configure.ac: Also check for Python 3.6.
[libsigrokdecode.git] / type_decoder.c
index 19fd3508bd723a3ed965f9c8a8b25ae165a23578..dda0de28a2aab2fd9c6a991604eabeb031d49ed2 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * This file is part of the sigrok project.
+ * This file is part of the libsigrokdecode project.
  *
  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
  *
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "sigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
-#include "sigrokdecode-internal.h"
-#include "config.h"
+#include <config.h>
+#include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
+#include "libsigrokdecode.h"
 #include <inttypes.h>
 
-/* This is only used for nicer srd_dbg() output. */
-static const char *OUTPUT_TYPES[] = {
-       "OUTPUT_ANN",
-       "OUTPUT_PROTO",
-       "OUTPUT_BINARY",
-};
+typedef struct {
+        PyObject_HEAD
+} srd_Decoder;
 
-static int convert_pyobj(struct srd_decoder_inst *di, PyObject *obj,
-                        int *ann_format, char ***ann)
+/* This is only used for nicer srd_dbg() output.
+ */
+static const char *output_type_name(unsigned int idx)
+{
+       static const char names[][16] = {
+               "OUTPUT_ANN",
+               "OUTPUT_PYTHON",
+               "OUTPUT_BINARY",
+               "OUTPUT_META",
+               "(invalid)"
+       };
+       return names[MIN(idx, G_N_ELEMENTS(names) - 1)];
+}
+
+static int convert_annotation(struct srd_decoder_inst *di, PyObject *obj,
+               struct srd_proto_data *pdata)
 {
        PyObject *py_tmp;
        struct srd_pd_output *pdo;
-       int ann_id;
+       struct srd_proto_data_annotation *pda;
+       int ann_class;
+       char **ann_text;
 
-       /* Should be a list of [annotation format, [string, ...]]. */
-       if (!PyList_Check(obj) && !PyTuple_Check(obj)) {
-               srd_err("Protocol decoder %s submitted %s instead of list.",
-                       di->decoder->name, obj->ob_type->tp_name);
+       /* Should be a list of [annotation class, [string, ...]]. */
+       if (!PyList_Check(obj)) {
+               srd_err("Protocol decoder %s submitted an annotation that"
+                       " is not a list", di->decoder->name);
                return SRD_ERR_PYTHON;
        }
 
        /* Should have 2 elements. */
        if (PyList_Size(obj) != 2) {
                srd_err("Protocol decoder %s submitted annotation list with "
-                       "%d elements instead of 2", di->decoder->name,
+                       "%zd elements instead of 2", di->decoder->name,
                        PyList_Size(obj));
                return SRD_ERR_PYTHON;
        }
 
        /*
         * The first element should be an integer matching a previously
-        * registered annotation format.
+        * registered annotation class.
         */
        py_tmp = PyList_GetItem(obj, 0);
        if (!PyLong_Check(py_tmp)) {
@@ -61,14 +74,12 @@ static int convert_pyobj(struct srd_decoder_inst *di, PyObject *obj,
                        "first element was not an integer.", di->decoder->name);
                return SRD_ERR_PYTHON;
        }
-
-       ann_id = PyLong_AsLong(py_tmp);
-       if (!(pdo = g_slist_nth_data(di->decoder->annotations, ann_id))) {
+       ann_class = PyLong_AsLong(py_tmp);
+       if (!(pdo = g_slist_nth_data(di->decoder->annotations, ann_class))) {
                srd_err("Protocol decoder %s submitted data to unregistered "
-                       "annotation format %d.", di->decoder->name, ann_id);
+                       "annotation class %d.", di->decoder->name, ann_class);
                return SRD_ERR_PYTHON;
        }
-       *ann_format = ann_id;
 
        /* Second element must be a list. */
        py_tmp = PyList_GetItem(obj, 1);
@@ -77,25 +88,126 @@ static int convert_pyobj(struct srd_decoder_inst *di, PyObject *obj,
                        "second element was not a list.", di->decoder->name);
                return SRD_ERR_PYTHON;
        }
-       if (py_strlist_to_char(py_tmp, ann) != SRD_OK) {
+       if (py_strseq_to_char(py_tmp, &ann_text) != SRD_OK) {
                srd_err("Protocol decoder %s submitted annotation list, but "
                        "second element was malformed.", di->decoder->name);
                return SRD_ERR_PYTHON;
        }
 
