From 2559e27414aae68bae414a8286b4a91f7b27c147 Mon Sep 17 00:00:00 2001
From: adamdunkels <adamdunkels>
Date: Thu, 25 Mar 2010 08:49:56 +0000
Subject: [PATCH] API change to the announcement module: an annoucement can now
 be registered without a value. Such announcements are never transmitted to
 neighbors, until the announcement's value is set.

---
 core/net/rime/announcement.c           | 29 +++++++++++++++-----------
 core/net/rime/announcement.h           | 21 ++++++++++---------
 core/net/rime/broadcast-announcement.c |  7 ++++---
 3 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/core/net/rime/announcement.c b/core/net/rime/announcement.c
index 113d72d7c..99fb4694a 100644
--- a/core/net/rime/announcement.c
+++ b/core/net/rime/announcement.c
@@ -33,7 +33,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: announcement.c,v 1.4 2010/03/19 13:16:11 adamdunkels Exp $
+ * $Id: announcement.c,v 1.5 2010/03/25 08:49:56 adamdunkels Exp $
  */
 
 /**
@@ -60,15 +60,16 @@ announcement_init(void)
 }
 /*---------------------------------------------------------------------------*/
 void
-announcement_register(struct announcement *a, uint16_t id, uint16_t value,
+announcement_register(struct announcement *a, uint16_t id,
 		      announcement_callback_t callback)
 {
   a->id = id;
-  a->value = value;
+  a->has_value = 0;
   a->callback = callback;
   list_add(announcements, a);
   if(observer_callback) {
-    observer_callback(a->id, a->value, 0, ANNOUNCEMENT_BUMP);
+    observer_callback(a->id, a->has_value,
+                      a->value, 0, ANNOUNCEMENT_BUMP);
   }
 }
 /*---------------------------------------------------------------------------*/
@@ -79,21 +80,24 @@ announcement_remove(struct announcement *a)
 }
 /*---------------------------------------------------------------------------*/
 void
-announcement_set_value(struct announcement *a, uint16_t value)
+announcement_remove_value(struct announcement *a)
 {
-  uint16_t oldvalue = a->value;
-  a->value = value;
+  a->has_value = 0;
   if(observer_callback) {
-    observer_callback(a->id, value, oldvalue, ANNOUNCEMENT_NOBUMP);
+    observer_callback(a->id, 0, 0, 0, ANNOUNCEMENT_NOBUMP);
   }
+
 }
 /*---------------------------------------------------------------------------*/
 void
-announcement_set_id(struct announcement *a, uint16_t id)
+announcement_set_value(struct announcement *a, uint16_t value)
 {
-  a->id = id;
+  uint16_t oldvalue = a->value;
+  a->has_value = 1;
+  a->value = value;
   if(observer_callback) {
-    observer_callback(a->id, a->value, a->value, ANNOUNCEMENT_NOBUMP);
+    observer_callback(a->id, a->has_value,
+                      value, oldvalue, ANNOUNCEMENT_NOBUMP);
   }
 }
 /*---------------------------------------------------------------------------*/
@@ -101,7 +105,8 @@ void
 announcement_bump(struct announcement *a)
 {
   if(observer_callback) {
-    observer_callback(a->id, a->value, a->value, ANNOUNCEMENT_BUMP);
+    observer_callback(a->id, a->has_value,
+                      a->value, a->value, ANNOUNCEMENT_BUMP);
   }
 }
 /*---------------------------------------------------------------------------*/
diff --git a/core/net/rime/announcement.h b/core/net/rime/announcement.h
index ffca0d4d5..0bf206143 100644
--- a/core/net/rime/announcement.h
+++ b/core/net/rime/announcement.h
@@ -54,7 +54,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: announcement.h,v 1.7 2010/03/19 13:16:11 adamdunkels Exp $
+ * $Id: announcement.h,v 1.8 2010/03/25 08:49:56 adamdunkels Exp $
  */
 
 /**
@@ -86,6 +86,7 @@ struct announcement {
   uint16_t id;
   uint16_t value;
   announcement_callback_t callback;
+  uint8_t has_value;
 };
 
 /**
@@ -96,7 +97,6 @@ struct announcement {
  * \brief      Register an announcement
  * \param a    A pointer to a struct announcement
  * \param id   The identifying number of the announcement
- * \param value The initial value of the announcement
  * \param callback A pointer to a callback function that is called
  *             when an announcement is heard
  *
@@ -112,7 +112,7 @@ struct announcement {
  *
  */
 void announcement_register(struct announcement *a,
-			   uint16_t id, uint16_t value,
+			   uint16_t id,
 			   announcement_callback_t callback);
 
 /**
@@ -140,18 +140,18 @@ void announcement_remove(struct announcement *a);
  */
 void announcement_set_value(struct announcement *a, uint16_t value);
 
-
 /**
- * \brief      Set the identifier of an announcement
+ * \brief      Remove the value of an announcement
  * \param a    A pointer to a struct announcement that has
  *             previously been registered
  *
- *             This function sets the identifier of an announcement
- *             that has previously been registered with
+ *             This function removes the value of an announcement that
+ *             has previously been registered with
  *             announcement_register().
  *
  */
-void announcement_set_id(struct announcement *a, uint16_t id);
+void announcement_remove_value(struct announcement *a);
+
 
 /**
  * \brief      Bump an announcement
@@ -244,8 +244,9 @@ enum {
   ANNOUNCEMENT_BUMP,
 };
 
-typedef void (* announcement_observer)(uint16_t id, uint16_t newvalue,
-                                       uint16_t oldvalue, uint8_t bump);
+typedef void (* announcement_observer)(uint16_t id, uint8_t has_value,
+                                       uint16_t newvalue, uint16_t oldvalue,
+                                       uint8_t bump);
 
 /**
  * \brief      Register an observer callback with the announcement module
diff --git a/core/net/rime/broadcast-announcement.c b/core/net/rime/broadcast-announcement.c
index a7791da4e..5d4f14fdb 100644
--- a/core/net/rime/broadcast-announcement.c
+++ b/core/net/rime/broadcast-announcement.c
@@ -33,7 +33,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: broadcast-announcement.c,v 1.2 2010/03/22 11:32:29 fros4943 Exp $
+ * $Id: broadcast-announcement.c,v 1.3 2010/03/25 08:49:56 adamdunkels Exp $
  */
 
 /**
@@ -104,7 +104,7 @@ send_adv(void *ptr)
   packetbuf_clear();
   adata = packetbuf_dataptr();
   adata->num = 0;
-  for(a = announcement_list(); a != NULL; a = a->next) {
+  for(a = announcement_list(); a != NULL && a->has_value; a = a->next) {
     adata->data[adata->num].id = a->id;
     adata->data[adata->num].value = a->value;
     adata->num++;
@@ -186,7 +186,8 @@ send_timer(void *ptr)
 }
 /*---------------------------------------------------------------------------*/
 static void
-new_announcement(uint16_t id, uint16_t newval, uint16_t oldval, uint8_t bump)
+new_announcement(uint16_t id, uint8_t has_value,
+                 uint16_t newval, uint16_t oldval, uint8_t bump)
 {
   if(bump == ANNOUNCEMENT_BUMP) {
     c.current_interval = c.initial_interval;