Move session-specific functionality into session.c

1 files changed, 334 insertions, 0 deletions

diff --git a/session.c b/session.c
new file mode 100644
index 0000000..109ede1
--- /dev/null
+++ b/session.c
@@ -0,0 +1,334 @@
+/*
+ * 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>
+
+/**
+ * @file
+ *
+ * Session handling.
+ */
+
+/**
+ * @defgroup grp_session Session handling
+ *
+ * Starting and handling decoding sessions.
+ *
+ * @{
+ */
+
+/** @cond PRIVATE */
+
+SRD_PRIV GSList *sessions = NULL;
+int max_session_id = -1;
+
+/** @endcond */
+
+/** @private */
+SRD_PRIV int session_is_valid(struct srd_session *sess)
+{
+
+	if (!sess || sess->session_id < 1)
+		return SRD_ERR;
+
+	return SRD_OK;
+}
+
+/**
+ * Create a decoding session.
+ *
+ * A session holds all decoder instances, their stack relationships and
+ * output callbacks.
+ *
+ * @param sess A pointer which will hold a pointer to a newly
+ *             initialized session on return.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.3.0
+ */
+SRD_API int srd_session_new(struct srd_session **sess)
+{
+
+	if (!sess) {
+		srd_err("Invalid session pointer.");
+		return SRD_ERR_ARG;
+	}
+
+	if (!(*sess = g_try_malloc(sizeof(struct srd_session))))
+		return SRD_ERR_MALLOC;
+	(*sess)->session_id = ++max_session_id;
+	(*sess)->di_list = (*sess)->callbacks = NULL;
+
+	/* Keep a list of all sessions, so we can clean up as needed. */
+	sessions = g_slist_append(sessions, *sess);
+
+	srd_dbg("Created session %d.", (*sess)->session_id);
+
+	return SRD_OK;
+}
+
+/**
+ * Start a decoding session.
+ *
+ * Decoders, instances and stack must have been prepared beforehand,
+ * and all SRD_CONF parameters set.
+ *
+ * @param sess The session to start.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.3.0
+ */
+SRD_API int srd_session_start(struct srd_session *sess)
+{
+	GSList *d;
+	struct srd_decoder_inst *di;
+	int ret;
+
+	if (session_is_valid(sess) != SRD_OK) {
+		srd_err("Invalid session pointer.");
+		return SRD_ERR;
+	}
+
+	srd_dbg("Calling start() on all instances in session %d.", sess->session_id);
+
+	/* Run the start() method on all decoders receiving frontend data. */
+	ret = SRD_OK;
+	for (d = sess->di_list; d; d = d->next) {
+		di = d->data;
+		if ((ret = srd_inst_start(di)) != SRD_OK)
+			break;
+	}
+
+	return ret;
+}
+
+/** @private */
+SRD_PRIV int srd_inst_send_meta(struct srd_decoder_inst *di, int key,
+		GVariant *data)
+{
+	PyObject *py_ret;
+
+	if (key != SRD_CONF_SAMPLERATE)
+		/* This is the only key we pass on to the decoder for now. */
+		return SRD_OK;
+
+	if (!PyObject_HasAttrString(di->py_inst, "metadata"))
+		/* This decoder doesn't want metadata, that's fine. */
+		return SRD_OK;
+
+	py_ret = PyObject_CallMethod(di->py_inst, "metadata", "lK",
+			(long)SRD_CONF_SAMPLERATE,
+			(unsigned long long)g_variant_get_uint64(data));
+	Py_XDECREF(py_ret);
+
+	return SRD_OK;
+}
+
+/**
+ * Set a metadata configuration key in a session.
+ *
+ * @param sess The session to configure.
+ * @param key The configuration key (SRD_CONF_*).
+ * @param data The new value for the key, as a GVariant with GVariantType
+ *             appropriate to that key. A floating reference can be passed
+ *             in; its refcount will be sunk and unreferenced after use.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.3.0
+ */
+SRD_API int srd_session_metadata_set(struct srd_session *sess, int key,
+		GVariant *data)
+{
+	GSList *l;
+	int ret;
+
+	if (session_is_valid(sess) != SRD_OK) {
+		srd_err("Invalid session.");
+		return SRD_ERR_ARG;
+	}
+
+	if (key != SRD_CONF_SAMPLERATE) {
+		srd_err("Unknown config key %d.", key);
+		return SRD_ERR_ARG;
+	}
+
+	srd_dbg("Setting session %d samplerate to %"PRIu64".",
+			sess->session_id, g_variant_get_uint64(data));
+
+	ret = SRD_OK;
+	for (l = sess->di_list; l; l = l->next) {
+		if ((ret = srd_inst_send_meta(l->data, key, data)) != SRD_OK)
+			break;
+	}
+
+	g_variant_unref(data);
+
+	return ret;
+}
+
+/**
+ * Send a chunk of logic sample data to a running decoder session.
