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Diffstat (limited to 'src/uca-plugin-manager.c')
| -rw-r--r-- | src/uca-plugin-manager.c | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/src/uca-plugin-manager.c b/src/uca-plugin-manager.c new file mode 100644 index 0000000..e99f478 --- /dev/null +++ b/src/uca-plugin-manager.c @@ -0,0 +1,345 @@ +/* Copyright (C) 2012 Matthias Vogelgesang <matthias.vogelgesang@kit.edu> + (Karlsruhe Institute of Technology) + + This library is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by the + Free Software Foundation; either version 2.1 of the License, or (at your + option) any later version. + + This library is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more + details. + + You should have received a copy of the GNU Lesser General Public License along + with this library; if not, write to the Free Software Foundation, Inc., 51 + Franklin St, Fifth Floor, Boston, MA 02110, USA */ + +/** + * SECTION:uca-plugin-manager + * @Short_description: Load an #UcaFilter from a shared object + * @Title: UcaPluginManager + * + * The plugin manager opens shared object modules searched for in locations + * specified with uca_plugin_manager_add_path(). A #UcaCamera can be + * instantiated with uca_plugin_manager_new_camera() with a one-to-one mapping + * between filter name xyz and module name libucaxyz.so. Any errors are reported + * as one of #UcaPluginManagerError codes. To get a list of available camera + * names call uca_plugin_manager_get_available_cameras(). + * + * By default, any path listed in the %UCA_CAMERA_PATH environment variable is + * added to the search path. + * + * @Since: 1.1 + */ +#include <gmodule.h> +#include "uca-plugin-manager.h" + +G_DEFINE_TYPE (UcaPluginManager, uca_plugin_manager, G_TYPE_OBJECT) + +#define UCA_PLUGIN_MANAGER_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE((obj), UCA_TYPE_PLUGIN_MANAGER, UcaPluginManagerPrivate)) + +struct _UcaPluginManagerPrivate { + GList *search_paths; +}; + +static const gchar *MODULE_PATTERN = "libuca([A-Za-z]+)"; + +typedef UcaCamera * (*GetCameraFunc) (GError **error); + +/** + * UcaPluginManagerError: + * @UCA_PLUGIN_MANAGER_ERROR_MODULE_NOT_FOUND: The module could not be found + * @UCA_PLUGIN_MANAGER_ERROR_MODULE_OPEN: Module could not be opened + * @UCA_PLUGIN_MANAGER_ERROR_SYMBOL_NOT_FOUND: Necessary entry symbol was not + * found + * + * Possible errors that uca_plugin_manager_get_filter() can return. + */ +GQuark +uca_plugin_manager_error_quark (void) +{ + return g_quark_from_static_string ("uca-plugin-manager-error-quark"); +} + +/** + * uca_plugin_manager_new: + * + * Create a plugin manager object to instantiate camera objects. + * + * Return value: A new plugin manager object. + */ +UcaPluginManager * +uca_plugin_manager_new () +{ + return UCA_PLUGIN_MANAGER (g_object_new (UCA_TYPE_PLUGIN_MANAGER, NULL)); +} + +/** + * uca_plugin_manager_add_path: + * @manager: A #UcaPluginManager + * @path: Path to look for camera modules + * + * Add a search path to the plugin manager. + */ +void +uca_plugin_manager_add_path (UcaPluginManager *manager, + const gchar *path) +{ + g_return_if_fail (UCA_IS_PLUGIN_MANAGER (manager)); + + if (g_file_test (path, G_FILE_TEST_EXISTS | G_FILE_TEST_IS_DIR)) { + UcaPluginManagerPrivate *priv; + + priv = manager->priv; + priv->search_paths = g_list_append (priv->search_paths, + g_strdup (path)); + } +} + +static GList * +get_camera_module_paths (const gchar *path) +{ + GRegex *pattern; + GDir *dir; + GList *result = NULL; + + pattern = g_regex_new (MODULE_PATTERN, 0, 0, NULL); + dir = g_dir_open (path, 0, NULL); + + if (dir != NULL) { + GMatchInfo *match_info = NULL; + const gchar *name = g_dir_read_name (dir); + + while (name != NULL) { + if (g_regex_match (pattern, name, 0, &match_info)) + result = g_list_append (result, g_build_filename (path, name, NULL)); + + g_match_info_free (match_info); + name = g_dir_read_name (dir); + } + } + + return result; +} + +static GList * +scan_search_paths (GList *search_paths) +{ + GList *camera_paths = NULL; + + for (GList *it = g_list_first (search_paths); it != NULL; it = g_list_next (it)) { + camera_paths = g_list_concat (camera_paths, + get_camera_module_paths ((const gchar*) it->data)); + } + + return camera_paths; +} + +static void +transform_camera_module_path_to_name (gchar *path, GList **result) +{ + GRegex *pattern; + GMatchInfo *match_info; + + pattern = g_regex_new (MODULE_PATTERN, 0, 0, NULL); + g_regex_match (pattern, path, 0, &match_info); + + *result = g_list_append (*result, g_match_info_fetch (match_info, 1)); + g_match_info_free (match_info); +} + +static void +list_free_full (GList *list) +{ + g_list_foreach (list, (GFunc) g_free, NULL); + g_list_free (list); +} + +/** + * uca_plugin_manager_get_available_cameras: + * @manager: A #UcaPluginManager + * + * Return value: (element-type utf8) (transfer full): A