[libsigrokdecode.git] / decoder.c

/*
 * This file is part of the sigrok project.
 *
 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
 * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"
#include "sigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
#include "sigrokdecode-internal.h"
#include <glib.h>

/** @cond PRIVATE */

/* The list of protocol decoders. */
SRD_PRIV GSList *pd_list = NULL;

/* module_sigrokdecode.c */
extern SRD_PRIV PyObject *mod_sigrokdecode;

/** @endcond */

/**
 * Returns the list of supported/loaded protocol decoders.
 *
 * This is a GSList containing the names of the decoders as strings.
 *
 * @return List of decoders, NULL if none are supported or loaded.
 */
SRD_API const GSList *srd_decoder_list(void)
{
	return pd_list;
}

/**
 * Get the decoder with the specified ID.
 *
 * @param id The ID string of the decoder to return.
 *
 * @return The decoder with the specified ID, or NULL if not found.
 */
SRD_API struct srd_decoder *srd_decoder_get_by_id(const char *id)
{
	GSList *l;
	struct srd_decoder *dec;

	for (l = pd_list; l; l = l->next) {
		dec = l->data;
		if (!strcmp(dec->id, id))
			return dec;
	}

	return NULL;
}

static int get_probes(const struct srd_decoder *d, const char *attr,
		      GSList **pl)
{
	PyObject *py_probelist, *py_entry;
	struct srd_probe *p;
	int ret, num_probes, i;

	if (!PyObject_HasAttrString(d->py_dec, attr))
		/* No probes of this type specified. */
		return SRD_OK;

	ret = SRD_ERR_PYTHON;
	py_probelist = py_entry = NULL;

	py_probelist = PyObject_GetAttrString(d->py_dec, attr);
	if (!PyList_Check(py_probelist)) {
		srd_err("Protocol decoder %s %s attribute is not "
			"a list.", d->name, attr);
		goto err_out;
	}

	num_probes = PyList_Size(py_probelist);
	if (num_probes == 0)
		/* Empty probelist. */
		return SRD_OK;

	for (i = 0; i < num_probes; i++) {
		py_entry = PyList_GetItem(py_probelist, i);
		if (!PyDict_Check(py_entry)) {
			srd_err("Protocol decoder %s %s attribute is not "
				"a list with dict elements.", d->name, attr);
			goto err_out;
		}

		if (!(p = g_try_malloc(sizeof(struct srd_probe)))) {
			srd_err("Failed to g_malloc() struct srd_probe.");
			ret = SRD_ERR_MALLOC;
			goto err_out;
		}

		if ((py_dictitem_as_str(py_entry, "id", &p->id)) != SRD_OK)
			goto err_out;
		if ((py_dictitem_as_str(py_entry, "name", &p->name)) != SRD_OK)
			goto err_out;
		if ((py_dictitem_as_str(py_entry, "desc", &p->desc)) != SRD_OK)
			goto err_out;
		p->order = i;

		*pl = g_slist_append(*pl, p);
	}
	ret = SRD_OK;

err_out:
	Py_DecRef(py_entry);
	Py_DecRef(py_probelist);

	return ret;
}

/**
 * Load a protocol decoder module into the embedded Python interpreter.
 *
 * @param module_name The module name to be loaded.
 *
 * @return SRD_OK upon success, a (negative) error code otherwise.
 */
SRD_API int srd_decoder_load(const char *module_name)
{
	PyObject *py_basedec, *py_method, *py_attr, *py_annlist, *py_ann;
	struct srd_decoder *d;
	int alen, ret, i;
	char **ann;
	struct srd_probe *p;
	GSList *l;

	srd_dbg("Loading protocol decoder '%s'.", module_name);

	py_basedec = py_method = py_attr = NULL;

	if (!(d = g_try_malloc0(sizeof(struct srd_decoder)))) {
		srd_dbg("Failed to g_malloc() struct srd_decoder.");
		ret = SRD_ERR_MALLOC;
		goto err_out;
	}

	ret = SRD_ERR_PYTHON;

	/* Import the Python module. */
	if (!(d->py_mod = PyImport_ImportModule(module_name))) {
		srd_exception_catch("Import of '%s' failed.", module_name);
		goto err_out;
	}

