlt_properties_set_data( this->consumers, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 118                         break;
 119                 case filter_type:
 120                         mlt_properties_set_data( this->filters, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 121                         break;
 122                 case producer_type:
 123                         mlt_properties_set_data( this->producers, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 124                         break;
 125                 case transition_type:
 126                         mlt_properties_set_data( this->transitions, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 127                         break;
 128                 default:
 129                         break;
 130         }
 131 }
 132
 133 static mlt_properties get_service_properties( mlt_repository this, mlt_service_type type, const char *service )
 134 {
 135         mlt_properties service_properties = NULL;
 136
 137         // Get the entry point from the corresponding service list
 138         switch ( type )
 139         {
 140                 case consumer_type:
 141                         service_properties = mlt_properties_get_data( this->consumers, service, NULL );
 142                         break;
 143                 case filter_type:
 144                         service_properties = mlt_properties_get_data( this->filters, service, NULL );
 145                         break;
 146                 case producer_type:
 147                         service_properties = mlt_properties_get_data( this->producers, service, NULL );
 148                         break;
 149                 case transition_type:
 150                         service_properties = mlt_properties_get_data( this->transitions, service, NULL );
 151                         break;
 152                 default:
 153                         break;
 154         }
 155         return service_properties;
 156 }
 157
 158 /** Construct a new instance of a service
 159 */
 160
 161 void *mlt_repository_create( mlt_repository this, mlt_profile profile, mlt_service_type type, const char *service, void *input )
 162 {
 163         mlt_properties properties = get_service_properties( this, type, service );
 164         if ( properties != NULL )
 165         {
 166                 void *( *symbol_ptr )( mlt_profile, mlt_service_type, const char *, void * ) =
 167                         mlt_properties_get_data( properties, "symbol", NULL );
 168
 169                 // Construct the service
 170                 return ( symbol_ptr != NULL ) ? symbol_ptr( profile, type, service, input ) : NULL;
 171         }
 172         return NULL;
 173 }
 174
 175 /** Destroy a repository
 176 */
 177
 178 void mlt_repository_close( mlt_repository this )
 179 {
 180         mlt_properties_close( this->consumers );
 181         mlt_properties_close( this->filters );
 182         mlt_properties_close( this->producers );
 183         mlt_properties_close( this->transitions );
 184         mlt_properties_close( &this->parent );
 185         free( this );
 186 }
 187
 188 /** Get the list of registered consumers
 189 */
 190
 191 mlt_properties mlt_repository_consumers( mlt_repository self )
 192 {
 193         return self->consumers;
 194 }
 195
 196 /** Get the list of registered filters
 197 */
 198
 199 mlt_properties mlt_repository_filters( mlt_repository self )
 200 {
 201         return self->filters;
 202 }
 203
 204 /** Get the list of registered producers
 205 */
 206
 207 mlt_properties mlt_repository_producers( mlt_repository self )
 208 {
 209         return self->producers;
 210 }
 211
 212 /** Get the list of registered transitions
 213 */
 214
 215 mlt_properties mlt_repository_transitions( mlt_repository self )
 216 {
 217         return self->transitions;
 218 }
 219
 220 /** Register the metadata for a service
 221     IMPORTANT: mlt_repository will take responsibility for deallocating the metadata properties that you supply!
 222 */
 223 void mlt_repository_register_metadata( mlt_repository self, mlt_service_type type, const char *service, mlt_properties metadata )
 224 {
 225         mlt_properties service_properties = get_service_properties( self, type, service );
 226         mlt_properties_set_data( service_properties, "metadata", metadata, 0, ( mlt_destructor )mlt_properties_close, NULL );
 227 }
 228
 229 /** Get the metadata about a service
 230 */
 231
 232 mlt_properties mlt_repository_metadata( mlt_repository self, mlt_service_type type, const char *service )
 233 {
 234         mlt_properties properties = get_service_properties( self, type, service );
 235         return mlt_properties_get_data( properties, "metadata", NULL );
 236 }