+       pda = g_malloc(sizeof(struct srd_proto_data_annotation));
+       pda->ann_class = ann_class;
+       pda->ann_text = ann_text;
+       pdata->data = pda;
+
+       return SRD_OK;
+}
+
+static int convert_binary(struct srd_decoder_inst *di, PyObject *obj,
+               struct srd_proto_data *pdata)
+{
+       struct srd_proto_data_binary *pdb;
+       PyObject *py_tmp;
+       Py_ssize_t size;
+       int bin_class;
+       char *class_name, *buf;
+
+       /* Should be a list of [binary class, bytes]. */
+       if (!PyList_Check(obj)) {
+               srd_err("Protocol decoder %s submitted non-list for SRD_OUTPUT_BINARY.",
+                       di->decoder->name);
+               return SRD_ERR_PYTHON;
+       }
+
+       /* Should have 2 elements. */
+       if (PyList_Size(obj) != 2) {
+               srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list "
+                               "with %zd elements instead of 2", di->decoder->name,
+                               PyList_Size(obj));
+               return SRD_ERR_PYTHON;
+       }
+
+       /* The first element should be an integer. */
+       py_tmp = PyList_GetItem(obj, 0);
+       if (!PyLong_Check(py_tmp)) {
+               srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, "
+                       "but first element was not an integer.", di->decoder->name);
+               return SRD_ERR_PYTHON;
+       }
+       bin_class = PyLong_AsLong(py_tmp);
+       if (!(class_name = g_slist_nth_data(di->decoder->binary, bin_class))) {
+               srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY with "
+                       "unregistered binary class %d.", di->decoder->name, bin_class);
+               return SRD_ERR_PYTHON;
+       }
+
+       /* Second element should be bytes. */
+       py_tmp = PyList_GetItem(obj, 1);
+       if (!PyBytes_Check(py_tmp)) {
+               srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, "
+                       "but second element was not bytes.", di->decoder->name);
+               return SRD_ERR_PYTHON;
+       }
+
+       /* Consider an empty set of bytes a bug. */
+       if (PyBytes_Size(py_tmp) == 0) {
+               srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY "
+                               "with empty data set.", di->decoder->name);
+               return SRD_ERR_PYTHON;
+       }
+
+       pdb = g_malloc(sizeof(struct srd_proto_data_binary));
+       if (PyBytes_AsStringAndSize(py_tmp, &buf, &size) == -1)
+               return SRD_ERR_PYTHON;
+       pdb->bin_class = bin_class;
+       pdb->size = size;
+       if (!(pdb->data = g_try_malloc(pdb->size)))
+               return SRD_ERR_MALLOC;
+       memcpy((void *)pdb->data, (const void *)buf, pdb->size);
+       pdata->data = pdb;
+
+       return SRD_OK;
+}
+
+static int convert_meta(struct srd_proto_data *pdata, PyObject *obj)
+{
+       long long intvalue;
+       double dvalue;
+
+       if (pdata->pdo->meta_type == G_VARIANT_TYPE_INT64) {
+               if (!PyLong_Check(obj)) {
+                       PyErr_Format(PyExc_TypeError, "This output was registered "
+                                       "as 'int', but something else was passed.");
+                       return SRD_ERR_PYTHON;
+               }
+               intvalue = PyLong_AsLongLong(obj);
+               if (PyErr_Occurred())
+                       return SRD_ERR_PYTHON;
+               pdata->data = g_variant_new_int64(intvalue);
+       } else if (pdata->pdo->meta_type == G_VARIANT_TYPE_DOUBLE) {
+               if (!PyFloat_Check(obj)) {
+                       PyErr_Format(PyExc_TypeError, "This output was registered "
+                                       "as 'float', but something else was passed.");
+                       return SRD_ERR_PYTHON;
+               }
+               dvalue = PyFloat_AsDouble(obj);
+               if (PyErr_Occurred())
+                       return SRD_ERR_PYTHON;
+               pdata->data = g_variant_new_double(dvalue);
+       }
+
        return SRD_OK;
 }
 
