Fix issue: Wrong duration for DB transaction event on ROR 7.1 #92

lib/aws-xray-sdk/facets/rails/active_record.rb

@@ -1,4 +1,5 @@
 require 'active_record'
+require 'aws-xray-sdk/utils/math_utils'
 
 module XRay
   module Rails
@@ -27,9 +28,10 @@ def record(transaction)
           subsegment = XRay.recorder.begin_subsegment name, namespace: 'remote'
           # subsegment is nil in case of context missing
           return if subsegment.nil?
-          subsegment.start_time = transaction.time.to_f
+
+          subsegment.start_time = convert_time_in_seconds(transaction.time.to_f)
           subsegment.sql = sql
-          XRay.recorder.end_subsegment end_time: transaction.end.to_f
+          XRay.recorder.end_subsegment end_time: convert_time_in_seconds(transaction.end.to_f)
         end
 
         private

lib/aws-xray-sdk/utils/math_utils.rb

@@ -0,0 +1,12 @@
+def get_exponent(num)
+    return 0 if num == 0
+    exp = Math.log10(num.abs).floor
+    num.negative? ? exp - 1 : exp
+end
+
+# X-Ray SDK expects time in seconds with nanosecond precision.
+def convert_time_in_seconds(time_float)
+    exponent = get_exponent(time_float)
+    division_factor = 10 ** (exponent - 9)
+    time_float / division_factor
+end

test/aws-xray-sdk/tc_time_conversion.rb

@@ -0,0 +1,13 @@
+require 'aws-xray-sdk/utils/math_utils'
+
+class TestGetTimeInSeconds < Minitest::Test
+    def convert_time_from_milliseconds
+        time_in_seconds = convert_time_in_seconds 1.723627099460531E12
+        assert_equal time_in_seconds 172362709.9460531
+    end
+
+    def convert_time_from_seconds
+        time_in_seconds = convert_time_in_seconds 1.7236270994659648E9
+        assert_equal time_in_seconds 1.7236270994659648E9
+    end
+end