glib/gio/gvfs.c
Philip Withnall a84a704dc6 docs: Move the GVfs SECTION
Move it to the struct docs.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

Helps: #3037
2023-11-14 15:12:53 +00:00

511 lines
14 KiB
C

/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include <string.h>
#include "gvfs.h"
#include "glib-private.h"
#include "glocalvfs.h"
#include "gresourcefile.h"
#include "giomodule-priv.h"
#include "glibintl.h"
/**
* GVfs:
*
* Entry point for using GIO functionality.
*/
static GRWLock additional_schemes_lock;
typedef struct _GVfsPrivate {
GHashTable *additional_schemes;
char const **supported_schemes;
} GVfsPrivate;
typedef struct {
GVfsFileLookupFunc uri_func;
gpointer uri_data;
GDestroyNotify uri_destroy;
GVfsFileLookupFunc parse_name_func;
gpointer parse_name_data;
GDestroyNotify parse_name_destroy;
} GVfsURISchemeData;
G_DEFINE_TYPE_WITH_PRIVATE (GVfs, g_vfs, G_TYPE_OBJECT)
static void
g_vfs_dispose (GObject *object)
{
GVfs *vfs = G_VFS (object);
GVfsPrivate *priv = g_vfs_get_instance_private (vfs);
g_clear_pointer (&priv->additional_schemes, g_hash_table_destroy);
g_clear_pointer (&priv->supported_schemes, g_free);
G_OBJECT_CLASS (g_vfs_parent_class)->dispose (object);
}
static void
g_vfs_class_init (GVfsClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->dispose = g_vfs_dispose;
}
static GFile *
resource_parse_name (GVfs *vfs,
const char *parse_name,
gpointer user_data)
{
if (g_str_has_prefix (parse_name, "resource:"))
return _g_resource_file_new (parse_name);
return NULL;
}
static GFile *
resource_get_file_for_uri (GVfs *vfs,
const char *uri,
gpointer user_data)
{
return _g_resource_file_new (uri);
}
static void
g_vfs_uri_lookup_func_closure_free (gpointer data)
{
GVfsURISchemeData *closure = data;
if (closure->uri_destroy)
closure->uri_destroy (closure->uri_data);
if (closure->parse_name_destroy)
closure->parse_name_destroy (closure->parse_name_data);
g_free (closure);
}
static void
g_vfs_init (GVfs *vfs)
{
GVfsPrivate *priv = g_vfs_get_instance_private (vfs);
priv->additional_schemes =
g_hash_table_new_full (g_str_hash, g_str_equal,
g_free, g_vfs_uri_lookup_func_closure_free);
g_vfs_register_uri_scheme (vfs, "resource",
resource_get_file_for_uri, NULL, NULL,
resource_parse_name, NULL, NULL);
}
/**
* g_vfs_is_active:
* @vfs: a #GVfs.
*
* Checks if the VFS is active.
*
* Returns: %TRUE if construction of the @vfs was successful
* and it is now active.
*/
gboolean
g_vfs_is_active (GVfs *vfs)
{
GVfsClass *class;
g_return_val_if_fail (G_IS_VFS (vfs), FALSE);
class = G_VFS_GET_CLASS (vfs);
return (* class->is_active) (vfs);
}
/**
* g_vfs_get_file_for_path:
* @vfs: a #GVfs.
* @path: a string containing a VFS path.
*
* Gets a #GFile for @path.
*
* Returns: (transfer full): a #GFile.
* Free the returned object with g_object_unref().
*/
GFile *
g_vfs_get_file_for_path (GVfs *vfs,
const char *path)
{
GVfsClass *class;
g_return_val_if_fail (G_IS_VFS (vfs), NULL);
g_return_val_if_fail (path != NULL, NULL);
class = G_VFS_GET_CLASS (vfs);
return (* class->get_file_for_path) (vfs, path);
}
static GFile *
parse_name_internal (GVfs *vfs,
const char *parse_name)
{
GVfsPrivate *priv = g_vfs_get_instance_private (vfs);
GHashTableIter iter;
GVfsURISchemeData *closure;
GFile *ret = NULL;
g_rw_lock_reader_lock (&additional_schemes_lock);
g_hash_table_iter_init (&iter, priv->additional_schemes);
while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &closure))
{
ret = closure->parse_name_func (vfs, parse_name,
closure->parse_name_data);
if (ret)
break;
}
g_rw_lock_reader_unlock (&additional_schemes_lock);
return ret;
}
static GFile *
get_file_for_uri_internal (GVfs *vfs,
const char *uri)
{
GVfsPrivate *priv = g_vfs_get_instance_private (vfs);
GFile *ret = NULL;
char *scheme;
GVfsURISchemeData *closure;
scheme = g_uri_parse_scheme (uri);
if (scheme == NULL)
return NULL;
g_rw_lock_reader_lock (&additional_schemes_lock);
closure = g_hash_table_lookup (priv->additional_schemes, scheme);
if (closure)
ret = closure->uri_func (vfs, uri, closure->uri_data);
g_rw_lock_reader_unlock (&additional_schemes_lock);
g_free (scheme);
return ret;
}
/**
* g_vfs_get_file_for_uri:
* @vfs: a#GVfs.
* @uri: a string containing a URI
*
* Gets a #GFile for @uri.
*
* This operation never fails, but the returned object
* might not support any I/O operation if the URI
* is malformed or if the URI scheme is not supported.
*
* Returns: (transfer full): a #GFile.
* Free the returned object with g_object_unref().
*/
GFile *
g_vfs_get_file_for_uri (GVfs *vfs,
const char *uri)
{
GVfsClass *class;
GFile *ret = NULL;
g_return_val_if_fail (G_IS_VFS (vfs), NULL);
g_return_val_if_fail (uri != NULL, NULL);
class = G_VFS_GET_CLASS (vfs);
ret = get_file_for_uri_internal (vfs, uri);
if (!ret)
ret = (* class->get_file_for_uri) (vfs, uri);
g_assert (ret != NULL);
return g_steal_pointer (&ret);
}
/**
* g_vfs_get_supported_uri_schemes:
* @vfs: a #GVfs.
*
* Gets a list of URI schemes supported by @vfs.
*
* Returns: (transfer none): a %NULL-terminated array of strings.
* The returned array belongs to GIO and must
* not be freed or modified.
*/
const gchar * const *
g_vfs_get_supported_uri_schemes (GVfs *vfs)
{
GVfsPrivate *priv;
g_return_val_if_fail (G_IS_VFS (vfs), NULL);
priv = g_vfs_get_instance_private (vfs);
if (!priv->supported_schemes)
{
GVfsClass *class;
const char * const *default_schemes;
const char *additional_scheme;
GPtrArray *supported_schemes;
GHashTableIter iter;
class = G_VFS_GET_CLASS (vfs);
default_schemes = (* class->get_supported_uri_schemes) (vfs);
supported_schemes = g_ptr_array_new ();
for (; default_schemes && *default_schemes; default_schemes++)
g_ptr_array_add (supported_schemes, (gpointer) *default_schemes);
g_rw_lock_reader_lock (&additional_schemes_lock);
g_hash_table_iter_init (&iter, priv->additional_schemes);
while (g_hash_table_iter_next
(&iter, (gpointer *) &additional_scheme, NULL))
g_ptr_array_add (supported_schemes, (gpointer) additional_scheme);
g_rw_lock_reader_unlock (&additional_schemes_lock);
g_ptr_array_add (supported_schemes, NULL);
g_free (priv->supported_schemes);
priv->supported_schemes =
(char const **) g_ptr_array_free (supported_schemes, FALSE);
}
return priv->supported_schemes;
}
/**
* g_vfs_parse_name:
* @vfs: a #GVfs.
* @parse_name: a string to be parsed by the VFS module.
*
* This operation never fails, but the returned object might
* not support any I/O operations if the @parse_name cannot
* be parsed by the #GVfs module.
*
* Returns: (transfer full): a #GFile for the given @parse_name.
* Free the returned object with g_object_unref().
*/
GFile *
g_vfs_parse_name (GVfs *vfs,
const char *parse_name)
{
GVfsClass *class;
GFile *ret;
g_return_val_if_fail (G_IS_VFS (vfs), NULL);
g_return_val_if_fail (parse_name != NULL, NULL);
class = G_VFS_GET_CLASS (vfs);
ret = parse_name_internal (vfs, parse_name);
if (ret)
return ret;
return (* class->parse_name) (vfs, parse_name);
}
static GVfs *vfs_default_singleton = NULL; /* (owned) (atomic) */
/**
* g_vfs_get_default:
*
* Gets the default #GVfs for the system.
*
* Returns: (not nullable) (transfer none): a #GVfs, which will be the local
* file system #GVfs if no other implementation is available.
*/
GVfs *
g_vfs_get_default (void)
{
if (GLIB_PRIVATE_CALL (g_check_setuid) ())
return g_vfs_get_local ();
if (g_once_init_enter_pointer (&vfs_default_singleton))
{
GVfs *singleton;
singleton = _g_io_module_get_default (G_VFS_EXTENSION_POINT_NAME,
"GIO_USE_VFS",
(GIOModuleVerifyFunc) g_vfs_is_active);
g_once_init_leave_pointer (&vfs_default_singleton, singleton);
}
return vfs_default_singleton;
}
/**
* g_vfs_get_local:
*
* Gets the local #GVfs for the system.
*
* Returns: (transfer none): a #GVfs.
