Use TBinaryProtocolAccelerated when serializing reports.

We're currently seeing our services spend a large amount of time inside of the lightstep sdk
serializing reports when they instrument themselves with tracing.  This is in large part due to
the fact that lightstep is using the pure python implemenation of Thrift.

Fixes lightstep#89

lightstep/thrift_connection.py

@@ -4,6 +4,7 @@
 import threading
 from thrift import Thrift
 from thrift.transport import THttpClient
+from thrift.transport import TTransport
 from thrift.protocol import TBinaryProtocol
 from .crouton import ReportingService
 
@@ -21,6 +22,7 @@ class _ThriftConnection(object):
     def __init__(self, collector_url):
         self._collector_url = collector_url
         self._lock = threading.Lock()
+        self._http_client = None
         self._transport = None
         self._client = None
         self.ready = False
@@ -38,9 +40,10 @@ def open(self):
         """
         self._lock.acquire()
         try:
-            self._transport = THttpClient.THttpClient(self._collector_url)
+            self._http_client = THttpClient.THttpClient(self._collector_url)
+            self._transport = TTransport.TBufferedTransport(self._http_client)
             self._transport.open()
-            protocol = TBinaryProtocol.TBinaryProtocol(self._transport)
+            protocol = TBinaryProtocol.TBinaryProtocolAccelerated(self._transport, fallback=True)
             self._client = ReportingService.Client(protocol)
         except Thrift.TException:
             self._open_exceptions_count += 1
@@ -61,7 +64,7 @@ def report(self, *args, **kwargs):
             try:
                 if self._client:
                     headers = {"Lightstep-Access-Token": args[0].access_token}
-                    self._transport.setCustomHeaders(headers)
+                    self._http_client.setCustomHeaders(headers)
                     resp = self._client.Report(*args, **kwargs)
                     self._report_consecutive_errors = 0
             except Thrift.TException: