avoid duplicate remainder standarize

Author: 0xbigz

programs/drift/src/controller/lp.rs

@@ -183,7 +183,7 @@ pub fn settle_lp_position(
 
     apply_lp_rebase_to_perp_position(market, position)?;
 
-    let mut lp_metrics: crate::math::lp::LPMetrics =
+    let lp_metrics: crate::math::lp::LPMetrics =
         calculate_settle_lp_metrics(&market.amm, position)?;
 
     let position_delta = PositionDelta {
@@ -192,30 +192,7 @@ pub fn settle_lp_position(
         remainder_base_asset_amount: Some(lp_metrics.remainder_base_asset_amount.cast::<i64>()?),
     };
 
-    let new_remainder_base_asset_amount = position
-        .remainder_base_asset_amount
-        .cast::<i64>()?
-        .safe_add(lp_metrics.remainder_base_asset_amount.cast()?)?;
-
-
-    let pnl = update_position_and_market(position, market, &position_delta)?;
-
-    if new_remainder_base_asset_amount.unsigned_abs() >= market.amm.order_step_size {
-        let (standardized_remainder_base_asset_amount, _remainder_base_asset_amount) =
-            crate::math::orders::standardize_base_asset_amount_with_remainder_i128(
-                new_remainder_base_asset_amount.cast()?,
-                market.amm.order_step_size.cast()?,
-            )?;
-
-        lp_metrics.base_asset_amount = lp_metrics
-            .base_asset_amount
-            .safe_add(standardized_remainder_base_asset_amount)?;
-    }
-
-    market.amm.base_asset_amount_with_unsettled_lp = market
-        .amm
-        .base_asset_amount_with_unsettled_lp
-        .safe_add(lp_metrics.base_asset_amount.cast()?)?;
+    let pnl: i64 = update_position_and_market(position, market, &position_delta)?;
 
     position.last_base_asset_amount_per_lp = market.amm.base_asset_amount_per_lp.cast()?;
     position.last_quote_asset_amount_per_lp = market.amm.quote_asset_amount_per_lp.cast()?;

programs/drift/src/controller/position.rs

@@ -111,27 +111,16 @@ pub fn update_position_and_market(
 
     let update_type = get_position_update_type(position, delta)?;
 
-    let (standardized_delta_base, _remainder_base_asset_amount) =
-        crate::math::orders::standardize_base_asset_amount_with_remainder_i128(
-            delta.base_asset_amount.cast()?,
-            market.amm.order_step_size.cast()?,
-        )?;
-    validate!(
-        _remainder_base_asset_amount == 0,
-        ErrorCode::InvalidPositionDelta
-    )?;
-
-    msg!("delta base");
-    crate::dlog!(standardized_delta_base, _remainder_base_asset_amount);
-
     // Update User
     let (
         new_base_asset_amount,
-        _new_settled_base_asset_amount,
+        new_settled_base_asset_amount,
         new_quote_asset_amount,
         new_remainder_base_asset_amount,
     ) = get_new_position_amounts(position, delta, market)?;
 
+    market.update_market_with_counterparty(delta, new_settled_base_asset_amount)?;
+
     let (new_quote_entry_amount, new_quote_break_even_amount, pnl) = match update_type {
         PositionUpdateType::Open | PositionUpdateType::Increase => {
             let new_quote_entry_amount = position

programs/drift/src/state/perp_market.rs

@@ -441,6 +441,23 @@ impl PerpMarket {
 
         Ok(depth)
     }
+
+    pub fn update_market_with_counterparty(
+        &mut self,
+        delta: &PositionDelta,
+        new_settled_base_asset_amount: i64,
+    ) -> DriftResult {
+        if delta.remainder_base_asset_amount.is_some() {
+            // todo: name for this is confusing, but adding is correct as is
+            // definition: net position of users in the market that has the LP as a counterparty (which have NOT settled)
+            self.amm.base_asset_amount_with_unsettled_lp = self
+                .amm
+                .base_asset_amount_with_unsettled_lp
+                .safe_add(new_settled_base_asset_amount.cast()?)?;
+        }
+
+        Ok(())
+    }
 }
 
 #[cfg(test)]