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plugin-loaders/python/gedit-plugin-loader-python.c

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+/*
+ * gedit-plugin-loader-python.c
+ * This file is part of gedit
+ *
+ * Copyright (C) 2008 - Jesse van den Kieboom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, 
+ * Boston, MA 02111-1307, USA. 
+ */
+
+#include "gedit-plugin-loader-python.h"
+#include "gedit-plugin-python.h"
+#include <gedit/gedit-object-module.h>
+
+#define NO_IMPORT_PYGOBJECT
+#define NO_IMPORT_PYGTK
+
+#include <Python.h>
+#include <pygobject.h>
+#include <pygtk/pygtk.h>
+#include <signal.h>
+#include "config.h"
+
+#if PY_VERSION_HEX < 0x02050000
+typedef int Py_ssize_t;
+#define PY_SSIZE_T_MAX INT_MAX
+#define PY_SSIZE_T_MIN INT_MIN
+#endif
+
+#define GEDIT_PLUGIN_LOADER_PYTHON_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE((object), GEDIT_TYPE_PLUGIN_LOADER_PYTHON, GeditPluginLoaderPythonPrivate))
+
+struct _GeditPluginLoaderPythonPrivate
+{
+	GHashTable *loaded_plugins;
+	guint idle_gc;
+	gboolean init_failed;
+};
+
+typedef struct
+{
+	PyObject *type;
+	PyObject *instance;
+	gchar    *path;
+} PythonInfo;
+
+static void gedit_plugin_loader_iface_init (gpointer g_iface, gpointer iface_data);
+
+/* Exported by pygedit module */
+void pygedit_register_classes (PyObject *d);
+void pygedit_add_constants (PyObject *module, const gchar *strip_prefix);
+extern PyMethodDef pygedit_functions[];
+
+/* Exported by pygeditutils module */
+void pygeditutils_register_classes (PyObject *d);
+extern PyMethodDef pygeditutils_functions[];
+
+/* Exported by pygeditcommands module */
+void pygeditcommands_register_classes (PyObject *d);
+extern PyMethodDef pygeditcommands_functions[];
+
+/* We retreive this to check for correct class hierarchy */
+static PyTypeObject *PyGeditPlugin_Type;
+
+GEDIT_PLUGIN_LOADER_REGISTER_TYPE (GeditPluginLoaderPython, gedit_plugin_loader_python, G_TYPE_OBJECT, gedit_plugin_loader_iface_init);
+
+
+static PyObject *
+find_python_plugin_type (GeditPluginInfo *info,
+			 PyObject        *pymodule)
+{
+	PyObject *locals, *key, *value;
+	Py_ssize_t pos = 0;
+	
+	locals = PyModule_GetDict (pymodule);
+
+	while (PyDict_Next (locals, &pos, &key, &value))
+	{
+		if (!PyType_Check(value))
+			continue;
+
+		if (PyObject_IsSubclass (value, (PyObject*) PyGeditPlugin_Type))
+			return value;
+	}
+	
+	g_warning ("No GeditPlugin derivative found in Python plugin '%s'",
+		   gedit_plugin_info_get_name (info));
+	return NULL;
+}
+
+static GeditPlugin *
+new_plugin_from_info (GeditPluginLoaderPython *loader,
+		      GeditPluginInfo         *info)
+{
+	PythonInfo *pyinfo;
+	PyTypeObject *pytype;
+	PyObject *pyobject;
+	PyGObject *pygobject;
+	GeditPlugin *instance;
+	PyObject *emptyarg;
+
+	pyinfo = (PythonInfo *)g_hash_table_lookup (loader->priv->loaded_plugins, info);
+	
+	if (pyinfo == NULL)
+		return NULL;
+	
+	pytype = (PyTypeObject *)pyinfo->type;
+	
+	if (pytype->tp_new == NULL)
+		return NULL;
+
+	emptyarg = PyTuple_New(0);
+	pyobject = pytype->tp_new (pytype, emptyarg, NULL);
+	Py_DECREF (emptyarg);
+	
+	if (pyobject == NULL)
+	{
+		g_error ("Could not create instance for %s.", gedit_plugin_info_get_name (info));
+		return NULL;
+	}
+
