Merge 9f3b990df8 into fb54d8b549

Added comments for better readbility.

timelineranker/server/src/main/scala/com/twitter/timelineranker/observe/ObservedRequests.scala

@@ -2,13 +2,26 @@ package com.twitter.timelineranker.observe
 
 import com.twitter.timelines.authorization.ReadRequest
 import com.twitter.timelines.model.UserId
-import com.twitter.timelines.observe.ObservedAndValidatedRequests
+import com.twitter.timelines.observe.{ObservedAndValidatedRequests, ServiceObserver, ServiceTracer}
-import com.twitter.timelines.observe.ServiceObserver
-import com.twitter.timelines.observe.ServiceTracer
 import com.twitter.util.Future
 
+/**
+ * A trait that provides methods to observe and validate requests.
+ */
 trait ObservedRequests extends ObservedAndValidatedRequests {
 
+  /**
+   * Observe and validate a request.
+   *
+   * @param request           the request to be observed and validated
+   * @param viewerIds         the IDs of the viewers who can access the request
+   * @param stats             the statistics to track for the request
+   * @param exceptionHandler  a partial function to handle exceptions thrown during validation or observation
+   * @param f                 a function that takes a request and returns a future of the response
+   * @tparam R                the type of the response
+   * @tparam Q                the type of the request
+   * @return a future of the response
+   */
   def observeAndValidate[R, Q](
     request: Q,
     viewerIds: Seq[UserId],
@@ -17,17 +30,23 @@ trait ObservedRequests extends ObservedAndValidatedRequests {
   )(
     f: Q => Future[R]
   ): Future[R] = {
-    super.observeAndValidate[Q, R](
+    super.observeAndValidate(
-      request,
+      request = request,
-      viewerIds,
+      viewerIds = viewerIds,
-      ReadRequest,
+      accessLevel = ReadRequest,
-      validateRequest,
+      validator = validateRequest[Q],
-      exceptionHandler,
+      errorHandler = exceptionHandler,
-      stats,
+      stats = stats,
-      ServiceTracer.identity[Q]
+      tracer = ServiceTracer.identity[Q]
     )(f)
   }
 
+  /**
+   * Validate a request.
+   *
+   * @param request the request to be validated
+   * @tparam Q     the type of the request
+   */
   def validateRequest[Q](request: Q): Unit = {
     // TimelineQuery and its derived classes do not permit invalid instances to be constructed.
     // Therefore no additional validation is required.