 static PyObject *Decoder_put(PyObject *self, PyObject *args)
 {
        GSList *l;
-       PyObject *data, *py_res;
+       PyObject *py_data, *py_res;
        struct srd_decoder_inst *di, *next_di;
        struct srd_pd_output *pdo;
        struct srd_proto_data *pdata;
        uint64_t start_sample, end_sample;
        int output_id;
-       void (*cb)();
+       struct srd_pd_callback *cb;
 
        if (!(di = srd_inst_find_by_obj(NULL, self))) {
                /* Shouldn't happen. */
@@ -104,7 +216,7 @@ static PyObject *Decoder_put(PyObject *self, PyObject *args)
        }
 
        if (!PyArg_ParseTuple(args, "KKiO", &start_sample, &end_sample,
-           &output_id, &data)) {
+               &output_id, &py_data)) {
                /*
                 * This throws an exception, but by returning NULL here we let
                 * Python raise it. This results in a much better trace in
@@ -122,12 +234,9 @@ static PyObject *Decoder_put(PyObject *self, PyObject *args)
 
        srd_spew("Instance %s put %" PRIu64 "-%" PRIu64 " %s on oid %d.",
                 di->inst_id, start_sample, end_sample,
-                OUTPUT_TYPES[pdo->output_type], output_id);
+                output_type_name(pdo->output_type), output_id);
 
-       if (!(pdata = g_try_malloc0(sizeof(struct srd_proto_data)))) {
-               srd_err("Failed to g_malloc() struct srd_proto_data.");
-               return NULL;
-       }
+       pdata = g_malloc0(sizeof(struct srd_proto_data));
        pdata->start_sample = start_sample;
        pdata->end_sample = end_sample;
        pdata->pdo = pdo;
@@ -135,35 +244,54 @@ static PyObject *Decoder_put(PyObject *self, PyObject *args)
        switch (pdo->output_type) {
        case SRD_OUTPUT_ANN:
                /* Annotations are only fed to callbacks. */
-               if ((cb = srd_pd_output_callback_find(pdo->output_type))) {
-                       /* Annotations need converting from PyObject. */
-                       if (convert_pyobj(di, data, &pdata->ann_format,
-                                         (char ***)&pdata->data) != SRD_OK) {
+               if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+                       /* Convert from PyDict to srd_proto_data_annotation. */
+                       if (convert_annotation(di, py_data, pdata) != SRD_OK) {
                                /* An error was already logged. */
                                break;
                        }
-                       cb(pdata);
+                       cb->cb(pdata, cb->cb_data);
                }
                break;
-       case SRD_OUTPUT_PROTO:
+       case SRD_OUTPUT_PYTHON:
                for (l = di->next_di; l; l = l->next) {
                        next_di = l->data;
-                       /* TODO: Is this needed? */
-                       Py_XINCREF(next_di->py_inst);
-                       srd_spew("Sending %d-%d to instance %s",
-                                start_sample, end_sample,
-                                next_di->inst_id);
+                       srd_spew("Sending %" PRIu64 "-%" PRIu64 " to instance %s",
+                                start_sample, end_sample, next_di->inst_id);
                        if (!(py_res = PyObject_CallMethod(
-                           next_di->py_inst, "decode", "KKO", start_sample,
-                           end_sample, data))) {
-                               catch_exception("Calling %s decode(): ",
-                                               next_di->inst_id);
+                               next_di->py_inst, "decode", "KKO", start_sample,
+                               end_sample, py_data))) {
+                               srd_exception_catch("Calling %s decode() failed",
+                                                       next_di->inst_id);
                        }
                        Py_XDECREF(py_res);
                }
+               if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+                       /* Frontends aren't really supposed to get Python
+                        * callbacks, but it's useful for testing. */
+                       pdata->data = py_data;
+                       cb->cb(pdata, cb->cb_data);
+               }
                break;
        case SRD_OUTPUT_BINARY:
-               srd_err("SRD_OUTPUT_BINARY not yet supported.");
+               if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+                       /* Convert from PyDict to srd_proto_data_binary. */
+                       if (convert_binary(di, py_data, pdata) != SRD_OK) {
+                               /* An error was already logged. */
+                               break;
+                       }
+                       cb->cb(pdata, cb->cb_data);
+               }
+               break;
+       case SRD_OUTPUT_META:
+               if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+                       /* Annotations need converting from PyObject. */
+                       if (convert_meta(pdata, py_data) != SRD_OK) {
+                               /* An exception was already set up. */
+                               break;
+                       }
+                       cb->cb(pdata, cb->cb_data);
+               }
                break;
        default:
                srd_err("Protocol decoder %s submitted invalid output type %d.",
@@ -176,44 +304,433 @@ static PyObject *Decoder_put(PyObject *self, PyObject *args)
        Py_RETURN_NONE;
 }
 