+ *
+ * The logic samples must be arranged in probe order, in the least
+ * amount of space possible. If no probes were configured, the default
+ * probe set consists of all required probes + all optional probes.
+ *
+ * The size of a sample in inbuf is the minimum number of bytes needed
+ * to store the configured (or default) probes.
+ *
+ * @param sess The session to use.
+ * @param start_samplenum The sample number of the first sample in this chunk.
+ * @param end_samplenum The sample number of the last sample in this chunk.
+ * @param inbuf Pointer to sample data.
+ * @param inbuflen Length in bytes of the buffer.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.3.0
+ */
+SRD_API int srd_session_send(struct srd_session *sess,
+		uint64_t start_samplenum, uint64_t end_samplenum,
+		const uint8_t *inbuf, uint64_t inbuflen)
+{
+	GSList *d;
+	int ret;
+
+	if (session_is_valid(sess) != SRD_OK) {
+		srd_err("Invalid session.");
+		return SRD_ERR_ARG;
+	}
+
+	srd_dbg("Calling decode() on all instances with starting sample "
+			"number %" PRIu64 ", %" PRIu64 " bytes at 0x%p",
+			start_samplenum, inbuflen, inbuf);
+
+	for (d = sess->di_list; d; d = d->next) {
+		if ((ret = srd_inst_decode(d->data, start_samplenum,
+				end_samplenum, inbuf, inbuflen)) != SRD_OK)
+			return ret;
+	}
+
+	return SRD_OK;
+}
+
+/**
+ * Destroy a decoding session.
+ *
+ * All decoder instances and output callbacks are properly released.
+ *
+ * @param sess The session to be destroyed.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.3.0
+ */
+SRD_API int srd_session_destroy(struct srd_session *sess)
+{
+	int session_id;
+
+	if (!sess) {
+		srd_err("Invalid session.");
+		return SRD_ERR_ARG;
+	}
+
+	session_id = sess->session_id;
+	if (sess->di_list)
+		srd_inst_free_all(sess, NULL);
+	if (sess->callbacks)
+		g_slist_free_full(sess->callbacks, g_free);
+	sessions = g_slist_remove(sessions, sess);
+	g_free(sess);
+
+	srd_dbg("Destroyed session %d.", session_id);
+
+	return SRD_OK;
+}
+
+/**
+ * Register/add a decoder output callback function.
+ *
+ * The function will be called when a protocol decoder sends output back
+ * to the PD controller (except for Python objects, which only go up the
+ * stack).
+ *
+ * @param sess The output session in which to register the callback.
+ * @param output_type The output type this callback will receive. Only one
+ *                    callback per output type can be registered.
+ * @param cb The function to call. Must not be NULL.
+ * @param cb_data Private data for the callback function. Can be NULL.
+ *
+ * @since 0.3.0
+ */
+SRD_API int srd_pd_output_callback_add(struct srd_session *sess,
+		int output_type, srd_pd_output_callback_t cb, void *cb_data)
+{
+	struct srd_pd_callback *pd_cb;
+
+	if (session_is_valid(sess) != SRD_OK) {
+		srd_err("Invalid session.");
+		return SRD_ERR_ARG;
+	}
+
+	srd_dbg("Registering new callback for output type %d.", output_type);
+
+	if (!(pd_cb = g_try_malloc(sizeof(struct srd_pd_callback)))) {
+		srd_err("Failed to g_malloc() struct srd_pd_callback.");
+		return SRD_ERR_MALLOC;
+	}
+
+	pd_cb->output_type = output_type;
+	pd_cb->cb = cb;
+	pd_cb->cb_data = cb_data;
+	sess->callbacks = g_slist_append(sess->callbacks, pd_cb);
+
+	return SRD_OK;
+}
+
+/** @private */
+SRD_PRIV struct srd_pd_callback *srd_pd_output_callback_find(
+		struct srd_session *sess, int output_type)
+{
+	GSList *l;
+	struct srd_pd_callback *tmp, *pd_cb;
+
+	if (session_is_valid(sess) != SRD_OK) {
+		srd_err("Invalid session.");
+		return NULL;
+	}
+
+	pd_cb = NULL;
+	for (l = sess->callbacks; l; l = l->next) {
+		tmp = l->data;
+		if (tmp->output_type == output_type) {
+			pd_cb = tmp;
+			break;
+		}
+	}
+
+	return pd_cb;
+}
+
+/** @} */