refactor(core): rewrite tasks using generators, better pruning (#265)

Signed-off-by: Alex Chi Z <[email protected]>

Author: skyzh

Diff for: Cargo.lock

@@ -19,6 +19,8 @@ serde = { version = "1.0", features = ["derive", "rc"] }
 arrow-schema = "53.3.0"
 chrono = "0.4"
 erased-serde = "0.4"
+pollster = "0.4"
+stacker = "0.1"
 
 [dev-dependencies]
 pretty_assertions = "1.4.1"

Diff for: optd-core/Cargo.toml

@@ -7,8 +7,8 @@
 
 mod memo;
 mod optimizer;
-mod tasks;
+pub mod rule_match;
+mod tasks2;
 
 pub use memo::{Memo, NaiveMemo};
 pub use optimizer::{CascadesOptimizer, ExprId, GroupId, OptimizerProperties, RelNodeContext};
-use tasks::Task;

Diff for: optd-core/src/cascades.rs

@@ -158,6 +158,11 @@ pub trait Memo<T: NodeType>: 'static + Send + Sync {
     ) -> Result<ArcPlanNode<T>> {
         get_best_group_binding_inner(self, group_id, &mut post_process)
     }
+
+    /// Get winner of a group and a subgroup.
+    fn get_group_winner(&self, group_id: GroupId) -> &Winner {
+        &self.get_group(group_id).info.winner
+    }
 }
 
 fn get_best_group_binding_inner<M: Memo<T> + ?Sized, T: NodeType>(