Fix timeout check for frequency queries with large results but small tuple frequency count

Author: thomaskrause

CHANGELOG.md

@@ -13,6 +13,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Queries with `@` could have extremly slow execution plans when the query
   planner introduces an inverted `@` operator and miscalculated the cost
   compared to the non-inverted version.
+- Frequency queries now execute the (additional) timeout check after a certain
+  number of matches are processed, not if a specific tuple value has reached a
+  treshold.
 
 ## [4.0.0] - 2025-08-20
 

core/src/util/disk_collections.rs

@@ -21,15 +21,6 @@ const BLOCK_MAX_SIZE: usize = 4 * KB;
 /// Uses a cache for each disk table with 8 MB capacity.
 pub const DEFAULT_BLOCK_CACHE_CAPACITY: usize = 8 * MB;
 
-#[derive(Serialize, Deserialize)]
-struct Entry<K, V>
-where
-    K: Ord,
-{
-    key: K,
-    value: V,
-}
-
 pub enum EvictionStrategy {
     MaximumItems(usize),
 }

graphannis/src/annis/db/corpusstorage.rs

@@ -69,6 +69,9 @@ mod subgraph;
 #[cfg(test)]
 mod tests;
 
+/// After how many produces tuples the timeout check should be manually triggered (in case the underlying joint did not already check the timeout)
+const TIMEOUT_CHECK_TUPLE_COUNT: u64 = 1_000;
+
 enum CacheEntry {
     Loaded(AnnotationGraph),
     NotLoaded,
@@ -1602,7 +1605,7 @@ impl CorpusStorage {
 
             for _ in plan {
                 total_count += 1;
-                if total_count % 1_000 == 0 {
+                if total_count.is_multiple_of(TIMEOUT_CHECK_TUPLE_COUNT) {
                     timeout.check()?;
                 }
             }
@@ -1666,7 +1669,7 @@ impl CorpusStorage {
                 }
                 match_count += 1;
 
-                if match_count % 1_000 == 0 {
+                if match_count.is_multiple_of(TIMEOUT_CHECK_TUPLE_COUNT) {
                     timeout.check()?;
                 }
             }
@@ -2307,9 +2310,11 @@ impl CorpusStorage {
 
             let plan =
                 ExecutionPlan::from_disjunction(&prep.query, db, &self.query_config, timeout)?;
+            let mut total_count: u64 = 0;
 
             for mgroup in plan {
                 let mgroup = mgroup?;
+
                 // for each match, extract the defined annotation (by its key) from the result node
                 let mut tuple: Vec<String> = Vec::with_capacity(annokeys.len());
                 for (node_ref, anno_keys) in &annokeys {
@@ -2328,7 +2333,8 @@ impl CorpusStorage {
                 let tuple_count: &mut usize = tuple_frequency.entry(tuple).or_insert(0);
                 *tuple_count += 1;
 
-                if *tuple_count % 1_000 == 0 {
+                total_count += 1;
+                if total_count.is_multiple_of(TIMEOUT_CHECK_TUPLE_COUNT) {
                     timeout.check()?;
                 }
             }