/* * This file is part of the libsigrokdecode project. * * Copyright (C) 2010 Uwe Hermann * Copyright (C) 2013 Bert Vermeulen * * 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 . */ #include #include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */ #include "libsigrokdecode.h" #include /** @cond PRIVATE */ /* Python module search paths */ SRD_PRIV GSList *searchpaths = NULL; /* session.c */ extern SRD_PRIV GSList *sessions; extern SRD_PRIV int max_session_id; /** @endcond */ /** * @mainpage libsigrokdecode API * * @section sec_intro Introduction * * The sigrok 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). * * libsigrokdecode is a * shared library written in C which provides the basic API for (streaming) * protocol decoding functionality. * * The protocol decoders * 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 is one mailing list for sigrok/libsigrokdecode: sigrok-devel. * * @section sec_irc IRC * * You can find the sigrok developers in the * \#sigrok * IRC channel on Freenode. * * @section sec_website Website * * sigrok.org/wiki/Libsigrokdecode */ /** * @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. * * @{ */ static int searchpath_add_xdg_dir(const char *datadir) { char *decdir; int ret; decdir = g_build_filename(datadir, PACKAGE_TARNAME, "decoders", NULL); if (g_file_test(decdir, G_FILE_TEST_IS_DIR)) ret = srd_decoder_searchpath_add(decdir); else ret = SRD_OK; /* just ignore non-existing directory */ g_free(decdir); return ret; } /** * 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) { const char *const *sys_datadirs; const char *env_path; size_t i; int ret; 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(); /* Locations relative to the XDG system data directories. */ sys_datadirs = g_get_system_data_dirs(); for (i = g_strv_length((char **)sys_datadirs); i > 0; i--) { ret = searchpath_add_xdg_dir(sys_datadirs[i-1]); if (ret != SRD_OK) { Py_Finalize(); return ret; } } #ifdef DECODERS_DIR /* Hardcoded decoders install location, if defined. */ if ((ret = srd_decoder_searchpath_add(DECODERS_DIR)) != SRD_OK) { Py_Finalize(); return ret; } #endif /* Location relative to the XDG user data directory. */ ret = searchpath_add_xdg_dir(g_get_user_data_dir()); if (ret != 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 = g_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_full(searchpaths, g_free); searchpaths = 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; srd_dbg("Adding '%s' to module path.", path); py_cur_path = PySys_GetObject("path"); if (!py_cur_path) return SRD_ERR_PYTHON; py_item = PyUnicode_FromString(path); if (!py_item) { srd_exception_catch("Failed to create Unicode object"); return SRD_ERR_PYTHON; } if (PyList_Insert(py_cur_path, 0, py_item) < 0) { srd_exception_catch("Failed to insert path element"); Py_DECREF(py_item); return SRD_ERR_PYTHON; } Py_DECREF(py_item); searchpaths = g_slist_prepend(searchpaths, g_strdup(path)); return SRD_OK; } /** @} */