	/* Get the 'Decoder' class as Python object. */
	if (!(d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder"))) {
		/* This generated an AttributeError exception. */
		PyErr_Clear();
		srd_err("Decoder class not found in protocol decoder %s.",
			module_name);
		goto err_out;
	}

	if (!(py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder"))) {
		srd_dbg("sigrokdecode module not loaded.");
		goto err_out;
	}

	if (!PyObject_IsSubclass(d->py_dec, py_basedec)) {
		srd_err("Decoder class in protocol decoder module %s is not "
			"a subclass of sigrokdecode.Decoder.", module_name);
		goto err_out;
	}
	Py_CLEAR(py_basedec);

	/* Check for a proper start() method. */
	if (!PyObject_HasAttrString(d->py_dec, "start")) {
		srd_err("Protocol decoder %s has no start() method Decoder "
			"class.", module_name);
		goto err_out;
	}
	py_method = PyObject_GetAttrString(d->py_dec, "start");
	if (!PyFunction_Check(py_method)) {
		srd_err("Protocol decoder %s Decoder class attribute 'start' "
			"is not a method.", module_name);
		goto err_out;
	}
	Py_CLEAR(py_method);

	/* Check for a proper decode() method. */
	if (!PyObject_HasAttrString(d->py_dec, "decode")) {
		srd_err("Protocol decoder %s has no decode() method Decoder "
			"class.", module_name);
		goto err_out;
	}
	py_method = PyObject_GetAttrString(d->py_dec, "decode");
	if (!PyFunction_Check(py_method)) {
		srd_err("Protocol decoder %s Decoder class attribute 'decode' "
			"is not a method.", module_name);
		goto err_out;
	}
	Py_CLEAR(py_method);

	/* If present, options must be a dictionary. */
	if (PyObject_HasAttrString(d->py_dec, "options")) {
		py_attr = PyObject_GetAttrString(d->py_dec, "options");
		if (!PyDict_Check(py_attr)) {
			srd_err("Protocol decoder %s options attribute is not "
				"a dictionary.", d->name);
			Py_DecRef(py_attr);
			goto err_out;
		}
		Py_DecRef(py_attr);
	}

	/* Check and import required probes. */
	if (get_probes(d, "probes", &d->probes) != SRD_OK)
		goto err_out;

	/* Check and import optional probes. */
	if (get_probes(d, "optional_probes", &d->opt_probes) != SRD_OK)
		goto err_out;

	/*
	 * Fix order numbers for the optional probes.
	 *
	 * Example:
	 * Required probes: r1, r2, r3. Optional: o1, o2, o3, o4.
	 * 'order' fields in the d->probes list = 0, 1, 2.
	 * 'order' fields in the d->opt_probes list = 3, 4, 5, 6.
	 */
	for (l = d->opt_probes; l; l = l->next) {
		p = l->data;
		p->order += g_slist_length(d->probes);
	}

	/* Store required fields in newly allocated strings. */
	if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
		goto err_out;

	if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
		goto err_out;

	if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
		goto err_out;

	if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
		goto err_out;

	if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
		goto err_out;

	/* Convert class annotation attribute to GSList of **char. */
	d->annotations = NULL;
	if (PyObject_HasAttrString(d->py_dec, "annotations")) {
		py_annlist = PyObject_GetAttrString(d->py_dec, "annotations");
		if (!PyList_Check(py_annlist)) {
			srd_err("Protocol decoder module %s annotations "
				"should be a list.", module_name);
			goto err_out;
		}
		alen = PyList_Size(py_annlist);
		for (i = 0; i < alen; i++) {
			py_ann = PyList_GetItem(py_annlist, i);
			if (!PyList_Check(py_ann) || PyList_Size(py_ann) != 2) {
				srd_err("Protocol decoder module %s "
					"annotation %d should be a list with "
					"two elements.", module_name, i + 1);
				goto err_out;
			}

			if (py_strlist_to_char(py_ann, &ann) != SRD_OK) {
				goto err_out;
			}
			d->annotations = g_slist_append(d->annotations, ann);
		}
	}

	/* Append it to the list of supported/loaded decoders. */
	pd_list = g_slist_append(pd_list, d);

	ret = SRD_OK;

err_out:
	if (ret != SRD_OK) {
		Py_XDECREF(py_method);
		Py_XDECREF(py_basedec);
		Py_XDECREF(d->py_dec);
		Py_XDECREF(d->py_mod);
		g_free(d);
	}

	return ret;
}

/**
 * Return a protocol decoder's docstring.
 *
 * @param dec The loaded protocol decoder.
 *
 * @return A newly allocated buffer containing the protocol decoder's
 *         documentation. The caller is responsible for free'ing the buffer.
 */
SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
{
	PyObject *py_str;
	char *doc;

	if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
		return NULL;

	if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
		srd_exception_catch("");
		return NULL;
	}

	doc = NULL;
	if (py_str != Py_None)
		py_str_as_str(py_str, &doc);
	Py_DecRef(py_str);

	return doc;
}

static void free_probes(GSList *probelist)
{
	GSList *l;
	struct srd_probe *p;

	if (probelist == NULL)
		return;

	for (l = probelist; l; l = l->next) {
		p = l->data;
		g_free(p->id);
		g_free(p->name);
		g_free(p->desc);
		g_free(p);
	}
	g_slist_free(probelist);
}

/**
 * Unload decoder module.
 *
 * @param dec The struct srd_decoder to be unloaded.
 *
 * @return SRD_OK upon success, a (negative) error code otherwise.
 */
SRD_API int srd_decoder_unload(struct srd_decoder *dec)
{
	srd_dbg("Unloading protocol decoder '%s'.", dec->name);

	/*
	 * Since any instances of this decoder need to be released as well,
	 * but they could be anywhere in the stack, just free the entire
	 * stack. A frontend reloading a decoder thus has to restart all
	 * instances, and rebuild the stack.
	 */
	srd_inst_free_all(NULL);

	free_probes(dec->probes);
	free_probes(dec->opt_probes);
	g_free(dec->id);
	g_free(dec->name);
	g_free(dec->longname);
	g_free(dec->desc);
	g_free(dec->license);

	/* The module's Decoder class. */
	Py_XDECREF(dec->py_dec);
	/* The module itself. */
	Py_XDECREF(dec->py_mod);

	/* TODO: (g_)free dec itself? */

	return SRD_OK;
}

/**
 * Load all installed protocol decoders.
 *
 * @return SRD_OK upon success, a (negative) error code otherwise.
 */
SRD_API int srd_decoder_load_all(void)
{
	GDir *dir;
	GError *error;
	const gchar *direntry;

	if (!(dir = g_dir_open(DECODERS_DIR, 0, &error))) {
		srd_err("Unable to open %s for reading.", DECODERS_DIR);
		return SRD_ERR_DECODERS_DIR;
	}

	while ((direntry = g_dir_read_name(dir)) != NULL) {
		/* The directory name is the module name (e.g. "i2c"). */
		srd_decoder_load(direntry);
	}
	g_dir_close(dir);

	return SRD_OK;
}

/**
 * Unload all loaded protocol decoders.
 *
 * @return SRD_OK upon success, a (negative) error code otherwise.
 */
SRD_API int srd_decoder_unload_all(void)
{
	GSList *l;
	struct srd_decoder *dec;

	for (l = pd_list; l; l = l->next) {
		dec = l->data;
		srd_decoder_unload(dec);
	}

