+/*
+ * This file is part of the libsigrokdecode project.
+ *
+ * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2013 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 "libsigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
+#include "libsigrokdecode-internal.h"
+#include "config.h"
+#include <glib.h>
+
+/** @cond PRIVATE */
+
+/* session.c */
+extern GSList *sessions;
+extern int max_session_id;
+
+/* decoder.c */
+extern SRD_PRIV GSList *pd_list;
+
+/* module_sigrokdecode.c */
+extern PyMODINIT_FUNC PyInit_sigrokdecode(void);
+
+/** @endcond */
+
+/**
+ * @mainpage libsigrokdecode API
+ *
+ * @section sec_intro Introduction
+ *
+ * The <a href="http://sigrok.org">sigrok</a> project aims at creating a
+ * portable, cross-platform, Free/Libre/Open-Source signal analysis software
+ * suite that supports various device types (such as logic analyzers,
+ * oscilloscopes, multimeters, and more).
+ *
+ * <a href="http://sigrok.org/wiki/Libsigrokdecode">libsigrokdecode</a> is a
+ * shared library written in C which provides the basic API for (streaming)
+ * protocol decoding functionality.
+ *
+ * The <a href="http://sigrok.org/wiki/Protocol_decoders">protocol decoders</a>
+ * are written in Python (>= 3.0).
+ *
+ * @section sec_api API reference
+ *
+ * See the "Modules" page for an introduction to various libsigrokdecode
+ * related topics and the detailed API documentation of the respective
+ * functions.
+ *
+ * You can also browse the API documentation by file, or review all
+ * data structures.
+ *
+ * @section sec_mailinglists Mailing lists
+ *
+ * There are two mailing lists for sigrok/libsigrokdecode: <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-devel">sigrok-devel</a> and <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-commits">sigrok-commits</a>.
+ *
+ * @section sec_irc IRC
+ *
+ * You can find the sigrok developers in the
+ * <a href="irc://chat.freenode.net/sigrok">\#sigrok</a>
+ * IRC channel on Freenode.
+ *
+ * @section sec_website Website
+ *
+ * <a href="http://sigrok.org/wiki/Libsigrokdecode">sigrok.org/wiki/Libsigrokdecode</a>
+ */
+
+/**
+ * @file
+ *
+ * Initializing and shutting down libsigrokdecode.
+ */
+
+/**
+ * @defgroup grp_init Initialization
+ *
+ * Initializing and shutting down libsigrokdecode.
+ *
+ * Before using any of the libsigrokdecode functionality, srd_init() must
+ * be called to initialize the library.
+ *
+ * When libsigrokdecode functionality is no longer needed, srd_exit() should
+ * be called.
+ *
+ * @{
+ */
+
+/**
+ * Initialize libsigrokdecode.
+ *
+ * This initializes the Python interpreter, and creates and initializes
+ * a "sigrokdecode" Python module.
+ *
+ * Then, it searches for sigrok protocol decoders in the "decoders"
+ * subdirectory of the the libsigrokdecode installation directory.
+ * All decoders that are found are loaded into memory and added to an
+ * internal list of decoders, which can be queried via srd_decoder_list().
+ *
+ * The caller is responsible for calling the clean-up function srd_exit(),
+ * which will properly shut down libsigrokdecode and free its allocated memory.
+ *
+ * Multiple calls to srd_init(), without calling srd_exit() in between,
+ * are not allowed.
+ *
+ * @param path Path to an extra directory containing protocol decoders
+ * which will be added to the Python sys.path. May be NULL.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ * Upon Python errors, SRD_ERR_PYTHON is returned. If the decoders
+ * directory cannot be accessed, SRD_ERR_DECODERS_DIR is returned.
+ * If not enough memory could be allocated, SRD_ERR_MALLOC is returned.