-static PyObject *Decoder_add(PyObject *self, PyObject *args)
+static PyObject *Decoder_register(PyObject *self, PyObject *args,
+               PyObject *kwargs)
 {
-       PyObject *ret;
        struct srd_decoder_inst *di;
-       char *proto_id;
-       int output_type, pdo_id;
+       struct srd_pd_output *pdo;
+       PyObject *py_new_output_id;
+       PyTypeObject *meta_type_py;
+       const GVariantType *meta_type_gv;
+       int output_type;
+       char *proto_id, *meta_name, *meta_descr;
+       char *keywords[] = {"output_type", "proto_id", "meta", NULL};
+
+       meta_type_py = NULL;
+       meta_type_gv = NULL;
+       meta_name = meta_descr = NULL;
 
        if (!(di = srd_inst_find_by_obj(NULL, self))) {
                PyErr_SetString(PyExc_Exception, "decoder instance not found");
                return NULL;
        }
 
-       if (!PyArg_ParseTuple(args, "is", &output_type, &proto_id)) {
+       /* Default to instance id, which defaults to class id. */
+       proto_id = di->inst_id;
+       if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i|s(Oss)", keywords,
+                       &output_type, &proto_id,
+                       &meta_type_py, &meta_name, &meta_descr)) {
                /* Let Python raise this exception. */
                return NULL;
        }
 