list with strings of + * available camera names. You have to free the individual strings with + * g_list_foreach(list, (GFunc) g_free, NULL) and the list itself with + * g_list_free. + */ +GList * +uca_plugin_manager_get_available_cameras (UcaPluginManager *manager) +{ + UcaPluginManagerPrivate *priv; + GList *camera_paths; + GList *camera_names = NULL; + + g_return_val_if_fail (UCA_IS_PLUGIN_MANAGER (manager), NULL); + + priv = manager->priv; + camera_paths = scan_search_paths (priv->search_paths); + + g_list_foreach (camera_paths, (GFunc) transform_camera_module_path_to_name, &camera_names); + list_free_full (camera_paths); + + return camera_names; +} + +static gchar * +find_camera_module_path (GList *search_paths, const gchar *name) +{ + gchar *result = NULL; + GList *paths; + + paths = scan_search_paths (search_paths); + + for (GList *it = g_list_first (paths); it != NULL; it = g_list_next (it)) { + gchar *path = (gchar *) it->data; + gchar *basename = g_path_get_basename ((gchar *) path); + + if (g_strrstr (basename, name)) { + result = g_strdup (path); + g_free (basename); + break; + } + + g_free (basename); + } + + list_free_full (paths); + return result; +} + +/** + * uca_plugin_manager_get_camera: + * @manager: A #UcaPluginManager + * @name: Name of the camera module, that maps to libuca<name>.so + * @error: Location for a #GError + * + * Create a new camera instance with camera @name. + * + * Returns: (transfer full): A new #UcaCamera object. + */ +UcaCamera * +uca_plugin_manager_get_camera (UcaPluginManager *manager, + const gchar *name, + GError **error) +{ + UcaPluginManagerPrivate *priv; + UcaCamera *camera; + GModule *module; + GetCameraFunc *func; + gchar *module_path; + GError *tmp_error = NULL; + + const gchar *symbol_name = "uca_camera_impl_new"; + + g_return_val_if_fail (UCA_IS_PLUGIN_MANAGER (manager) && (name != NULL), NULL); + + priv = manager->priv; + module_path = find_camera_module_path (priv->search_paths, name); + + if (module_path == NULL) { + g_set_error (error, UCA_PLUGIN_MANAGER_ERROR, UCA_PLUGIN_MANAGER_ERROR_MODULE_NOT_FOUND, + "Camera module `%s' not found", name); + return NULL; + } + + module = g_module_open (module_path, G_MODULE_BIND_LAZY); + g_free (module_path); + + if (!module) { + g_set_error (error, UCA_PLUGIN_MANAGER_ERROR, UCA_PLUGIN_MANAGER_ERROR_MODULE_OPEN, + "Camera module `%s' could not be opened: %s", name, g_module_error ()); + return NULL; + } + + func = g_malloc0 (sizeof (GetCameraFunc)); + + if (!g_module_symbol (module, symbol_name, (gpointer *) func)) { + g_set_error (error, UCA_PLUGIN_MANAGER_ERROR, UCA_PLUGIN_MANAGER_ERROR_SYMBOL_NOT_FOUND, + "%s", g_module_error ()); + g_free (func); + + if (!g_module_close (module)) + g_warning ("%s", g_module_error ()); + + return NULL; + } + + camera = (*func) (&tmp_error); + + if (tmp_error != NULL) { + g_propagate_error (error, tmp_error); + return NULL; + } + + return camera; +} + +static void +uca_plugin_manager_get_property (GObject *object, guint property_id, GValue *value, GParamSpec *pspec) +{ + switch (property_id) { + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); + break; + } +} + +static void +uca_plugin_manager_set_property (GObject *object, guint property_id, const GValue *value, GParamSpec *pspec) +{ + switch (property_id) { + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); + break; + } +} + +static void +uca_plugin_manager_dispose (GObject *object) +{ + G_OBJECT_CLASS (uca_plugin_manager_parent_class)->dispose (object); +} + +static void +uca_plugin_manager_finalize (GObject *object) +{ + UcaPluginManagerPrivate *priv = UCA_PLUGIN_MANAGER_GET_PRIVATE (object); + + g_list_foreach (priv->search_paths, (GFunc) g_free, NULL); + g_list_free (priv->search_paths); + + G_OBJECT_CLASS (uca_plugin_manager_parent_class)->finalize (object); +} + +static void +uca_plugin_manager_class_init (UcaPluginManagerClass *klass) +{ + GObjectClass *gobject_class = G_OBJECT_CLASS (klass); + gobject_class->get_property = uca_plugin_manager_get_property; + gobject_class->set_property = uca_plugin_manager_set_property; + gobject_class->dispose = uca_plugin_manager_dispose; + gobject_class->finalize = uca_plugin_manager_finalize; + + g_type_class_add_private (klass, sizeof (UcaPluginManagerPrivate)); +} + +static void +uca_plugin_manager_init (UcaPluginManager *manager) +{ + UcaPluginManagerPrivate *priv; + const gchar *uca_camera_path; + + manager->priv = priv = UCA_PLUGIN_MANAGER_GET_PRIVATE (manager); + priv->search_paths = NULL; + + uca_camera_path = g_getenv ("UCA_CAMERA_PATH"); + + if (uca_camera_path != NULL) + uca_plugin_manager_add_path (manager, uca_camera_path); + + uca_plugin_manager_add_path (manager, "/usr/lib/uca"); + uca_plugin_manager_add_path (manager, "/usr/lib64/uca"); + uca_plugin_manager_add_path (manager, "/usr/local/lib/uca"); + uca_plugin_manager_add_path (manager, "/usr/local/lib64/uca"); +} |