Create Local channel messages on the Stasis message bus and produce AMI events

This patch does the following:

* It adds a virtual table of callbacks to core_unreal. These callbacks can be
  supplied by concrete implementations of "unreal" channel drivers, which lets
  the unreal channel driver call specific functionality when it performs some
  action. Currently, this is done to notify implementations when an
  optimization operation has begun, and when an optimization operation has
  succeeded.

* It adds Stasis-Core messages for Local channel bridging and Local channel
  optimization. Local channel optimization is now two events: a Begin and an
  End. Some consumers of Stasis-Core may want to know when an operation is
  beginning so that they can 'prepare' their information; others will be more
  concerned about when the operation has completed, so that they can 'fix up'
  information. Stasis-Core allows for both, as does AMI.

Review: https://reviewboard.asterisk.org/r/2552



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@393801 65c4cc65-6c06-0410-ace0-fbb531ad65f3

3 files changed, 222 insertions, 58 deletions

diff --git a/main/bridging.c b/main/bridging.c
index 1dc8b6ea3..d01a66ad7 100644
--- a/main/bridging.c
+++ b/main/bridging.c
@@ -61,6 +61,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/cli.h"
 #include "asterisk/parking.h"
 #include "asterisk/core_local.h"
+#include "asterisk/core_unreal.h"
 #include "asterisk/features_config.h"
 
 /*! All bridges container. */
@@ -628,6 +629,12 @@ static void bridge_channel_pull(struct ast_bridge_channel *bridge_channel)
 	ast_debug(1, "Bridge %s: pulling %p(%s)\n",
 		bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan));
 
+	ast_verb(3, "Channel %s left '%s' %s-bridge <%s>\n",
+		ast_channel_name(bridge_channel->chan),
+		bridge->technology->name,
+		bridge->v_table->name,
+		bridge->uniqueid);
+
 /* BUGBUG This is where incoming HOLD/UNHOLD memory should write UNHOLD into bridge. (if not local optimizing) */
 /* BUGBUG This is where incoming DTMF begin/end memory should write DTMF end into bridge. (if not local optimizing) */
 	if (!bridge_channel->just_joined) {
@@ -713,6 +720,16 @@ static int bridge_channel_push(struct ast_bridge_channel *bridge_channel)
 	if (!bridge_channel->suspended) {
 		++bridge->num_active;
 	}
+
+	ast_verb(3, "Channel %s %s%s%s '%s' %s-bridge <%s>\n",
+		ast_channel_name(bridge_channel->chan),
+		swap ? "swapped with " : "joined",
+		swap ? ast_channel_name(swap->chan) : "",
+		swap ? " into" : "",
+		bridge->technology->name,
+		bridge->v_table->name,
+		bridge->uniqueid);
+
 	ast_bridge_publish_enter(bridge, bridge_channel->chan);
 	if (swap) {
 		ast_bridge_change_state(swap, AST_BRIDGE_CHANNEL_STATE_HANGUP);
@@ -1895,7 +1912,7 @@ static int smart_bridge_operation(struct ast_bridge *bridge)
 	 * must not release the bridge lock until we have installed the
 	 * new bridge technology.
 	 */
-	ast_debug(1, "Bridge %s: switching %s technology to %s\n",
+	ast_verb(4, "Bridge %s: switching from %s technology to %s\n",
 		bridge->uniqueid, old_technology->name, new_technology->name);
 
