GDTR collision checks, ordered storage

libuavcan/include/uavcan/global_data_type_registry.hpp

@@ -30,6 +30,17 @@ class GlobalDataTypeRegistry : Noncopyable
         { }
     };
 
+    struct EntryInsertionComparator
+    {
+        const uint16_t id;
+        EntryInsertionComparator(Entry* dtd) : id(dtd->decriptor.getID()) { }
+        bool operator()(const Entry* entry) const
+        {
+            assert(entry);
+            return entry->decriptor.getID() > id;
+        }
+    };
+
     typedef LinkedListRoot<Entry> List;
     List msgs_;
     List srvs_;

libuavcan/src/global_data_type_registry.cpp

@@ -63,7 +63,33 @@ bool GlobalDataTypeRegistry::add(Entry* dtd)
     if (!list)
         return false;
 
-    list->insert(dtd);
+    {   // Collision check
+        Entry* p = list->get();
+        while (p)
+        {
+            if (p->decriptor.getID() == dtd->decriptor.getID()) // ID collision
+                return false;
+            p = p->getNextListNode();
+        }
+    }
+    list->insertBefore(dtd, EntryInsertionComparator(dtd));
+
+#if UAVCAN_DEBUG
+    {   // Order check
+        Entry* p = list->get();
+        int id = -1;
+        while (p)
+        {
+            if (id >= p->decriptor.getID())
+            {
+                assert(0);
+                std::abort();
+            }
+            id = p->decriptor.getID();
+            p = p->getNextListNode();
+        }
+    }
+#endif
     return true;
 }
 

libuavcan/test/global_data_type_registry.cpp

@@ -127,6 +127,7 @@ TEST(GlobalDataTypeRegistry, Basic)
     /*
      * These types will be necessary for the aggregate signature test
      */
+    ASSERT_FALSE(GlobalDataTypeRegistry::instance().assign<DataTypeC>(741));               // COLLISION - error
     ASSERT_TRUE(GlobalDataTypeRegistry::instance().assign<DataTypeC>(DataTypeC::DefaultDataTypeID));
     uavcan::DefaultDataTypeRegistrator<DataTypeD> reg_DataTypeD;