	return SRD_OK;
}
Commit	Line	Data
	1	/*
	2	* This file is part of the sigrok project.
	3	*
	4	* Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
	5	* Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
	6	*
	7	* This program is free software: you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation, either version 3 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20
	21	#include "config.h"
	22	#include "sigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
	23	#include "sigrokdecode-internal.h"
	24	#include <glib.h>
	25
	26	/** @cond PRIVATE */
	27
	28	/* The list of protocol decoders. */
	29	SRD_PRIV GSList *pd_list = NULL;
	30
	31	/* module_sigrokdecode.c */
	32	extern SRD_PRIV PyObject *mod_sigrokdecode;
	33
	34	/** @endcond */
	35
	36	/**
	37	* Returns the list of supported/loaded protocol decoders.
	38	*
	39	* This is a GSList containing the names of the decoders as strings.
	40	*
	41	* @return List of decoders, NULL if none are supported or loaded.
	42	*/
	43	SRD_API const GSList *srd_decoder_list(void)
	44	{
	45	return pd_list;
	46	}
	47
	48	/**
	49	* Get the decoder with the specified ID.
	50	*
	51	* @param id The ID string of the decoder to return.
	52	*
	53	* @return The decoder with the specified ID, or NULL if not found.
	54	*/
	55	SRD_API struct srd_decoder srd_decoder_get_by_id(const char id)
	56	{
	57	GSList *l;
	58	struct srd_decoder *dec;
	59
	60	for (l = pd_list; l; l = l->next) {
	61	dec = l->data;
	62	if (!strcmp(dec->id, id))
	63	return dec;
	64	}
	65
	66	return NULL;
	67	}
	68
	69	static int get_probes(const struct srd_decoder d, const char attr,
	70	GSList **pl)
	71	{
	72	PyObject py_probelist, py_entry;
	73	struct srd_probe *p;
	74	int ret, num_probes, i;
	75
	76	if (!PyObject_HasAttrString(d->py_dec, attr))
	77	/* No probes of this type specified. */
	78	return SRD_OK;
	79
	80	ret = SRD_ERR_PYTHON;
	81	py_probelist = py_entry = NULL;
	82
	83	py_probelist = PyObject_GetAttrString(d->py_dec, attr);
	84	if (!PyList_Check(py_probelist)) {
	85	srd_err("Protocol decoder %s %s attribute is not "
	86	"a list.", d->name, attr);
	87	goto err_out;
	88	}
	89
	90	num_probes = PyList_Size(py_probelist);
	91	if (num_probes == 0)
	92	/* Empty probelist. */
	93	return SRD_OK;
	94
	95	for (i = 0; i < num_probes; i++) {
	96	py_entry = PyList_GetItem(py_probelist, i);
	97	if (!PyDict_Check(py_entry)) {
	98	srd_err("Protocol decoder %s %s attribute is not "
	99	"a list with dict elements.", d->name, attr);
	100	goto err_out;
	101	}
	102
	103	if (!(p = g_try_malloc(sizeof(struct srd_probe)))) {
	104	srd_err("Failed to g_malloc() struct srd_probe.");
	105	ret = SRD_ERR_MALLOC;
	106	goto err_out;
	107	}
	108
	109	if ((py_dictitem_as_str(py_entry, "id", &p->id)) != SRD_OK)
	110	goto err_out;
	111	if ((py_dictitem_as_str(py_entry, "name", &p->name)) != SRD_OK)
	112	goto err_out;
	113	if ((py_dictitem_as_str(py_entry, "desc", &p->desc)) != SRD_OK)
	114	goto err_out;
	115	p->order = i;
	116
	117	pl = g_slist_append(pl, p);
	118	}
	119	ret = SRD_OK;
	120
	121	err_out:
	122	Py_DecRef(py_entry);
	123	Py_DecRef(py_probelist);
	124
	125	return ret;
	126	}
	127
	128	/**
	129	* Load a protocol decoder module into the embedded Python interpreter.
	130	*
	131	* @param module_name The module name to be loaded.
	132	*
	133	* @return SRD_OK upon success, a (negative) error code otherwise.
	134	*/
	135	SRD_API int srd_decoder_load(const char *module_name)
	136	{
	137	PyObject py_basedec, py_method, py_attr, py_annlist, *py_ann;
	138	struct srd_decoder *d;
	139	int alen, ret, i;
	140	char **ann;
	141	struct srd_probe *p;
	142	GSList *l;
	143
	144	srd_dbg("Loading protocol decoder '%s'.", module_name);
	145
	146	py_basedec = py_method = py_attr = NULL;
	147
	148	if (!(d = g_try_malloc0(sizeof(struct srd_decoder)))) {
	149	srd_dbg("Failed to g_malloc() struct srd_decoder.");
	150	ret = SRD_ERR_MALLOC;
	151	goto err_out;
	152	}