+	pygobject = (PyGObject *)pyobject;
+	
+	if (pygobject->obj != NULL)
+	{
+		Py_DECREF (pyobject);
+		g_error ("Could not create instance for %s (GObject already initialized).", gedit_plugin_info_get_name (info));
+		return NULL;
+	}
+	
+	pygobject_construct (pygobject,
+			     "install-dir", pyinfo->path,
+			     "data-dir-name", gedit_plugin_info_get_module_name (info),
+			     NULL);
+	
+	if (pygobject->obj == NULL)
+	{
+		g_error ("Could not create instance for %s (GObject not constructed).", gedit_plugin_info_get_name (info));
+		Py_DECREF (pyobject);
+
+		return NULL;
+	}
+
+	/* now call tp_init manually */
+	if (PyType_IsSubtype (pyobject->ob_type, pytype) && 
+	    pyobject->ob_type->tp_init != NULL)
+	{
+		emptyarg = PyTuple_New(0);
+		pyobject->ob_type->tp_init (pyobject, emptyarg, NULL);
+		Py_DECREF (emptyarg);
+	}
+
+	instance = GEDIT_PLUGIN (pygobject->obj);
+	pyinfo->instance = (PyObject *)pygobject;
+
+	/* make sure to register the python instance for the GeditPluginPython
+	   object to it can wrap the virtual gedit plugin funcs back to python */
+	_gedit_plugin_python_set_instance (GEDIT_PLUGIN_PYTHON (instance), (PyObject *)pygobject);
+	
+	/* we return a reference here because the other is owned by python */
+	return GEDIT_PLUGIN (g_object_ref (instance));
+}
+
+static GeditPlugin *
+add_python_info (GeditPluginLoaderPython *loader,
+		 GeditPluginInfo         *info,
+		 PyObject		 *module,
+		 const gchar             *path,
+		 PyObject                *type)
+{
+	PythonInfo *pyinfo;
+	
+	pyinfo = g_new (PythonInfo, 1);
+	pyinfo->path = g_strdup (path);
+	pyinfo->type = type;
+
+	Py_INCREF (pyinfo->type);
+	
+	g_hash_table_insert (loader->priv->loaded_plugins, info, pyinfo);
+	
+	return new_plugin_from_info (loader, info);
+}
+
+static const gchar *
+gedit_plugin_loader_iface_get_id (void)
+{
+	return "Python";
+}
+
+static GeditPlugin *
+gedit_plugin_loader_iface_load (GeditPluginLoader *loader,
+				GeditPluginInfo   *info,
+				const gchar       *path)
+{
+	GeditPluginLoaderPython *pyloader = GEDIT_PLUGIN_LOADER_PYTHON (loader);
+	PyObject *main_module, *main_locals, *pytype;
+	PyObject *pymodule, *fromlist;
+	gchar *module_name;
+	GeditPlugin *result;
+	
+	if (pyloader->priv->init_failed)
+	{
+		g_warning ("Cannot load python plugin Python '%s' since gedit was"
+		           "not able to initialize the Python interpreter.",
+		           gedit_plugin_info_get_name (info));
+		return NULL;
+	}
+	
+	/* see if py definition for the plugin is already loaded */
+	result = new_plugin_from_info (pyloader, info);
+	
+	if (result != NULL)
+		return result;
+	
+	main_module = PyImport_AddModule ("gedit.plugins");
+	if (main_module == NULL)
+	{
+		g_warning ("Could not get gedit.plugins.");
+		return NULL;
+	}
+	
+	/* If we have a special path, we register it */
+	if (path != NULL)
+	{
+		PyObject *sys_path = PySys_GetObject ("path");
+		PyObject *pypath = PyString_FromString (path);
+
+		if (PySequence_Contains (sys_path, pypath) == 0)
+			PyList_Insert (sys_path, 0, pypath);
+
+		Py_DECREF (pypath);
+	}
+	
+	main_locals = PyModule_GetDict (main_module);
+	
+	/* we need a fromlist to be able to import modules with a '.' in the
+	   name. */
+	fromlist = PyTuple_New(0);
