Jmacd/static method grpc names (#24)

* Add lightstep::CollectorServiceFullName() and lightstep::CollectorMethodName()

* Bump to 0.15

* Light testing / regression-prevention

Author: jmacd

Makefile.am

@@ -1,3 +1,3 @@
-EXTRA_DIST = LICENSE lightstep-tracer-common
+EXTRA_DIST = LICENSE lightstep-tracer-common/collector.proto
 
 SUBDIRS = src test

configure.ac

@@ -4,7 +4,7 @@
 # by homebrew, see the commands to set PKG_CONFIG_PATH in build.sh.
 
 AC_PREREQ([2.69])
-AC_INIT([lightstep-tracer-cpp], [0.14],
+AC_INIT([lightstep-tracer-cpp], [0.15],
         [https://github.com/lightstep/lightstep-tracer-cpp/issues])
 LT_INIT([disable-shared])
 AM_INIT_AUTOMAKE([1.14 foreign subdir-objects])

src/c++11/lightstep/options.h

@@ -38,6 +38,7 @@ class TracerOptions {
   Attributes tracer_attributes;
 
   // Optional: a user-defined guid generator to use.
+  // TODO remove this in favor of thread-local PRNGs?
   std::function<uint64_t()> guid_generator;
 };
 

src/c++11/lightstep/tracer.h

@@ -119,6 +119,10 @@ typedef std::function<std::unique_ptr<Recorder>(const TracerImpl&)> RecorderFact
 
 Tracer NewUserDefinedTransportLightStepTracer(const TracerOptions& topts, RecorderFactory rf);
 
+// For use routing ReportRequests via generic gRPC endpoints, use these names:
+const std::string& CollectorServiceFullName();
+const std::string& CollectorMethodName();
+
 }  // namespace lightstep
 
 #endif // __LIGHTSTEP_TRACER_H__

src/c++11/tracer.cc

@@ -10,6 +10,11 @@ namespace {
 
 std::atomic<ImplPtr*> global_tracer;
 
+// Note: These must be kept up-to-date with the collector endpoint
+// gRPC service and method names.
+const char collectorServiceFullName[] = "lightstep.collector.CollectorService";
+const char collectorMethodName[] = "Report";
+
 }  // namespace
 
 BuiltinCarrierFormat BuiltinCarrierFormat::BinaryCarrier{BuiltinCarrierFormat::Binary};
@@ -76,4 +81,14 @@ ReportBuilder::ReportBuilder(const TracerImpl &impl)
   preamble_.mutable_auth()->set_access_token(impl.access_token());
 }
 
+const std::string& CollectorServiceFullName() {
+  static std::string name = collectorServiceFullName;
+  return name;
+}
+
+const std::string& CollectorMethodName() {
+  static std::string name = collectorMethodName;
+  return name;
+}
+
 }  // namespace lightstep

test/c++11/flushproto_test.cc

@@ -1,6 +1,7 @@
 #include <vector>
 #include <iostream>
 #include <mutex>
+#include <sstream>
 
 #include "lightstep/tracer.h"
 #include "lightstep/impl.h"
@@ -36,8 +37,20 @@ uint64_t my_guids() {
   return unsafe++;
 }
 
+void check_tracer_names() throw(error) {
+  // The official value is not exported from gRPC, so hard-code it again:
+  const char grpc_path[] = "/lightstep.collector.CollectorService/Report";
+  std::stringstream assembled;
+  assembled << "/" << lightstep::CollectorServiceFullName() << "/" << lightstep::CollectorMethodName();
+  if (assembled.str() != grpc_path) {
+    throw error("Incorrect gRPC service and method names hard-coded");
+  }
+}
+
 int main() {
   try {
+    check_tracer_names();
+
     lightstep::TracerOptions topts;
 
     topts.access_token = "i_am_an_access_token";