PIKApp/libpikamodule/pikamodule.c

682 lines
18 KiB
C
Raw Normal View History

2023-09-26 00:35:21 +02:00
/* LIBPIKA - The PIKA Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* pikamodule.c
* (C) 1999 Austin Donnelly <austin@gimp.org>
*
* 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 3 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, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <string.h>
#include <gio/gio.h>
#include "libpikabase/pikabase.h"
#include "pikamodule.h"
#include "libpika/libpika-intl.h"
/**
* SECTION: pikamodule
* @title: PikaModule
* @short_description: A #GTypeModule subclass which implements module
* loading using #GModule.
* @see_also: #GModule, #GTypeModule
*
* #PikaModule is a generic mechanism to dynamically load modules into
* PIKA. It is a #GTypeModule subclass, implementing module loading
* using #GModule. #PikaModule does not know which functionality is
* implemented by the modules, it just provides a framework to get
* arbitrary #GType implementations loaded from disk.
**/
enum
{
PROP_0,
PROP_AUTO_LOAD,
PROP_ON_DISK,
N_PROPS
};
static GParamSpec *obj_props[N_PROPS] = { NULL, };
struct _PikaModulePrivate
{
GFile *file; /* path to the module */
gboolean auto_load; /* auto-load the module on creation */
gboolean verbose; /* verbose error reporting */
PikaModuleInfo *info; /* returned values from module_query */
PikaModuleState state; /* what's happened to the module */
gchar *last_error;
gboolean on_disk; /* TRUE if file still exists */
GModule *module; /* handle on the module */
PikaModuleQueryFunc query_module;
PikaModuleRegisterFunc register_module;
};
static void pika_module_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec);
static void pika_module_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
static void pika_module_finalize (GObject *object);
static gboolean pika_module_load (GTypeModule *module);
static void pika_module_unload (GTypeModule *module);
static gboolean pika_module_open (PikaModule *module);
static gboolean pika_module_close (PikaModule *module);
static void pika_module_set_last_error (PikaModule *module,
const gchar *error_str);
static PikaModuleInfo * pika_module_info_new (guint32 abi_version,
const gchar *purpose,
const gchar *author,
const gchar *version,
const gchar *copyright,
const gchar *date);
static PikaModuleInfo * pika_module_info_copy (const PikaModuleInfo *info);
static void pika_module_info_free (PikaModuleInfo *info);
G_DEFINE_TYPE_WITH_PRIVATE (PikaModule, pika_module, G_TYPE_TYPE_MODULE)
#define parent_class pika_module_parent_class
static void
pika_module_class_init (PikaModuleClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GTypeModuleClass *module_class = G_TYPE_MODULE_CLASS (klass);
object_class->set_property = pika_module_set_property;
object_class->get_property = pika_module_get_property;
object_class->finalize = pika_module_finalize;
obj_props[PROP_AUTO_LOAD] = g_param_spec_boolean ("auto-load", "auto-load", "auto-load",
FALSE, PIKA_PARAM_READWRITE);
obj_props[PROP_ON_DISK] = g_param_spec_boolean ("on-disk", "on-disk", "on-disk",
FALSE, PIKA_PARAM_READABLE);
g_object_class_install_properties (object_class, N_PROPS, obj_props);
module_class->load = pika_module_load;
module_class->unload = pika_module_unload;
}
static void
pika_module_init (PikaModule *module)
{
module->priv = pika_module_get_instance_private (module);
module->priv->state = PIKA_MODULE_STATE_ERROR;
}
static void
pika_module_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
PikaModule *module = PIKA_MODULE (object);
switch (property_id)
{
