irreco/src/core/irreco_backend_lib.c

   1 /*
   2  * irreco - Ir Remote Control
   3  * Copyright (C) 2007  Arto Karppinen (arto.karppinen@iki.fi)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  */
  20
  21 #include "irreco_backend_lib.h"
  22 #include <gmodule.h>
  23
  24
  25 /**
  26  * @addtogroup IrrecoBackendLib
  27  * @ingroup Irreco
  28  *
  29  * Load backend libraries and stores information about them.
  30  *
  31  * @{
  32  */
  33
  34 /**
  35  * @file
  36  * Source file of @ref IrrecoBackendLib.
  37  */
  38
  39
  40 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
  41 /* Prototypes                                                                 */
  42 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
  43
  44 IrrecoBackendLib* irreco_backend_lib_load_with_name(const gchar *filepath,
  45                                                   const gchar *filename);
  46 void irreco_backend_lib_load_dir_foreach(IrrecoDirForeachData * dir_data);
  47
  48
  49
  50
  51 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
  52 /* Function pointer cheking.                                                  */
  53 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
  54
  55 /**
  56  * @name Function pointer cheking
  57  * @{
  58  */
  59
  60 /*
  61  * Check function pointers using a way that does not create errors in GCC -Wall.
  62  */
  63 typedef void (*IrrecoVoidFunction) (void);
  64 typedef union {
  65         IrrecoVoidFunction function;
  66         gpointer pointer;
  67 } IrrecoVoidFunctionUnion;
  68
  69 #define HAS_FUNCTION(__lib, __name) irreco_backend_lib_has_function(\
  70                 (IrrecoVoidFunction) __lib->api->__name, #__name )
  71
  72 gboolean irreco_backend_lib_has_function(IrrecoVoidFunction function,
  73                                           const gchar * name)
  74 {
  75         IrrecoVoidFunctionUnion function_union;
  76         IRRECO_ENTER
  77
  78         function_union.function = function;
  79         if (function_union.pointer == NULL) {
  80                 IRRECO_ERROR("Could not get function pointer for \"%s\".\n",
  81                              name);
  82                 IRRECO_RETURN_BOOL(FALSE);
  83         }
  84         IRRECO_RETURN_BOOL(TRUE);
  85 }
  86
  87 /** @} */
  88
  89
  90
  91 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
  92 /* Backend loading.                                                           */
  93 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
  94
  95 /**
  96  * @name Backend loading
  97  * @{
  98  */
  99
 100
 101 /*
 102  * Fix "warning: dereferencing type-punned pointer will break strict-aliasing
 103  * rules" warning during g_module_symbol() call the way GCC docs suggest.
 104  */
 105 typedef union {
 106         GetIrrecoBackendFunctionTable function;
 107         gpointer pointer;
 108 } GetFunctionTableUnion;
 109
 110 /*
 111  * Load backend from file.
 112  *
 113  * Args:
 114  *     filepath  Complete path to library.
 115  *     filename  Basename of the library.
 116  */
 117 IrrecoBackendLib* irreco_backend_lib_load_with_name(const gchar *filepath,
 118                                                     const gchar *filename)
 119 {
 120         GetFunctionTableUnion get_irreco_backend_function_table;
 121         IrrecoBackendLib* backend_lib;
 122         IRRECO_ENTER
 123
 124         IRRECO_PRINTF("Loading backend lib: \"%s\"\n", filename);
 125         IRRECO_PRINTF("Path: \"%s\"\n", filepath);
 126         backend_lib = g_slice_new0(IrrecoBackendLib);
 127
 128         backend_lib->module = g_module_open(filepath, G_MODULE_BIND_LOCAL);
 129         if (backend_lib->module == NULL) {
 130                 IRRECO_ERROR("Failed to open library \"%s\" with "
 131                              "g_module_open().\n", filepath);
 132                 goto error;
 133         }
 134
 135         if (!g_module_symbol(backend_lib->module,
 136                              "get_irreco_backend_function_table",
 137                              &get_irreco_backend_function_table.pointer)) {
 138                 IRRECO_ERROR("Could not find function "
 139                              "\"get_irreco_backend_function_table\""
 140                              "in backend \"%s\"\n", filepath);
 141                 goto error;
 142         }
