[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>

/**
 * @file
 *
 * Listing, loading, unloading, and handling protocol decoders.
 */

/**
 * @defgroup grp_decoder Protocol decoders
 *
 * Handling protocol decoders.
 *
 * @{
 */

/** @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	/**
	27	* @file
	28	*
	29	* Listing, loading, unloading, and handling protocol decoders.
	30	*/
	31
	32	/**
	33	* @defgroup grp_decoder Protocol decoders
	34	*
	35	* Handling protocol decoders.
	36	*
	37	* @{
	38	*/
	39
	40	/** @cond PRIVATE */
	41
	42	/* The list of protocol decoders. */
	43	SRD_PRIV GSList *pd_list = NULL;
	44
	45	/* module_sigrokdecode.c */
	46	extern SRD_PRIV PyObject *mod_sigrokdecode;
	47
	48	/** @endcond */
	49
	50	/**
	51	* Returns the list of supported/loaded protocol decoders.
	52	*
	53	* This is a GSList containing the names of the decoders as strings.
	54	*
	55	* @return List of decoders, NULL if none are supported or loaded.
	56	*/
	57	SRD_API const GSList *srd_decoder_list(void)
	58	{
	59	return pd_list;
	60	}
	61
	62	/**
	63	* Get the decoder with the specified ID.
	64	*
	65	* @param id The ID string of the decoder to return.
	66	*
	67	* @return The decoder with the specified ID, or NULL if not found.
	68	*/
	69	SRD_API struct srd_decoder srd_decoder_get_by_id(const char id)
	70	{
	71	GSList *l;
	72	struct srd_decoder *dec;
	73
	74	for (l = pd_list; l; l = l->next) {
	75	dec = l->data;
	76	if (!strcmp(dec->id, id))
	77	return dec;
	78	}
	79
	80	return NULL;
	81	}
	82
	83	static int get_probes(const struct srd_decoder d, const char attr,
	84	GSList **pl)
	85	{
	86	PyObject py_probelist, py_entry;
	87	struct srd_probe *p;
	88	int ret, num_probes, i;
	89
	90	if (!PyObject_HasAttrString(d->py_dec, attr))
	91	/* No probes of this type specified. */
	92	return SRD_OK;
	93
	94	ret = SRD_ERR_PYTHON;
	95	py_probelist = py_entry = NULL;
	96
	97	py_probelist = PyObject_GetAttrString(d->py_dec, attr);
	98	if (!PyList_Check(py_probelist)) {
	99	srd_err("Protocol decoder %s %s attribute is not "
	100	"a list.", d->name, attr);
	101	goto err_out;
	102	}
	103
	104	num_probes = PyList_Size(py_probelist);
	105	if (num_probes == 0)
	106	/* Empty probelist. */
	107	return SRD_OK;
	108
	109	for (i = 0; i < num_probes; i++) {
	110	py_entry = PyList_GetItem(py_probelist, i);
	111	if (!PyDict_Check(py_entry)) {
	112	srd_err("Protocol decoder %s %s attribute is not "
	113	"a list with dict elements.", d->name, attr);
	114	goto err_out;
	115	}
	116
	117	if (!(p = g_try_malloc(sizeof(struct srd_probe)))) {
	118	srd_err("Failed to g_malloc() struct srd_probe.");
	119	ret = SRD_ERR_MALLOC;
	120	goto err_out;
	121	}
	122
	123	if ((py_dictitem_as_str(py_entry, "id", &p->id)) != SRD_OK)
	124	goto err_out;
	125	if ((py_dictitem_as_str(py_entry, "name", &p->name)) != SRD_OK)
	126	goto err_out;
	127	if ((py_dictitem_as_str(py_entry, "desc", &p->desc)) != SRD_OK)
	128	goto err_out;
	129	p->order = i;
	130
	131	pl = g_slist_append(pl, p);
	132	}
	133	ret = SRD_OK;
	134
	135	err_out:
	136	Py_DecRef(py_entry);
	137	Py_DecRef(py_probelist);
	138
	139	return ret;
	140	}
	141
	142	/**
	143	* Load a protocol decoder module into the embedded Python interpreter.
	144	*
	145	* @param module_name The module name to be loaded.
	146	*
	147	* @return SRD_OK upon success, a (negative) error code otherwise.