+	module_name = g_strdup (gedit_plugin_info_get_module_name (info));
+	
+	pymodule = PyImport_ImportModuleEx (module_name, 
+					    main_locals, 
+					    main_locals, 
+					    fromlist);
+	
+	Py_DECREF(fromlist);
+
+	if (!pymodule)
+	{
+		g_free (module_name);
+		PyErr_Print ();
+		return NULL;
+	}
+
+	PyDict_SetItemString (main_locals, module_name, pymodule);
+	g_free (module_name);
+	
+	pytype = find_python_plugin_type (info, pymodule);
+	
+	if (pytype)
+		return add_python_info (pyloader, info, pymodule, path, pytype);
+
+	return NULL;
+}
+
+static void
+gedit_plugin_loader_iface_unload (GeditPluginLoader *loader,
+				  GeditPluginInfo   *info)
+{
+	GeditPluginLoaderPython *pyloader = GEDIT_PLUGIN_LOADER_PYTHON (loader);
+	PythonInfo *pyinfo;
+	PyGILState_STATE state;
+	
+	pyinfo = (PythonInfo *)g_hash_table_lookup (pyloader->priv->loaded_plugins, info);
+	
+	if (!pyinfo)
+		return;
+	
+	state = pyg_gil_state_ensure ();
+	Py_XDECREF (pyinfo->instance);
+	pyg_gil_state_release (state);
+	
+	pyinfo->instance = NULL;
+}
+
+static gboolean
+run_gc (GeditPluginLoaderPython *loader)
+{
+	while (PyGC_Collect ())
+		;
+
+	loader->priv->idle_gc = 0;
+	return FALSE;
+}
+
+static void
+gedit_plugin_loader_iface_garbage_collect (GeditPluginLoader *loader)
+{
+	GeditPluginLoaderPython *pyloader;
+	
+	if (!Py_IsInitialized())
+		return;
+
+	pyloader = GEDIT_PLUGIN_LOADER_PYTHON (loader);
+
+	/*
+	 * We both run the GC right now and we schedule
+	 * a further collection in the main loop.
+	 */
+
+	while (PyGC_Collect ())
+		;
+
+	if (pyloader->priv->idle_gc == 0)
+		pyloader->priv->idle_gc = g_idle_add ((GSourceFunc)run_gc, pyloader);
+}
+
+static void
+gedit_plugin_loader_iface_init (gpointer g_iface, 
+				gpointer iface_data)
+{
+	GeditPluginLoaderInterface *iface = (GeditPluginLoaderInterface *)g_iface;
+	
+	iface->get_id = gedit_plugin_loader_iface_get_id;
+	iface->load = gedit_plugin_loader_iface_load;
+	iface->unload = gedit_plugin_loader_iface_unload;
+	iface->garbage_collect = gedit_plugin_loader_iface_garbage_collect;
+}
+
+static void
+gedit_python_shutdown (GeditPluginLoaderPython *loader)
+{
+	if (!Py_IsInitialized ())
+		return;
+
+	if (loader->priv->idle_gc != 0)
+	{
+		g_source_remove (loader->priv->idle_gc);
+		loader->priv->idle_gc = 0;
+	}
+
+	while (PyGC_Collect ())
+		;	
+
+	Py_Finalize ();
+}
+
+
+/* C equivalent of
+ *    import pygtk
+ *    pygtk.require ("2.0")
+ */
+static gboolean
+gedit_check_pygtk2 (void)
+{
+	PyObject *pygtk, *mdict, *require;
+
+	/* pygtk.require("2.0") */
+	pygtk = PyImport_ImportModule ("pygtk");
+	if (pygtk == NULL)
+	{
+		g_warning ("Error initializing Python interpreter: could not import pygtk.");
+		return FALSE;
+	}
+
+	mdict = PyModule_GetDict (pygtk);
+	require = PyDict_GetItemString (mdict, "require");
+	PyObject_CallObject (require,
+			     Py_BuildValue ("(S)", PyString_FromString ("2.0")));
+	if (PyErr_Occurred())
+	{
+		g_warning ("Error initializing Python interpreter: pygtk 2 is required.");
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+/* Note: the following two functions are needed because
+ * init_pyobject and init_pygtk which are *macros* which in case
+ * case of error set the PyErr and then make the calling
+ * function return behind our back.
