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, 0 insertions, 528 deletions

diff --git a/decode.c b/decode.c
deleted file mode 100644
index f4b9cdf..0000000
--- a/decode.c
+++ /dev/null
@@ -1,528 +0,0 @@
-/*
- * This file is part of the sigrok project.
- *
- * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
- *
- * 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 2 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, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
- */
-
-#include "config.h"
-#include <sigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */
-#include <stdio.h>
-#include <string.h>
-#include <dirent.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
-
-/* The list of protocol decoders. */
-static GSList *list_pds = NULL;
-/* The list of protocol decoder instances: struct srd_decoder_instance */
-static GSList *decoders;
-
-/*
- * 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_XDECREF() it.
- *
- *  - If it returns a "borrowed reference", you MUST NOT Py_XDECREF() it.
- *
- *  - If a function "steals" a reference, you no longer are responsible for
- *    Py_XDECREF()ing it (someone else will do it for you at some point).
- */
-
-static int srd_load_decoder(PyObject *py_res);
-
-static PyObject *emb_register(PyObject *self, PyObject *args)
-{
-	PyObject *arg;
-
-	(void)self;
-
-	if (!PyArg_ParseTuple(args, "O:decoder", &arg))
-		return NULL;
-
-	srd_load_decoder(arg);
-
-	Py_RETURN_NONE;
-}
-
-static PyObject *emb_put(PyObject *self, PyObject *args)
-{
-	PyObject *arg;
-
-	(void)self;
-
-	if (!PyArg_ParseTuple(args, "O:put", &arg))
-		return NULL;
-
-	PyObject_Print(arg, stdout, Py_PRINT_RAW);
-	puts("");
-
-	Py_RETURN_NONE;
-}
-
-static PyMethodDef EmbMethods[] = {
-	{"register", emb_register, METH_VARARGS,
-	 "Register a protocol decoder object with libsigrokdecode."},
-	{"put", emb_put, METH_VARARGS,
-	 "Accepts a dictionary with the following keys: time, duration, data"},
-	{NULL, NULL, 0, NULL}
-};
-
-/**
- * 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)
-{
-	DIR *dir;
-	struct dirent *dp;
-	char *decodername;
-	struct srd_decoder *dec;
-	int ret;
-
-	/* Py_Initialize() returns void and usually cannot fail. */
-	Py_Initialize();
-
-	/* TODO: Use Py_InitModule3() to add a docstring? */
-	if (!Py_InitModule("sigrok", EmbMethods)) {
-		Py_Finalize(); /* Returns void. */
-		return SRD_ERR_PYTHON;
-	}
-
-	/* Add search directory for the protocol decoders. */
-	/* FIXME: What happens if this function is called multiple times? */
-	ret = PyRun_SimpleString("import sys;"
-				 "sys.path.append(r'" DECODERS_DIR "');");
-	if (ret != 0) {
-		Py_Finalize(); /* Returns void. */
-		return SRD_ERR_PYTHON;
-	}
-
-	if (!(dir = opendir(DECODERS_DIR))) {
-		Py_Finalize(); /* Returns void. */
-		return SRD_ERR_DECODERS_DIR;
-	}
-
-	while ((dp = readdir(dir)) != NULL) {
-		/* Ignore filenames which don't end with ".py". */
-		if (!g_str_has_suffix(dp->d_name, ".py"))
-			continue;
-
-		/* Decoder name == filename (without .py suffix). */
-		decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3);
-
-		/* TODO: Error handling. Use g_try_malloc(). */
-		if (!(dec = malloc(sizeof(struct srd_decoder)))) {
-			Py_Finalize(); /* Returns void. */
-			return SRD_ERR_MALLOC;
-		}
-
-		/* Load the decoder. */
-		/* "Import" the Python module. */
-		PyObject *py_mod;
-		if (!(py_mod = PyImport_ImportModule(decodername))) { /* NEWREF */
-			PyErr_Print(); /* Returns void. */
-			return SRD_ERR_PYTHON; /* TODO: More specific error? */
-		}
-		/* We release here.  If any decoders were registered they
-		 * will hold references. */
-		Py_XDECREF(py_mod);
-	}
-	closedir(dir);
-
-	return SRD_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 *srd_list_decoders(void)
-{
-	return list_pds;
-}
-
-/**
- * Get the decoder with the specified ID.
- *
- * @param id The ID string of the decoder to return.
- * @return The decoder with the specified ID, or NULL if not found.
- */
-struct srd_decoder *srd_get_decoder_by_id(const char *id)
-{
-	GSList *l;
-	struct srd_decoder *dec;
-
-	for (l = srd_list_decoders(); l; l = l->next) {
-		dec = l->data;
-		if (!strcmp(dec->id, id))
-			return dec;
-	}
-
-	return NULL;
-}
-
-/**
- * Helper function to handle Python strings.
- *
- * TODO: @param entries.
