gstreamer/subprojects/gst-python/plugin/gstpythonplugin.c
Stéphane Cerveau 853963ba21 pythonplugin: fails silently on plugin issue
If a gst python plugin fails to load, the meta plugin
should continue to try loading the following.
If no plugin can be loaded, the meta plugin should
not be blacklisted by returning false.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2253>
2022-04-28 08:57:47 +00:00

344 lines
9.9 KiB
C

/* gst-python
* Copyright (C) 2009 Edward Hervey <bilboed@bilboed.com>
* 2005 Benjamin Otte <otte@gnome.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/* include this first, before NO_IMPORT_PYGOBJECT is defined */
#include <pygobject.h>
#include <gst/gst.h>
#include <gmodule.h>
#include <Python.h>
void *_PyGstElement_Type;
GST_DEBUG_CATEGORY_STATIC (pyplugindebug);
#define GST_CAT_DEFAULT pyplugindebug
#define GST_ORIGIN "http://gstreamer.freedesktop.org"
static gboolean
gst_python_plugin_load_file (GstPlugin * plugin, const char *name)
{
PyObject *main_module, *main_locals;
PyObject *elementfactory;
PyObject *module;
const gchar *facname;
guint rank;
PyObject *class;
GST_DEBUG ("loading plugin %s", name);
main_module = PyImport_AddModule ("__main__");
if (main_module == NULL) {
GST_WARNING ("Could not get __main__, ignoring plugin %s", name);
PyErr_Print ();
PyErr_Clear ();
return FALSE;
}
main_locals = PyModule_GetDict (main_module);
module =
PyImport_ImportModuleEx ((char *) name, main_locals, main_locals, NULL);
if (!module) {
GST_DEBUG ("Could not load module, ignoring plugin %s", name);
PyErr_Print ();
PyErr_Clear ();
return FALSE;
}
/* Get __gstelementfactory__ from file */
elementfactory = PyObject_GetAttrString (module, "__gstelementfactory__");
if (!elementfactory) {
GST_DEBUG ("python file doesn't contain __gstelementfactory__");
PyErr_Clear ();
return FALSE;
}
/* parse tuple : name, rank, gst.ElementClass */
if (!PyArg_ParseTuple (elementfactory, "sIO", &facname, &rank, &class)) {
GST_WARNING ("__gstelementfactory__ isn't correctly formatted");
PyErr_Print ();
PyErr_Clear ();
Py_DECREF (elementfactory);
return FALSE;
}
if (!PyObject_IsSubclass (class, (PyObject *) & PyGObject_Type)) {
GST_WARNING ("the class provided isn't a subclass of GObject.Object");
PyErr_Print ();
PyErr_Clear ();
Py_DECREF (elementfactory);
Py_DECREF (class);
return FALSE;
}
if (!g_type_is_a (pyg_type_from_object (class), GST_TYPE_ELEMENT)) {
GST_WARNING ("the class provided isn't a subclass of Gst.Element");
PyErr_Print ();
PyErr_Clear ();
Py_DECREF (elementfactory);
Py_DECREF (class);
return FALSE;
}
GST_INFO ("Valid plugin");
Py_DECREF (elementfactory);
return gst_element_register (plugin, facname, rank,
pyg_type_from_object (class));
}
static gboolean
gst_python_load_directory (GstPlugin * plugin, const gchar * path)
{
GDir *dir;
const gchar *file;
GError *error = NULL;
dir = g_dir_open (path, 0, &error);
if (!dir) {
/*retval should probably be depending on error, but since we ignore it... */
GST_DEBUG ("Couldn't open Python plugin dir: %s", error->message);
g_error_free (error);
return FALSE;
}
while ((file = g_dir_read_name (dir))) {
/* FIXME : go down in subdirectories */
if (g_str_has_suffix (file, ".py")) {
gsize len = strlen (file) - 3;
gchar *name = g_strndup (file, len);
gst_python_plugin_load_file (plugin, name);
g_free (name);
}
}
return TRUE;
}
static gboolean
gst_python_plugin_load (GstPlugin * plugin)
{
PyObject *sys_path;
const gchar *plugin_path;
gboolean ret = TRUE;
sys_path = PySys_GetObject ("path");
/* Mimic the order in which the registry is checked in core */
/* 1. check env_variable GST_PLUGIN_PATH */
plugin_path = g_getenv ("GST_PLUGIN_PATH_1_0");
if (plugin_path == NULL)
plugin_path = g_getenv ("GST_PLUGIN_PATH");
if (plugin_path) {
char **list;
int i;
GST_DEBUG ("GST_PLUGIN_PATH set to %s", plugin_path);
list = g_strsplit (plugin_path, G_SEARCHPATH_SEPARATOR_S, 0);
for (i = 0; list[i]; i++) {
gchar *sysdir = g_build_filename (list[i], "python", NULL);
PyList_Insert (sys_path, 0, PyUnicode_FromString (sysdir));
gst_python_load_directory (plugin, sysdir);
g_free (sysdir);
}
g_strfreev (list);
}
/* 2. Check for GST_PLUGIN_SYSTEM_PATH */
plugin_path = g_getenv ("GST_PLUGIN_SYSTEM_PATH_1_0");
if (plugin_path == NULL)
plugin_path = g_getenv ("GST_PLUGIN_SYSTEM_PATH");
if (plugin_path == NULL) {
char *home_plugins;
/* 2.a. Scan user and system-wide plugin directory */
GST_DEBUG ("GST_PLUGIN_SYSTEM_PATH not set");
