[Not to Pull. Just discussion] adding some C++11 aspects and a HOT tracer

app_tracing.cpp

@@ -0,0 +1,7 @@
+
+#include <app_tracing.h>
+
+namespace opentracing {
+template<> MyHotTracer* MyHotTracer::s_tracer = 0;
+}
+

app_tracing.h

@@ -0,0 +1,36 @@
+#ifndef INCLUDED_TRACING_H
+#define INCLUDED_TRACING_H
+
+#include <opentracing/tracer.h>
+#include <opentracing/noop.h>
+
+#include <hot.h>
+
+using namespace opentracing;
+
+// Defining two "different" tracer implementations
+typedef NoopTracer ZipkinV1;
+typedef NoopTracer ZipkinV2;
+
+// Setting up stuff... Would be nice if they weren't that many...
+// is there any way `GenericTracer` to deduce those from just MyHotTracer?
+typedef HotTracer<ZipkinV1, ZipkinV2> MyHotTracer;
+typedef HotSpan<ZipkinV1, ZipkinV2> MyHotSpan;
+typedef HotOptions<ZipkinV1, ZipkinV2> MyHotOptions;
+typedef HotContext<ZipkinV1, ZipkinV2> MyHotContext;
+typedef HotAdapter<ZipkinV1, ZipkinV2> MyHotAdapter;
+
+typedef GenericTracer<MyHotTracer,
+                      MyHotSpan,
+                      MyHotOptions,
+                      MyHotContext,
+                      MyHotAdapter>
+    GlobalTracer;
+
+#include <tracing_cpp11.h>
+
+// Now we "upgrade" the entire system to C++11. Yeiii!
+typedef Cpp11Tracer<GlobalTracer> Cpp11GlobalTracer;
+
+
+#endif // INCLUDED_TRACING_H

