make catalog trait object available from datafusion iceberg catalog

Author: JanKaul

datafusion_iceberg/src/catalog/catalog.rs

@@ -18,6 +18,10 @@ impl IcebergCatalog {
             catalog: Arc::new(Mirror::new(catalog, branch.map(ToOwned::to_owned)).await?),
         })
     }
+
+    pub fn catalog(&self) -> &dyn Catalog {
+        self.catalog.catalog()
+    }
 }
 
 impl CatalogProvider for IcebergCatalog {

datafusion_iceberg/src/catalog/mirror.rs

@@ -1,6 +1,7 @@
 use dashmap::DashMap;
 use datafusion::{datasource::TableProvider, error::DataFusionError};
 use futures::{executor::LocalPool, task::LocalSpawnExt};
+use std::ops::Deref;
 use std::{collections::HashSet, sync::Arc};
 
 use iceberg_rust::spec::{tabular::TabularMetadata, view_metadata::REF_PREFIX};
@@ -304,4 +305,8 @@ impl Mirror {
         // Currently can't synchronously return a table which has to be fetched asynchronously
         Ok(None)
     }
+
+    pub fn catalog(&self) -> &dyn Catalog {
+        self.catalog.deref()
+    }
 }