-       pdo_id = pd_add(di, output_type, proto_id);
-       if (pdo_id < 0)
-               Py_RETURN_NONE;
-       else
-               ret = Py_BuildValue("i", pdo_id);
+       /* Check if the meta value's type is supported. */
+       if (output_type == SRD_OUTPUT_META) {
+               if (meta_type_py == &PyLong_Type)
+                       meta_type_gv = G_VARIANT_TYPE_INT64;
+               else if (meta_type_py == &PyFloat_Type)
+                       meta_type_gv = G_VARIANT_TYPE_DOUBLE;
+               else {
+                       PyErr_Format(PyExc_TypeError, "Unsupported type.");
+                       return NULL;
+               }
+       }
+
+       srd_dbg("Instance %s creating new output type %d for %s.",
+               di->inst_id, output_type, proto_id);
+
+       pdo = g_malloc(sizeof(struct srd_pd_output));
+
+       /* pdo_id is just a simple index, nothing is deleted from this list anyway. */
+       pdo->pdo_id = g_slist_length(di->pd_output);
+       pdo->output_type = output_type;
+       pdo->di = di;
+       pdo->proto_id = g_strdup(proto_id);
+
+       if (output_type == SRD_OUTPUT_META) {
+               pdo->meta_type = meta_type_gv;
+               pdo->meta_name = g_strdup(meta_name);
+               pdo->meta_descr = g_strdup(meta_descr);
+       }
+
+       di->pd_output = g_slist_append(di->pd_output, pdo);
+       py_new_output_id = Py_BuildValue("i", pdo->pdo_id);
+
+       return py_new_output_id;
+}
+
+static int get_term_type(const char *v)
+{
+       switch (v[0]) {
+       case 'h':
+               return SRD_TERM_HIGH;
+       case 'l':
+               return SRD_TERM_LOW;
+       case 'r':
+               return SRD_TERM_RISING_EDGE;
+       case 'f':
+               return SRD_TERM_FALLING_EDGE;
+       case 'e':
+               return SRD_TERM_EITHER_EDGE;
+       case 'n':
+               return SRD_TERM_NO_EDGE;
+       }
+
+       return -1;
+}
+
+/**
+ * Get the pin values at the current sample number.
+ *
+ * @param di The decoder instance to use. Must not be NULL.
+ *           The number of channels must be >= 1.
+ *
+ * @return A newly allocated PyTuple containing the pin values at the
+ *         current sample number.
+ */
+static PyObject *get_current_pinvalues(const struct srd_decoder_inst *di)
+{
+       int i;
+       uint8_t sample;
+       const uint8_t *sample_pos;
+       int byte_offset, bit_offset;
+       PyObject *py_pinvalues;
+
+       if (!di) {
+               srd_err("Invalid decoder instance.");
+               return NULL;
+       }
+
+       py_pinvalues = PyTuple_New(di->dec_num_channels);
+
+       for (i = 0; i < di->dec_num_channels; i++) {
+               /* A channelmap value of -1 means "unused optional channel". */
+               if (di->dec_channelmap[i] == -1) {
+                       /* Value of unused channel is 0xff, instead of 0 or 1. */
+                       PyTuple_SetItem(py_pinvalues, i, PyLong_FromLong(0xff));
+               } else {
+                       sample_pos = di->inbuf + ((di->cur_samplenum - di->start_samplenum) * di->data_unitsize);
+                       byte_offset = di->dec_channelmap[i] / 8;
+                       bit_offset = di->dec_channelmap[i] % 8;
+                       sample = *(sample_pos + byte_offset) & (1 << bit_offset) ? 1 : 0;
+                       PyTuple_SetItem(py_pinvalues, i, PyLong_FromLong(sample));
+               }
+       }
+
+       Py_IncRef(py_pinvalues);
+
+       return py_pinvalues;
+}
+
+/**
+ * Create a list of terms in the specified condition.
+ *
+ * If there are no terms in the condition, 'term_list' will be NULL.
+ *
+ * @param py_dict A Python dict containing terms. Must not be NULL.
+ * @param term_list Pointer to a GSList which will be set to the newly
+ *                  created list of terms. Must not be NULL.
+ *
+ * @return SRD_OK upon success, a negative error code otherwise.
+ */
+static int create_term_list(PyObject *py_dict, GSList **term_list)
+{
+       Py_ssize_t pos = 0;
+       PyObject *py_key, *py_value;
+       struct srd_term *term;
+       uint64_t num_samples_to_skip;
+       char *term_str;
+
+       if (!py_dict || !term_list)
+               return SRD_ERR_ARG;
+
+       /* "Create" an empty GSList of terms. */
+       *term_list = NULL;
+
+       /* Iterate over all items in the current dict. */
+       while (PyDict_Next(py_dict, &pos, &py_key, &py_value)) {
+               /* Check whether the current key is a string or a number. */
+               if (PyLong_Check(py_key)) {
+                       /* The key is a number. */
