feat(utilities): create method for returning timestamp in nanoseconds (#1910)

Co-authored-by: Kayla Reopelle <[email protected]>

Author: bschrag620

common/lib/opentelemetry/common/utilities.rb

@@ -42,6 +42,14 @@ def timeout_timestamp
         Process.clock_gettime(Process::CLOCK_MONOTONIC)
       end
 
+      # Converts the provided timestamp to nanosecond integer
+      #
+      # @param timestamp [Time] the timestamp to convert, defaults to Time.now
+      # @return [Integer]
+      def time_in_nanoseconds(timestamp = Time.now)
+        (timestamp.to_r * 1_000_000_000).to_i
+      end
+
       # Encodes a string in utf8
       #
       # @param [String] string The string to be utf8 encoded
@@ -129,7 +137,7 @@ def cleanse_url(url)
       # @param default The fallback value to return if the requested
       #  env var(s) are not present
       #
-      # @returns [String]
+      # @return [String]
       def config_opt(*env_vars, default: nil)
         ENV.values_at(*env_vars).compact.fetch(0, default)
       end

common/test/opentelemetry/common/utilities_test.rb

@@ -35,6 +35,21 @@ def shutdown(timeout: nil); end
     end
   end
 
+  describe '#time_in_nanoseconds' do
+    it 'returns Time.now in nanoseconds when called without an argument' do
+      Time.stub :now, Time.at(0) do
+        expectation = (Time.now.to_r * 1_000_000_000).to_i
+        assert_equal expectation, common_utils.time_in_nanoseconds
+      end
+    end
+
+    it 'can accept a timestamp to be converted' do
+      time = Time.now
+      expectation = (time.to_r * 1_000_000_000).to_i
+      assert_equal expectation, common_utils.time_in_nanoseconds(time)
+    end
+  end
+
   describe '#utf8_encode' do
     it 'happy path' do
       str = 'pristine ￢'.encode(Encoding::UTF_8)

metrics_sdk/lib/opentelemetry/sdk/metrics/state/asynchronous_metric_stream.rb

@@ -30,7 +30,7 @@ def initialize(
 
             # Initialize asynchronous-specific attributes
             @callback = callback
-            @start_time = now_in_nano
+            @start_time = OpenTelemetry::Common::Utilities.time_in_nanoseconds
             @timeout = timeout
             @attributes = attributes
           end
@@ -70,10 +70,6 @@ def invoke_callback(timeout, attributes)
               end
             end
           end
-
-          def now_in_nano
-            (Time.now.to_r * 1_000_000_000).to_i
-          end
         end
       end
     end

metrics_sdk/lib/opentelemetry/sdk/metrics/state/metric_store.rb

@@ -15,14 +15,14 @@ module State
         class MetricStore
           def initialize
             @mutex = Mutex.new
-            @epoch_start_time = now_in_nano
+            @epoch_start_time = OpenTelemetry::Common::Utilities.time_in_nanoseconds
             @epoch_end_time = nil
             @metric_streams = []
           end
 
           def collect
             @mutex.synchronize do
-              @epoch_end_time = now_in_nano
+              @epoch_end_time = OpenTelemetry::Common::Utilities.time_in_nanoseconds
               snapshot = @metric_streams.flat_map { |ms| ms.collect(@epoch_start_time, @epoch_end_time) }
               @epoch_start_time = @epoch_end_time
 
@@ -36,12 +36,6 @@ def add_metric_stream(metric_stream)
               nil
             end
           end
-
-          private
-
-          def now_in_nano
-            (Time.now.to_r * 1_000_000_000).to_i
-          end
         end
       end
     end

test_helpers/lib/opentelemetry/test_helpers.rb

@@ -42,7 +42,7 @@ def with_test_logger
     end
 
     def exportable_timestamp(time = Time.now)
-      (time.to_r * 1_000_000_000).to_i
+      OpenTelemetry::Common::Utilities.time_in_nanoseconds(time)
     end
 
     def with_env(new_env)