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         mlt_properties object_list;
  33 };
  34
  35 static char *construct_full_file( char *output, char *prefix, char *file )
  36 {
  37         strcpy( output, prefix );
  38         if ( prefix[ strlen( prefix ) - 1 ] != '/' )
  39                 strcat( output, "/" );
  40         strcat( output, file );
  41         return output;
  42 }
  43
  44 static char *chomp( char *input )
  45 {
  46         if ( input[ strlen( input ) - 1 ] == '\n' )
  47                 input[ strlen( input ) - 1 ] = '\0';
  48         return input;
  49 }
  50
  51 static mlt_properties construct_object( char *prefix, char *id )
  52 {
  53         mlt_properties output = mlt_properties_new( );
  54         mlt_properties_init( output, NULL );
  55         mlt_properties_set( output, "prefix", prefix );
  56         mlt_properties_set( output, "id", id );
  57         return output;
  58 }
  59
  60 static mlt_properties construct_service( mlt_properties object, char *id )
  61 {
  62         mlt_properties output = mlt_properties_new( );
  63         mlt_properties_init( output, NULL );
  64         mlt_properties_set_data( output, "object", object, 0, NULL, NULL );
  65         mlt_properties_set( output, "id", id );
  66         return output;
  67 }
  68
  69 static void *construct_instance( mlt_properties service_properties, char *symbol, void *input )
  70 {
  71         // Extract the service
  72         char *service = mlt_properties_get( service_properties, "id" );
  73
  74         // Get the object properties
  75         void *object_properties = mlt_properties_get_data( service_properties, "object", NULL );
  76
  77         // Get the dlopen'd object
  78         void *object = mlt_properties_get_data( object_properties, "dlopen", NULL );
  79
  80         // Get the dlsym'd symbol
  81         void *( *symbol_ptr )( char *, void * ) = mlt_properties_get_data( object_properties, symbol, NULL );
  82
  83         // Check that we have object and open if we don't
  84         if ( object == NULL )
  85         {
  86                 char full_file[ 512 ];
  87
  88                 // Get the prefix and id of the shared object
  89                 char *prefix = mlt_properties_get( object_properties, "prefix" );
  90                 char *file = mlt_properties_get( object_properties, "id" );
  91
  92                 // Construct the full file
  93                 construct_full_file( full_file, prefix, file );
  94
  95                 // Open the shared object
  96                 object = dlopen( full_file, RTLD_NOW | RTLD_GLOBAL );
  97                 if ( object == NULL )
  98                         fprintf( stderr, "Failed to load plugin: %s\n", dlerror() );
  99
 100                 // Set it on the properties
 101                 mlt_properties_set_data( object_properties, "dlopen", object, 0, ( void (*)( void * ) )dlclose, NULL );
 102         }
 103
 104         // Now check if we have this symbol pointer
 105         if ( object != NULL && symbol_ptr == NULL )
 106         {
 107                 // Construct it now
 108                 symbol_ptr = dlsym( object, symbol );
 109
 110                 // Set it on the properties
 111                 mlt_properties_set_data( object_properties, "dlsym", symbol_ptr, 0, NULL, NULL );
 112         }
 113
 114         // Construct the service
 115         return symbol_ptr != NULL ? symbol_ptr( service, input ) : NULL;
 116 }
 117
 118 mlt_repository mlt_repository_init( mlt_properties object_list, char *prefix, char *data, char *symbol )
 119 {
 120         char full_file[ 512 ];
 121         FILE *file;
 122
 123         // Construct the repository
 124         mlt_repository this = calloc( sizeof( struct mlt_repository_s ), 1 );
 125         mlt_properties_init( &this->parent, this );
 126
 127         // Add the symbol to THIS repository properties.
 128         mlt_properties_set( &this->parent, "_symbol", symbol );
 129
 130         // Asociate the repository to the global object_list
 131         this->object_list = object_list;
 132
 133         // Construct full file
 134         construct_full_file( full_file, prefix, data );
 135
 136         // Open the file
 137         file = fopen( full_file, "r" );
 138
 139         // Parse the contents
 140         if ( file != NULL )
 141         {
 142                 char full[ 512 ];
 143                 char service[ 256 ];
 144                 char object[ 256 ];
 145
 146                 while( fgets( full, 512, file ) )
 147                 {
 148                         chomp( full );
 149
 150                         if ( full[ 0 ] != '#' && full[ 0 ] != '\0' && sscanf( full, "%s %s", service, object ) == 2 )
 151                         {
 152                                 // Get the object properties first
 153                                 mlt_properties object_properties = mlt_properties_get_data( object_list, object, NULL );
 154
 155                                 // If their are no properties, create them now
 156                                 if ( object_properties == NULL )
 157                                 {
 158                                         // Construct the object
 159                                         object_properties = construct_object( prefix, object );
 160
 161                                         // Add it to the object list
 162                                         mlt_properties_set_data( object_list, object, object_properties, 0, ( mlt_destructor )mlt_properties_close, NULL );
 163                                 }
 164
 165                                 // Now construct a property for the service
 166                                 mlt_properties service_properties = construct_service( object_properties, service );
 167
 168                                 // Add it to the repository
 169                                 mlt_properties_set_data( &this->parent, service, service_properties, 0, ( mlt_destructor )mlt_properties_close, NULL );
 170                         }
 171                 }
 172
 173                 // Close the file
 174                 fclose( file );
 175         }
 176
 177         return this;
 178 }
 179
 180 void *mlt_repository_fetch( mlt_repository this, char *service, void *input )
 181 {
 182         // Get the service properties
 183         mlt_properties service_properties = mlt_properties_get_data( &this->parent, service, NULL );
 184
 185         // If the service exists
 186         if ( service_properties != NULL )
 187         {
 188                 // Get the symbol that is used to generate this service
 189                 char *symbol = mlt_properties_get( &this->parent, "_symbol" );
 190
 191                 // Now get an instance of the service
 192                 return construct_instance( service_properties, symbol, input );
 193         }
 194
 195         return NULL;
 196 }
 197
 198 void mlt_repository_close( mlt_repository this )
 199 {
 200         mlt_properties_close( &this->parent );
 201         free( this );
 202 }
 203
 204