X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decode.c;h=c2beab29a6bc619fbb783aae3d2d14db2d3f8858;hp=de37913cddf9bd13d0f7be8e754b34bb473a5827;hb=f800adc478591cff0a462ae51af105eebfb7a9f4;hpb=910e5fd8a73ac006bd5fa341b3f3cf3d9318b4f0 diff --git a/decode.c b/decode.c index de37913..c2beab2 100644 --- a/decode.c +++ b/decode.c @@ -20,105 +20,250 @@ #include /* First, so we avoid a _POSIX_C_SOURCE warning. */ #include +#include +#include +#include + +/* Re-define some string functions for Python >= 3.0. */ +#if PY_VERSION_HEX >= 0x03000000 +#define PyString_AsString PyBytes_AsString +#define PyString_FromString PyBytes_FromString +#define PyString_Check PyBytes_Check +#endif + +/* The list of protocol decoders. */ +GSList *list_pds = NULL; + +/* + * Here's a quick overview of Python/C API reference counting. + * + * Check the Python/C API docs for what type of reference a function returns. + * + * - If it returns a "new reference", you're responsible to Py_DECREF() it. + * + * - If it returns a "borrowed reference", you MUST NOT Py_DECREF() it. + * + * - If a function "steals" a reference, you no longer are responsible for + * Py_DECREF()ing it (someone else will do it for you at some point). + */ /** * Initialize libsigrokdecode. * - * @return 0 upon success, non-zero otherwise. + * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. */ int sigrokdecode_init(void) { + DIR *dir; + struct dirent *dp; + char *tmp; + /* Py_Initialize() returns void and usually cannot fail. */ Py_Initialize(); - /* FIXME */ - /* Allows for ./gui/sigrok-gui in the top-level directory. */ - PySys_SetPath("libsigrokdecode/scripts"); - /* Allows for ./sigrok-gui in the gui/ directory. */ - PySys_SetPath("../libsigrokdecode/scripts"); - /* Allows for sigrok-gui from anywhere given sigrok is installed. */ - PySys_SetPath("/usr/local/share/sigrok"); + /* Add search directory for the protocol decoders. */ + /* FIXME: Check error code. */ + /* FIXME: What happens if this function is called multiple times? */ + PyRun_SimpleString("import sys;" + "sys.path.append(r'" DECODERS_DIR "');"); + + if (!(dir = opendir(DECODERS_DIR))) + return SIGROKDECODE_ERR_DECODERS_DIR; - return 0; + while ((dp = readdir(dir)) != NULL) { + if (!g_str_has_suffix(dp->d_name, ".py")) + continue; + /* For now use the filename (without .py) as decoder name. */ + if ((tmp = g_strndup(dp->d_name, strlen(dp->d_name) - 3))) + list_pds = g_slist_append(list_pds, tmp); + } + closedir(dir); + + return SIGROKDECODE_OK; +} + +/** + * 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. + */ +GSList *sigrokdecode_list_decoders(void) +{ + return list_pds; +} + +/** + * Helper function to handle Python strings. + * + * TODO: @param entries. + * + * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. + * The 'outstr' argument points to a malloc()ed string upon success. + */ +static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, + const char *key, char **outstr) +{ + PyObject *py_str; + char *str; + + py_str = PyMapping_GetItemString(py_res, (char *)key); + if (!py_str || !PyString_Check(py_str)) { + if (PyErr_Occurred()) + PyErr_Print(); + Py_DECREF(py_func); + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + + if (!(str = PyString_AsString(py_str))) { + if (PyErr_Occurred()) + PyErr_Print(); + Py_DECREF(py_str); + Py_DECREF(py_func); + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + + if (!(*outstr = strdup(str))) { + if (PyErr_Occurred()) + PyErr_Print(); + Py_DECREF(py_str); + Py_DECREF(py_func); + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_MALLOC; + } + + Py_DECREF(py_str); + + return SIGROKDECODE_OK; } /** * TODO * * @param name TODO - * @return 0 upon success, non-zero otherwise. + * + * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. */ -int sigrokdecode_load_decoder_file(const char *name) +int sigrokdecode_load_decoder(const char *name, + struct sigrokdecode_decoder **dec) { - /* QUICK HACK */ - name = name; + struct sigrokdecode_decoder *d; + PyObject *py_name, *py_mod, *py_func, *py_res /* , *py_tuple */; + int r; - /* TODO */ - return 0; + /* Get the name of the decoder module as Python string. */ + if (!(py_name = PyString_FromString(name))) { + PyErr_Print(); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + + /* "Import" the Python module. */ + if (!(py_mod = PyImport_Import(py_name))) { + PyErr_Print(); + Py_DECREF(py_name); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + Py_DECREF(py_name); + + /* Get the 'register' function name as Python callable object. */ + py_func = PyObject_GetAttrString(py_mod, "register"); + if (!py_func || !PyCallable_Check(py_func)) { + if (PyErr_Occurred()) + PyErr_Print(); + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + + /* Call the 'register' function without arguments, get the result. */ + if (!(py_res = PyObject_CallFunction(py_func, NULL))) { + PyErr_Print(); + Py_DECREF(py_func); + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + + if (!