From f3132e5304d9f1a049ffde82b57622c826b70f74 Mon Sep 17 00:00:00 2001
From: Tom Tan <Tom.Tan@microsoft.com>
Date: Wed, 17 Jan 2024 00:11:06 -0800
Subject: [PATCH] [EXPORTER] Fix forward protocol encoding for ETW exporter
 (#2473)

---
 .../exporters/etw/etw_provider.h              | 22 ++++++---
 .../opentelemetry/exporters/etw/utils.h       | 49 +++++++++++++++++--
 2 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/exporters/etw/include/opentelemetry/exporters/etw/etw_provider.h b/exporters/etw/include/opentelemetry/exporters/etw/etw_provider.h
index 4d7e37a98c..0ffccebc0b 100644
--- a/exporters/etw/include/opentelemetry/exporters/etw/etw_provider.h
+++ b/exporters/etw/include/opentelemetry/exporters/etw/etw_provider.h
@@ -33,10 +33,6 @@
 #include "opentelemetry/exporters/etw/etw_fields.h"
 #include "opentelemetry/exporters/etw/utils.h"
 
-#ifdef HAVE_MSGPACK
-#  include "nlohmann/json.hpp"
-#endif
-
 #include "opentelemetry/exporters/etw/etw_traceloggingdynamic.h"
 
 #include <map>
@@ -241,7 +237,7 @@ class ETWProvider
   }
 
   unsigned long writeMsgPack(Handle &providerData,
-                             exporter::etw::Properties &eventData,
+                             Properties &eventData,
                              LPCGUID ActivityId        = nullptr,
                              LPCGUID RelatedActivityId = nullptr,
                              uint8_t Opcode            = 0)
@@ -286,7 +282,6 @@ class ETWProvider
     /* clang-format off */
     nlohmann::json jObj =
     {
-      { ETW_FIELD_NAME, eventName },
       { ETW_FIELD_OPCODE, Opcode }
     };
     /* clang-format on */
@@ -367,7 +362,18 @@ class ETWProvider
       }
     }
 
-    std::vector<uint8_t> v = nlohmann::json::to_msgpack(jObj);
+    // forwardMessage.push_back(nameField);
+    nlohmann::json payloadPair = nlohmann::json::array();
+
+    payloadPair.push_back(
+        utils::GetMsgPackEventTimeFromSystemTimestamp(std::chrono::system_clock::now()));
+    payloadPair.push_back(jObj);
+
+    nlohmann::json payloadArray = nlohmann::json::array({payloadPair});
+
+    nlohmann::json forwardMessage = nlohmann::json::array({eventName, payloadArray});
+
+    std::vector<uint8_t> v = nlohmann::json::to_msgpack(forwardMessage);
 
     EVENT_DESCRIPTOR evtDescriptor;
     // TODO: event descriptor may be populated with additional values as follows:
@@ -377,7 +383,7 @@ class ETWProvider
     // Level    - verbosity level
     // Task     - TaskId
     // Opcode   - described in evntprov.h:259 : 0 - info, 1 - activity start, 2 - activity stop.
-    EventDescCreate(&evtDescriptor, 0, 0x1, 0, 0, 0, Opcode, 0);
+    EventDescCreate(&evtDescriptor, 100, 0x1, 0, 0, 0, Opcode, 0);
     EVENT_DATA_DESCRIPTOR evtData[1];
     EventDataDescCreate(&evtData[0], v.data(), static_cast<ULONG>(v.size()));
     ULONG writeResponse = 0;
diff --git a/exporters/etw/include/opentelemetry/exporters/etw/utils.h b/exporters/etw/include/opentelemetry/exporters/etw/utils.h
index 6a887b6831..f3665efc80 100644
--- a/exporters/etw/include/opentelemetry/exporters/etw/utils.h
+++ b/exporters/etw/include/opentelemetry/exporters/etw/utils.h
@@ -12,6 +12,7 @@
 #include <string>
 
 #include "opentelemetry/common/macros.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/exporters/etw/uuid.h"
 #include "opentelemetry/version.h"
 
@@ -27,11 +28,12 @@
 #  include <codecvt>
 #endif
 
-#if defined(ENABLE_ENV_PROPERTIES)
-
+#if defined(ENABLE_ENV_PROPERTIES) || defined(HAVE_MSGPACK)
 #  include <nlohmann/json.hpp>
-#  include "etw_properties.h"
+#endif
 
+#if defined(ENABLE_ENV_PROPERTIES)
+#  include "etw_properties.h"
 #endif
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -383,6 +385,47 @@ static inline void PopulateAttribute(nlohmann::json &attribute,
 
 #endif  // defined(ENABLE_ENV_PROPERTIES)
 
+#if defined(HAVE_MSGPACK)
+
+static inline nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>>
+get_msgpack_eventtimeext(int32_t seconds = 0, int32_t nanoseconds = 0)
+{
+  if ((seconds == 0) && (nanoseconds == 0))
+  {
+    std::chrono::system_clock::time_point tp = std::chrono::system_clock::now();
+    auto duration                            = tp.time_since_epoch();
+    seconds =
+        static_cast<int32_t>(std::chrono::duration_cast<std::chrono::seconds>(duration).count());
+    nanoseconds = static_cast<int32_t>(
+        std::chrono::duration_cast<std::chrono::nanoseconds>(duration).count() % 1000000000);
+  }
+
+  uint64_t timestamp =
+      ((seconds / 100) & ((1ull << 34) - 1)) |
+      (((seconds % 100 * 10000000 + nanoseconds / 100) & ((1ull << 30) - 1)) << 34);
+
+  nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>> ts{std::vector<uint8_t>(8)};
+
+  *reinterpret_cast<uint64_t *>(ts.data()) = timestamp;
+  ts.set_subtype(0x00);
+
+  return ts;
+}
+
+static inline nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>>
+GetMsgPackEventTimeFromSystemTimestamp(opentelemetry::common::SystemTimestamp timestamp) noexcept
+{
+  return get_msgpack_eventtimeext(
+      // Add all whole seconds to the event time
+      static_cast<int32_t>(
+          std::chrono::duration_cast<std::chrono::seconds>(timestamp.time_since_epoch()).count()),
+      // Add any remaining nanoseconds past the last whole second
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timestamp.time_since_epoch()).count() %
+          1000000000);
+}
+
+#endif  // defined(HAVE_MSGPACK)
+
 };  // namespace utils
 
 OPENTELEMETRY_END_NAMESPACE