+ * It's up to the caller to check the result with PyErr_Occurred()
+ */
+static void
+gedit_init_pygobject (void)
+{
+	init_pygobject_check (2, 11, 5); /* FIXME: get from config */
+}
+
+static void
+gedit_init_pygtk (void)
+{
+	PyObject *gtk, *mdict, *version, *required_version;
+
+	init_pygtk ();
+
+	/* there isn't init_pygtk_check(), do the version
+	 * check ourselves */
+	gtk = PyImport_ImportModule("gtk");
+	mdict = PyModule_GetDict(gtk);
+	version = PyDict_GetItemString (mdict, "pygtk_version");
+	if (!version)
+	{
+		PyErr_SetString (PyExc_ImportError,
+				 "PyGObject version too old");
+		return;
+	}
+
+	required_version = Py_BuildValue ("(iii)", 2, 4, 0); /* FIXME */
+
+	if (PyObject_Compare (version, required_version) == -1)
+	{
+		PyErr_SetString (PyExc_ImportError,
+				 "PyGObject version too old");
+		Py_DECREF (required_version);
+		return;
+	}
+
+	Py_DECREF (required_version);
+}
+
+static void
+old_gtksourceview_init (void)
+{
+	PyErr_SetString(PyExc_ImportError,
+			"gtksourceview module not allowed, use gtksourceview2");
+}
+
+static void
+gedit_init_pygtksourceview (void)
+{
+	PyObject *gtksourceview, *mdict, *version, *required_version;
+
+	gtksourceview = PyImport_ImportModule("gtksourceview2");
+	if (gtksourceview == NULL)
+	{
+		PyErr_SetString (PyExc_ImportError,
+				 "could not import gtksourceview");
+		return;
+	}
+
+	mdict = PyModule_GetDict (gtksourceview);
+	version = PyDict_GetItemString (mdict, "pygtksourceview2_version");
+	if (!version)
+	{
+		PyErr_SetString (PyExc_ImportError,
+				 "PyGtkSourceView version too old");
+		return;
+	}
+
+	required_version = Py_BuildValue ("(iii)", 0, 8, 0); /* FIXME */
+
+	if (PyObject_Compare (version, required_version) == -1)
+	{
+		PyErr_SetString (PyExc_ImportError,
+				 "PyGtkSourceView version too old");
+		Py_DECREF (required_version);
+		return;
+	}
+
+	Py_DECREF (required_version);
+
+	/* Create a dummy 'gtksourceview' module to prevent
+	 * loading of the old 'gtksourceview' modules that
+	 * has conflicting symbols with the gtksourceview2 module.
+	 * Raise an exception when trying to import it.
