fix: Reduce type complexity

As now caught by clippy. https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

cache_system/src/backend/resource_consumption.rs

@@ -34,6 +34,8 @@ pub trait ResourceEstimator: Debug + Send + Sync + 'static {
     fn consumption(&self, k: &Self::K, v: &Self::V) -> Self::S;
 }
 
+type BoxedEstimatorFn<K, V, S> = Box<dyn (Fn(&K, &V) -> S) + Send + Sync>;
+
 /// A simple function-based [`ResourceEstimator].
 pub struct FunctionEstimator<K, V, S>
 where
@@ -41,7 +43,7 @@ where
     V: 'static,
     S: Resource,
 {
-    estimator: Box<dyn (Fn(&K, &V) -> S) + Send + Sync>,
+    estimator: BoxedEstimatorFn<K, V, S>,
 }
 
 impl<K, V, S> FunctionEstimator<K, V, S>

query_functions/src/selectors.rs

@@ -195,6 +195,9 @@ impl SelectorOutput {
 }
 
 type ReturnTypeFunction = Arc<dyn Fn(&[DataType]) -> DataFusionResult<Arc<DataType>> + Send + Sync>;
+type StateTypeFactory =
+    Arc<dyn Fn(&DataType) -> DataFusionResult<Arc<Vec<DataType>>> + Send + Sync>;
+type Factory = Arc<dyn Fn() -> DataFusionResult<Box<dyn Accumulator>> + Send + Sync>;
 
 /// Factory function for creating the UDA function for DataFusion
 fn make_uda<SELECTOR>(name: &'static str, output: SelectorOutput) -> AggregateUDF
@@ -208,11 +211,9 @@ where
     );
 
     let state_type = Arc::new(vec![value_data_type.clone(), TIME_DATA_TYPE()]);
-    let state_type_factory: Arc<
-        dyn Fn(&DataType) -> DataFusionResult<Arc<Vec<DataType>>> + Send + Sync,
-    > = Arc::new(move |_| Ok(Arc::clone(&state_type)));
+    let state_type_factory: StateTypeFactory = Arc::new(move |_| Ok(Arc::clone(&state_type)));
 
-    let factory: Arc<dyn Fn() -> DataFusionResult<Box<dyn Accumulator>> + Send + Sync> =
+    let factory: Factory =
         Arc::new(move || Ok(Box::new(SelectorAccumulator::<SELECTOR>::new(output))));
 
     let return_type = Arc::new(output.return_type(&value_data_type));

test_helpers_end_to_end/src/steps.rs

@@ -66,6 +66,9 @@ impl<'a> StepTestState<'a> {
 /// ```
 pub type FCustom = Box<dyn for<'b> FnOnce(&'b mut StepTestState) -> BoxFuture<'b, ()>>;
 
+/// Function to do custom validation on metrics. Expected to panic on validation failure.
+pub type MetricsValidationFn = Box<dyn Fn(&mut StepTestState, String)>;
+
 /// Possible test steps that a test can perform
 pub enum Step {
     /// Writes the specified line protocol to the `/api/v2/write`
@@ -115,7 +118,7 @@ pub enum Step {
     ///
     /// The validation function is expected to panic on validation
     /// failure.
-    VerifiedMetrics(Box<dyn Fn(&mut StepTestState, String)>),
+    VerifiedMetrics(MetricsValidationFn),
 
     /// A custom step that can be used to implement special cases that
     /// are only used once.