*/
GVfs *
g_vfs_get_local (void)
{
static GVfs *vfs = 0;
if (g_once_init_enter_pointer (&vfs))
g_once_init_leave_pointer (&vfs, _g_local_vfs_new ());
return vfs;
}
/**
* g_vfs_register_uri_scheme:
* @vfs: a #GVfs
* @scheme: an URI scheme, e.g. "http"
* @uri_func: (scope notified) (nullable): a #GVfsFileLookupFunc
* @uri_data: (nullable): custom data passed to be passed to @uri_func, or %NULL
* @uri_destroy: (nullable): function to be called when unregistering the
* URI scheme, or when @vfs is disposed, to free the resources used
* by the URI lookup function
* @parse_name_func: (scope notified) (nullable): a #GVfsFileLookupFunc
* @parse_name_data: (nullable): custom data passed to be passed to
* @parse_name_func, or %NULL
* @parse_name_destroy: (nullable): function to be called when unregistering the
* URI scheme, or when @vfs is disposed, to free the resources used
* by the parse name lookup function
*
* Registers @uri_func and @parse_name_func as the #GFile URI and parse name
* lookup functions for URIs with a scheme matching @scheme.
* Note that @scheme is registered only within the running application, as
* opposed to desktop-wide as it happens with GVfs backends.
*
* When a #GFile is requested with an URI containing @scheme (e.g. through
* g_file_new_for_uri()), @uri_func will be called to allow a custom
* constructor. The implementation of @uri_func should not be blocking, and
* must not call g_vfs_register_uri_scheme() or g_vfs_unregister_uri_scheme().
*
* When g_file_parse_name() is called with a parse name obtained from such file,
* @parse_name_func will be called to allow the #GFile to be created again. In
* that case, it's responsibility of @parse_name_func to make sure the parse
* name matches what the custom #GFile implementation returned when
* g_file_get_parse_name() was previously called. The implementation of
* @parse_name_func should not be blocking, and must not call
* g_vfs_register_uri_scheme() or g_vfs_unregister_uri_scheme().
*
* It's an error to call this function twice with the same scheme. To unregister
* a custom URI scheme, use g_vfs_unregister_uri_scheme().
*
* Returns: %TRUE if @scheme was successfully registered, or %FALSE if a handler
* for @scheme already exists.
*
* Since: 2.50
*/
gboolean
g_vfs_register_uri_scheme (GVfs *vfs,
const char *scheme,
GVfsFileLookupFunc uri_func,
gpointer uri_data,
GDestroyNotify uri_destroy,
GVfsFileLookupFunc parse_name_func,
gpointer parse_name_data,
GDestroyNotify parse_name_destroy)
{
GVfsPrivate *priv;
GVfsURISchemeData *closure;
g_return_val_if_fail (G_IS_VFS (vfs), FALSE);
g_return_val_if_fail (scheme != NULL, FALSE);
priv = g_vfs_get_instance_private (vfs);
g_rw_lock_reader_lock (&additional_schemes_lock);
closure = g_hash_table_lookup (priv->additional_schemes, scheme);
g_rw_lock_reader_unlock (&additional_schemes_lock);
if (closure != NULL)
return FALSE;
closure = g_new0 (GVfsURISchemeData, 1);
closure->uri_func = uri_func;
closure->uri_data = uri_data;
closure->uri_destroy = uri_destroy;
closure->parse_name_func = parse_name_func;
closure->parse_name_data = parse_name_data;
closure->parse_name_destroy = parse_name_destroy;
g_rw_lock_writer_lock (&additional_schemes_lock);
g_hash_table_insert (priv->additional_schemes, g_strdup (scheme), closure);
g_rw_lock_writer_unlock (&additional_schemes_lock);
/* Invalidate supported schemes */
g_clear_pointer (&priv->supported_schemes, g_free);
return TRUE;
}
/**
* g_vfs_unregister_uri_scheme:
* @vfs: a #GVfs
* @scheme: an URI scheme, e.g. "http"
*
* Unregisters the URI handler for @scheme previously registered with
* g_vfs_register_uri_scheme().
*
* Returns: %TRUE if @scheme was successfully unregistered, or %FALSE if a
* handler for @scheme does not exist.
*
* Since: 2.50
*/
gboolean
g_vfs_unregister_uri_scheme (GVfs *vfs,
const char *scheme)
{
GVfsPrivate *priv;
gboolean res;
g_return_val_if_fail (G_IS_VFS (vfs), FALSE);
g_return_val_if_fail (scheme != NULL, FALSE);
priv = g_vfs_get_instance_private (vfs);
g_rw_lock_writer_lock (&additional_schemes_lock);
res = g_hash_table_remove (priv->additional_schemes, scheme);
g_rw_lock_writer_unlock (&additional_schemes_lock);
if (res)
{
/* Invalidate supported schemes */
g_clear_pointer (&priv->supported_schemes, g_free);
return TRUE;
}
return FALSE;
}