Simplify queue time calculation

- Remove abbreviations (timestamp_str -> timestamp_string)
- Always assume timestamps are in seconds (remove millisecond/microsecond detection)
- Remove corresponding millisecond test case

Author: samuel-williams-shopify

lib/metrics/provider/async/http/server.rb

@@ -38,31 +38,17 @@ def call(request)
 	private
 
 	# Parse x-request-start header and calculate queue time in seconds.
-	# Supports multiple formats:
+	# Supports formats:
 	# - "t=1234567890.123" (nginx format with 't=' prefix)
 	# - "1234567890.123" (Unix timestamp in seconds)
-	# - "1234567890123" (Unix timestamp in milliseconds)
 	def calculate_queue_time(header_value)
 		return nil unless header_value
 
 		# Remove 't=' prefix if present (nginx format)
-		timestamp_str = header_value.sub(/^t=/, "")
+		timestamp_string = header_value.sub(/^t=/, "")
 
 		begin
-			timestamp = Float(timestamp_str)
-			
-			# If timestamp is very large, it's likely in milliseconds or microseconds
-			# Convert to seconds if necessary
-			if timestamp > 10_000_000_000
-				# Likely milliseconds (13 digits) or microseconds (16 digits)
-				if timestamp > 10_000_000_000_000
-					# Microseconds (16 digits)
-					timestamp = timestamp / 1_000_000.0
-				else
-					# Milliseconds (13 digits)
-					timestamp = timestamp / 1000.0
-				end
-			end
+			timestamp = Float(timestamp_string)
 
 			current_time = Process.clock_gettime(Process::CLOCK_REALTIME)
 			queue_time = current_time - timestamp

test/metrics/provider/async/http/server.rb

@@ -94,28 +94,6 @@
 			server_task.stop
 		end
 
-		it "handles millisecond timestamp format" do
-			server_task = server.run
-			bound_endpoint = server_task.wait_until_ready
-			
-			request_start_ms = (Process.clock_gettime(Process::CLOCK_REALTIME) * 1000).to_i - 50
-			
-			expect(Async::HTTP::Server::ASYNC_HTTP_SERVER_REQUEST_QUEUE_TIME).to receive(:emit) do |value, tags:|
-				expect(value).to be > 0
-				expect(value).to be < 1
-			end
-			
-			client = Async::HTTP::Client.new(bound_endpoint)
-			headers = [["x-request-start", request_start_ms.to_s]]
-			response = client.get("/", headers)
-			
-			expect(response.status).to be == 200
-			response.finish
-			
-			client.close
-			server_task.stop
-		end
-		
 		it "does not emit queue time metric when x-request-start header is missing" do
 			server_task = server.run
 			bound_endpoint = server_task.wait_until_ready