 143
 144         IRRECO_PRINTF("Getting function table.\n");
 145         backend_lib->api = get_irreco_backend_function_table.function();
 146         if (backend_lib->api == NULL) {
 147                 IRRECO_ERROR("Could not get function table "
 148                              "from backend \"%s\"\n", filepath);
 149                 goto error;
 150         }
 151
 152         /* Check api version. */
 153         if (backend_lib->api->version < IRRECO_BACKEND_API_VERSION) {
 154                 IRRECO_ERROR("Backend must implement atleast version %i of "
 155                              "backend api. Only version %i implemented by"
 156                              "backend \"%s\"\n",
 157                              IRRECO_BACKEND_API_VERSION,
 158                              backend_lib->api->version, filepath);
 159                 goto error;
 160         }
 161
 162         if (!HAS_FUNCTION(backend_lib, get_error_msg)
 163             || !HAS_FUNCTION(backend_lib, create)
 164             || !HAS_FUNCTION(backend_lib, destroy)
 165             || !HAS_FUNCTION(backend_lib, from_conf)
 166             || !HAS_FUNCTION(backend_lib, to_conf)
 167             || !HAS_FUNCTION(backend_lib, get_devices)
 168             || !HAS_FUNCTION(backend_lib, get_commands)
 169             || !HAS_FUNCTION(backend_lib, send_command)
 170             || !HAS_FUNCTION(backend_lib, configure)) {
 171                 IRRECO_ERROR("Could not get complete function table "
 172                              "from backend \"%s\"\n", filepath);
 173                 goto error;
 174         }
 175
 176         if ((backend_lib->api->flags & IRRECO_BACKEND_EDITABLE_DEVICES) && (
 177             !HAS_FUNCTION(backend_lib, create_device)
 178             || !HAS_FUNCTION(backend_lib, is_device_editable)
 179             || !HAS_FUNCTION(backend_lib, edit_device)
 180             || !HAS_FUNCTION(backend_lib, delete_device)
 181             )) {
 182                 IRRECO_ERROR("Backend \"%s\" claims to support "
 183                              "editable devices, but does not provide "
 184                              "the needed functions.\n", filepath);
 185                 goto error;
 186         }
 187
 188         if ((backend_lib->api->flags & IRRECO_BACKEND_CONFIGURATION_EXPORT) && (
 189             !HAS_FUNCTION(backend_lib, export_conf)
 190             || !HAS_FUNCTION(backend_lib, import_conf)
 191             || !HAS_FUNCTION(backend_lib, check_conf)
 192             )) {
 193                 IRRECO_ERROR("Backend \"%s\" claims to support "
 194                              "configuration export, but does not provide "
 195                              "the needed functions.\n", filepath);
 196                 goto error;
 197         }
 198         if (backend_lib->api->name == NULL) {
 199                 IRRECO_ERROR("Backend name is not set in function table.\n");
 200                 goto error;
 201         }
 202
 203         backend_lib->filepath = g_strdup(filepath);
 204         backend_lib->filename = g_strdup(filename);
 205         backend_lib->name = g_strdup(backend_lib->api->name);
 206         g_module_make_resident(backend_lib->module);
 207
 208         IRRECO_PRINTF("Backend \"%s\" loaded successfully\n",
 209                       backend_lib->name);
 210         IRRECO_RETURN_PTR(backend_lib);
 211
 212
 213         /* Loading of module failed. Close module and free memory. */
 214         error:
 215         if (backend_lib->module) g_module_close(backend_lib->module);
 216         g_slice_free(IrrecoBackendLib, backend_lib);
 217         IRRECO_RETURN_PTR(NULL);
 218 }
 219
 220 void irreco_backend_lib_close(IrrecoBackendLib * backend_lib)
 221 {
 222         IRRECO_ENTER
 223         if (backend_lib == NULL) IRRECO_RETURN
 224
 225         g_module_close(backend_lib->module);
 226         backend_lib->module = NULL;
 227         g_free(backend_lib->name);
 228         backend_lib->name = NULL;
 229         g_free(backend_lib->filename);
 230         backend_lib->filename = NULL;
 231         g_free(backend_lib->filepath);
 232         backend_lib->filepath = NULL;
 233
 234         g_slice_free(IrrecoBackendLib, backend_lib);
 235
 236         IRRECO_RETURN
 237 }
 238
 239 /** @} */
 240 /** @} */
 241
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