iterator: rename RowIteratorWorker to PagerWorker

Not to use legacy naming, (SingleConnection)RowIteratorWorker is renamed
to (SingleConnection)PagerWorker.

Author: wprzytula

scylla/src/transport/iterator.rs

@@ -127,9 +127,9 @@ use checked_channel_sender::{ProvingSender, SendAttemptedProof};
 
 type PageSendAttemptedProof = SendAttemptedProof<Result<ReceivedPage, QueryError>>;
 
-// RowIteratorWorker works in the background to fetch pages
-// RowIterator receives them through a channel
-struct RowIteratorWorker<'a, QueryFunc, SpanCreatorFunc> {
+// PagerWorker works in the background to fetch pages
+// QueryPager receives them through a channel
+struct PagerWorker<'a, QueryFunc, SpanCreatorFunc> {
     sender: ProvingSender<Result<ReceivedPage, QueryError>>,
 
     // Closure used to perform a single page query
@@ -153,7 +153,7 @@ struct RowIteratorWorker<'a, QueryFunc, SpanCreatorFunc> {
     span_creator: SpanCreatorFunc,
 }
 
-impl<QueryFunc, QueryFut, SpanCreator> RowIteratorWorker<'_, QueryFunc, SpanCreator>
+impl<QueryFunc, QueryFut, SpanCreator> PagerWorker<'_, QueryFunc, SpanCreator>
 where
     QueryFunc: Fn(Arc<Connection>, Consistency, PagingState) -> QueryFut,
     QueryFut: Future<Output = Result<QueryResponse, UserRequestError>>,
@@ -260,7 +260,7 @@ where
             }
         }
 
-        // Send last_error to RowIterator - query failed fully
+        // Send last_error to QueryPager - query failed fully
         self.log_query_error(&last_error);
         let (proof, _) = self.sender.send(Err(last_error)).await;
         proof
@@ -333,10 +333,10 @@ where
 
                 let received_page = ReceivedPage { rows, tracing_id };
 
-                // Send next page to RowIterator
+                // Send next page to QueryPager
                 let (proof, res) = self.sender.send(Ok(received_page)).await;
                 if res.is_err() {
-                    // channel was closed, RowIterator was dropped - should shutdown
+                    // channel was closed, QueryPager was dropped - should shutdown
                     return Ok(ControlFlow::Break(proof));
                 }
 
@@ -469,15 +469,15 @@ where
     }
 }
 
-/// A massively simplified version of the RowIteratorWorker. It does not have
+/// A massively simplified version of the PagerWorker. It does not have
 /// any complicated logic related to retries, it just fetches pages from
 /// a single connection.
-struct SingleConnectionRowIteratorWorker<Fetcher> {
+struct SingleConnectionPagerWorker<Fetcher> {
     sender: ProvingSender<Result<ReceivedPage, QueryError>>,
     fetcher: Fetcher,
 }
 
-impl<Fetcher, FetchFut> SingleConnectionRowIteratorWorker<Fetcher>
+impl<Fetcher, FetchFut> SingleConnectionPagerWorker<Fetcher>
 where
     Fetcher: Fn(PagingState) -> FetchFut + Send + Sync,
     FetchFut: Future<Output = Result<QueryResponse, UserRequestError>> + Send,
@@ -508,7 +508,7 @@ where
                         .await;
 
                     if send_result.is_err() {
-                        // channel was closed, RowIterator was dropped - should shutdown
+                        // channel was closed, QueryPager was dropped - should shutdown
                         return Ok(proof);
                     }
 
@@ -742,7 +742,7 @@ impl QueryPager {
                 span
             };
 
-            let worker = RowIteratorWorker {
+            let worker = PagerWorker {
                 sender: sender.into(),
                 page_query,
                 statement_info: routing_info,
@@ -860,7 +860,7 @@ impl QueryPager {
                 span
             };
 
-            let worker = RowIteratorWorker {
+            let worker = PagerWorker {
                 sender: sender.into(),
                 page_query,
                 statement_info,
@@ -894,7 +894,7 @@ impl QueryPager {
         let page_size = query.get_validated_page_size();
 
         let worker_task = async move {
-            let worker = SingleConnectionRowIteratorWorker {
+            let worker = SingleConnectionPagerWorker {
                 sender: sender.into(),
                 fetcher: |paging_state| {
                     connection.query_raw_with_consistency(
@@ -924,7 +924,7 @@ impl QueryPager {
         let page_size = prepared.get_validated_page_size();
 
         let worker_task = async move {
-            let worker = SingleConnectionRowIteratorWorker {
+            let worker = SingleConnectionPagerWorker {
                 sender: sender.into(),
                 fetcher: |paging_state| {
                     connection.execute_raw_with_consistency(