	153
	154	ret = SRD_ERR_PYTHON;
	155
	156	/* Import the Python module. */
	157	if (!(d->py_mod = PyImport_ImportModule(module_name))) {
	158	srd_exception_catch("Import of '%s' failed.", module_name);
	159	goto err_out;
	160	}
	161
	162	/* Get the 'Decoder' class as Python object. */
	163	if (!(d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder"))) {
	164	/* This generated an AttributeError exception. */
	165	PyErr_Clear();
	166	srd_err("Decoder class not found in protocol decoder %s.",
	167	module_name);
	168	goto err_out;
	169	}
	170
	171	if (!(py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder"))) {
	172	srd_dbg("sigrokdecode module not loaded.");
	173	goto err_out;
	174	}
	175
	176	if (!PyObject_IsSubclass(d->py_dec, py_basedec)) {
	177	srd_err("Decoder class in protocol decoder module %s is not "
	178	"a subclass of sigrokdecode.Decoder.", module_name);
	179	goto err_out;
	180	}
	181	Py_CLEAR(py_basedec);
	182
	183	/* Check for a proper start() method. */
	184	if (!PyObject_HasAttrString(d->py_dec, "start")) {
	185	srd_err("Protocol decoder %s has no start() method Decoder "
	186	"class.", module_name);
	187	goto err_out;
	188	}
	189	py_method = PyObject_GetAttrString(d->py_dec, "start");
	190	if (!PyFunction_Check(py_method)) {
	191	srd_err("Protocol decoder %s Decoder class attribute 'start' "
	192	"is not a method.", module_name);
	193	goto err_out;
	194	}
	195	Py_CLEAR(py_method);
	196
	197	/* Check for a proper decode() method. */
	198	if (!PyObject_HasAttrString(d->py_dec, "decode")) {
	199	srd_err("Protocol decoder %s has no decode() method Decoder "
	200	"class.", module_name);
	201	goto err_out;
	202	}
	203	py_method = PyObject_GetAttrString(d->py_dec, "decode");
	204	if (!PyFunction_Check(py_method)) {
	205	srd_err("Protocol decoder %s Decoder class attribute 'decode' "
	206	"is not a method.", module_name);
	207	goto err_out;
	208	}
	209	Py_CLEAR(py_method);
	210
	211	/* If present, options must be a dictionary. */
	212	if (PyObject_HasAttrString(d->py_dec, "options")) {
	213	py_attr = PyObject_GetAttrString(d->py_dec, "options");
	214	if (!PyDict_Check(py_attr)) {
	215	srd_err("Protocol decoder %s options attribute is not "
	216	"a dictionary.", d->name);
	217	Py_DecRef(py_attr);
	218	goto err_out;
	219	}
	220	Py_DecRef(py_attr);
	221	}
	222
	223	/* Check and import required probes. */
	224	if (get_probes(d, "probes", &d->probes) != SRD_OK)
	225	goto err_out;
	226
	227	/* Check and import optional probes. */
	228	if (get_probes(d, "optional_probes", &d->opt_probes) != SRD_OK)
	229	goto err_out;
	230
	231	/*
	232	* Fix order numbers for the optional probes.
	233	*
	234	* Example:
	235	* Required probes: r1, r2, r3. Optional: o1, o2, o3, o4.
	236	* 'order' fields in the d->probes list = 0, 1, 2.
	237	* 'order' fields in the d->opt_probes list = 3, 4, 5, 6.
	238	*/
	239	for (l = d->opt_probes; l; l = l->next) {
	240	p = l->data;
	241	p->order += g_slist_length(d->probes);
	242	}
	243
	244	/* Store required fields in newly allocated strings. */
	245	if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
	246	goto err_out;
	247
	248	if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
	249	goto err_out;
	250
	251	if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
	252	goto err_out;
	253
	254	if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
	255	goto err_out;
	256
	257	if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
	258	goto err_out;
	259
	260	/* Convert class annotation attribute to GSList of *char. /
	261	d->annotations = NULL;
	262	if (PyObject_HasAttrString(d->py_dec, "annotations")) {
	263	py_annlist = PyObject_GetAttrString(d->py_dec, "annotations");
	264	if (!PyList_Check(py_annlist)) {
	265	srd_err("Protocol decoder module %s annotations "
	266	"should be a list.", module_name);
	267	goto err_out;
	268	}
	269	alen = PyList_Size(py_annlist);
	270	for (i = 0; i < alen; i++) {