+ *
+ * @since 0.1.0
+ */
+SRD_API int srd_init(const char *path)
+{
+ int ret;
+ char *env_path;
+
+ if (max_session_id != -1) {
+ srd_err("libsigrokdecode is already initialized.");
+ return SRD_ERR;
+ }
+
+ srd_dbg("Initializing libsigrokdecode.");
+
+ /* Add our own module to the list of built-in modules. */
+ PyImport_AppendInittab("sigrokdecode", PyInit_sigrokdecode);
+
+ /* Initialize the Python interpreter. */
+ Py_Initialize();
+
+ /* Installed decoders. */
+ if ((ret = srd_decoder_searchpath_add(DECODERS_DIR)) != SRD_OK) {
+ Py_Finalize();
+ return ret;
+ }
+
+ /* Path specified by the user. */
+ if (path) {
+ if ((ret = srd_decoder_searchpath_add(path)) != SRD_OK) {
+ Py_Finalize();
+ return ret;
+ }
+ }
+
+ /* Environment variable overrides everything, for debugging. */
+ if ((env_path = getenv("SIGROKDECODE_DIR"))) {
+ if ((ret = srd_decoder_searchpath_add(env_path)) != SRD_OK) {
+ Py_Finalize();
+ return ret;
+ }
+ }
+
+ max_session_id = 0;
+
+ return SRD_OK;
+}
+
+/**
+ * Shutdown libsigrokdecode.
+ *
+ * This frees all the memory allocated for protocol decoders and shuts down
+ * the Python interpreter.
+ *
+ * This function should only be called if there was a (successful!) invocation
+ * of srd_init() before. Calling this function multiple times in a row, without
+ * any successful srd_init() calls in between, is not allowed.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.1.0
+ */
+SRD_API int srd_exit(void)
+{
+ GSList *l;
+
+ srd_dbg("Exiting libsigrokdecode.");
+
+ for (l = sessions; l; l = l->next)
+ srd_session_destroy((struct srd_session *)l->data);
+
+ srd_decoder_unload_all();
+ g_slist_free(pd_list);
+ pd_list = NULL;
+
+ /* Py_Finalize() returns void, any finalization errors are ignored. */
+ Py_Finalize();
+
+ max_session_id = -1;
+
+ return SRD_OK;
+}
+
+/**
+ * Add an additional search directory for the protocol decoders.
+ *
+ * The specified directory is prepended (not appended!) to Python's sys.path,
+ * in order to search for sigrok protocol decoders in the specified
+ * directories first, and in the generic Python module directories (and in
+ * the current working directory) last. This avoids conflicts if there are
+ * Python modules which have the same name as a sigrok protocol decoder in
+ * sys.path or in the current working directory.
+ *
+ * @param path Path to the directory containing protocol decoders which shall
+ * be added to the Python sys.path, or NULL.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @private
+ *
+ * @since 0.1.0
+ */
+SRD_PRIV int srd_decoder_searchpath_add(const char *path)
+{
+ PyObject *py_cur_path, *py_item;
+ GString *new_path;
+ int wc_len, i;
+ wchar_t *wc_new_path;
+ char *item;
+
+ srd_dbg("Adding '%s' to module path.", path);
+
+ new_path = g_string_sized_new(256);
+ g_string_assign(new_path, path);
+ py_cur_path = PySys_GetObject("path");
+ for (i = 0; i < PyList_Size(py_cur_path); i++) {
+ g_string_append(new_path, G_SEARCHPATH_SEPARATOR_S);
+ py_item = PyList_GetItem(py_cur_path, i);
+ if (!PyUnicode_Check(py_item))
+ /* Shouldn't happen. */
+ continue;
+ if (py_str_as_str(py_item, &item) != SRD_OK)
+ continue;
+ g_string_append(new_path, item);
+ g_free(item);
+ }
+
+ /* Convert to wide chars. */
+ wc_len = sizeof(wchar_t) * (new_path->len + 1);
+ if (!(wc_new_path = g_try_malloc(wc_len))) {
+ srd_dbg("malloc failed");
+ return SRD_ERR_MALLOC;
+ }
+ mbstowcs(wc_new_path, new_path->str, wc_len);
+ PySys_SetPath(wc_new_path);
+ g_string_free(new_path, TRUE);
+ g_free(wc_new_path);
+
+ return SRD_OK;
+}
+
+/** @} */
projects / libsigrokdecode.git / commitdiff