From b0da0cd33d8b51cdd49764d70f92dc41bc221031 Mon Sep 17 00:00:00 2001
From: Serafin Leschke <serafin.leschke@dentsplysirona.com>
Date: Thu, 6 Oct 2022 09:29:06 +0200
Subject: [PATCH] feat: Add flushing destructor for Tracer

Rational: In short lived applications (e.g. Kubernetes Jobs) most
of the time all traces get lost becasue they are not synced. Users
need to call `Close` manually, but as all spans hold a shared_ptr
on the tracer it is hard to have the correct place to call it.
Calling it in the destructor assures all spans will be included in the
flush.
---
 src/tracer.cpp | 7 +++++++
 src/tracer.h   | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/src/tracer.cpp b/src/tracer.cpp
index dfd81d6e..4dbcf6a2 100644
--- a/src/tracer.cpp
+++ b/src/tracer.cpp
@@ -241,6 +241,13 @@ Tracer::Tracer(TracerOptions options, std::shared_ptr<Writer> writer,
                         options.service, traceTagsPropagationMaxLength(options, *logger_)});
 }
 
+Tracer::~Tracer() {
+  try {
+    Close();
+  } catch (...) {
+  }
+}
+
 std::unique_ptr<ot::Span> Tracer::StartSpanWithOptions(ot::string_view operation_name,
                                                        const ot::StartSpanOptions &options) const
     noexcept try {
diff --git a/src/tracer.h b/src/tracer.h
index 4439f084..1a8912be 100644
--- a/src/tracer.h
+++ b/src/tracer.h
@@ -45,6 +45,9 @@ class Tracer : public ot::Tracer, public std::enable_shared_from_this<Tracer> {
 
   Tracer() = delete;
 
+  // Destructs tracer and flushes internal buffers
+  virtual ~Tracer();
+
   // Starts a new span.
   std::unique_ptr<ot::Span> StartSpanWithOptions(ot::string_view operation_name,
                                                  const ot::StartSpanOptions &options) const