2 * This file is part of the libsigrokdecode project.
4 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
5 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
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.
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.
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/>.
22 #include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
23 #include "libsigrokdecode.h"
28 /* Python module search paths */
29 SRD_PRIV GSList *searchpaths = NULL;
32 extern SRD_PRIV GSList *sessions;
33 extern SRD_PRIV int max_session_id;
38 * @mainpage libsigrokdecode API
40 * @section sec_intro Introduction
42 * The <a href="http://sigrok.org">sigrok</a> project aims at creating a
43 * portable, cross-platform, Free/Libre/Open-Source signal analysis software
44 * suite that supports various device types (such as logic analyzers,
45 * oscilloscopes, multimeters, and more).
47 * <a href="http://sigrok.org/wiki/Libsigrokdecode">libsigrokdecode</a> is a
48 * shared library written in C which provides the basic API for (streaming)
49 * protocol decoding functionality.
51 * The <a href="http://sigrok.org/wiki/Protocol_decoders">protocol decoders</a>
52 * are written in Python (>= 3.0).
54 * @section sec_api API reference
56 * See the "Modules" page for an introduction to various libsigrokdecode
57 * related topics and the detailed API documentation of the respective
60 * You can also browse the API documentation by file, or review all
63 * @section sec_mailinglists Mailing lists
65 * There is one mailing list for sigrok/libsigrokdecode: <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-devel">sigrok-devel</a>.
67 * @section sec_irc IRC
69 * You can find the sigrok developers in the
70 * <a href="irc://chat.freenode.net/sigrok">\#sigrok</a>
71 * IRC channel on Freenode.
73 * @section sec_website Website
75 * <a href="http://sigrok.org/wiki/Libsigrokdecode">sigrok.org/wiki/Libsigrokdecode</a>
81 * Initializing and shutting down libsigrokdecode.
85 * @defgroup grp_init Initialization
87 * Initializing and shutting down libsigrokdecode.
89 * Before using any of the libsigrokdecode functionality, srd_init() must
90 * be called to initialize the library.
92 * When libsigrokdecode functionality is no longer needed, srd_exit() should
98 static int searchpath_add_xdg_dir(const char *datadir)
103 decdir = g_build_filename(datadir, PACKAGE_TARNAME, "decoders", NULL);
105 if (g_file_test(decdir, G_FILE_TEST_IS_DIR))
106 ret = srd_decoder_searchpath_add(decdir);
108 ret = SRD_OK; /* just ignore non-existing directory */
116 * Initialize libsigrokdecode.
118 * This initializes the Python interpreter, and creates and initializes
119 * a "sigrokdecode" Python module.
121 * Then, it searches for sigrok protocol decoders in the "decoders"
122 * subdirectory of the the libsigrokdecode installation directory.
123 * All decoders that are found are loaded into memory and added to an
124 * internal list of decoders, which can be queried via srd_decoder_list().
126 * The caller is responsible for calling the clean-up function srd_exit(),
127 * which will properly shut down libsigrokdecode and free its allocated memory.
129 * Multiple calls to srd_init(), without calling srd_exit() in between,
132 * @param path Path to an extra directory containing protocol decoders
133 * which will be added to the Python sys.path. May be NULL.
135 * @return SRD_OK upon success, a (negative) error code otherwise.
136 * Upon Python errors, SRD_ERR_PYTHON is returned. If the decoders
137 * directory cannot be accessed, SRD_ERR_DECODERS_DIR is returned.
138 * If not enough memory could be allocated, SRD_ERR_MALLOC is returned.
142 SRD_API int srd_init(const char *path)
144 const char *const *sys_datadirs;
145 const char *env_path;
149 if (max_session_id != -1) {
150 srd_err("libsigrokdecode is already initialized.");
154 srd_dbg("Initializing libsigrokdecode.");
156 /* Add our own module to the list of built-in modules. */
157 PyImport_AppendInittab("sigrokdecode", PyInit_sigrokdecode);
159 /* Initialize the Python interpreter. */
162 /* Locations relative to the XDG system data directories. */
163 sys_datadirs = g_get_system_data_dirs();
164 for (i = g_strv_length((char **)sys_datadirs); i > 0; i--) {
165 ret = searchpath_add_xdg_dir(sys_datadirs[i-1]);
172 /* Common modules for use by any decoder. */
173 if ((ret = srd_decoder_searchpath_add(COMMON_DIR)) != SRD_OK) {
178 /* Hardcoded decoders install location, if defined. */
179 if ((ret = srd_decoder_searchpath_add(DECODERS_DIR)) != SRD_OK) {
184 /* Location relative to the XDG user data directory. */
185 ret = searchpath_add_xdg_dir(g_get_user_data_dir());
191 /* Path specified by the user. */
193 if ((ret = srd_decoder_searchpath_add(path)) != SRD_OK) {
199 /* Environment variable overrides everything, for debugging. */
200 if ((env_path = g_getenv("SIGROKDECODE_DIR"))) {
201 if ((ret = srd_decoder_searchpath_add(env_path)) != SRD_OK) {
213 * Shutdown libsigrokdecode.
215 * This frees all the memory allocated for protocol decoders and shuts down
216 * the Python interpreter.
218 * This function should only be called if there was a (successful!) invocation
219 * of srd_init() before. Calling this function multiple times in a row, without
220 * any successful srd_init() calls in between, is not allowed.
222 * @return SRD_OK upon success, a (negative) error code otherwise.
226 SRD_API int srd_exit(void)
230 srd_dbg("Exiting libsigrokdecode.");
232 for (l = sessions; l; l = l->next)
233 srd_session_destroy((struct srd_session *)l->data);
235 srd_decoder_unload_all();
236 g_slist_free_full(searchpaths, g_free);
239 /* Py_Finalize() returns void, any finalization errors are ignored. */
248 * Add an additional search directory for the protocol decoders.
250 * The specified directory is prepended (not appended!) to Python's sys.path,
251 * in order to search for sigrok protocol decoders in the specified
252 * directories first, and in the generic Python module directories (and in
253 * the current working directory) last. This avoids conflicts if there are
254 * Python modules which have the same name as a sigrok protocol decoder in
255 * sys.path or in the current working directory.
257 * @param path Path to the directory containing protocol decoders which shall
258 * be added to the Python sys.path, or NULL.
260 * @return SRD_OK upon success, a (negative) error code otherwise.
266 SRD_PRIV int srd_decoder_searchpath_add(const char *path)
268 PyObject *py_cur_path, *py_item;
270 srd_dbg("Adding '%s' to module path.", path);
272 py_cur_path = PySys_GetObject("path");
274 return SRD_ERR_PYTHON;
276 py_item = PyUnicode_FromString(path);
278 srd_exception_catch("Failed to create Unicode object");
279 return SRD_ERR_PYTHON;
281 if (PyList_Insert(py_cur_path, 0, py_item) < 0) {
282 srd_exception_catch("Failed to insert path element");
284 return SRD_ERR_PYTHON;
288 searchpaths = g_slist_prepend(searchpaths, g_strdup(path));