Make SpanContext it's own independent object (#224)

* Make SpanContext it's own independent object

* Add baggage interfaces

* Change assertion type

Author: pglombardo

instana/binary_propagator.py

@@ -4,7 +4,7 @@
 
 from .log import logger
 from .util import header_to_id
-from .span_context import InstanaSpanContext
+from .span import SpanContext
 
 
 class BinaryPropagator():
@@ -72,7 +72,7 @@ def extract(self, carrier):  # noqa
 
             ctx = None
             if trace_id is not None and span_id is not None:
-                ctx = InstanaSpanContext(span_id=span_id,
+                ctx = SpanContext(span_id=span_id,
                                          trace_id=trace_id,
                                          level=level,
                                          baggage={},

instana/http_propagator.py

@@ -1,9 +1,9 @@
 from __future__ import absolute_import
 
 import opentracing as ot
-from .span_context import InstanaSpanContext
 
 from .log import logger
+from .span import SpanContext
 from .util import header_to_id
 
 # The carrier can be a dict or a list.
@@ -95,7 +95,7 @@ def extract(self, carrier):  # noqa
 
             ctx = None
             if trace_id is not None and span_id is not None:
-                ctx = InstanaSpanContext(span_id=span_id,
+                ctx = SpanContext(span_id=span_id,
                                          trace_id=trace_id,
                                          level=level,
                                          baggage={},

instana/span.py

@@ -4,6 +4,35 @@
 import opentracing.ext.tags as ot_tags
 
 
+class SpanContext():
+    def __init__(
+            self,
+            trace_id=None,
+            span_id=None,
+            baggage=None,
+            sampled=True,
+            level=1):
+
+        self.level = level
+        self.trace_id = trace_id
+        self.span_id = span_id
+        self.sampled = sampled
+        self._baggage = baggage or {}
+
+    @property
+    def baggage(self):
+        return self._baggage
+
+    def with_baggage_item(self, key, value):
+        new_baggage = self._baggage.copy()
+        new_baggage[key] = value
+        return SpanContext(
+            trace_id=self.trace_id,
+            span_id=self.span_id,
+            sampled=self.sampled,
+            baggage=new_baggage)
+
+
 class InstanaSpan(BasicSpan):
     stack = None
 

instana/span_context.py

@@ -1,9 +1,9 @@
 from __future__ import absolute_import
 
 import opentracing as ot
-from .span_context import InstanaSpanContext
 
 from .log import logger
+from .span import SpanContext
 from .util import header_to_id
 
 
@@ -68,7 +68,7 @@ def extract(self, carrier):  # noqa
 
             ctx = None
             if trace_id is not None and span_id is not None:
-                ctx = InstanaSpanContext(span_id=span_id,
+                ctx = SpanContext(span_id=span_id,
                                          trace_id=trace_id,
                                          level=level,
                                          baggage={},

instana/text_propagator.py

@@ -11,9 +11,8 @@
 from .binary_propagator import BinaryPropagator
 from .http_propagator import HTTPPropagator
 from .text_propagator import TextPropagator
-from .span_context import InstanaSpanContext
 from .recorder import StandardRecorder, InstanaSampler
-from .span import InstanaSpan, RegisteredSpan
+from .span import InstanaSpan, RegisteredSpan, SpanContext
 from .util import generate_id
 
 
@@ -70,7 +69,7 @@ def start_span(self,
         parent_ctx = None
         if child_of is not None:
             parent_ctx = (
-                child_of if isinstance(child_of, ot.SpanContext)
+                child_of if isinstance(child_of, SpanContext)
                 else child_of.context)
         elif references is not None and len(references) > 0:
             # TODO only the first reference is currently used
@@ -84,7 +83,7 @@ def start_span(self,
 
         # Assemble the child ctx
         gid = generate_id()
-        ctx = InstanaSpanContext(span_id=gid)
+        ctx = SpanContext(span_id=gid)
         if parent_ctx is not None:
             if parent_ctx._baggage is not None:
                 ctx._baggage = parent_ctx._baggage.copy()

instana/tracer.py

@@ -5,7 +5,7 @@
 
 import instana.http_propagator as ihp
 import instana.text_propagator as itp
-from instana import options, span_context
+from instana import span
 from instana.tracer import InstanaTracer
 
 
@@ -54,7 +54,7 @@ def test_http_basic_extract():
     carrier = {'X-Instana-T': '1', 'X-Instana-S': '1', 'X-Instana-L': '1'}
     ctx = ot.tracer.extract(ot.Format.HTTP_HEADERS, carrier)
 
-    assert type(ctx) is span_context.InstanaSpanContext
+    assert isinstance(ctx, span.SpanContext)
     assert_equals('0000000000000001', ctx.trace_id)
     assert_equals('0000000000000001', ctx.span_id)
 
@@ -65,7 +65,7 @@ def test_http_mixed_case_extract():
     carrier = {'x-insTana-T': '1', 'X-inSTANa-S': '1', 'X-INstana-l': '1'}
     ctx = ot.tracer.extract(ot.Format.HTTP_HEADERS, carrier)
 
-    assert type(ctx) is span_context.InstanaSpanContext
+    assert isinstance(ctx, span.SpanContext)
     assert_equals('0000000000000001', ctx.trace_id)
     assert_equals('0000000000000001', ctx.span_id)
 
@@ -86,7 +86,7 @@ def test_http_128bit_headers():
                'X-Instana-S': '0000000000000000b0789916ff8f319f', 'X-Instana-L': '1'}
     ctx = ot.tracer.extract(ot.Format.HTTP_HEADERS, carrier)
 
-    assert type(ctx) is span_context.InstanaSpanContext
+    assert isinstance(ctx, span.SpanContext)
     assert_equals('b0789916ff8f319f', ctx.trace_id)
     assert_equals('b0789916ff8f319f', ctx.span_id)
 
@@ -136,7 +136,7 @@ def test_text_basic_extract():
     carrier = {'X-INSTANA-T': '1', 'X-INSTANA-S': '1', 'X-INSTANA-L': '1'}
     ctx = ot.tracer.extract(ot.Format.TEXT_MAP, carrier)
 
-    assert type(ctx) is span_context.InstanaSpanContext
+    assert isinstance(ctx, span.SpanContext)
     assert_equals('0000000000000001', ctx.trace_id)
     assert_equals('0000000000000001', ctx.span_id)
 
@@ -166,6 +166,6 @@ def test_text_128bit_headers():
                'X-INSTANA-S': ' 0000000000000000b0789916ff8f319f', 'X-INSTANA-L': '1'}
     ctx = ot.tracer.extract(ot.Format.TEXT_MAP, carrier)
 
-    assert type(ctx) is span_context.InstanaSpanContext
+    assert isinstance(ctx, span.SpanContext)
     assert_equals('b0789916ff8f319f', ctx.trace_id)
     assert_equals('b0789916ff8f319f', ctx.span_id)