case PROP_AUTO_LOAD:
pika_module_set_auto_load (module, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
pika_module_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
PikaModule *module = PIKA_MODULE (object);
switch (property_id)
{
case PROP_AUTO_LOAD:
g_value_set_boolean (value, pika_module_get_auto_load (module));
break;
case PROP_ON_DISK:
g_value_set_boolean (value, pika_module_is_on_disk (module));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
pika_module_finalize (GObject *object)
{
PikaModule *module = PIKA_MODULE (object);
g_clear_object (&module->priv->file);
g_clear_pointer (&module->priv->info, pika_module_info_free);
g_clear_pointer (&module->priv->last_error, g_free);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static gboolean
pika_module_load (GTypeModule *module)
{
PikaModule *pika_module = PIKA_MODULE (module);
gpointer func;
g_return_val_if_fail (pika_module->priv->file != NULL, FALSE);
g_return_val_if_fail (pika_module->priv->module == NULL, FALSE);
if (pika_module->priv->verbose)
g_print ("Loading module '%s'\n",
pika_file_get_utf8_name (pika_module->priv->file));
if (! pika_module_open (pika_module))
return FALSE;
if (! pika_module_query_module (pika_module))
return FALSE;
/* find the pika_module_register symbol */
if (! g_module_symbol (pika_module->priv->module, "pika_module_register",
&func))
{
pika_module_set_last_error (pika_module,
"Missing pika_module_register() symbol");
g_message (_("Module '%s' load error: %s"),
pika_file_get_utf8_name (pika_module->priv->file),
pika_module->priv->last_error);
pika_module_close (pika_module);
pika_module->priv->state = PIKA_MODULE_STATE_ERROR;
return FALSE;
}
pika_module->priv->register_module = func;
if (! pika_module->priv->register_module (module))
{
pika_module_set_last_error (pika_module,
"pika_module_register() returned FALSE");
g_message (_("Module '%s' load error: %s"),
pika_file_get_utf8_name (pika_module->priv->file),
pika_module->priv->last_error);
pika_module_close (pika_module);
pika_module->priv->state = PIKA_MODULE_STATE_LOAD_FAILED;
return FALSE;
}
pika_module->priv->state = PIKA_MODULE_STATE_LOADED;
return TRUE;
}
static void
pika_module_unload (GTypeModule *module)
{
PikaModule *pika_module = PIKA_MODULE (module);
g_return_if_fail (pika_module->priv->module != NULL);
if (pika_module->priv->verbose)
g_print ("Unloading module '%s'\n",
pika_file_get_utf8_name (pika_module->priv->file));
pika_module_close (pika_module);
}
/* public functions */
/**
* pika_module_new:
* @file: A #GFile pointing to a loadable module.
* @auto_load: Pass %TRUE to exclude this module from auto-loading.
* @verbose: Pass %TRUE to enable debugging output.
*
* Creates a new #PikaModule instance.
*
* Returns: The new #PikaModule object.
**/
PikaModule *
pika_module_new (GFile *file,
gboolean auto_load,
gboolean verbose)
{
PikaModule *module;
g_return_val_if_fail (G_IS_FILE (file), NULL);
g_return_val_if_fail (g_file_is_native (file), NULL);
module = g_object_new (PIKA_TYPE_MODULE, NULL);
module->priv->file = g_object_ref (file);
module->priv->auto_load = auto_load ? TRUE : FALSE;
module->priv->verbose = verbose ? TRUE : FALSE;
if (module->priv->auto_load)
{
if (pika_module_load (G_TYPE_MODULE (module)))
pika_module_unload (G_TYPE_MODULE (module));
}
else
{
if (verbose)
g_print ("Skipping module '%s'\n",
pika_file_get_utf8_name (file));
module->priv->state = PIKA_MODULE_STATE_NOT_LOADED;
}
return module;
}
/**
* pika_module_get_file:
* @module: A #PikaModule
*
* Returns #GFile of the @module,
*
* Returns: (transfer none): The @module's #GFile.
