Move session-specific functionality into session.c
diff --git a/controller.c b/controller.c
index 9f9b7b1..1c94d7a 100644
--- a/controller.c
+++ b/controller.c
@@ -89,10 +89,8 @@
 
 /** @cond PRIVATE */
 
-SRD_PRIV GSList *sessions = NULL;
-static int max_session_id = -1;
-
-static int session_is_valid(struct srd_session *sess);
+extern GSList *sessions;
+extern int max_session_id;
 
 /* decoder.c */
 extern SRD_PRIV GSList *pd_list;
@@ -901,297 +899,3 @@
 
 /** @} */
 
-/**
- * @defgroup grp_session Session handling
- *
- * Starting and handling decoding sessions.
- *
- * @{
- */
-
-static 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;
-}
-
-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;
-}
-
-/** @} */