hot.h

@@ -0,0 +1,297 @@
+#ifndef INCLUDED_OPENTRACING_HOT_H
+#define INCLUDED_OPENTRACING_HOT_H
+
+// -------------- Copied from noop.h --------------
+
+#include <opentracing/baggage.h>
+#include <opentracing/span.h>
+#include <opentracing/spancontext.h>
+#include <opentracing/spanoptions.h>
+#include <opentracing/stringref.h>
+#include <opentracing/tracer.h>
+#include <stdint.h>
+
+namespace opentracing {
+
+template <typename T1, typename T2> class HotAdapter;
+template <typename T1, typename T2> class HotContext;
+template <typename T1, typename T2> class HotOptions;
+template <typename T1, typename T2> class HotSpan;
+template <typename T1, typename T2> class HotTracer;
+
+template <typename T1, typename T2>
+class HotAdapter {
+    typedef HotContext<T1, T2> MyHotContext;
+  public:
+    typedef MyHotContext*       iterator;
+    typedef const MyHotContext* const_iterator;
+
+    BaggageRef ref(const const_iterator& it) const
+    {
+        static const char empty[] = "";
+        return BaggageRef(empty, empty);
+    }
+
+    Baggage copy(const const_iterator& it) const
+    {
+        return Baggage("", "");
+    }
+};
+
+
+/**
+ * Note: VERY TRICKY. Pay attention to const-ness here. Span's context mustnn't
+ * be const but `extract()`'s has to be const. To be properly thought/implemented.
+ */
+template <typename T1, typename T2>
+class HotContext : public GenericSpanContext<HotContext<T1, T2>, HotAdapter<T1, T2> > {
+    typedef typename T1::SpanContext SpanContext1;
+    typedef typename T2::SpanContext SpanContext2;
+
+    const SpanContext1 * ctx1; // Note: Might be NULL
+    const SpanContext2 * ctx2; // Note: Might be NULL
+
+    friend class HotTracer<T1, T2>;
+    friend class HotSpan<T1, T2>;
+
+    HotContext(const SpanContext1 * ctx1_, const SpanContext2 * ctx2_)
+        : ctx1(ctx1_)
+        , ctx2(ctx2_)
+    {
+    }
+
+    HotContext()
+    {
+    }
+
+  public:
+
+    typedef GenericSpanContext<HotContext<T1, T2>, HotAdapter<T1, T2> > BaggageIterator;
+
+    BaggageIterator baggageBeginImp() const
+    {
+        return baggageEndImp();
+    }
+    BaggageIterator baggageEndImp() const
+    {
+        return BaggageIterator(this);
+    }
+
+    int getBaggageImp(const StringRef&, std::string*) const
+    {
+        return 1;
+    }
+    int getBaggageImp(const StringRef&, std::vector<std::string>*) const
+    {
+        return 1;
+    }
+};
+
+template <typename T1, typename T2>
+class HotOptions
+    : public GenericSpanOptions<HotOptions<T1, T2>, HotContext<T1, T2>, HotAdapter<T1, T2> > {
+  public:
+    int setOperationImp(const StringRef&)
+    {
+        return 0;
+    }
+    int setStartTimeImp(const uint64_t)
+    {
+        return 0;
+    }
+    int setReferenceImp(const SpanReferenceType::Value, const HotContext<T1, T2>&)
+    {
+        return 0;
+    }
+
+    template <typename T>
+    int setTagImp(const StringRef&, const T&)
+    {
+        return 0;
+    }
+};
+
+template <typename T1, typename T2>
+class HotSpan : public GenericSpan<HotSpan<T1,T2>, HotContext<T1,T2>, HotAdapter<T1,T2> > {
+    typedef typename T1::Span SpanT1;
+    typedef typename T2::Span SpanT2;
+
+    // Note: Might be NULL
+    SpanT1 * span1;
+    // Note: Might be NULL
+    SpanT2 * span2;
+
+    friend class HotTracer<T1, T2>;
+
+    HotSpan(SpanT1 * span1_, SpanT2 * span2_)
+        : span1(span1_)
+        , span2(span2_)
+    {
+    }
+
+  public:
+
+    const HotContext<T1,T2>* contextImp() const
+    {
+        return &m_context;
+    }
+
+    int setOperationImp(const StringRef&)
+    {
+        return 0;
+    }
+    int setBaggageImp(const StringRef&, const StringRef&)
+    {
+        return 0;
+    }
+
+    int getBaggageImp(const StringRef&, std::string*) const
+    {
+        return 1;
+    }
+    int getBaggageImp(const StringRef&, std::vector<std::string>*) const
+    {
+        return 1;
+    }
+
+    int finishImp()
+    {
+        return 0;
+    }
+    int finishImp(const uint64_t)
+    {
+        return 0;
+    }
+
+    template <typename T>
+    int tagImp(const StringRef&, const T&)
+    {
+        return 0;
+    }
+
+    template <typename T>
+    int logImp(const StringRef&, const T&)
+    {
+        return 0;
+    }
+
+    template <typename T>
+    int logImp(const StringRef&, const T&, const uint64_t)
+    {
+        return 0;
+    }
+
+    HotContext<T1,T2> m_context;
+};
+
+template <typename T1, typename T2>
+class HotTracer : public GenericTracer<HotTracer<T1, T2>,
+                                       HotSpan<T1, T2>,
+                                       HotOptions<T1, T2>,
+                                       HotContext<T1, T2>,
+                                       HotAdapter<T1, T2> > {
+    typedef GenericTracer<HotTracer<T1, T2>,
+            HotSpan<T1, T2>,
+            HotOptions<T1, T2>,
+            HotContext<T1, T2>,
+            HotAdapter<T1, T2> > Parent;
+
+    T1 & t1;
+    T2 & t2;
+  public:
+
+    HotTracer(T1& t1_, T2&t2_)
+        : t1(t1_)
+        , t2(t2_)
+    {
+    }
+
+    static void installImp(HotTracer*tracer)
+    {
+        s_tracer = tracer;
+    }
+    static void uninstallImp()
+    {
+        s_tracer = 0;
+    }
+    static HotTracer* instanceImp()
+    {
+        return s_tracer;
+    }
+
+    HotOptions<T1,T2>* makeSpanOptionsImp()
+    {
+        return new HotOptions<T1,T2>();
+    }
+
+    HotSpan<T1,T2>* startImp(const StringRef&name)
+    {
+        typename T1::Span * sp1 = t1.start(name); // note: might be NULL
+        typename T2::Span * sp2 = t2.start(name); // note: might be NULL
+
+        return new HotSpan<T1,T2>(sp1, sp2);
+    }
+    HotSpan<T1,T2>* startImp(const HotOptions<T1,T2>& options)
+    {
+        typename T1::Span * sp1 = t1.start(options); // note: might be NULL
+        typename T2::Span * sp2 = t2.start(options); // note: might be NULL
+
+        return new HotSpan<T1,T2>(sp1, sp2);
+    }
+
+    template <typename CARRIER>
+    int injectImp(CARRIER* carrier, const HotSpan<T1,T2> & span) const
+    {
+        // What happens if one of those two fails?
+        if (span.span1)
+        {
+            t1.inject(carrier, *span.span1);
+        }
+
+        if (span.span2)
+        {
+            t2.inject(carrier, *span.span2);
+        }
+
+        return 0;
+    }
+
+    template <typename CARRIER>
+    HotContext<T1,T2>* extractImp(const CARRIER& carrier)
+    {
+        const typename T1::SpanContext* ctx1 = t1.extract(carrier);
+
+        const typename T2::SpanContext* ctx2 = t2.extract(carrier);
+
+        return new HotContext<T1,T2>(ctx1, ctx2);
+    }
+
+    void cleanupImp(const HotOptions<T1,T2>* ob)
+    {
+        if (ob)
+        {
+            delete ob;
+        }
+    }
+    void cleanupImp(const typename Parent::Span*ob)
+    {
+        if (ob)
+        {
+            delete ob;
+        }
+    }
+
+    void cleanupImp(const HotContext<T1,T2>*ob)
+    {
+        if (ob)
+        {
+            delete ob;
+        }
+    }
+
+  private:
+    static HotTracer* s_tracer;
+};
+
+}  // namespace opentracing
+#endif  // INCLUDED_OPENTRACING_HOT_H

main.cpp

@@ -0,0 +1,35 @@
+#include <app_tracing.h>
+
+/**
+ * To run:
+ * clear && g++ -I. -D__USE_XOPEN2K8 main.cpp build/opentracing/libopentracing.a -o main && ./main
+ */
+int main()
+{
+    // Setup
+    ZipkinV1 t1;
+    ZipkinV2 t2;
+
+    MyHotTracer imp(t1, t2);
+
+    GlobalTracer::install(&imp);
+
+
+    {
+        // Application code
+        auto tracer = Cpp11GlobalTracer::instance();
+
+        auto span = tracer.start("hi");
+
+        std::vector<opentracing::TextMapPair> pairs;
+
+        tracer.inject(&pairs, *span);
+
+        auto ctx = tracer.extract(pairs);
+    }
+
+    // Cleanup
+    GlobalTracer::uninstall();
+
+    return 0;
+}