 	/*
@@ -4644,14 +4661,17 @@ static enum bridge_allow_swap bridges_allow_swap_optimization(struct ast_bridge
  * \param chan_bridge_channel
  * \param peer_bridge
  * \param peer_bridge_channel
+ * \param pvt Unreal data containing callbacks to call if the optimization actually
+ * happens
  *
  * \retval 1 if unreal channels failed to optimize out.
  * \retval 0 if unreal channels were not optimized out.
  * \retval -1 if unreal channels were optimized out.
  */
-static int check_swap_optimize_out(struct ast_bridge *chan_bridge,
+static int try_swap_optimize_out(struct ast_bridge *chan_bridge,
 	struct ast_bridge_channel *chan_bridge_channel, struct ast_bridge *peer_bridge,
-	struct ast_bridge_channel *peer_bridge_channel)
+	struct ast_bridge_channel *peer_bridge_channel,
+	struct ast_unreal_pvt *pvt)
 {
 	struct ast_bridge *dst_bridge;
 	struct ast_bridge_channel *dst_bridge_channel;
@@ -4696,10 +4716,18 @@ static int check_swap_optimize_out(struct ast_bridge *chan_bridge,
 			ast_channel_name(dst_bridge_channel->chan),
 			ast_channel_name(other->chan));
 
+		if (pvt && !ast_test_flag(pvt, AST_UNREAL_OPTIMIZE_BEGUN) && pvt->callbacks
+				&& pvt->callbacks->optimization_started) {
+			pvt->callbacks->optimization_started(pvt);
+			ast_set_flag(pvt, AST_UNREAL_OPTIMIZE_BEGUN);
+		}
 		other->swap = dst_bridge_channel->chan;
 		if (!bridge_move_do(dst_bridge, other, 1)) {
 			ast_bridge_change_state(src_bridge_channel, AST_BRIDGE_CHANNEL_STATE_HANGUP);
 			res = -1;
+			if (pvt && pvt->callbacks && pvt->callbacks->optimization_finished) {
+				pvt->callbacks->optimization_finished(pvt);
+			}
 		}
 	}
 	return res;
@@ -4761,13 +4789,16 @@ static enum bridge_allow_merge bridges_allow_merge_optimization(struct ast_bridg
  * \param chan_bridge_channel
  * \param peer_bridge
  * \param peer_bridge_channel
+ * \param pvt Unreal data containing callbacks to call if the optimization actually
+ * happens
  *
  * \retval 0 if unreal channels were not optimized out.
  * \retval -1 if unreal channels were optimized out.
  */
-static int check_merge_optimize_out(struct ast_bridge *chan_bridge,
+static int try_merge_optimize_out(struct ast_bridge *chan_bridge,
 	struct ast_bridge_channel *chan_bridge_channel, struct ast_bridge *peer_bridge,
-	struct ast_bridge_channel *peer_bridge_channel)
+	struct ast_bridge_channel *peer_bridge_channel,
+	struct ast_unreal_pvt *pvt)
 {
 	struct merge_direction merge;
 	struct ast_bridge_channel *kick_me[] = {
@@ -4798,12 +4829,20 @@ static int check_merge_optimize_out(struct ast_bridge *chan_bridge,
 		ast_channel_name(chan_bridge_channel->chan),
 		ast_channel_name(peer_bridge_channel->chan));
 
+	if (pvt && !ast_test_flag(pvt, AST_UNREAL_OPTIMIZE_BEGUN) && pvt->callbacks
+			&& pvt->callbacks->optimization_started) {
+		pvt->callbacks->optimization_started(pvt);
+		ast_set_flag(pvt, AST_UNREAL_OPTIMIZE_BEGUN);
+	}
 	bridge_merge_do(merge.dest, merge.src, kick_me, ARRAY_LEN(kick_me));
+	if (pvt && pvt->callbacks && pvt->callbacks->optimization_finished) {
+		pvt->callbacks->optimization_finished(pvt);
+	}
 
 	return -1;
 }
 
-int ast_bridge_unreal_optimized_out(struct ast_channel *chan, struct ast_channel *peer)
+int ast_bridge_unreal_optimize_out(struct ast_channel *chan, struct ast_channel *peer, struct ast_unreal_pvt *pvt)
 {
 	struct ast_bridge *chan_bridge;
 	struct ast_bridge *peer_bridge;
@@ -4821,11 +4860,11 @@ int ast_bridge_unreal_optimized_out(struct ast_channel *chan, struct ast_channel
 	if (peer_bridge) {
 		peer_bridge_channel = ast_channel_internal_bridge_channel(peer);
 