	148	*/
	149	SRD_API int srd_decoder_load(const char *module_name)
	150	{
	151	PyObject py_basedec, py_method, py_attr, py_annlist, *py_ann;
	152	struct srd_decoder *d;
	153	int alen, ret, i;
	154	char **ann;
	155	struct srd_probe *p;
	156	GSList *l;
	157
	158	srd_dbg("Loading protocol decoder '%s'.", module_name);
	159
	160	py_basedec = py_method = py_attr = NULL;
	161
	162	if (!(d = g_try_malloc0(sizeof(struct srd_decoder)))) {
	163	srd_dbg("Failed to g_malloc() struct srd_decoder.");
	164	ret = SRD_ERR_MALLOC;
	165	goto err_out;
	166	}
	167
	168	ret = SRD_ERR_PYTHON;
	169
	170	/* Import the Python module. */
	171	if (!(d->py_mod = PyImport_ImportModule(module_name))) {
	172	srd_exception_catch("Import of '%s' failed.", module_name);
	173	goto err_out;
	174	}
	175
	176	/* Get the 'Decoder' class as Python object. */
	177	if (!(d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder"))) {
	178	/* This generated an AttributeError exception. */
	179	PyErr_Clear();
	180	srd_err("Decoder class not found in protocol decoder %s.",
	181	module_name);
	182	goto err_out;
	183	}
	184
	185	if (!(py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder"))) {
	186	srd_dbg("sigrokdecode module not loaded.");
	187	goto err_out;
	188	}
	189
	190	if (!PyObject_IsSubclass(d->py_dec, py_basedec)) {
	191	srd_err("Decoder class in protocol decoder module %s is not "
	192	"a subclass of sigrokdecode.Decoder.", module_name);
	193	goto err_out;
	194	}
	195	Py_CLEAR(py_basedec);
	196
	197	/* Check for a proper start() method. */
	198	if (!PyObject_HasAttrString(d->py_dec, "start")) {
	199	srd_err("Protocol decoder %s has no start() method Decoder "
	200	"class.", module_name);
	201	goto err_out;
	202	}
	203	py_method = PyObject_GetAttrString(d->py_dec, "start");
	204	if (!PyFunction_Check(py_method)) {
	205	srd_err("Protocol decoder %s Decoder class attribute 'start' "
	206	"is not a method.", module_name);
	207	goto err_out;
	208	}
	209	Py_CLEAR(py_method);
	210
	211	/* Check for a proper decode() method. */
	212	if (!PyObject_HasAttrString(d->py_dec, "decode")) {
	213	srd_err("Protocol decoder %s has no decode() method Decoder "
	214	"class.", module_name);
	215	goto err_out;
	216	}
	217	py_method = PyObject_GetAttrString(d->py_dec, "decode");
	218	if (!PyFunction_Check(py_method)) {
	219	srd_err("Protocol decoder %s Decoder class attribute 'decode' "
	220	"is not a method.", module_name);
	221	goto err_out;
	222	}
	223	Py_CLEAR(py_method);
	224
	225	/* If present, options must be a dictionary. */
	226	if (PyObject_HasAttrString(d->py_dec, "options")) {
	227	py_attr = PyObject_GetAttrString(d->py_dec, "options");
	228	if (!PyDict_Check(py_attr)) {
	229	srd_err("Protocol decoder %s options attribute is not "
	230	"a dictionary.", d->name);
	231	Py_DecRef(py_attr);
	232	goto err_out;
	233	}
	234	Py_DecRef(py_attr);
	235	}
	236
	237	/* Check and import required probes. */
	238	if (get_probes(d, "probes", &d->probes) != SRD_OK)
	239	goto err_out;
	240
	241	/* Check and import optional probes. */
	242	if (get_probes(d, "optional_probes", &d->opt_probes) != SRD_OK)
	243	goto err_out;
	244
	245	/*
	246	* Fix order numbers for the optional probes.
	247	*
	248	* Example:
	249	* Required probes: r1, r2, r3. Optional: o1, o2, o3, o4.
	250	* 'order' fields in the d->probes list = 0, 1, 2.
	251	* 'order' fields in the d->opt_probes list = 3, 4, 5, 6.
	252	*/
	253	for (l = d->opt_probes; l; l = l->next) {
	254	p = l->data;
	255	p->order += g_slist_length(d->probes);
	256	}
	257
	258	/* Store required fields in newly allocated strings. */
	259	if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
	260	goto err_out;
	261
	262	if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
	263	goto err_out;
	264
	265	if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
	266	goto err_out;
	267
	268	if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
	269	goto err_out;
	270
	271	if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
	272	goto err_out;
	273
	274	/* Convert class annotation attribute to GSList of *char. /
	275	d->annotations = NULL;
	276	if (PyObject_HasAttrString(d->py_dec, "annotations")) {
	277	py_annlist = PyObject_GetAttrString(d->py_dec, "annotations");
	278	if (!PyList_Check(py_annlist)) {
	279	srd_err("Protocol decoder module %s annotations "
	280	"should be a list.", module_name);
	281	goto err_out;
	282	}
	283	alen = PyList_Size(py_annlist);
	284	for (i = 0; i < alen; i++) {
	285	py_ann = PyList_GetItem(py_annlist, i);
	286	if (!PyList_Check(py_ann) \|\| PyList_Size(py_ann) != 2) {
	287	srd_err("Protocol decoder module %s "
	288	"annotation %d should be a list with "
	289	"two elements.", module_name, i + 1);
	290	goto err_out;
	291	}
	292
	293	if (py_strlist_to_char(py_ann, &ann) != SRD_OK) {
	294	goto err_out;
	295	}
	296	d->annotations = g_slist_append(d->annotations, ann);
	297	}
	298	}
	299
	300	/* Append it to the list of supported/loaded decoders. */
	301	pd_list = g_slist_append(pd_list, d);
	302
	303	ret = SRD_OK;
	304
	305	err_out:
	306	if (ret != SRD_OK) {
	307	Py_XDECREF(py_method);
	308	Py_XDECREF(py_basedec);
	309	Py_XDECREF(d->py_dec);
	310	Py_XDECREF(d->py_mod);
	311	g_free(d);
	312	}
	313
	314	return ret;
	315	}
	316
	317	/**
	318	* Return a protocol decoder's docstring.
