Ignore match nodes that are not part of the output and return unique results in execute_query_on_graph

Author: thomaskrause

graphannis/src/annis/db/aql/mod.rs

@@ -6,6 +6,7 @@ pub mod operators;
 
 use boolean_expression::Expr;
 use graphannis_core::annostorage::MatchGroup;
+use itertools::Itertools;
 lalrpop_mod!(
     #[allow(clippy::all)]
     #[allow(clippy::panic)]
@@ -77,7 +78,28 @@ pub fn execute_query_on_graph<'a>(
     let timeout = TimeoutCheck::new(timeout);
 
     let config = Config { use_parallel_joins };
-    let it = ExecutionPlan::from_disjunction(query, graph, &config, timeout)?;
+    let it = ExecutionPlan::from_disjunction(query, graph, &config, timeout)?
+        .map_ok(|mg| {
+            // Rewrite match group to only include nodes that are included in the query
+            // check if query node actually should be included
+            let mut new_match_group = MatchGroup::with_capacity(mg.len());
+            for (node_nr, m) in mg.into_iter().enumerate() {
+                let include_in_output = query
+                    .get_variable_by_node_nr(node_nr)
+                    .is_some_and(|var| query.is_included_in_output(&var));
+                if include_in_output {
+                    new_match_group.push(m);
+                }
+            }
+            new_match_group
+        })
+        .unique_by(move |mg| {
+            // Map an error to an empty match group
+            match mg {
+                Ok(mg) => mg.clone(),
+                Err(_) => MatchGroup::new(),
+            }
+        });
 
     Ok(Box::from(it))
 }