(d = malloc(sizeof(struct sigrokdecode_decoder)))) + return SIGROKDECODE_ERR_MALLOC; + + if ((r = h_str(py_res, py_func, py_mod, "id", &(d->id))) < 0) + return r; + + if ((r = h_str(py_res, py_func, py_mod, "name", &(d->name))) < 0) + return r; + + if ((r = h_str(py_res, py_func, py_mod, "desc", &(d->desc))) < 0) + return r; + + d->py_mod = py_mod; + + Py_DECREF(py_res); + Py_DECREF(py_func); + + /* Get the 'decode' function name as Python callable object. */ + py_func = PyObject_GetAttrString(py_mod, "decode"); + if (!py_func || !PyCallable_Check(py_func)) { + if (PyErr_Occurred()) + PyErr_Print(); + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ + } + + d->py_func = py_func; + + /* TODO: Handle inputformats, outputformats. */ + + *dec = d; + + return SIGROKDECODE_OK; } /** * Run the specified decoder function. * - * @param decodername TODO + * @param dec TODO * @param inbuf TODO * @param inbuflen TODO * @param outbuf TODO * @param outbuflen TODO - * @return 0 upon success, non-zero otherwise. + * + * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. */ -int sigrokdecode_run_decoder(const char *decodername, uint8_t *inbuf, - uint64_t inbuflen, uint8_t **outbuf, - uint64_t *outbuflen) +int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, + uint8_t *inbuf, uint64_t inbuflen, + uint8_t **outbuf, uint64_t *outbuflen) { - const char *decoder_filename = "transitioncounter"; /* FIXME */ - PyObject *py_name, *py_module, *py_func, *py_args; - PyObject *py_value, *py_result; + PyObject *py_mod, *py_func, *py_args, *py_value, *py_res; int ret; /* TODO: Use #defines for the return codes. */ /* Return an error upon unusable input. */ - if (decodername == NULL) - return -1; + if (dec == NULL) + return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ if (inbuf == NULL) - return -2; + return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ if (inbuflen == 0) /* No point in working on empty buffers. */ - return -3; + return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ if (outbuf == NULL) - return -4; + return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ if (outbuflen == NULL) - return -5; + return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ - /* Get the name of the decoder module/file as Python string. */ - if (!(py_name = PyString_FromString(decoder_filename))) { - PyErr_Print(); - return -6; - } + /* TODO: Error handling. */ + py_mod = dec->py_mod; + py_func = dec->py_func; - /* "Import" the python file/module. */ - if (!(py_module = PyImport_Import(py_name))) { - PyErr_Print(); - Py_DECREF(py_name); - return -7; - } - Py_DECREF(py_name); - - /* Get the decoder/function name as Python callable object. */ - py_func = PyObject_GetAttrString(py_module, decodername); - if (!py_func || !PyCallable_Check(py_func)) { - if (PyErr_Occurred()) - PyErr_Print(); - Py_DECREF(py_module); - return -8; - } + /* TODO: Really run Py_DECREF on py_mod/py_func? */ /* Create a Python tuple of size 1. */ if (!(py_args = PyTuple_New(1))) { PyErr_Print(); Py_DECREF(py_func); - Py_DECREF(py_module); - return -9; + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } /* Get the input buffer as Python "string" (byte array). */ @@ -127,57 +272,59 @@ int sigrokdecode_run_decoder(const char *decodername, uint8_t *inbuf, PyErr_Print(); Py_DECREF(py_args); Py_DECREF(py_func); - Py_DECREF(py_module); - return -10; + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } + /* + * IMPORTANT: PyTuple_SetItem() "steals" a reference to py_value! + * That means we are no longer responsible for Py_DECREF()'ing it. + * It will automatically be free'd when the 'py_args' tuple is free'd. + */ if (PyTuple_SetItem(py_args, 0, py_value) != 0) { PyErr_Print(); - Py_DECREF(py_value); + Py_DECREF(py_value); /* TODO: Ref. stolen upon error? */ Py_DECREF(py_args); Py_DECREF(py_func); - Py_DECREF(py_module); - return -11; + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } - if (!(py_result = PyObject_CallObject(py_func, py_args))) { + if (!(py_res = PyObject_CallObject(py_func, py_args))) { PyErr_Print(); - Py_DECREF(py_value); Py_DECREF(py_args); Py_DECREF(py_func); - Py_DECREF(py_module); - return -12; + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } - if ((ret = PyObject_AsCharBuffer(py_result, (const char **)outbuf, + if ((ret = PyObject_AsCharBuffer(py_res, (const char **)outbuf, (Py_ssize_t *)outbuflen))) { PyErr_Print(); - Py_DECREF(py_result); - Py_DECREF(py_value); + Py_DECREF(py_res); Py_DECREF(py_args); Py_DECREF(py_func); - Py_DECREF(py_module); - return -13; + Py_DECREF(py_mod); + return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ } - Py_DECREF(py_result); - // Py_DECREF(py_value); + Py_DECREF(py_res); Py_DECREF(py_args); Py_DECREF(py_func); - Py_DECREF(py_module); + Py_DECREF(py_mod); - return 0; + return SIGROKDECODE_OK; } /** * Shutdown libsigrokdecode. * - * @return 0 upon success, non-zero otherwise. + * @return LIBSIGROKDECODE_OK upon success, a (negative) error code otherwise. */ int sigrokdecode_shutdown(void) { /* Py_Finalize() returns void, any finalization errors are ignored. */ Py_Finalize(); - return 0; + return SIGROKDECODE_OK; }