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 program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * 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;
  32 };
  33
  34 static char *construct_full_file( char *output, char *prefix, char *file )
  35 {
  36         strcpy( output, prefix );
  37         if ( prefix[ strlen( prefix ) - 1 ] != '/' )
  38                 strcat( output, "/" );
  39         strcat( output, file );
  40         return output;
  41 }
  42
  43 static char *chomp( char *input )
  44 {
  45         if ( input[ strlen( input ) - 1 ] == '\n' )
  46                 input[ strlen( input ) - 1 ] = '\0';
  47         return input;
  48 }
  49
  50 static mlt_properties construct_object( char *prefix, char *id )
  51 {
  52         mlt_properties output = mlt_properties_new( );
  53         mlt_properties_set( output, "prefix", prefix );
  54         mlt_properties_set( output, "id", id );
  55         return output;
  56 }
  57
  58 static mlt_properties construct_service( mlt_properties object, char *id )
  59 {
  60         mlt_properties output = mlt_properties_new( );
  61         mlt_properties_set_data( output, "object", object, 0, NULL, NULL );
  62         mlt_properties_set( output, "id", id );
  63         return output;
  64 }
  65
  66 static void *construct_instance( mlt_properties service_properties, char *symbol, void *input )
  67 {
  68         // Extract the service
  69         char *service = mlt_properties_get( service_properties, "id" );
  70
  71         // Get the object properties
  72         void *object_properties = mlt_properties_get_data( service_properties, "object", NULL );
  73
  74         // Get the dlopen'd object
  75         void *object = mlt_properties_get_data( object_properties, "dlopen", NULL );
  76
  77         // Get the dlsym'd symbol
  78         void *( *symbol_ptr )( char *, void * ) = mlt_properties_get_data( object_properties, symbol, NULL );
  79
  80         // Check that we have object and open if we don't
  81         if ( object == NULL )
  82         {
  83                 char full_file[ 512 ];
  84
  85                 // Get the prefix and id of the shared object
  86                 char *prefix = mlt_properties_get( object_properties, "prefix" );
  87                 char *file = mlt_properties_get( object_properties, "id" );
  88
  89                 // Construct the full file
  90                 construct_full_file( full_file, prefix, file );
  91
  92                 // Open the shared object
  93                 object = dlopen( full_file, RTLD_NOW | RTLD_GLOBAL );
  94                 if ( object == NULL )
  95                         fprintf( stderr, "Failed to load plugin: %s\n", dlerror() );
  96
  97                 // Set it on the properties
  98                 mlt_properties_set_data( object_properties, "dlopen", object, 0, ( mlt_destructor )dlclose, NULL );
  99         }
 100
 101         // Now check if we have this symbol pointer
 102         if ( object != NULL && symbol_ptr == NULL )
 103         {
 104                 // Construct it now
 105                 symbol_ptr = dlsym( object, symbol );
 106
 107                 // Set it on the properties
 108                 mlt_properties_set_data( object_properties, "dlsym", symbol_ptr, 0, NULL, NULL );
 109         }
 110
 111         // Construct the service
 112         return symbol_ptr != NULL ? symbol_ptr( service, input ) : NULL;
 113 }
 114
 115 mlt_repository mlt_repository_init( mlt_properties object_list, char *prefix, char *data, char *symbol )
 116 {
 117         char full_file[ 512 ];
 118         FILE *file;
 119
 120         // Construct the repository
 121         mlt_repository this = calloc( sizeof( struct mlt_repository_s ), 1 );
 122         mlt_properties_init( &this->parent, this );
 123
 124         // Add the symbol to THIS repository properties.
 125         mlt_properties_set( &this->parent, "_symbol", symbol );
 126
 127         // Construct full file
 128         construct_full_file( full_file, prefix, data );
 129
 130         // Open the file
 131         file = fopen( full_file, "r" );
 132
 133         // Parse the contents
 134         if ( file != NULL )
 135         {
 136                 char full[ 512 ];
 137                 char service[ 256 ];
 138                 char object[ 256 ];
 139
 140                 while( fgets( full, 512, file ) )
 141                 {
 142                         chomp( full );
 143
 144                         if ( full[ 0 ] != '#' && full[ 0 ] != '\0' && sscanf( full, "%s %s", service, object ) == 2 )
 145                         {
 146                                 // Get the object properties first
 147                                 mlt_properties object_properties = mlt_properties_get_data( object_list, object, NULL );
 148
 149                                 // If their are no properties, create them now
 150                                 if ( object_properties == NULL )
 151                                 {
 152                                         // Construct the object
 153                                         object_properties = construct_object( prefix, object );
 154
 155                                         // Add it to the object list
 156                                         mlt_properties_set_data( object_list, object, object_properties, 0, ( mlt_destructor )mlt_properties_close, NULL );
 157                                 }
 158
 159                                 // Now construct a property for the service
 160                                 mlt_properties service_properties = construct_service( object_properties, service );
 161
 162                                 // Add it to the repository
 163                                 mlt_properties_set_data( &this->parent, service, service_properties, 0, ( mlt_destructor )mlt_properties_close, NULL );
 164                         }
 165                 }
 166
 167                 // Close the file
 168                 fclose( file );
 169         }
 170
 171         return this;
 172 }
 173
 174 void *mlt_repository_fetch( mlt_repository this, char *service, void *input )
 175 {
 176         // Get the service properties
 177         mlt_properties service_properties = mlt_properties_get_data( &this->parent, service, NULL );
 178
 179         // If the service exists
 180         if ( service_properties != NULL )
 181         {
 182                 // Get the symbol that is used to generate this service
 183                 char *symbol = mlt_properties_get( &this->parent, "_symbol" );
 184
 185                 // Now get an instance of the service
 186                 return construct_instance( service_properties, symbol, input );
 187         }
 188
 189         return NULL;
 190 }
 191
 192 void mlt_repository_close( mlt_repository this )
 193 {
 194         mlt_properties_close( &this->parent );
 195         free( this );
 196 }
 197
 198