*
* Since: 3.0
**/
GFile *
pika_module_get_file (PikaModule *module)
{
g_return_val_if_fail (PIKA_IS_MODULE (module), NULL);
return module->priv->file;
}
/**
* pika_module_set_auto_load:
* @module: A #PikaModule
* @auto_load: Pass %FALSE to exclude this module from auto-loading
*
* Sets the @auto_load property of the module
*
* Since: 3.0
**/
void
pika_module_set_auto_load (PikaModule *module,
gboolean auto_load)
{
g_return_if_fail (PIKA_IS_MODULE (module));
if (auto_load != module->priv->auto_load)
{
module->priv->auto_load = auto_load;
g_object_notify_by_pspec (G_OBJECT (module), obj_props[PROP_AUTO_LOAD]);
}
}
/**
* pika_module_get_auto_load:
* @module: A #PikaModule
*
* Returns whether this @module in automatically loaded at startup.
*
* Returns: The @module's 'auto_load' property.
*
* Since: 3.0
**/
gboolean
pika_module_get_auto_load (PikaModule *module)
{
g_return_val_if_fail (PIKA_IS_MODULE (module), FALSE);
return module->priv->auto_load;
}
/**
* pika_module_is_on_disk:
* @module: A #PikaModule
*
* Returns: Whether the @module is present on diak.
*
* Since: 3.0
**/
gboolean
pika_module_is_on_disk (PikaModule *module)
{
gboolean old_on_disk;
g_return_val_if_fail (PIKA_IS_MODULE (module), FALSE);
old_on_disk = module->priv->on_disk;
module->priv->on_disk =
(g_file_query_file_type (module->priv->file,
G_FILE_QUERY_INFO_NONE, NULL) ==
G_FILE_TYPE_REGULAR);
if (module->priv->on_disk != old_on_disk)
g_object_notify_by_pspec (G_OBJECT (module), obj_props[PROP_ON_DISK]);
return module->priv->on_disk;
}
/**
* pika_module_is_loaded:
* @module: A #PikaModule
*
* Returns: Whether the @module is currently loaded.
*
* Since: 3.0
**/
gboolean
pika_module_is_loaded (PikaModule *module)
{
g_return_val_if_fail (PIKA_IS_MODULE (module), FALSE);
return module->priv->module != NULL;
}
/**
* pika_module_get_info:
* @module: A #PikaModule
*
* Returns: (transfer none): The @module's #PikaModuleInfo as provided
* by the actual module, or %NULL.
*
* Since: 3.0
**/
const PikaModuleInfo *
pika_module_get_info (PikaModule *module)
{
g_return_val_if_fail (PIKA_IS_MODULE (module), NULL);
return module->priv->info;
}
/**
* pika_module_get_state:
* @module: A #PikaModule
*
* Returns: The @module's state.
*
* Since: 3.0
**/
PikaModuleState
pika_module_get_state (PikaModule *module)
{
g_return_val_if_fail (PIKA_IS_MODULE (module), PIKA_MODULE_STATE_ERROR);
return module->priv->state;
}
/**
* pika_module_get_last_error:
* @module: A #PikaModule
*
* Returns: The @module's last error message.
*
* Since: 3.0
**/
const gchar *
pika_module_get_last_error (PikaModule *module)
{
g_return_val_if_fail (PIKA_IS_MODULE (module), NULL);
return module->priv->last_error;
}
/**
* pika_module_query_module:
* @module: A #PikaModule.
*
* Queries the module without actually registering any of the types it
* may implement. After successful query, pika_module_get_info() can be
* used to get further about the module.
*
* Returns: %TRUE on success.
**/
gboolean
pika_module_query_module (PikaModule *module)
{
const PikaModuleInfo *info;
gboolean close_module = FALSE;
gpointer func;
g_return_val_if_fail (PIKA_IS_MODULE (module), FALSE);
if (! module->priv->module)
{
if (! pika_module_open (module))
return FALSE;
close_module = TRUE;
}
/* find the pika_module_query symbol */
if (! g_module_symbol (module->priv->module, "pika_module_query", &func))
{
pika_module_set_last_error (module,
"Missing pika_module_query() symbol");
g_message (_("Module '%s' load error: %s"),
pika_file_get_utf8_name (module->priv->file),
module->priv->last_error);
pika_module_close (module);
module->priv->state = PIKA_MODULE_STATE_ERROR;
return FALSE;
}
module->priv->query_module = func;
g_clear_pointer (&module->priv->info, pika_module_info_free);
info = module->priv->query_module (G_TYPE_MODULE (module));
if (! info || info->abi_version != PIKA_MODULE_ABI_VERSION)
{
pika_module_set_last_error (module,
info ?