	319	*
	320	* @param dec The loaded protocol decoder.
	321	*
	322	* @return A newly allocated buffer containing the protocol decoder's
	323	* documentation. The caller is responsible for free'ing the buffer.
	324	*/
	325	SRD_API char srd_decoder_doc_get(const struct srd_decoder dec)
	326	{
	327	PyObject *py_str;
	328	char *doc;
	329
	330	if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
	331	return NULL;
	332
	333	if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
	334	srd_exception_catch("");
	335	return NULL;
	336	}
	337
	338	doc = NULL;
	339	if (py_str != Py_None)
	340	py_str_as_str(py_str, &doc);
	341	Py_DecRef(py_str);
	342
	343	return doc;
	344	}
	345
	346	static void free_probes(GSList *probelist)
	347	{
	348	GSList *l;
	349	struct srd_probe *p;
	350
	351	if (probelist == NULL)
	352	return;
	353
	354	for (l = probelist; l; l = l->next) {
	355	p = l->data;
	356	g_free(p->id);
	357	g_free(p->name);
	358	g_free(p->desc);
	359	g_free(p);
	360	}
	361	g_slist_free(probelist);
	362	}
	363
	364	/**
	365	* Unload decoder module.
	366	*
	367	* @param dec The struct srd_decoder to be unloaded.
	368	*
	369	* @return SRD_OK upon success, a (negative) error code otherwise.
	370	*/
	371	SRD_API int srd_decoder_unload(struct srd_decoder *dec)
	372	{
	373	srd_dbg("Unloading protocol decoder '%s'.", dec->name);
	374
	375	/*
	376	* Since any instances of this decoder need to be released as well,
	377	* but they could be anywhere in the stack, just free the entire
	378	* stack. A frontend reloading a decoder thus has to restart all
	379	* instances, and rebuild the stack.
	380	*/
	381	srd_inst_free_all(NULL);
	382
	383	free_probes(dec->probes);
	384	free_probes(dec->opt_probes);
	385	g_free(dec->id);
	386	g_free(dec->name);
	387	g_free(dec->longname);
	388	g_free(dec->desc);
	389	g_free(dec->license);
	390
	391	/* The module's Decoder class. */
	392	Py_XDECREF(dec->py_dec);
	393	/* The module itself. */
	394	Py_XDECREF(dec->py_mod);
	395
	396	/* TODO: (g_)free dec itself? */
	397
	398	return SRD_OK;
	399	}
	400
	401	/**
	402	* Load all installed protocol decoders.
	403	*
	404	* @return SRD_OK upon success, a (negative) error code otherwise.
	405	*/
	406	SRD_API int srd_decoder_load_all(void)
	407	{
	408	GDir *dir;
	409	GError *error;
	410	const gchar *direntry;
	411
	412	if (!(dir = g_dir_open(DECODERS_DIR, 0, &error))) {
	413	srd_err("Unable to open %s for reading.", DECODERS_DIR);
	414	return SRD_ERR_DECODERS_DIR;
	415	}
	416
	417	while ((direntry = g_dir_read_name(dir)) != NULL) {
	418	/* The directory name is the module name (e.g. "i2c"). */
	419	srd_decoder_load(direntry);
	420	}
	421	g_dir_close(dir);
	422
	423	return SRD_OK;
	424	}
	425
	426	/**
	427	* Unload all loaded protocol decoders.
	428	*
	429	* @return SRD_OK upon success, a (negative) error code otherwise.
	430	*/
	431	SRD_API int srd_decoder_unload_all(void)
	432	{
	433	GSList *l;
	434	struct srd_decoder *dec;
	435
	436	for (l = pd_list; l; l = l->next) {
	437	dec = l->data;
	438	srd_decoder_unload(dec);
	439	}
	440
	441	return SRD_OK;
	442	}
	443
	444	/** @} */