Add materialized view iterator

Added CassViewMetaIterator struct to enable iteration over materialized
view metadata for keyspace and table metadata, as well as iteration over
view metadata fields such as columns.

scylla-rust-wrapper/src/query_result.rs

@@ -3,8 +3,8 @@ use crate::cass_error::CassError;
 use crate::cass_types::{cass_data_type_type, CassDataType, CassDataTypeArc, CassValueType};
 use crate::inet::CassInet;
 use crate::session::{
-    CassColumnMeta, CassKeyspaceMeta, CassKeyspaceMeta_, CassSchemaMeta, CassSchemaMeta_,
-    CassTableMeta, CassTableMeta_,
+    CassColumnMeta, CassKeyspaceMeta, CassKeyspaceMeta_, CassMaterializedViewMeta,
+    CassMaterializedViewMeta_, CassSchemaMeta, CassSchemaMeta_, CassTableMeta, CassTableMeta_,
 };
 use crate::statement::CassStatement;
 use crate::types::*;
@@ -108,6 +108,12 @@ pub struct CassTableMetaIterator {
     position: Option<usize>,
 }
 
+pub struct CassViewMetaIterator {
+    value: CassMaterializedViewMeta_,
+    count: usize,
+    position: Option<usize>,
+}
+
 pub enum CassIterator {
     CassResultIterator(CassResultIterator),
     CassRowIterator(CassRowIterator),
@@ -117,6 +123,7 @@ pub enum CassIterator {
     CassSchemaMetaIterator(CassSchemaMetaIterator),
     CassKeyspaceMetaIterator(CassKeyspaceMetaIterator),
     CassTableMetaIterator(CassTableMetaIterator),
+    CassViewMetaIterator(CassViewMetaIterator),
 }
 
 #[no_mangle]
@@ -195,6 +202,13 @@ pub unsafe extern "C" fn cass_iterator_next(iterator: *mut CassIterator) -> cass
 
             (new_pos < table_iterator.count) as cass_bool_t
         }
+        CassIterator::CassViewMetaIterator(view_iterator) => {
+            let new_pos: usize = view_iterator.position.map_or(0, |prev_pos| prev_pos + 1);
+
+            view_iterator.position = Some(new_pos);
+
+            (new_pos < view_iterator.count) as cass_bool_t
+        }
     }
 }
 
@@ -509,6 +523,19 @@ pub unsafe extern "C" fn cass_iterator_get_column_meta(
     std::ptr::null()
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn cass_iterator_get_materialized_view_meta(
+    iterator: *const CassIterator,
+) -> *const CassMaterializedViewMeta {
+    let iter = ptr_to_ref(iterator);
+
+    if let CassIterator::CassViewMetaIterator(view_meta_iterator) = iter {
+        return view_meta_iterator.value as *const CassMaterializedViewMeta;
+    }
+
+    std::ptr::null()
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn cass_iterator_from_result(result: *const CassResult) -> *mut CassIterator {
     let result_from_raw: CassResult_ = clone_arced(result);
@@ -646,6 +673,21 @@ pub unsafe extern "C" fn cass_iterator_tables_from_keyspace_meta(
     Box::into_raw(Box::new(CassIterator::CassKeyspaceMetaIterator(iterator)))
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn cass_iterator_materialized_views_from_keyspace_meta(
+    keyspace_meta: *const CassKeyspaceMeta,
+) -> *mut CassIterator {
+    let metadata = ptr_to_ref(keyspace_meta);
+
+    let iterator = CassKeyspaceMetaIterator {
+        value: metadata,
+        count: metadata.views.len(),
+        position: None,
+    };
+
+    Box::into_raw(Box::new(CassIterator::CassKeyspaceMetaIterator(iterator)))
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn cass_iterator_user_types_from_keyspace_meta(
     keyspace_meta: *const CassKeyspaceMeta,
@@ -676,6 +718,37 @@ pub unsafe extern "C" fn cass_iterator_columns_from_table_meta(
     Box::into_raw(Box::new(CassIterator::CassTableMetaIterator(iterator)))
 }
 
+pub unsafe extern "C" fn cass_iterator_materialized_views_from_table_meta(
+    table_meta: *const CassTableMeta,
+) -> *mut CassIterator {
+    let metadata = ptr_to_ref(table_meta);
+
+    let iterator = CassTableMetaIterator {
+        value: metadata,
+        count: metadata
+            .views
+            .as_ref()
+            .map_or(0, |views_meta| views_meta.len()),
+        position: None,
+    };
+
+    Box::into_raw(Box::new(CassIterator::CassTableMetaIterator(iterator)))
+}
+
+pub unsafe extern "C" fn cass_iterator_columns_from_materialized_view_meta(
+    view_meta: *const CassMaterializedViewMeta,
+) -> *mut CassIterator {
+    let metadata = ptr_to_ref(view_meta);
+
+    let iterator = CassViewMetaIterator {
+        value: metadata,
+        count: metadata.view_metadata.columns_metadata.len(),
+        position: None,
+    };
+
+    Box::into_raw(Box::new(CassIterator::CassViewMetaIterator(iterator)))
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn cass_result_free(result_raw: *const CassResult) {
     free_arced(result_raw);

scylla-rust-wrapper/src/session.rs

@@ -52,6 +52,8 @@ pub struct CassTableMeta {
     pub views: Option<HashMap<String, Arc<CassMaterializedViewMeta>>>,
 }
 
+pub type CassMaterializedViewMeta_ = &'static CassMaterializedViewMeta;
+
 pub struct CassMaterializedViewMeta {
     pub name: String,
     pub view_metadata: CassTableMeta,