dex(volume_tracker): stub out cumvol tracking

crates/core/component/dex/src/component/position_manager/volume_tracker.rs

@@ -0,0 +1,40 @@
+use anyhow::Result;
+use cnidarium::StateWrite;
+use penumbra_sdk_num::Amount;
+use position::State::*;
+use tracing::instrument;
+
+use crate::lp::position::{self, Position};
+use crate::state_key::engine;
+use crate::DirectedTradingPair;
+use async_trait::async_trait;
+use penumbra_sdk_proto::{StateReadProto, StateWriteProto};
+
+#[async_trait]
+pub(crate) trait PositionVolumeTracker: StateWrite {
+    async fn increase_volume_index(
+        &mut self,
+        id: &position::Id,
+        prev_state: &Option<Position>,
+        new_state: &Position,
+    ) -> Result<()> {
+        unimplemented!("increase_volume_index")
+    }
+}
+
+impl<T: StateWrite + ?Sized> PositionVolumeTracker for T {}
+
+trait Inner: StateWrite {
+    #[instrument(skip(self))]
+    async fn update_volume(
+        &mut self,
+        id: &position::Id,
+        pair: DirectedTradingPair,
+        old_volume: Amount,
+        new_volume: Amount,
+    ) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<T: StateWrite + ?Sized> Inner for T {}