refactored PD framework, now using new sigrok.Decoder object

This uses the new python unified type/class object API to construct
an object for PDs to subclass. The sigrok.Decoder class has a method
put() which is implemented as a C function, and receives the PD's
object instance as its first parameter.

1 files changed, 394 insertions, 0 deletions

diff --git a/controller.c b/controller.c
new file mode 100644
index 0000000..db2ed9b
--- /dev/null
+++ b/controller.c
@@ -0,0 +1,394 @@
+/*
+ * This file is part of the sigrok project.
+ *
+ * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2011 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 "config.h"
+#include <sigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */
+#include <glib.h>
+
+/* TODO: this should probably be in sigrokdecode.h */
+/* 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
+
+
+static GSList *pipelines = NULL;
+
+/* lives in decoder.c */
+extern GSList *list_pds;
+extern GSList *decoders;
+
+struct srd_pipeline {
+	int id;
+	GSList *decoders;
+};
+
+
+
+static PyObject *Decoder_init(PyObject *self, PyObject *args)
+{
+	(void)self;
+	(void)args;
+//	printf("init object %x\n", self);
+
+	Py_RETURN_NONE;
+}
+
+
+static PyObject *Decoder_put(PyObject *self, PyObject *args)
+{
+	PyObject *arg;
+
+//	printf("put object %x\n", self);
+
+	if (!PyArg_ParseTuple(args, "O:put", &arg))
+		return NULL;
+
+	// fprintf(stdout, "sigrok.put() called by decoder:\n");
+	PyObject_Print(arg, stdout, Py_PRINT_RAW);
+	puts("");
+
+	Py_RETURN_NONE;
+}
+
+static PyMethodDef no_methods[] = { {NULL, NULL, 0, NULL} };
+static PyMethodDef Decoder_methods[] = {
+	{"__init__", Decoder_init, METH_VARARGS, ""},
+	{"put", Decoder_put, METH_VARARGS,
+	 "Accepts a dictionary with the following keys: time, duration, data"},
+	{NULL, NULL, 0, NULL}
+};
+
+
+// class Decoder(sigrok.Decoder):
+typedef struct {
+	PyObject_HEAD
+} sigrok_Decoder_object;
+
+static PyTypeObject sigrok_Decoder_type = {
+	PyObject_HEAD_INIT(NULL)
+	0,
+	"sigrok.Decoder",
+	sizeof(sigrok_Decoder_object),
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+	"Sigrok Decoder object",
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	Decoder_methods,
+};
+
+PyMODINIT_FUNC init_sigrok_Decoder(void)
+{
+	PyObject *mod;
+
+	sigrok_Decoder_type.tp_new = PyType_GenericNew;
+	if (PyType_Ready(&sigrok_Decoder_type) < 0)
+		return;
+
+	mod = Py_InitModule3("sigrok", no_methods, "sigrok base classes");
+	Py_INCREF(&sigrok_Decoder_type);
+	PyModule_AddObject(mod, "Decoder", (PyObject *)&sigrok_Decoder_type);
+
+}
+
+
+/**
+ * Initialize libsigrokdecode.
+ *
+ * This initializes the Python interpreter, and creates and initializes
+ * a "sigrok" Python module with a single put() method.
+ *
+ * Then, it searches for sigrok protocol decoder files (*.py) in the
+ * "decoders" subdirectory of the the sigrok 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_list_decoders().
+ *
+ * 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() inbetween,
+ * are not allowed.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *         Upon Python errors, return SRD_ERR_PYTHON. If the sigrok decoders
+ *         directory cannot be accessed, return SRD_ERR_DECODERS_DIR.
+ *         If not enough memory could be allocated, return SRD_ERR_MALLOC.
+ */
+int srd_init(void)
+{
+	int ret;
+
+	/* Py_Initialize() returns void and usually cannot fail. */
+	Py_Initialize();
+
+	init_sigrok_Decoder();
+
+	PyRun_SimpleString("import sys;");
+	if ((ret = set_modulepath()) != SRD_OK) {
+		Py_Finalize();
+		return ret;
+	}
+
+	if ((ret = srd_load_all_decoders()) != SRD_OK) {
+		Py_Finalize();
+		return ret;
+	}
+
+	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 inbetween, is not allowed.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ */
+int srd_exit(void)
+{
+	/* Unload/free all decoders, and then the list of decoders itself. */
+	/* TODO: Error handling. */
+	srd_unload_all_decoders();
+	g_slist_free(list_pds);
+
+	/* Py_Finalize() returns void, any finalization errors are ignored. */
+	Py_Finalize();
+
+	return SRD_OK;
+}
+
+
+/**
+ * Add search directories for the protocol decoders.
+ *
+ * TODO: add path from env var SIGROKDECODE_PATH, config etc
+ */
+int set_modulepath(void)
+{
+	int ret;
+
+	ret = PyRun_SimpleString("sys.path.append(r'" DECODERS_DIR "');");
+
+	return ret;
+}
+
+
+struct srd_decoder_instance *srd_instance_new(const char *id)
+{
+	struct srd_decoder *dec;
+	struct srd_decoder_instance *di;
+	PyObject *py_args;
+
+	fprintf(stdout, "%s: %s\n", __func__, id);
+
+	if (!(dec = srd_get_decoder_by_id(id)))
+		return NULL;
+
+	/* TODO: Error handling. Use g_try_malloc(). */
+	di = g_malloc(sizeof(*di));
+	di->decoder = dec;
+	di->pd_output = NULL;
+
+	/* Create an empty Python tuple. */
+	if (!(py_args = PyTuple_New(0))) { /* NEWREF */
+		if (PyErr_Occurred())
+			PyErr_Print(); /* Returns void. */
+
+		return NULL; /* TODO: More specific error? */
+	}
+
+	/* Create an instance of the 'Decoder' class. */
+	di->py_instance = PyObject_Call(dec->py_decobj, py_args, NULL);
+	if (!di->py_instance) {
+		if (PyErr_Occurred())
+			PyErr_Print(); /* Returns void. */
+		Py_XDECREF(py_args);
+		return NULL; /* TODO: More specific error? */
+	}
+	decoders = g_slist_append(decoders, di);
+
+	Py_XDECREF(py_args);
+
+	return di;
+}
+
+
+int srd_instance_set_probe(struct srd_decoder_instance *di,
+			   const char *probename, int num)
+{
+	PyObject *probedict, *probenum;
+
+	probedict = PyObject_GetAttrString(di->py_instance, "probes"); /* NEWREF */
+	if (!probedict) {
+		if (PyErr_Occurred())
+			PyErr_Print(); /* Returns void. */
+
+		return SRD_ERR_PYTHON; /* TODO: More specific error? */
+	}
+
+	probenum = PyInt_FromLong(num);
+	PyMapping_SetItemString(probedict, (char *)probename, probenum);
+
+	Py_XDECREF(probenum);
+	Py_XDECREF(probedict);
+
+	return SRD_OK;
+}
+
+
+int srd_session_start(const char *driver, int unitsize, uint64_t starttime,
+		uint64_t samplerate)
+{
+	PyObject *py_res;
+	GSList *d;
+	struct srd_decoder_instance *di;
+
+	fprintf(stdout, "%s: %s\n", __func__, driver);
+
+	for (d = decoders; d; d = d->next) {
+		di = d->data;
+		if (!(py_res = PyObject_CallMethod(di->py_instance, "start",
+						 "{s:s,s:i,s:d}",
+						 "driver", driver,
+						 "unitsize", unitsize,
+						 "starttime", starttime))) {
+			if (PyErr_Occurred())
+				PyErr_Print(); /* Returns void. */
+
+			return SRD_ERR_PYTHON; /* TODO: More specific error? */
+		}
+		Py_XDECREF(py_res);
+	}
+
+	return SRD_OK;
+}
+
+
+/**
+ * Run the specified decoder function.
+ *
+ * @param dec TODO
+ * @param inbuf TODO
+ * @param inbuflen TODO
+ * @param outbuf TODO
+ * @param outbuflen TODO
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ */
+int srd_run_decoder(struct srd_decoder_instance *dec,
+		    uint8_t *inbuf, uint64_t inbuflen)
+{
+	PyObject *py_instance, *py_res;
+	/* FIXME: Don't have a timebase available here. Make one up. */
+	static int _timehack = 0;
+
+	_timehack += inbuflen;
+
+//	fprintf(stdout, "%s: %s\n", __func__, dec->decoder->name);
+
+	/* Return an error upon unusable input. */
+	if (dec == NULL)
+		return SRD_ERR_ARGS; /* TODO: More specific error? */
+	if (inbuf == NULL)
+		return SRD_ERR_ARGS; /* TODO: More specific error? */
+	if (inbuflen == 0) /* No point in working on empty buffers. */
+		return SRD_ERR_ARGS; /* TODO: More specific error? */
+
+	/* TODO: Error handling. */
+	py_instance = dec->py_instance;
+	Py_XINCREF(py_instance);
+
+	if (!(py_res = PyObject_CallMethod(py_instance, "decode",
+					   "{s:i,s:i,s:s#}",
+					   "time", _timehack,
+					   "duration", 10,
+					   "data", inbuf, inbuflen))) { /* NEWREF */
+		if (PyErr_Occurred())
+			PyErr_Print(); /* Returns void. */
+
+		return SRD_ERR_PYTHON; /* TODO: More specific error? */
+	}
+
+	Py_XDECREF(py_res);
+	return SRD_OK;
+}
+
+
+/* Feed logic samples to decoder session. */
+int srd_session_feed(uint8_t *inbuf, uint64_t inbuflen)
+{
+	GSList *d;
+	int ret;
+
+//	fprintf(stdout, "%s: %d bytes\n", __func__, inbuflen);
+
+	for (d = decoders; d; d = d->next) {
+		if ((ret = srd_run_decoder(d->data, inbuf, inbuflen)) != SRD_OK)
+			return ret;
+	}
+
+	return SRD_OK;
+}
+
+
+//int srd_pipeline_new(int plid)
+//{
+//
+//
+//}
+//
+//
+//int pd_output_new(int output_type, char *output_id, char *description)
+//{
+//
+//
+//}
+
+
+
+