+	 */
+	PyImport_AppendInittab ("gtksourceview", old_gtksourceview_init);
+}
+
+static gboolean
+gedit_python_init (GeditPluginLoaderPython *loader)
+{
+	PyObject *mdict, *tuple;
+	PyObject *gedit, *geditutils, *geditcommands, *geditplugins;
+	PyObject *gettext, *install, *gettext_args;
+	//char *argv[] = { "gedit", NULL };
+	char *argv[] = { GEDIT_PLUGINS_LIBS_DIR, NULL };
+#ifdef HAVE_SIGACTION
+	gint res;
+	struct sigaction old_sigint;
+#endif
+
+	if (loader->priv->init_failed)
+	{
+		/* We already failed to initialized Python, don't need to
+		 * retry again */
+		return FALSE;
+	}
+	
+	if (Py_IsInitialized ())
+	{
+		/* Python has already been successfully initialized */
+		return TRUE;
+	}
+
+	/* We are trying to initialize Python for the first time,
+	   set init_failed to FALSE only if the entire initialization process
+	   ends with success */
+	loader->priv->init_failed = TRUE;
+
+	/* Hack to make python not overwrite SIGINT: this is needed to avoid
+	 * the crash reported on bug #326191 */
+
+	/* CHECK: can't we use Py_InitializeEx instead of Py_Initialize in order
+          to avoid to manage signal handlers ? - Paolo (Dec. 31, 2006) */
+
+#ifdef HAVE_SIGACTION
+	/* Save old handler */
+	res = sigaction (SIGINT, NULL, &old_sigint);  
+	if (res != 0)
+	{
+		g_warning ("Error initializing Python interpreter: cannot get "
+		           "handler to SIGINT signal (%s)",
+		           g_strerror (errno));
+
+		return FALSE;
+	}
+#endif
+
+	/* Python initialization */
+	Py_Initialize ();
+
+#ifdef HAVE_SIGACTION
+	/* Restore old handler */
+	res = sigaction (SIGINT, &old_sigint, NULL);
+	if (res != 0)
+	{
+		g_warning ("Error initializing Python interpreter: cannot restore "
+		           "handler to SIGINT signal (%s).",
+		           g_strerror (errno));
+
+		goto python_init_error;
+	}
+#endif
+
+	PySys_SetArgv (1, argv);
+
+	if (!gedit_check_pygtk2 ())
+	{
+		/* Warning message already printed in check_pygtk2 */
+		goto python_init_error;
+	}
+
+	/* import gobject */	
+	gedit_init_pygobject ();
+	if (PyErr_Occurred ())
+	{
+		g_warning ("Error initializing Python interpreter: could not import pygobject.");
+
+		goto python_init_error;		
+	}
+
+	/* import gtk */
+	gedit_init_pygtk ();
+	if (PyErr_Occurred ())
+	{
+		g_warning ("Error initializing Python interpreter: could not import pygtk.");
+
+		goto python_init_error;
+	}
+	
+	/* import gtksourceview */
+	gedit_init_pygtksourceview ();
+	if (PyErr_Occurred ())
+	{
+		PyErr_Print ();
+
+		g_warning ("Error initializing Python interpreter: could not import pygtksourceview.");
+
+		goto python_init_error;
+	}	
+	
+	/* import gedit */
+	gedit = Py_InitModule ("gedit", pygedit_functions);
+	mdict = PyModule_GetDict (gedit);
+
+	pygedit_register_classes (mdict);
+	pygedit_add_constants (gedit, "GEDIT_");
+
+	/* gedit version */
+	tuple = Py_BuildValue("(iii)", 
+			      GEDIT_MAJOR_VERSION,
+			      GEDIT_MINOR_VERSION,
+			      GEDIT_MICRO_VERSION);
+	PyDict_SetItemString(mdict, "version", tuple);
+	Py_DECREF(tuple);
+	
+	/* Retrieve the Python type for gedit.Plugin */
+	PyGeditPlugin_Type = (PyTypeObject *) PyDict_GetItemString (mdict, "Plugin"); 
