From 9d48cf5fa44618eefd7ea0827255246d3be82d8d Mon Sep 17 00:00:00 2001
From: tammy-baylis-swi <tammy.baylis@solarwinds.com>
Date: Thu, 1 Feb 2024 10:03:32 -0800
Subject: [PATCH] otlp response_time metrics as ms

---
 solarwinds_apm/trace/base_metrics_processor.py     | 10 +++++++---
 solarwinds_apm/trace/inbound_metrics_processor.py  |  1 +
 solarwinds_apm/trace/otlp_metrics_processor.py     |  2 ++
 .../test_processors/test_base_metrics_processor.py | 14 ++++++++++++--
 4 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/solarwinds_apm/trace/base_metrics_processor.py b/solarwinds_apm/trace/base_metrics_processor.py
index b6c3e32e..d0527cc1 100644
--- a/solarwinds_apm/trace/base_metrics_processor.py
+++ b/solarwinds_apm/trace/base_metrics_processor.py
@@ -90,9 +90,13 @@ def calculate_span_time(
         self,
         start_time: int,
         end_time: int,
+        time_conversion: int = 1e3,
     ) -> int:
-        """Calculate span time in microseconds (us) using start and end time
-        in nanoseconds (ns). OTel span start/end_time are optional."""
+        """Calculate span time (via time_conversion e.g. 1e3, 1e6)
+        using start and end time in nanoseconds (ns). OTel span
+        start/end_time are optional."""
         if not start_time or not end_time:
             return 0
-        return int((end_time - start_time) // 1e3)
+        ms_start_time = int(start_time // time_conversion)
+        ms_end_time = int(end_time // time_conversion)
+        return ms_end_time - ms_start_time
diff --git a/solarwinds_apm/trace/inbound_metrics_processor.py b/solarwinds_apm/trace/inbound_metrics_processor.py
index 867b694b..e4bae07b 100644
--- a/solarwinds_apm/trace/inbound_metrics_processor.py
+++ b/solarwinds_apm/trace/inbound_metrics_processor.py
@@ -70,6 +70,7 @@ def on_end(self, span: "ReadableSpan") -> None:
             trans_name = tnames.custom_name
 
         is_span_http = self.is_span_http(span)
+        # convert from ns to microseconds
         span_time = self.calculate_span_time(
             span.start_time,
             span.end_time,
diff --git a/solarwinds_apm/trace/otlp_metrics_processor.py b/solarwinds_apm/trace/otlp_metrics_processor.py
index 17c3db88..4b8fcc70 100644
--- a/solarwinds_apm/trace/otlp_metrics_processor.py
+++ b/solarwinds_apm/trace/otlp_metrics_processor.py
@@ -91,9 +91,11 @@ def on_end(self, span: "ReadableSpan") -> None:
             meter_attrs.update({"sw.is_error": "false"})
 
         is_span_http = self.is_span_http(span)
+        # convert from ns to milliseconds
         span_time = self.calculate_span_time(
             span.start_time,
             span.end_time,
+            1e6,
         )
 
         if is_span_http:
diff --git a/tests/unit/test_processors/test_base_metrics_processor.py b/tests/unit/test_processors/test_base_metrics_processor.py
index f9dc657a..2af9c1a4 100644
--- a/tests/unit/test_processors/test_base_metrics_processor.py
+++ b/tests/unit/test_processors/test_base_metrics_processor.py
@@ -310,8 +310,18 @@ def test_calculate_span_time_missing(self, mocker):
         assert 0 == processor.calculate_span_time(0, 1000)
         assert 0 == processor.calculate_span_time(1000, 0)
 
-    def test_calculate_span_time(self, mocker):
+    def test_calculate_span_time_default_1e3(self, mocker):
         processor = _SwBaseMetricsProcessor(
             mocker.Mock(),
         )
-        assert 1 == processor.calculate_span_time(2000, 3000)
\ No newline at end of file
+        assert 1 == processor.calculate_span_time(2000, 3000)
+
+    def test_calculate_span_time_1e6(self, mocker):
+        processor = _SwBaseMetricsProcessor(
+            mocker.Mock(),
+        )
+        assert 1 == processor.calculate_span_time(
+            2000000,
+            3000000,
+            1e6,
+        )
\ No newline at end of file