"module ABI version does not match" :
"pika_module_query() returned NULL");
g_message (_("Module '%s' load error: %s"),
pika_file_get_utf8_name (module->priv->file),
module->priv->last_error);
pika_module_close (module);
module->priv->state = PIKA_MODULE_STATE_ERROR;
return FALSE;
}
module->priv->info = pika_module_info_copy (info);
if (close_module)
return pika_module_close (module);
return TRUE;
}
/**
* pika_module_error_quark:
*
* This function is never called directly. Use PIKA_MODULE_ERROR() instead.
*
* Returns: the #GQuark that defines the PIKA module error domain.
*
* Since: 2.8
**/
GQuark
pika_module_error_quark (void)
{
return g_quark_from_static_string ("pika-module-error-quark");
}
/* private functions */
static gboolean
pika_module_open (PikaModule *module)
{
gchar *path = g_file_get_path (module->priv->file);
module->priv->module = g_module_open (path, 0);
g_free (path);
if (! module->priv->module)
{
module->priv->state = PIKA_MODULE_STATE_ERROR;
pika_module_set_last_error (module, g_module_error ());
g_message (_("Module '%s' load error: %s"),
pika_file_get_utf8_name (module->priv->file),
module->priv->last_error);
return FALSE;
}
return TRUE;
}
static gboolean
pika_module_close (PikaModule *module)
{
g_module_close (module->priv->module); /* FIXME: error handling */
module->priv->module = NULL;
module->priv->query_module = NULL;
module->priv->register_module = NULL;
module->priv->state = PIKA_MODULE_STATE_NOT_LOADED;
return TRUE;
}
static void
pika_module_set_last_error (PikaModule *module,
const gchar *error_str)
{
if (module->priv->last_error)
g_free (module->priv->last_error);
module->priv->last_error = g_strdup (error_str);
}
/* PikaModuleInfo functions */
/**
* pika_module_info_new:
* @abi_version: The #PIKA_MODULE_ABI_VERSION the module was compiled against.
* @purpose: The module's general purpose.
* @author: The module's author.
* @version: The module's version.
* @copyright: The module's copyright.
* @date: The module's release date.
*
* Creates a newly allocated #PikaModuleInfo struct.
*
* Returns: The new #PikaModuleInfo struct.
**/
static PikaModuleInfo *
pika_module_info_new (guint32 abi_version,
const gchar *purpose,
const gchar *author,
const gchar *version,
const gchar *copyright,
const gchar *date)
{
PikaModuleInfo *info = g_slice_new0 (PikaModuleInfo);
info->abi_version = abi_version;
info->purpose = g_strdup (purpose);
info->author = g_strdup (author);
info->version = g_strdup (version);
info->copyright = g_strdup (copyright);
info->date = g_strdup (date);
return info;
}
/**
* pika_module_info_copy:
* @info: The #PikaModuleInfo struct to copy.
*
* Copies a #PikaModuleInfo struct.
*
* Returns: The new copy.
**/
static PikaModuleInfo *
pika_module_info_copy (const PikaModuleInfo *info)
{
g_return_val_if_fail (info != NULL, NULL);
return pika_module_info_new (info->abi_version,
info->purpose,
info->author,
info->version,
info->copyright,
info->date);
}
/**
* pika_module_info_free:
* @info: The #PikaModuleInfo struct to free
*
* Frees the passed #PikaModuleInfo.
**/
static void
pika_module_info_free (PikaModuleInfo *info)
{
g_return_if_fail (info != NULL);
g_free (info->purpose);
g_free (info->author);
g_free (info->version);
g_free (info->copyright);
g_free (info->date);
g_slice_free (PikaModuleInfo, info);
}