/* plugins in the user's home directory take precedence over
* system-installed ones */
home_plugins = g_build_filename (g_get_home_dir (),
".gstreamer-" GST_API_VERSION, "plugins", "python", NULL);
PyList_Insert (sys_path, 0, PyUnicode_FromString (home_plugins));
gst_python_load_directory (plugin, home_plugins);
g_free (home_plugins);
/* add the main (installed) library path */
PyList_Insert (sys_path, 0, PyUnicode_FromString (PLUGINDIR "/python"));
gst_python_load_directory (plugin, PLUGINDIR "/python");
} else {
gchar **list;
gint i;
/* 2.b. Scan GST_PLUGIN_SYSTEM_PATH */
GST_DEBUG ("GST_PLUGIN_SYSTEM_PATH set to %s", plugin_path);
list = g_strsplit (plugin_path, G_SEARCHPATH_SEPARATOR_S, 0);
for (i = 0; list[i]; i++) {
gchar *sysdir;
sysdir = g_build_filename (list[i], "python", NULL);
PyList_Insert (sys_path, 0, PyUnicode_FromString (sysdir));
gst_python_load_directory (plugin, sysdir);
g_free (sysdir);
}
g_strfreev (list);
}
return ret;
}
static gboolean
plugin_init (GstPlugin * plugin)
{
PyGILState_STATE state = 0;
PyObject *gi, *require_version, *args, *gst, *dict, *pyplugin;
gboolean we_initialized = FALSE;
GModule *libpython;
gpointer has_python = NULL;
const gchar *override_path;
GST_DEBUG_CATEGORY_INIT (pyplugindebug, "pyplugin", 0,
"Python plugin loader");
gst_plugin_add_dependency_simple (plugin,
"HOME/.gstreamer-" GST_API_VERSION
"/plugins/python:GST_PLUGIN_SYSTEM_PATH/python:GST_PLUGIN_PATH/python",
PLUGINDIR "/python:HOME/.gstreamer-" GST_API_VERSION "/plugins/python:"
"GST_PLUGIN_SYSTEM_PATH/python:GST_PLUGIN_PATH/python", NULL,
GST_PLUGIN_DEPENDENCY_FLAG_NONE);
GST_LOG ("Checking to see if libpython is already loaded");
if (g_module_symbol (g_module_open (NULL, G_MODULE_BIND_LOCAL),
"_Py_NoneStruct", &has_python) && has_python) {
GST_LOG ("libpython is already loaded");
} else {
const gchar *libpython_path =
PY_LIB_LOC "/libpython" PYTHON_VERSION PY_ABI_FLAGS "." PY_LIB_SUFFIX;
GST_LOG ("loading libpython from '%s'", libpython_path);
libpython = g_module_open (libpython_path, 0);
if (!libpython) {
g_critical ("Couldn't g_module_open libpython. Reason: %s",
g_module_error ());
return FALSE;
}
}
if (!Py_IsInitialized ()) {
GST_LOG ("python wasn't initialized");
/* set the correct plugin for registering stuff */
Py_Initialize ();
we_initialized = TRUE;
} else {
GST_LOG ("python was already initialized");
state = PyGILState_Ensure ();
}
if ((override_path = g_getenv ("GST_OVERRIDE_SRC_PATH"))) {
gchar *overrides_setup =
g_build_filename (override_path, "..", "..", "testsuite",
"overrides_hack.py", NULL);
FILE *fd = fopen (overrides_setup, "rb");
if (!fd || PyRun_SimpleFileExFlags (fd, overrides_setup, 1, 0)) {
g_free (overrides_setup);
return FALSE;
} else {
g_free (overrides_setup);
GST_INFO ("Imported overrides setup");
}
}
GST_LOG ("Running with python version '%s'", Py_GetVersion ());
GST_LOG ("initializing pygobject");
if (!pygobject_init (3, 0, 0)) {
g_critical ("pygobject initialization failed");
return FALSE;
}
gi = PyImport_ImportModule ("gi");
if (!gi) {
g_critical ("can't find gi");
return FALSE;
}
require_version = PyObject_GetAttrString (gi, (char *) "require_version");
args = PyTuple_Pack (2, PyUnicode_FromString ("Gst"),
PyUnicode_FromString ("1.0"));
PyObject_CallObject (require_version, args);
Py_DECREF (require_version);
Py_DECREF (args);
Py_DECREF (gi);
gst = PyImport_ImportModule ("gi.repository.Gst");
if (!gst) {
g_critical ("can't find gi.repository.Gst");
return FALSE;
}
if (we_initialized) {
PyObject *tmp;
dict = PyModule_GetDict (gst);
if (!dict) {
g_critical ("gi.repository.Gst is no dict");
return FALSE;
}
tmp =
PyObject_GetAttr (PyMapping_GetItemString (dict,
"_introspection_module"), PyUnicode_FromString ("__dict__"));
_PyGstElement_Type = PyMapping_GetItemString (tmp, "Element");
if (!_PyGstElement_Type) {
g_critical ("Could not get Gst.Element");
return FALSE;
}
pyplugin = pygobject_new (G_OBJECT (plugin));
if (!pyplugin || PyModule_AddObject (gst, "__plugin__", pyplugin) != 0) {
g_critical ("Couldn't set __plugin__ attribute");
if (pyplugin)
Py_DECREF (pyplugin);
return FALSE;
}
}
gst_python_plugin_load (plugin);
if (we_initialized) {
/* We need to release the GIL since we're going back to C land */
PyEval_SaveThread ();
} else
PyGILState_Release (state);
return TRUE;
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR, python,
"loader for plugins written in python",
plugin_init, VERSION, "LGPL", PACKAGE_NAME, GST_ORIGIN)