Remove required type field from channel blobs

When we first introduced the channel blob types, the JSON blobs were
self identifying by a required "type" field in the JSON object
itself. This, as it turns out, was a bad idea.

When we introduced the message router, it was useless for routing based
on the JSON type. And messages had two type fields to check: the
stasis_message_type() of the message itself, plus the type field in the
JSON blob (but only if it was a blob message).

This patch corrects that mistake by removing the required type field
from JSON blobs, and introducing first class stasis_message_type objects
for the actual message type.

Since we now will have a proliferation of message types, I introduced a
few macros to help reduce the amount of boilerplate necessary to set
them up.

Review: https://reviewboard.asterisk.org/r/2509


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@388005 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 37 insertions, 0 deletions

diff --git a/include/asterisk/stasis.h b/include/asterisk/stasis.h
index 48d51e369..da8168746 100644
--- a/include/asterisk/stasis.h
+++ b/include/asterisk/stasis.h
@@ -543,6 +543,43 @@ struct ao2_container *stasis_cache_dump(struct stasis_caching_topic *caching_top
 /*! @{ */
 
 /*!
+ * \brief Boiler-plate removing macro for defining message types.
+ *
+ * \param name Name of message type.
+ * \since 12
+ */
+#define STASIS_MESSAGE_TYPE_DEFN(name)				\
+	static struct stasis_message_type *__ ## name;	\
+	struct stasis_message_type *name(void) {	\
+		ast_assert(__ ## name != NULL);		\
+		return __ ## name;			\
+	}
+
+/*!
+ * \brief Boiler-plate removing macro for initializing message types.
+ *
+ * \param name Name of message type.
+ * \return 0 if initialization is successful.
+ * \return Non-zero on failure.
+ * \since 12
+ */
+#define STASIS_MESSAGE_TYPE_INIT(name)				\
+	({						\
+	__ ## name = stasis_message_type_create(#name);	\
+	__ ## name ? 0 : -1;				\
+	})
+
+#define STASIS_MESSAGE_TYPE_CLEANUP(name)		\
+	({					\
+		ao2_cleanup(__ ## name);	\
+		__ ## name = NULL;		\
+	})
+
+/*! @} */
+
+/*! @{ */
+
+/*!
  * \brief Initialize the Stasis subsystem
  * \return 0 on success.
  * \return Non-zero on error.