tracers-zipkin(envoyproxy#4839): adds span serializer interface and s…

…ets v1 as the default serializer. Signed-off-by: José Carlos Chávez <jcchavezs@gmail.com>
jcchavezs · May 6, 2019 · 5cfbed5 · 5cfbed5
1 parent 74563b2
commit 5cfbed5
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Showing 5 changed files with 48 additions and 7 deletions.
diff --git a/source/extensions/tracers/zipkin/span_buffer.cc b/source/extensions/tracers/zipkin/span_buffer.cc
@@ -16,15 +16,15 @@ bool SpanBuffer::addSpan(const Span& span) {
   return true;
 }
 
-std::string SpanBuffer::toStringifiedJsonArray() {
+std::string SpanBuffer::toStringifiedJsonArray(SpanSerializer& span_serialier) {
   std::string stringified_json_array = "[";
 
   if (pendingSpans()) {
-    stringified_json_array += span_buffer_[0].toJson();
+    stringified_json_array += span_serialier.serialize(span_buffer_[0]);
     const uint64_t size = span_buffer_.size();
     for (uint64_t i = 1; i < size; i++) {
       stringified_json_array += ",";
-      stringified_json_array += span_buffer_[i].toJson();
+      stringified_json_array += span_serialier.serialize(span_buffer_[i]);
     }
   }
   stringified_json_array += "]";

diff --git a/source/extensions/tracers/zipkin/span_buffer.h b/source/extensions/tracers/zipkin/span_buffer.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "extensions/tracers/zipkin/span_serializer.h"
 #include "extensions/tracers/zipkin/zipkin_core_types.h"
 
 namespace Envoy {
@@ -57,7 +58,7 @@ class SpanBuffer {
    * @return the contents of the buffer as a stringified array of JSONs, where
    * each JSON in the array corresponds to one Zipkin span.
    */
-  std::string toStringifiedJsonArray();
+  std::string toStringifiedJsonArray(SpanSerializer& span_serializer);
 
 private:
   // We use a pre-allocated vector to improve performance

diff --git a/source/extensions/tracers/zipkin/span_serializer.h b/source/extensions/tracers/zipkin/span_serializer.h
@@ -0,0 +1,26 @@
+#pragma once
+
+#include "extensions/tracers/zipkin/zipkin_core_types.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Tracers {
+namespace Zipkin {
+class SpanSerializer {
+public:
+  /**
+   * Destructor.
+   */
+  virtual ~SpanSerializer() {}
+
+  /**
+   * Method that a concrete SpanSerializer class must implement to serialize spans.
+   *
+   * @param span The span that needs action.
+   */
+  virtual std::string serialize(const Span& span);
+};
+} // namespace Zipkin
+} // namespace Tracers
+} // namespace Extensions
+} // namespace Envoy
diff --git a/source/extensions/tracers/zipkin/zipkin_tracer_impl.cc b/source/extensions/tracers/zipkin/zipkin_tracer_impl.cc
@@ -122,15 +122,21 @@ Tracing::SpanPtr Driver::startSpan(const Tracing::Config& config, Http::HeaderMa
   return std::move(active_span);
 }
 
+V1SpanSerializer::V1SpanSerializer() {}
+
+const std::string V1SpanSerializer::serialize(const Span& span) { return span.toJson(); }
+
 ReporterImpl::ReporterImpl(Driver& driver, Event::Dispatcher& dispatcher,
-                           const std::string& collector_endpoint)
+                           const std::string& collector_endpoint, SpanSerializer& span_serializer)
     : driver_(driver), collector_endpoint_(collector_endpoint) {
   flush_timer_ = dispatcher.createTimer([this]() -> void {
     driver_.tracerStats().timer_flushed_.inc();
     flushSpans();
     enableTimer();
   });
 
+  span_serializer_ = span_serializer;
+
   const uint64_t min_flush_spans =
       driver_.runtime().snapshot().getInteger("tracing.zipkin.min_flush_spans", 5U);
   span_buffer_.allocateBuffer(min_flush_spans);
@@ -140,7 +146,14 @@ ReporterImpl::ReporterImpl(Driver& driver, Event::Dispatcher& dispatcher,
 
 ReporterPtr ReporterImpl::NewInstance(Driver& driver, Event::Dispatcher& dispatcher,
                                       const std::string& collector_endpoint) {
-  return ReporterPtr(new ReporterImpl(driver, dispatcher, collector_endpoint));
+  return ReporterPtr(
+      new ReporterImpl(driver, dispatcher, collector_endpoint, new V1SpanSerializer()));
+}
+
+ReporterPtr ReporterImpl::NewInstanceWithSerializer(Driver& driver, Event::Dispatcher& dispatcher,
+                                                    const std::string& collector_endpoint,
+                                                    SpanSerializer span_serializer) {
+  return ReporterPtr(new ReporterImpl(driver, dispatcher, collector_endpoint, span_serializer));
 }
 
 // TODO(fabolive): Need to avoid the copy to improve performance.
@@ -165,7 +178,7 @@ void ReporterImpl::flushSpans() {
   if (span_buffer_.pendingSpans()) {
     driver_.tracerStats().spans_sent_.add(span_buffer_.pendingSpans());
 
-    const std::string request_body = span_buffer_.toStringifiedJsonArray();
+    const std::string request_body = span_buffer_.toStringifiedJsonArray(span_serializer_);
     Http::MessagePtr message(new Http::RequestMessageImpl());
     message->headers().insertMethod().value().setReference(Http::Headers::get().MethodValues.Post);
     message->headers().insertPath().value(collector_endpoint_);

diff --git a/source/extensions/tracers/zipkin/zipkin_tracer_impl.h b/source/extensions/tracers/zipkin/zipkin_tracer_impl.h
@@ -208,6 +208,7 @@ class ReporterImpl : public Reporter, Http::AsyncClient::Callbacks {
   Event::TimerPtr flush_timer_;
   SpanBuffer span_buffer_;
   const std::string collector_endpoint_;
+  SpanSerializer span_serializer_;
 };
 } // namespace Zipkin
 } // namespace Tracers