- *
- * @return SRD_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, const char *key, char **outstr)
-{
-	PyObject *py_str;
-	char *str;
-	int ret;
-
-	py_str = PyObject_GetAttrString(py_res, (char *)key); /* NEWREF */
-	if (!py_str || !PyString_Check(py_str)) {
-		ret = SRD_ERR_PYTHON; /* TODO: More specific error? */
-		goto err_h_decref_mod;
-	}
-
-	/*
-	 * PyString_AsString()'s returned string refers to an internal buffer
-	 * (not a copy), i.e. the data must not be modified, and the memory
-	 * must not be free()'d.
-	 */
-	if (!(str = PyString_AsString(py_str))) {
-		ret = SRD_ERR_PYTHON; /* TODO: More specific error? */
-		goto err_h_decref_str;
-	}
-
-	if (!(*outstr = g_strdup(str))) {
-		ret = SRD_ERR_MALLOC;
-		goto err_h_decref_str;
-	}
-
-	Py_XDECREF(py_str);
-
-	return SRD_OK;
-
-err_h_decref_str:
-	Py_XDECREF(py_str);
-err_h_decref_mod:
-
-	if (PyErr_Occurred())
-		PyErr_Print(); /* Returns void. */
-
-	return ret;
-}
-
-/**
- * TODO
- *
- * @param name TODO
- *
- * @return SRD_OK upon success, a (negative) error code otherwise.
- */
-static int srd_load_decoder(PyObject *py_res)
-{
-	struct srd_decoder *d;
-	int r;
-
-	if (!(d = malloc(sizeof(struct srd_decoder))))
-		return SRD_ERR_MALLOC;
-
-	if ((r = h_str(py_res, "id", &(d->id))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "name", &(d->name))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "longname",
-		       &(d->longname))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "desc", &(d->desc))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "longdesc",
-		       &(d->longdesc))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "author", &(d->author))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "email", &(d->email))) < 0)
-		return r;
-
-	if ((r = h_str(py_res, "license", &(d->license))) < 0)
-		return r;
-
-	d->py_decobj = py_res;
-
-	/* TODO: Handle func, inputformats, outputformats. */
-	/* Note: They must at least be set to NULL, will segfault otherwise. */
-	d->func = NULL;
-	d->inputformats = NULL;
-	d->outputformats = NULL;
-
-	Py_INCREF(py_res);
-	fprintf(stderr, "srd: registered '%s'\n", d->id);
-	list_pds = g_slist_append(list_pds, d);
-
-	return SRD_OK;
-}
-
-/** Create a new decoder instance and add to session. */
-struct srd_decoder_instance *srd_instance_new(const char *id)
-{
-	struct srd_decoder *dec;
-	struct srd_decoder_instance *di;
-	PyObject *py_args;
-
-	if (!(dec = srd_get_decoder_by_id(id)))
-		return NULL;
-
-	/* TODO: Error handling. Use g_try_malloc(). */
-	di = g_malloc(sizeof(*di));
-
-	/* 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? */
-	}
-
-	/* Append to list of PD instances */
-	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;
-}
-
-/** Start decoding session.  Feed metadata to decoder instances. */
-int srd_session_start(const char *driver, int unitsize, uint64_t starttime,
-			uint64_t samplerate)
-{
-	PyObject *py_res;
-	GSList *d;
-	for (d = decoders; d; d = d->next) {
-		struct srd_decoder_instance *di = d->data;
-		/* TODO: Error handling. */
-		if (!(py_res = PyObject_CallMethod(di->py_instance, "start",
-					"{s:s,s:l,s:l,s:l}", 
-					"driver", driver,
-					"unitsize", (long)unitsize,
-					"starttime", (long)starttime,
-					"samplerate", (long)samplerate))) {
-			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.
- */
-static 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;
-
-	/* TODO: Use #defines for the return codes. */
-
-	/* 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;
-	for (d = decoders; d; d = d->next) {
-		/* TODO: Error handling. */
-		
-		int ret = srd_run_decoder(d->data, inbuf, inbuflen);
-
-		if (ret != SRD_OK) {
-			/* This probably shouldn't fail catastrophically. */
-			fprintf(stderr, "Decoder runtime error (%d)\n", ret);
-			exit(1);
-		}
-	}
-	return SRD_OK;
-}
-
-/**
- * TODO
- */
-static int srd_unload_decoder(struct srd_decoder *dec)
-{
-	g_free(dec->id);
-	g_free(dec->name);
-	g_free(dec->desc);
-	g_free(dec->func);
-
-	/* TODO: Free everything in inputformats and outputformats. */
-
-	if (dec->inputformats != NULL)
-		g_slist_free(dec->inputformats);
-	if (dec->outputformats != NULL)
-		g_slist_free(dec->outputformats);
-
-	Py_XDECREF(dec->py_decobj);
-
-	/* TODO: (g_)free dec itself? */
-
-	return SRD_OK;
-}
-
-/**
- * TODO
- */
-static int srd_unload_all_decoders(void)
-{
-	GSList *l;
-	struct srd_decoder *dec;
-
-	for (l = srd_list_decoders(); l; l = l->next) {
-		dec = l->data;
-		/* TODO: Error handling. */
-		srd_unload_decoder(dec);
-	}
-
-	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;
-}