iterator: return NextRowError from next() methods

Author: muzarski

scylla/src/client/pager.rs

@@ -29,7 +29,7 @@ use crate::cluster::{ClusterState, NodeRef};
 #[allow(deprecated)]
 use crate::cql_to_rust::{FromRow, FromRowError};
 use crate::deserialize::DeserializeOwnedRow;
-use crate::errors::{QueryError, RequestAttemptError, RequestError};
+use crate::errors::{RequestAttemptError, RequestError};
 use crate::frame::response::result;
 use crate::network::Connection;
 use crate::observability::driver_tracing::RequestSpan;
@@ -584,11 +584,11 @@ impl QueryPager {
     /// borrows from self.
     ///
     /// This is cancel-safe.
-    async fn next(&mut self) -> Option<Result<ColumnIterator, QueryError>> {
+    async fn next(&mut self) -> Option<Result<ColumnIterator, NextRowError>> {
         let res = std::future::poll_fn(|cx| Pin::new(&mut *self).poll_fill_page(cx)).await;
         match res {
             Some(Ok(())) => {}
-            Some(Err(err)) => return Some(Err(err.into())),
+            Some(Err(err)) => return Some(Err(err)),
             None => return None,
         }
 
@@ -597,7 +597,7 @@ impl QueryPager {
             self.current_page
                 .next()
                 .unwrap()
-                .map_err(|err| NextRowError::RowDeserializationError(err).into()),
+                .map_err(NextRowError::RowDeserializationError),
         )
     }
 
@@ -1035,14 +1035,14 @@ impl<RowT> Stream for TypedRowStream<RowT>
 where
     RowT: DeserializeOwnedRow,
 {
-    type Item = Result<RowT, QueryError>;
+    type Item = Result<RowT, NextRowError>;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let next_fut = async {
             self.raw_row_lending_stream.next().await.map(|res| {
                 res.and_then(|column_iterator| {
                     <RowT as DeserializeRow>::deserialize(column_iterator)
-                        .map_err(|err| NextRowError::RowDeserializationError(err).into())
+                        .map_err(NextRowError::RowDeserializationError)
                 })
             })
         };
@@ -1177,7 +1177,7 @@ mod legacy {
     pub enum LegacyNextRowError {
         /// Query to fetch next page has failed
         #[error(transparent)]
-        QueryError(#[from] QueryError),
+        NextRowError(#[from] NextRowError),
 
         /// Parsing values in row as given types failed
         #[error(transparent)]

scylla/src/cluster/metadata.rs

@@ -847,6 +847,7 @@ async fn query_peers(conn: &Arc<Connection>, connect_port: u16) -> Result<Vec<Pe
             Ok::<_, QueryError>(rows_stream)
         })
         .into_stream()
+        .map(|result| result.map(|stream| stream.map_err(QueryError::from)))
         .try_flatten()
         .and_then(|row_result| future::ok((NodeInfoSource::Peer, row_result)));
 
@@ -864,6 +865,7 @@ async fn query_peers(conn: &Arc<Connection>, connect_port: u16) -> Result<Vec<Pe
             Ok::<_, QueryError>(rows_stream)
         })
         .into_stream()
+        .map(|result| result.map(|stream| stream.map_err(QueryError::from)))
         .try_flatten()
         .and_then(|row_result| future::ok((NodeInfoSource::Local, row_result)));
 
@@ -1007,7 +1009,9 @@ where
             pager.rows_stream::<R>().map_err(convert_typecheck_error)?;
         Ok::<_, QueryError>(stream)
     };
-    fut.into_stream().try_flatten()
+    fut.into_stream()
+        .map(|result| result.map(|stream| stream.map_err(QueryError::from)))
+        .try_flatten()
 }
 
 async fn query_keyspaces(
@@ -1861,6 +1865,7 @@ async fn query_table_partitioners(
             Ok::<_, QueryError>(stream)
         })
         .into_stream()
+        .map(|result| result.map(|stream| stream.map_err(QueryError::from)))
         .try_flatten();
 
     let result = rows