-		res = check_swap_optimize_out(chan_bridge, chan_bridge_channel,
-			peer_bridge, peer_bridge_channel);
+		res = try_swap_optimize_out(chan_bridge, chan_bridge_channel,
+			peer_bridge, peer_bridge_channel, pvt);
 		if (!res) {
-			res = check_merge_optimize_out(chan_bridge, chan_bridge_channel,
-				peer_bridge, peer_bridge_channel);
+			res = try_merge_optimize_out(chan_bridge, chan_bridge_channel,
+				peer_bridge, peer_bridge_channel, pvt);
 		} else if (0 < res) {
 			res = 0;
 		}
diff --git a/main/core_local.c b/main/core_local.c
index 16abc428c..b35e03110 100644
--- a/main/core_local.c
+++ b/main/core_local.c
@@ -46,6 +46,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/bridging.h"
 #include "asterisk/core_unreal.h"
 #include "asterisk/core_local.h"
+#include "asterisk/stasis.h"
+#include "asterisk/stasis_channels.h"
 #include "asterisk/_private.h"
 #include "asterisk/stasis_channels.h"
 
@@ -161,6 +163,34 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 			</syntax>
 		</managerEventInstance>
 	</managerEvent>
+	<managerEvent language="en_US" name="LocalOptimizationBegin">
+		<managerEventInstance class="EVENT_FLAG_CALL">
+			<synopsis>Raised when two halves of a Local Channel begin to optimize
+			themselves out of the media path.</synopsis>
+			<syntax>
+				<xi:include xpointer="xpointer(/docs/managerEvent[@name='LocalBridge']/managerEventInstance/syntax/parameter[contains(@name, 'LocalOne')])" />
+				<xi:include xpointer="xpointer(/docs/managerEvent[@name='LocalBridge']/managerEventInstance/syntax/parameter[contains(@name, 'LocalTwo')])" />
+			</syntax>
+			<see-also>
+				<ref type="managerEvent">LocalOptimizationEnd</ref>
+				<ref type="manager">LocalOptimizeAway</ref>
+			</see-also>
+		</managerEventInstance>
+	</managerEvent>
+	<managerEvent language="en_US" name="LocalOptimizationEnd">
+		<managerEventInstance class="EVENT_FLAG_CALL">
+			<synopsis>Raised when two halves of a Local Channel have finished optimizing
+			themselves out of the media path.</synopsis>
+			<syntax>
+				<xi:include xpointer="xpointer(/docs/managerEvent[@name='LocalBridge']/managerEventInstance/syntax/parameter[contains(@name, 'LocalOne')])" />
+				<xi:include xpointer="xpointer(/docs/managerEvent[@name='LocalBridge']/managerEventInstance/syntax/parameter[contains(@name, 'LocalTwo')])" />
+			</syntax>
+			<see-also>
+				<ref type="managerEvent">LocalOptimizationBegin</ref>
+				<ref type="manager">LocalOptimizeAway</ref>
+			</see-also>
+		</managerEventInstance>
+	</managerEvent>
  ***/
 
 static const char tdesc[] = "Local Proxy Channel Driver";
@@ -171,6 +201,30 @@ static struct ast_channel *local_request(const char *type, struct ast_format_cap
 static int local_call(struct ast_channel *ast, const char *dest, int timeout);
 static int local_hangup(struct ast_channel *ast);
 static int local_devicestate(const char *data);
+static void local_optimization_started_cb(struct ast_unreal_pvt *base);
+static void local_optimization_finished_cb(struct ast_unreal_pvt *base);
+
+static struct ast_manager_event_blob *local_message_to_ami(struct stasis_message *msg);
+
+/*!
+ * @{ \brief Define local channel message types.
+ */
+STASIS_MESSAGE_TYPE_DEFN(ast_local_bridge_type,
+	.to_ami = local_message_to_ami,
+	);
+STASIS_MESSAGE_TYPE_DEFN(ast_local_optimization_begin_type,
+	.to_ami = local_message_to_ami,
+	);
+STASIS_MESSAGE_TYPE_DEFN(ast_local_optimization_end_type,
+	.to_ami = local_message_to_ami,
+	);
+/*! @} */
+
+/*! \brief Callbacks from the unreal core when channel optimization occurs */
+struct ast_unreal_pvt_callbacks local_unreal_callbacks = {
+	.optimization_started = local_optimization_started_cb,
+	.optimization_finished = local_optimization_finished_cb,
+};
 
