Refactored return types and statements.

src/frontend/src/handler/create_sink.rs

@@ -306,11 +306,7 @@ pub async fn handle_create_sink(
             bail_not_implemented!(issue = 13818, "create sink into table with incoming sinks");
         }
 
-        if check_cycle_for_sink(session.as_ref(), sink.clone(), table_catalog.id())? {
-            return Err(RwError::from(ErrorCode::BindError(
-                "Creating such a sink will result in circular dependency.".to_string(),
-            )));
-        }
+        check_cycle_for_sink(session.as_ref(), sink.clone(), table_catalog.id())?;
 
         let (mut graph, mut table, source) =
             reparse_table_for_sink(&session, &table_catalog).await?;
@@ -357,7 +353,7 @@ fn check_cycle_for_sink(
     session: &SessionImpl,
     sink_catalog: SinkCatalog,
     table_id: catalog::TableId,
-) -> Result<bool> {
+) -> Result<()> {
     let reader = session.env().catalog_reader().read_guard();
 
     let mut sinks = HashMap::new();
@@ -373,17 +369,16 @@ fn check_cycle_for_sink(
         sink_index: &HashMap<u32, &SinkCatalog>,
         sink: &SinkCatalog,
         visited_tables: &mut HashSet<u32>,
-    ) -> Result<bool> {
+    ) -> Result<()> {
         for table_id in &sink.dependent_relations {
             if let Ok(table) = reader.get_table_by_id(table_id) {
-                if visit_table(session, reader, sink_index, table.as_ref(), visited_tables)? {
-                    return Ok(true);
-                }
+                visit_table(session, reader, sink_index, table.as_ref(), visited_tables)?
             } else {
                 bail!("table not found: {:?}", table_id);
             }
         }
-        Ok(false)
+
+        Ok(())
     }
 
     fn visit_table(
@@ -392,22 +387,23 @@ fn check_cycle_for_sink(
         sink_index: &HashMap<u32, &SinkCatalog>,
         table: &TableCatalog,
         visited_tables: &mut HashSet<u32>,
-    ) -> Result<bool> {
+    ) -> Result<()> {
         if visited_tables.contains(&table.id.table_id) {
-            Ok(true)
-        } else {
-            let _ = visited_tables.insert(table.id.table_id);
-            for sink_id in &table.incoming_sinks {
-                if let Some(sink) = sink_index.get(sink_id) {
-                    if visit_sink(session, reader, sink_index, sink, visited_tables)? {
-                        return Ok(true);
-                    }
-                } else {
-                    bail!("sink not found: {:?}", sink_id);
-                }
+            return Err(RwError::from(ErrorCode::BindError(
+                "Creating such a sink will result in circular dependency.".to_string(),
+            )));
+        }
+
+        let _ = visited_tables.insert(table.id.table_id);
+        for sink_id in &table.incoming_sinks {
+            if let Some(sink) = sink_index.get(sink_id) {
+                visit_sink(session, reader, sink_index, sink, visited_tables)?
+            } else {
+                bail!("sink not found: {:?}", sink_id);
             }
-            Ok(false)
         }
+
+        Ok(())
     }
 
     let mut visited_tables = HashSet::new();