diff options
Diffstat (limited to 'srd.c')
| -rw-r--r-- | srd.c | 266 |
1 files changed, 266 insertions, 0 deletions
@@ -0,0 +1,266 @@ +/* + * 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; +} + +/** @} */ |