 /* PBX interface structure for channel registration */
 static struct ast_channel_tech local_tech = {
@@ -326,59 +380,115 @@ static int local_devicestate(const char *data)
 	return res;
 }
 
-static struct ast_manager_event_blob *local_bridge_to_ami(struct stasis_message *msg)
+static void publish_local_optimization(struct local_pvt *p, int complete)
 {
-	RAII_VAR(struct ast_str *, channel_one_string, NULL, ast_free);
-	RAII_VAR(struct ast_str *, channel_two_string, NULL, ast_free);
-	struct ast_multi_channel_blob *obj = stasis_message_data(msg);
-	struct ast_json *blob, *context, *exten, *optimize;
-	struct ast_channel_snapshot *chan_one, *chan_two;
-
-	chan_one = ast_multi_channel_blob_get_channel(obj, "1");
-	chan_two = ast_multi_channel_blob_get_channel(obj, "2");
-	blob = ast_multi_channel_blob_get_json(obj);
-
-	channel_one_string = ast_manager_build_channel_state_string_prefix(chan_one, "LocalOne");
-	if (!channel_one_string) {
+	RAII_VAR(struct ast_multi_channel_blob *, payload, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_json *, blob, ast_json_null(), ast_json_unref);
+	RAII_VAR(struct ast_channel_snapshot *, local_one_snapshot, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_channel_snapshot *, local_two_snapshot, NULL, ao2_cleanup);
+
+	if (!blob) {
+		return;
+	}
+
+	local_one_snapshot = ast_channel_snapshot_create(p->base.owner);
+	if (!local_one_snapshot) {
+		return;
+	}
+
+	local_two_snapshot = ast_channel_snapshot_create(p->base.chan);
+	if (!local_two_snapshot) {
+		return;
+	}
+
+	payload = ast_multi_channel_blob_create(blob);
+	if (!payload) {
+		return;
+	}
+	ast_multi_channel_blob_add_channel(payload, "1", local_one_snapshot);
+	ast_multi_channel_blob_add_channel(payload, "2", local_two_snapshot);
+
+	msg = stasis_message_create(
+			complete ? ast_local_optimization_end_type() : ast_local_optimization_begin_type(),
+			payload);
+	if (!msg) {
+		return;
+	}
+
+	stasis_publish(ast_channel_topic(p->base.owner), msg);
+
+}
+
+/*! \brief Callback for \ref ast_unreal_pvt_callbacks \ref optimization_started_cb */
+static void local_optimization_started_cb(struct ast_unreal_pvt *base)
+{
+	struct local_pvt *p = (struct local_pvt *)base;
+	publish_local_optimization(p, 0);
+}
+
+/*! \brief Callback for \ref ast_unreal_pvt_callbacks \ref optimization_finished_cb */
+static void local_optimization_finished_cb(struct ast_unreal_pvt *base)
+{
+	struct local_pvt *p = (struct local_pvt *)base;
+	publish_local_optimization(p, 1);
+}
+
+static struct ast_manager_event_blob *local_message_to_ami(struct stasis_message *message)
+{
+	struct ast_multi_channel_blob *obj = stasis_message_data(message);
+	struct ast_json *blob = ast_multi_channel_blob_get_json(obj);
+	struct ast_channel_snapshot *local_snapshot_one;
+	struct ast_channel_snapshot *local_snapshot_two;
+	RAII_VAR(struct ast_str *, local_channel_one, NULL, ast_free);
+	RAII_VAR(struct ast_str *, local_channel_two, NULL, ast_free);
+	struct ast_str *event_buffer = ast_str_alloca(128);
+	const char *event;
+
+	local_snapshot_one = ast_multi_channel_blob_get_channel(obj, "1");
+	local_snapshot_two = ast_multi_channel_blob_get_channel(obj, "2");
+	if (!local_snapshot_one || !local_snapshot_two) {
 		return NULL;
 	}
 
