benchmark: add a small benchmark script

tests/benchmark.py

@@ -0,0 +1,41 @@
+
+import time
+from ddtrace import Tracer
+from test_tracer import DummyWriter
+
+
+def trace(tracer):
+    # explicit vars
+    with tracer.trace("a", service="s", resource="r", span_type="t") as s:
+        s.set_tag("a", "b")
+        s.set_tag("b", 1)
+        with tracer.trace("another.thing"): pass
+        with tracer.trace("another.thing"): pass
+        try:
+            with tracer.trace("another.thing"):
+                1/0
+        except ZeroDivisionError:
+            pass
+
+
+
+def trace_error(tracer):
+    # explicit vars
+    with tracer.trace("a", service="s", resource="r", span_type="t") as s:
+        1/0
+
+
+def run():
+    tracer = Tracer()
+    tracer.writer = DummyWriter()
+
+    loops = 10000
+    start = time.time()
+    for i in range(10000):
+        trace(tracer)
+    dur = time.time() - start
+    print 'loops:%s duration:%.5fs' % (loops, dur)
+
+if __name__ == '__main__':
+    run()
+