+                       /* TODO: Check if the number is a valid channel. */
+                       /* Get the value string. */
+                       if ((py_pydictitem_as_str(py_dict, py_key, &term_str)) != SRD_OK) {
+                               srd_err("Failed to get the value.");
+                               return SRD_ERR;
+                       }
+                       term = g_malloc0(sizeof(struct srd_term));
+                       term->type = get_term_type(term_str);
+                       term->channel = PyLong_AsLong(py_key);
+                       g_free(term_str);
+               } else if (PyUnicode_Check(py_key)) {
+                       /* The key is a string. */
+                       /* TODO: Check if it's "skip". */
+                       if ((py_pydictitem_as_long(py_dict, py_key, &num_samples_to_skip)) != SRD_OK) {
+                               srd_err("Failed to get number of samples to skip.");
+                               return SRD_ERR;
+                       }
+                       term = g_malloc0(sizeof(struct srd_term));
+                       term->type = SRD_TERM_SKIP;
+                       term->num_samples_to_skip = num_samples_to_skip;
+                       term->num_samples_already_skipped = 0;
+               } else {
+                       srd_err("Term key is neither a string nor a number.");
+                       return SRD_ERR;
+               }
+
+               /* Add the term to the list of terms. */
+               *term_list = g_slist_append(*term_list, term);
+       }
+
+       return SRD_OK;
+}
+
+/**
+ * Replace the current condition list with the new one.
+ *
+ * @param self TODO. Must not be NULL.
+ * @param args TODO. Must not be NULL.
+ *
+ * @retval SRD_OK The new condition list was set successfully.
+ * @retval SRD_ERR There was an error setting the new condition list.
+ *                 The contents of di->condition_list are undefined.
+ * @retval 9999 TODO.
+ */
+static int set_new_condition_list(PyObject *self, PyObject *args)
+{
+       struct srd_decoder_inst *di;
+       GSList *term_list;
+       PyObject *py_conditionlist, *py_conds, *py_dict;
+       int i, num_conditions, ret;
+
+       if (!self || !args)
+               return SRD_ERR_ARG;
+
+       /* Get the decoder instance. */
+       if (!(di = srd_inst_find_by_obj(NULL, self))) {
+               PyErr_SetString(PyExc_Exception, "decoder instance not found");
+               return SRD_ERR;
+       }
+
+       /* Parse the argument of self.wait() into 'py_conds'. */
+       if (!PyArg_ParseTuple(args, "O", &py_conds)) {
+               /* Let Python raise this exception. */
+               return SRD_ERR;
+       }
+
+       /* Check whether 'py_conds' is a dict or a list. */
+       if (PyList_Check(py_conds)) {
+               /* 'py_conds' is a list. */
+               py_conditionlist = py_conds;
+               num_conditions = PyList_Size(py_conditionlist);
+               if (num_conditions == 0)
+                       return 9999; /* The PD invoked self.wait([]). */
+       } else if (PyDict_Check(py_conds)) {
+               /* 'py_conds' is a dict. */
+               if (PyDict_Size(py_conds) == 0)
+                       return 9999; /* The PD invoked self.wait({}). */
+               /* Make a list and put the dict in there for convenience. */
+               py_conditionlist = PyList_New(1);
+               PyList_SetItem(py_conditionlist, 0, py_conds);
+               num_conditions = 1;
+       } else {
+               srd_err("Condition list is neither a list nor a dict.");
+               return SRD_ERR;
+       }
+
+       /* Free the old condition list. */
+       condition_list_free(di);
+
+       ret = SRD_OK;
+
+       /* Iterate over the conditions, set di->condition_list accordingly. */
+       for (i = 0; i < num_conditions; i++) {
+               /* Get a condition (dict) from the condition list. */
+               py_dict = PyList_GetItem(py_conditionlist, i);
+               if (!PyDict_Check(py_dict)) {
+                       srd_err("Condition is not a dict.");
+                       ret = SRD_ERR;
+                       break;
+               }
+
+               /* Create the list of terms in this condition. */
+               if ((ret = create_term_list(py_dict, &term_list)) < 0)
+                       break;
+
+               /* Add the new condition to the PD instance's condition list. */
+               di->condition_list = g_slist_append(di->condition_list, term_list);
+       }
+
+       Py_DecRef(py_conditionlist);
 