-	channel_two_string = ast_manager_build_channel_state_string_prefix(chan_two, "LocalTwo");
-	if (!channel_two_string) {
+	local_channel_one = ast_manager_build_channel_state_string_prefix(local_snapshot_one, "LocalOne");
+	local_channel_two = ast_manager_build_channel_state_string_prefix(local_snapshot_two, "LocalTwo");
+	if (!local_channel_one || !local_channel_two) {
 		return NULL;
 	}
 
-	context = ast_json_object_get(blob, "context");
-	exten = ast_json_object_get(blob, "exten");
-	optimize = ast_json_object_get(blob, "optimize");
+	if (stasis_message_type(message) == ast_local_optimization_begin_type()) {
+		event = "LocalOptimizationBegin";
+	} else if (stasis_message_type(message) == ast_local_optimization_end_type()) {
+		event = "LocalOptimizationEnd";
+	} else if (stasis_message_type(message) == ast_local_bridge_type()) {
+		event = "LocalBridge";
+		ast_str_append(&event_buffer, 0, "Context: %s\r\n", ast_json_string_get(ast_json_object_get(blob, "context")));
+		ast_str_append(&event_buffer, 0, "Exten: %s\r\n", ast_json_string_get(ast_json_object_get(blob, "exten")));
+		ast_str_append(&event_buffer, 0, "LocalOptimization: %s\r\n", ast_json_is_true(ast_json_object_get(blob, "can_optimize")) ? "Yes" : "No");
+	} else {
+		return NULL;
+	}
 
-	return ast_manager_event_blob_create(EVENT_FLAG_CALL, "LocalBridge",
+	return ast_manager_event_blob_create(EVENT_FLAG_CALL, event,
 		"%s"
 		"%s"
-		"Context: %s\r\n"
-		"Exten: %s\r\n"
-		"LocalOptimization: %s\r\n",
-		ast_str_buffer(channel_one_string),
-		ast_str_buffer(channel_two_string),
-		ast_json_string_get(context),
-		ast_json_string_get(exten),
-		ast_json_is_true(optimize) ? "Yes" : "No");
+		"%s",
+		ast_str_buffer(local_channel_one),
+		ast_str_buffer(local_channel_two),
+		ast_str_buffer(event_buffer));
 }
 
-STASIS_MESSAGE_TYPE_DEFN_LOCAL(local_bridge_type,
-	.to_ami = local_bridge_to_ami,
-	);
-
 /*!
  * \internal
- * \brief Post the LocalBridge AMI event.
+ * \brief Post the \ref ast_local_bridge_type \ref stasis message
  * \since 12.0.0
  *
- * \param p local_pvt to raise the bridge event.
+ * \param p local_pvt to raise the local bridge message
  *
  * \return Nothing
  */
-static void local_bridge_event(struct local_pvt *p)
+static void publish_local_bridge_message(struct local_pvt *p)
 {
 	RAII_VAR(struct ast_multi_channel_blob *, multi_blob, NULL, ao2_cleanup);
 	RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
@@ -390,7 +500,7 @@ static void local_bridge_event(struct local_pvt *p)
 	blob = ast_json_pack("{s: s, s: s, s: b}",
 		"context", p->context,
 		"exten", p->exten,
-		"optimize", ast_test_flag(&p->base, AST_UNREAL_NO_OPTIMIZATION));
+		"can_optimize", !ast_test_flag(&p->base, AST_UNREAL_NO_OPTIMIZATION));
 	if (!blob) {
 		return;
 	}
@@ -413,7 +523,7 @@ static void local_bridge_event(struct local_pvt *p)
 	ast_multi_channel_blob_add_channel(multi_blob, "1", one_snapshot);
 	ast_multi_channel_blob_add_channel(multi_blob, "2", two_snapshot);
 
-	msg = stasis_message_create(local_bridge_type(), multi_blob);
+	msg = stasis_message_create(ast_local_bridge_type(), multi_blob);
 	if (!msg) {
 		return;
 	}
@@ -564,14 +674,14 @@ static int local_call(struct ast_channel *ast, const char *dest, int timeout)
 			ast_log(LOG_NOTICE, "No such extension/context %s@%s while calling Local channel\n",
 				p->exten, p->context);
 		} else {
-			local_bridge_event(p);
+			publish_local_bridge_message(p);
 
 			/* Start switch on sub channel */
 			res = ast_pbx_start(chan);
 		}
 		break;
 	case LOCAL_CALL_ACTION_BRIDGE:
-		local_bridge_event(p);
+		publish_local_bridge_message(p);
 		ast_answer(chan);
 		res = ast_bridge_impart(p->action.bridge.join, chan, p->action.bridge.swap,
 			p->action.bridge.features, 1);
@@ -582,7 +692,7 @@ static int local_call(struct ast_channel *ast, const char *dest, int timeout)
 		p->action.bridge.features = NULL;
 		break;
 	case LOCAL_CALL_ACTION_MASQUERADE:
-		local_bridge_event(p);
+		publish_local_bridge_message(p);
 		ast_answer(chan);
 		res = ast_channel_move(p->action.masq, chan);
 		if (!res) {
@@ -699,6 +809,7 @@ static struct local_pvt *local_alloc(const char *data, struct ast_format_cap *ca
 	if (!pvt) {
 		return NULL;
 	}
+	pvt->base.callbacks = &local_unreal_callbacks;
 
 	parse = ast_strdupa(data);
 
@@ -883,12 +994,24 @@ static void local_shutdown(void)
 	locals = NULL;
 
 	ast_format_cap_destroy(local_tech.capabilities);
-	STASIS_MESSAGE_TYPE_CLEANUP(local_bridge_type);
+
+	STASIS_MESSAGE_TYPE_CLEANUP(ast_local_optimization_begin_type);
+	STASIS_MESSAGE_TYPE_CLEANUP(ast_local_optimization_end_type);
+	STASIS_MESSAGE_TYPE_CLEANUP(ast_local_bridge_type);
 }
 
 int ast_local_init(void)
 {
-	if (STASIS_MESSAGE_TYPE_INIT(local_bridge_type)) {
+
+	if (STASIS_MESSAGE_TYPE_INIT(ast_local_optimization_begin_type)) {
+		return -1;
+	}
+
+	if (STASIS_MESSAGE_TYPE_INIT(ast_local_optimization_end_type)) {
+		return -1;
+	}
+
+	if (STASIS_MESSAGE_TYPE_INIT(ast_local_bridge_type)) {
 		return -1;
 	}
 
diff --git a/main/core_unreal.c b/main/core_unreal.c
index d5e588111..71d0f6c8f 100644
--- a/main/core_unreal.c
+++ b/main/core_unreal.c
@@ -281,18 +281,20 @@ int ast_unreal_answer(struct ast_channel *ast)
  */
 static int got_optimized_out(struct ast_channel *ast, struct ast_unreal_pvt *p)
 {
+	int res = 0;
+
 	/* Do a few conditional checks early on just to see if this optimization is possible */
 	if (ast_test_flag(p, AST_UNREAL_NO_OPTIMIZATION) || !p->chan || !p->owner) {
-		return 0;
+		return res;
 	}
+
 	if (ast == p->owner) {
-		return ast_bridge_unreal_optimized_out(p->owner, p->chan);
+		res = ast_bridge_unreal_optimize_out(p->owner, p->chan, p);
+	} else if (ast == p->chan) {
+		res = ast_bridge_unreal_optimize_out(p->chan, p->owner, p);
 	}
-	if (ast == p->chan) {
-		return ast_bridge_unreal_optimized_out(p->chan, p->owner);
-	}
-	/* ast is not valid to optimize. */
-	return 0;
+
+	return res;
 }
 
 struct ast_frame  *ast_unreal_read(struct ast_channel *ast)