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         }
  92
  93         return this;
  94 }
  95
  96 static mlt_properties new_service( void *symbol )
  97 {
  98         mlt_properties properties = mlt_properties_new();
  99         mlt_properties_set_data( properties, "symbol", symbol, 0, NULL, NULL );
 100         return properties;
 101 }
 102
 103 /** Register a service with the repository
 104     Typically, this is invoked by a module within its mlt_register().
 105 */
 106
 107 void mlt_repository_register( mlt_repository this, mlt_service_type service_type, const char *service, void *symbol )
 108 {
 109         // Add the entry point to the corresponding service list
 110         switch ( service_type )
 111         {
 112                 case consumer_type:
 113                         mlt_properties_set_data( this->consumers, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 114                         break;
 115                 case filter_type:
 116                         mlt_properties_set_data( this->filters, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 117                         break;
 118                 case producer_type:
 119                         mlt_properties_set_data( this->producers, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 120                         break;
 121                 case transition_type:
 122                         mlt_properties_set_data( this->transitions, service, new_service( symbol ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 123                         break;
 124                 default:
 125                         break;
 126         }
 127 }
 128
 129 static mlt_properties get_service_properties( mlt_repository this, mlt_service_type type, const char *service )
 130 {
 131         mlt_properties service_properties = NULL;
 132
 133         // Get the entry point from the corresponding service list
 134         switch ( type )
 135         {
 136                 case consumer_type:
 137                         service_properties = mlt_properties_get_data( this->consumers, service, NULL );
 138                         break;
 139                 case filter_type:
 140                         service_properties = mlt_properties_get_data( this->filters, service, NULL );
 141                         break;
 142                 case producer_type:
 143                         service_properties = mlt_properties_get_data( this->producers, service, NULL );
 144                         break;
 145                 case transition_type:
 146                         service_properties = mlt_properties_get_data( this->transitions, service, NULL );
 147                         break;
 148                 default:
 149                         break;
 150         }
 151         return service_properties;
 152 }
 153
 154 /** Construct a new instance of a service
 155 */
 156
 157 void *mlt_repository_create( mlt_repository this, mlt_profile profile, mlt_service_type type, const char *service, void *input )
 158 {
 159         mlt_properties properties = get_service_properties( this, type, service );
 160         if ( properties != NULL )
 161         {
 162                 void *( *symbol_ptr )( mlt_profile, mlt_service_type, const char *, void * ) =
 163                         mlt_properties_get_data( properties, "symbol", NULL );
 164
 165                 // Construct the service
 166                 return ( symbol_ptr != NULL ) ? symbol_ptr( profile, type, service, input ) : NULL;
 167         }
 168         return NULL;
 169 }
 170
 171 /** Destroy a repository
 172 */
 173
 174 void mlt_repository_close( mlt_repository this )
 175 {
 176         mlt_properties_close( this->consumers );
 177         mlt_properties_close( this->filters );
 178         mlt_properties_close( this->producers );
 179         mlt_properties_close( this->transitions );
 180         mlt_properties_close( &this->parent );
 181         free( this );
 182 }
 183
 184 /** Get the list of registered consumers
 185 */
 186
 187 mlt_properties mlt_repository_consumers( mlt_repository self )
 188 {
 189         return self->consumers;
 190 }
 191
 192 /** Get the list of registered filters
 193 */
 194
 195 mlt_properties mlt_repository_filters( mlt_repository self )
 196 {
 197         return self->filters;
 198 }
 199
 200 /** Get the list of registered producers
 201 */
 202
 203 mlt_properties mlt_repository_producers( mlt_repository self )
 204 {
 205         return self->producers;
 206 }
 207
 208 /** Get the list of registered transitions
 209 */
 210
 211 mlt_properties mlt_repository_transitions( mlt_repository self )
 212 {
 213         return self->transitions;
 214 }
 215
 216 /** Register the metadata for a service
 217     IMPORTANT: mlt_repository will take responsibility for deallocating the metadata properties that you supply!
 218 */
 219 void mlt_repository_register_metadata( mlt_repository self, mlt_service_type type, const char *service, mlt_properties metadata )
 220 {
 221         mlt_properties service_properties = get_service_properties( self, type, service );
 222         mlt_properties_set_data( service_properties, "metadata", metadata, 0, ( mlt_destructor )mlt_properties_close, NULL );
 223 }
 224
 225 /** Get the metadata about a service
 226 */
 227
 228 mlt_properties mlt_repository_metadata( mlt_repository self, mlt_service_type type, const char *service )
 229 {
 230         mlt_properties properties = get_service_properties( self, type, service );
 231         return mlt_properties_get_data( properties, "metadata", NULL );
 232 }