+	if (PyGeditPlugin_Type == NULL)
+	{
+		PyErr_Print ();
+
+		goto python_init_error;
+	}
+
+	/* import gedit.utils */
+	geditutils = Py_InitModule ("gedit.utils", pygeditutils_functions);
+	PyDict_SetItemString (mdict, "utils", geditutils);
+
+	/* import gedit.commands */
+	geditcommands = Py_InitModule ("gedit.commands", pygeditcommands_functions);
+	PyDict_SetItemString (mdict, "commands", geditcommands);
+
+	/* initialize empty gedit.plugins module */
+	geditplugins = Py_InitModule ("gedit.plugins", NULL);
+	PyDict_SetItemString (mdict, "plugins", geditplugins);
+
+	mdict = PyModule_GetDict (geditutils);
+	pygeditutils_register_classes (mdict);
+	
+	mdict = PyModule_GetDict (geditcommands);
+	pygeditcommands_register_classes (mdict);
+
+	/* i18n support */
+	gettext = PyImport_ImportModule ("gettext");
+	if (gettext == NULL)
+	{
+		g_warning ("Error initializing Python interpreter: could not import gettext.");
+
+		goto python_init_error;
+	}
+
+	mdict = PyModule_GetDict (gettext);
+	install = PyDict_GetItemString (mdict, "install");
+	gettext_args = Py_BuildValue ("ss", GETTEXT_PACKAGE, GEDIT_LOCALEDIR);
+	PyObject_CallObject (install, gettext_args);
+	Py_DECREF (gettext_args);
+	
+	/* Python has been successfully initialized */
+	loader->priv->init_failed = FALSE;
+	
+	return TRUE;
+	
+python_init_error:
+
+	g_warning ("Please check the installation of all the Python related packages required "
+	           "by gedit and try again.");
+
+	PyErr_Clear ();
+
+	gedit_python_shutdown (loader);
+
+	return FALSE;
+}
+
+static void
+gedit_plugin_loader_python_finalize (GObject *object)
+{
+	GeditPluginLoaderPython *pyloader = GEDIT_PLUGIN_LOADER_PYTHON (object);
+	
+	g_hash_table_destroy (pyloader->priv->loaded_plugins);
+	gedit_python_shutdown (pyloader);
+
+	G_OBJECT_CLASS (gedit_plugin_loader_python_parent_class)->finalize (object);
+}
+
+static void
+gedit_plugin_loader_python_class_init (GeditPluginLoaderPythonClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (klass);
+	
+	object_class->finalize = gedit_plugin_loader_python_finalize;
+
+	g_type_class_add_private (object_class, sizeof (GeditPluginLoaderPythonPrivate));
+}
+
+static void
+gedit_plugin_loader_python_class_finalize (GeditPluginLoaderPythonClass *klass)
+{
+}
+
+static void
+destroy_python_info (PythonInfo *info)
+{
+	PyGILState_STATE state = pyg_gil_state_ensure ();
+	Py_XDECREF (info->type);	
+	pyg_gil_state_release (state);
+	
+	g_free (info->path);
+	g_free (info);
+}
+
+static void
+gedit_plugin_loader_python_init (GeditPluginLoaderPython *self)
+{
+	self->priv = GEDIT_PLUGIN_LOADER_PYTHON_GET_PRIVATE (self);
+	
+	/* initialize python interpreter */
+	gedit_python_init (self);
+
+	/* loaded_plugins maps GeditPluginInfo to a PythonInfo */
+	self->priv->loaded_plugins = g_hash_table_new_full (g_direct_hash,
+						            g_direct_equal,
+						            NULL,
+						            (GDestroyNotify)destroy_python_info);
+}
+
+GeditPluginLoaderPython *
+gedit_plugin_loader_python_new ()
+{
+	GObject *loader = g_object_new (GEDIT_TYPE_PLUGIN_LOADER_PYTHON, NULL);
+
+	return GEDIT_PLUGIN_LOADER_PYTHON (loader);
+}
+