	271	py_ann = PyList_GetItem(py_annlist, i);
	272	if (!PyList_Check(py_ann) \|\| PyList_Size(py_ann) != 2) {
	273	srd_err("Protocol decoder module %s "
	274	"annotation %d should be a list with "
	275	"two elements.", module_name, i + 1);
	276	goto err_out;
	277	}
	278
	279	if (py_strlist_to_char(py_ann, &ann) != SRD_OK) {
	280	goto err_out;
	281	}
	282	d->annotations = g_slist_append(d->annotations, ann);
	283	}
	284	}
	285
	286	/* Append it to the list of supported/loaded decoders. */
	287	pd_list = g_slist_append(pd_list, d);
	288
	289	ret = SRD_OK;
	290
	291	err_out:
	292	if (ret != SRD_OK) {
	293	Py_XDECREF(py_method);
	294	Py_XDECREF(py_basedec);
	295	Py_XDECREF(d->py_dec);
	296	Py_XDECREF(d->py_mod);
	297	g_free(d);
	298	}
	299
	300	return ret;
	301	}
	302
	303	/**
	304	* Return a protocol decoder's docstring.
	305	*
	306	* @param dec The loaded protocol decoder.
	307	*
	308	* @return A newly allocated buffer containing the protocol decoder's
	309	* documentation. The caller is responsible for free'ing the buffer.
	310	*/
	311	SRD_API char srd_decoder_doc_get(const struct srd_decoder dec)
	312	{
	313	PyObject *py_str;
	314	char *doc;
	315
	316	if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
	317	return NULL;
	318
	319	if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
	320	srd_exception_catch("");
	321	return NULL;
	322	}
	323
	324	doc = NULL;
	325	if (py_str != Py_None)
	326	py_str_as_str(py_str, &doc);
	327	Py_DecRef(py_str);
	328
	329	return doc;
	330	}
	331
	332	static void free_probes(GSList *probelist)
	333	{
	334	GSList *l;
	335	struct srd_probe *p;
	336
	337	if (probelist == NULL)
	338	return;
	339
	340	for (l = probelist; l; l = l->next) {
	341	p = l->data;
	342	g_free(p->id);
	343	g_free(p->name);
	344	g_free(p->desc);
	345	g_free(p);
	346	}
	347	g_slist_free(probelist);
	348	}
	349
	350	/**
	351	* Unload decoder module.
	352	*
	353	* @param dec The struct srd_decoder to be unloaded.
	354	*
	355	* @return SRD_OK upon success, a (negative) error code otherwise.
	356	*/
	357	SRD_API int srd_decoder_unload(struct srd_decoder *dec)
	358	{
	359	srd_dbg("Unloading protocol decoder '%s'.", dec->name);
	360
	361	/*
	362	* Since any instances of this decoder need to be released as well,
	363	* but they could be anywhere in the stack, just free the entire
	364	* stack. A frontend reloading a decoder thus has to restart all
	365	* instances, and rebuild the stack.
	366	*/
	367	srd_inst_free_all(NULL);
	368
	369	free_probes(dec->probes);
	370	free_probes(dec->opt_probes);
	371	g_free(dec->id);
	372	g_free(dec->name);
	373	g_free(dec->longname);
	374	g_free(dec->desc);
	375	g_free(dec->license);
	376
	377	/* The module's Decoder class. */
	378	Py_XDECREF(dec->py_dec);
	379	/* The module itself. */
	380	Py_XDECREF(dec->py_mod);
	381
	382	/* TODO: (g_)free dec itself? */
	383
	384	return SRD_OK;
	385	}
	386
	387	/**
	388	* Load all installed protocol decoders.
	389	*
	390	* @return SRD_OK upon success, a (negative) error code otherwise.
	391	*/
	392	SRD_API int srd_decoder_load_all(void)
	393	{
	394	GDir *dir;
	395	GError *error;
	396	const gchar *direntry;
	397
	398	if (!(dir = g_dir_open(DECODERS_DIR, 0, &error))) {
	399	srd_err("Unable to open %s for reading.", DECODERS_DIR);
	400	return SRD_ERR_DECODERS_DIR;
	401	}
	402
	403	while ((direntry = g_dir_read_name(dir)) != NULL) {
	404	/* The directory name is the module name (e.g. "i2c"). */
	405	srd_decoder_load(direntry);
	406	}
	407	g_dir_close(dir);
	408
	409	return SRD_OK;
	410	}
	411
	412	/**
	413	* Unload all loaded protocol decoders.
	414	*
	415	* @return SRD_OK upon success, a (negative) error code otherwise.
	416	*/
	417	SRD_API int srd_decoder_unload_all(void)
	418	{
	419	GSList *l;
	420	struct srd_decoder *dec;
	421
	422	for (l = pd_list; l; l = l->next) {
	423	dec = l->data;
	424	srd_decoder_unload(dec);
	425	}
	426
	427	return SRD_OK;
	428	}