program: track total_fee_earned_per_lp on amm (#526)

* bigz/add-total_fee_earned_per_lp-to-amm * CHANGELOG --------- Co-authored-by: Chris Heaney <[email protected]>
drift-labs · Jul 10, 2023 · 5bce22b · 5bce22b
1 parent da890e2
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Features
 
+- program: track `total_fee_earned_per_lp` on amm (([#526](https://github.com/drift-labs/protocol-v2/pull/526)))
 - program: add additional withdraw/borrow guards around fast utilization changes (([#517](https://github.com/drift-labs/protocol-v2/pull/517)))
 - program: new margin type for when orders are being filled (([#518](https://github.com/drift-labs/protocol-v2/pull/518)))
 - program: new fill price bands (([#516](https://github.com/drift-labs/protocol-v2/pull/516)))

diff --git a/programs/drift/src/controller/position.rs b/programs/drift/src/controller/position.rs
@@ -434,19 +434,23 @@ pub fn update_lp_market_position(
     .safe_mul(user_lp_shares.cast::<i128>()?)?
     .safe_div(total_lp_shares.cast::<i128>()?)?;
 
-    let per_lp_fee = if lp_fee > 0 {
+    let per_lp_fee: i128 = if lp_fee > 0 {
         lp_fee
             .safe_mul(AMM_RESERVE_PRECISION_I128)?
             .safe_div(user_lp_shares.cast::<i128>()?)?
     } else {
         0
     };
 
-    // update per lp position
-    market.amm.quote_asset_amount_per_lp = market
+    // track total fee earned by lps (to attribute breakdown of IL)
+    market.amm.total_fee_earned_per_lp = market
         .amm
-        .quote_asset_amount_per_lp
-        .safe_add(per_lp_fee.cast()?)?;
+        .total_fee_earned_per_lp
+        .saturating_add(per_lp_fee.cast()?);
+
+    // update per lp position
+    market.amm.quote_asset_amount_per_lp =
+        market.amm.quote_asset_amount_per_lp.safe_add(per_lp_fee)?;
 
     market.amm.base_asset_amount_with_amm = market
         .amm

diff --git a/programs/drift/src/instructions/admin.rs b/programs/drift/src/instructions/admin.rs
@@ -717,7 +717,9 @@ pub fn handle_initialize_perp_market(
 
             last_oracle_valid: false,
             target_base_asset_amount_per_lp: 0,
-            padding: [0; 44],
+            padding1: 0,
+            total_fee_earned_per_lp: 0,
+            padding: [0; 32],
         },
     };
 

diff --git a/programs/drift/src/state/perp_market.rs b/programs/drift/src/state/perp_market.rs
@@ -630,7 +630,9 @@ pub struct AMM {
     /// the target value for `base_asset_amount_per_lp`, used during AMM JIT with LP split
     /// precision: BASE_PRECISION
     pub target_base_asset_amount_per_lp: i32,
-    pub padding: [u8; 44],
+    pub padding1: u32,
+    pub total_fee_earned_per_lp: u64,
+    pub padding: [u8; 32],
 }
 
 impl Default for AMM {
@@ -712,7 +714,9 @@ impl Default for AMM {
             oracle_source: OracleSource::default(),
             last_oracle_valid: false,
             target_base_asset_amount_per_lp: 0,
-            padding: [0; 44],
+            padding1: 0,
+            total_fee_earned_per_lp: 0,
+            padding: [0; 32],
         }
     }
 }