        return ret;
 }
 
+static PyObject *Decoder_wait(PyObject *self, PyObject *args)
+{
+       int ret;
+       unsigned int i;
+       gboolean found_match;
+       struct srd_decoder_inst *di;
+       PyObject *py_pinvalues, *py_matched;
+
+       if (!self || !args)
+               return NULL;
+
+       if (!(di = srd_inst_find_by_obj(NULL, self))) {
+               PyErr_SetString(PyExc_Exception, "decoder instance not found");
+               Py_RETURN_NONE;
+       }
+
+       ret = set_new_condition_list(self, args);
+
+       if (ret == 9999) {
+               /* Empty condition list, automatic match. */
+               PyObject_SetAttrString(di->py_inst, "matched", Py_None);
+               /* Leave self.samplenum unchanged (== di->cur_samplenum). */
+               return get_current_pinvalues(di);
+       }
+
+       while (1) {
+               /* Wait for new samples to process. */
+               g_mutex_lock(&di->data_mutex);
+               while (!di->got_new_samples)
+                       g_cond_wait(&di->got_new_samples_cond, &di->data_mutex);
+
+               /* Check whether any of the current condition(s) match. */
+               ret = process_samples_until_condition_match(di, &found_match);
+
+               /* If there's a match, set self.samplenum etc. and return. */
+               if (found_match) {
+                       /* Set self.samplenum to the (absolute) sample number that matched. */
+                       PyObject_SetAttrString(di->py_inst, "samplenum",
+                               PyLong_FromLong(di->cur_samplenum));
+
+                       if (di->match_array && di->match_array->len > 0) {
+                               py_matched = PyTuple_New(di->match_array->len);
+                               for (i = 0; i < di->match_array->len; i++)
+                                       PyTuple_SetItem(py_matched, i, PyBool_FromLong(di->match_array->data[i]));
+                               PyObject_SetAttrString(di->py_inst, "matched", py_matched);
+                               match_array_free(di);
+                       } else {
+                               PyObject_SetAttrString(di->py_inst, "matched", Py_None);
+                       }
+       
+                       py_pinvalues = get_current_pinvalues(di);
+
+                       g_mutex_unlock(&di->data_mutex);
+
+                       return py_pinvalues;
+               }
+
+               /* No match, reset state for the next chunk. */
+               di->got_new_samples = FALSE;
+               di->handled_all_samples = TRUE;
+               di->start_samplenum = 0;
+               di->end_samplenum = 0;
+               di->inbuf = NULL;
+               di->inbuflen = 0;
+
+               /* Signal the main thread that we handled all samples. */
+               g_cond_signal(&di->handled_all_samples_cond);
+
+               g_mutex_unlock(&di->data_mutex);
+       }
+
+       Py_RETURN_NONE;
+}
+
+/**
+ * Return whether the specified channel was supplied to the decoder.
+ *
+ * @param self TODO. Must not be NULL.
+ * @param args TODO. Must not be NULL.
+ *
+ * @retval Py_True The channel has been supplied by the frontend.
+ * @retval Py_False The channel has been supplied by the frontend.
+ * @retval NULL An error occurred.
+ */
+static PyObject *Decoder_has_channel(PyObject *self, PyObject *args)
+{
+       int idx, max_idx;
+       struct srd_decoder_inst *di;
+       PyObject *py_channel;
+
+       if (!self || !args)
+               return NULL;
+
+       if (!(di = srd_inst_find_by_obj(NULL, self))) {
+               PyErr_SetString(PyExc_Exception, "decoder instance not found");
+               return NULL;
+       }
+
+       /* Parse the argument of self.has_channel() into 'py_channel'. */
+       if (!PyArg_ParseTuple(args, "O", &py_channel)) {
+               /* Let Python raise this exception. */
+               return NULL;
+       }
+
+       if (!PyLong_Check(py_channel)) {
+               PyErr_SetString(PyExc_Exception, "channel index not a number");
+               return NULL;
+       }
+
+       idx = PyLong_AsLong(py_channel);
+       max_idx = g_slist_length(di->decoder->channels)
+               + g_slist_length(di->decoder->opt_channels) - 1;
+
+       if (idx < 0 || idx > max_idx) {
+               srd_err("Invalid channel index %d/%d.", idx, max_idx);
+               PyErr_SetString(PyExc_Exception, "invalid channel");
+               return NULL;
+       }
+
+       return (di->dec_channelmap[idx] == -1) ? Py_False : Py_True;
+}
+
 static PyMethodDef Decoder_methods[] = {
        {"put", Decoder_put, METH_VARARGS,
         "Accepts a dictionary with the following keys: startsample, endsample, data"},
-       {"add", Decoder_add, METH_VARARGS, "Create a new output stream"},
+       {"register", (PyCFunction)Decoder_register, METH_VARARGS|METH_KEYWORDS,
+                       "Register a new output stream"},
+       {"wait", Decoder_wait, METH_VARARGS,
+                       "Wait for one or more conditions to occur"},
+       {"has_channel", Decoder_has_channel, METH_VARARGS,
+                       "Report whether a channel was supplied"},
        {NULL, NULL, 0, NULL}
 };
 
-SRD_PRIV PyTypeObject srd_Decoder_type = {
-       PyVarObject_HEAD_INIT(NULL, 0)
-       .tp_name = "sigrokdecode.Decoder",
-       .tp_basicsize = sizeof(srd_Decoder),
-       .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
-       .tp_doc = "sigrok Decoder base class",
-       .tp_methods = Decoder_methods,
-};
+/**
+ * Create the sigrokdecode.Decoder type.
+ *
+ * @return The new type object.
+ *
+ * @private
+ */
+SRD_PRIV PyObject *srd_Decoder_type_new(void)
+{
+       PyType_Spec spec;
+       PyType_Slot slots[] = {
+               { Py_tp_doc, "sigrok Decoder base class" },
+               { Py_tp_methods, Decoder_methods },
+               { Py_tp_new, (void *)&PyType_GenericNew },
+               { 0, NULL }
+       };
+       spec.name = "sigrokdecode.Decoder";
+       spec.basicsize = sizeof(srd_Decoder);
+       spec.itemsize = 0;
+       spec.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE;
+       spec.slots = slots;
+
+       return PyType_FromSpec(&spec);
+}