Proper id <--> header conversion

Author: pglombardo

instana/propagator.py

@@ -1,6 +1,6 @@
 from __future__ import absolute_import
-
 import opentracing as ot
+from instana import util
 
 prefix_tracer_state = 'HTTP_X_INSTANA_'
 field_name_trace_id = prefix_tracer_state + 'T'
@@ -9,11 +9,11 @@
 
 
 class HTTPPropagator():
-    """A Propagator for Format.TEXT_MAP."""
+    """A Propagator for Format.HTTP_HEADERS. """
 
     def inject(self, span_context, carrier):
-        carrier[field_name_trace_id] = '{0:x}'.format(span_context.trace_id)
-        carrier[field_name_span_id] = '{0:x}'.format(span_context.span_id)
+        carrier[field_name_trace_id] = util.id_to_header(span_context.trace_id)
+        carrier[field_name_span_id] = util.id_to_header(span_context.span_id)
 
     def extract(self, carrier):  # noqa
         count = 0
@@ -22,10 +22,10 @@ def extract(self, carrier):  # noqa
             v = carrier[k]
             k = k.lower()
             if k == field_name_span_id:
-                span_id = int(v, 16)
+                span_id = util.header_to_id(v)
                 count += 1
             elif k == field_name_trace_id:
-                trace_id = int(v, 16)
+                trace_id = util.header_to_id(v)
                 count += 1
 
         if count != field_count: