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;
  32 };
  33
  34 static char *construct_full_file( char *output, const char *prefix, const 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( const char *prefix, const 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, const 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, const 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 )( const 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                 int flags = RTLD_NOW;
  89
  90                 // Very temporary hack to allow the quicktime plugins to work
  91                 // TODO: extend repository to allow this to be used on a case by case basis
  92                 if ( !strcmp( service, "kino" ) )
  93                         flags |= RTLD_GLOBAL;
  94
  95                 // Construct the full file
  96                 construct_full_file( full_file, prefix, file );
  97
  98                 // Open the shared object
  99                 object = dlopen( full_file, flags );
 100                 if ( object != NULL )
 101                 {
 102                         // Set it on the properties
 103                         mlt_properties_set_data( object_properties, "dlopen", object, 0, ( mlt_destructor )dlclose, NULL );
 104                 }
 105                 else
 106                 {
 107                         fprintf( stderr, "Failed to load plugin: %s\n", dlerror() );
 108                 }
 109         }
 110
 111         // Now check if we have this symbol pointer
 112         if ( object != NULL && symbol_ptr == NULL )
 113         {
 114                 // Construct it now
 115                 symbol_ptr = dlsym( object, symbol );
 116
 117                 // Set it on the properties
 118                 mlt_properties_set_data( object_properties, "dlsym", symbol_ptr, 0, NULL, NULL );
 119         }
 120
 121         // Construct the service
 122         return symbol_ptr != NULL ? symbol_ptr( service, input ) : NULL;
 123 }
 124
 125 mlt_repository mlt_repository_init( mlt_properties object_list, const char *prefix, const char *data, const char *symbol )
 126 {
 127         char full_file[ 512 ];
 128         FILE *file;
 129
 130         // Construct the repository
 131         mlt_repository this = calloc( sizeof( struct mlt_repository_s ), 1 );
 132         mlt_properties_init( &this->parent, this );
 133
 134         // Add the symbol to THIS repository properties.
 135         mlt_properties_set( &this->parent, "_symbol", symbol );
 136
 137         // Construct full file
 138         construct_full_file( full_file, prefix, data );
 139         strcat( full_file, ".dat" );
 140
 141         // Open the file
 142         file = fopen( full_file, "r" );
 143
 144         // Parse the contents
 145         if ( file != NULL )
 146         {
 147                 char full[ 512 ];
 148                 char service[ 256 ];
 149                 char object[ 256 ];
 150
 151                 while( fgets( full, 512, file ) )
 152                 {
 153                         chomp( full );
 154
 155                         if ( full[ 0 ] != '#' && full[ 0 ] != '\0' && sscanf( full, "%s %s", service, object ) == 2 )
 156                         {
 157                                 // Get the object properties first
 158                                 mlt_properties object_properties = mlt_properties_get_data( object_list, object, NULL );
 159
 160                                 // If their are no properties, create them now
 161                                 if ( object_properties == NULL )
 162                                 {
 163                                         // Construct the object
 164                                         object_properties = construct_object( prefix, object );
 165
 166                                         // Add it to the object list
 167                                         mlt_properties_set_data( object_list, object, object_properties, 0, ( mlt_destructor )mlt_properties_close, NULL );
 168                                 }
 169
 170                                 // Now construct a property for the service
 171                                 mlt_properties service_properties = construct_service( object_properties, service );
 172
 173                                 // Add it to the repository
 174                                 mlt_properties_set_data( &this->parent, service, service_properties, 0, ( mlt_destructor )mlt_properties_close, NULL );
 175                         }
 176                 }
 177
 178                 // Close the file
 179                 fclose( file );
 180         }
 181
 182         return this;
 183 }
 184
 185 void *mlt_repository_fetch( mlt_repository this, const char *service, void *input )
 186 {
 187         // Get the service properties
 188         mlt_properties service_properties = mlt_properties_get_data( &this->parent, service, NULL );
 189
 190         // If the service exists
 191         if ( service_properties != NULL )
 192         {
 193                 // Get the symbol that is used to generate this service
 194                 char *symbol = mlt_properties_get( &this->parent, "_symbol" );
 195
 196                 // Now get an instance of the service
 197                 return construct_instance( service_properties, symbol, input );
 198         }
 199
 200         return NULL;
 201 }
 202
 203 void mlt_repository_close( mlt_repository this )
 204 {
 205         mlt_properties_close( &this->parent );
 206         free( this );
 207 }
 208
 209