feat: collateral tracking (#192)

* feat: collateral tracking

* fix: update only snapshot and info in market struct

* chore: remove comments and dead code

* cargo: fmt

* chore: some small naming + comments

* test: add comprehensive tests for snapshot

* cargo: fmt

* cargo: clippy

* chore: small change on (500) to 500

* chore: increase test precision

* chore: make crate public fields in snapshot for use in common module

* test: improve testing time boundaries of snapshots

* cargo: fmt

* test: increase divisor and sleeps on multiple_snapshots_show_progression

* test: try other method of finding snapshot state for test

---------

Co-authored-by: peer2 <peer2@templarprotocol.com>

Author: joshuajbouw

common/src/borrow.rs

@@ -378,6 +378,8 @@ impl<'a> BorrowPositionGuard<'a> {
             .increase_collateral_asset_deposit(amount)
             .unwrap_or_else(|| env::panic_str("Borrow position collateral asset overflow"));
 
+        asset_op!(self.market.collateral_asset_deposited += amount);
+
         MarketEvent::CollateralDeposited {
             account_id: self.account_id.clone(),
             collateral_asset_amount: amount,
@@ -394,6 +396,8 @@ impl<'a> BorrowPositionGuard<'a> {
             .decrease_collateral_asset_deposit(amount)
             .unwrap_or_else(|| env::panic_str("Borrow position collateral asset underflow"));
 
+        asset_op!(self.market.collateral_asset_deposited -= amount);
+
         MarketEvent::CollateralWithdrawn {
             account_id: self.account_id.clone(),
             collateral_asset_amount: amount,

common/src/market/impl.rs

@@ -6,21 +6,19 @@ use near_sdk::{
 };
 
 use crate::{
-    asset::BorrowAssetAmount,
+    asset::{BorrowAssetAmount, CollateralAssetAmount},
     asset_op,
     borrow::{BorrowPosition, BorrowPositionGuard, BorrowPositionRef},
     chunked_append_only_list::ChunkedAppendOnlyList,
     event::MarketEvent,
-    market::MarketConfiguration,
+    market::{MarketConfiguration, WithdrawalResolution},
     number::Decimal,
     snapshot::Snapshot,
     static_yield::StaticYieldRecord,
     supply::{SupplyPosition, SupplyPositionGuard, SupplyPositionRef},
     withdrawal_queue::{error::WithdrawalQueueLockError, WithdrawalQueue},
 };
 
-use super::WithdrawalResolution;
-
 #[derive(BorshStorageKey)]
 #[near]
 enum StorageKey {
@@ -35,10 +33,20 @@ enum StorageKey {
 pub struct Market {
     prefix: Vec<u8>,
     pub configuration: MarketConfiguration,
+    /// Total amount of borrow asset earning interest in the market.
     pub borrow_asset_deposited_active: BorrowAssetAmount,
+    /// Mapping of upcoming snapshot indices to amounts of borrow asset that will be activated.
     pub borrow_asset_deposited_incoming: HashMap<u32, BorrowAssetAmount>,
+    /// Sending borrow asset out, because if somebody sends the contract borrow asset, it's ok for the
+    /// contract to attempt to fulfill withdrawal request, even if the market thinks it doesn't have
+    /// enough to fulfill.
     pub borrow_asset_in_flight: BorrowAssetAmount,
+    /// Amount of borrow asset that has been withdrawn (is in use by) by borrowers.
+    ///
+    /// `borrow_asset_deposited_active - borrow_asset_borrowed >= 0` should always be true.
     pub borrow_asset_borrowed: BorrowAssetAmount,
+    /// Market-wide collateral asset deposit tracking.
+    pub collateral_asset_deposited: CollateralAssetAmount,
     pub(crate) supply_positions: UnorderedMap<AccountId, SupplyPosition>,
     pub(crate) borrow_positions: UnorderedMap<AccountId, BorrowPosition>,
     pub current_snapshot: Snapshot,
@@ -66,7 +74,7 @@ impl Market {
 
         let first_snapshot = Snapshot::new(configuration.time_chunk_configuration.previous());
         let mut current_snapshot = first_snapshot.clone();
-        current_snapshot.time_chunk = configuration.time_chunk_configuration.now();
+        current_snapshot.set_time_chunk(configuration.time_chunk_configuration.now());
 
         let mut self_ = Self {
             prefix: prefix.clone(),
@@ -75,6 +83,7 @@ impl Market {
             borrow_asset_deposited_incoming: HashMap::new(),
             borrow_asset_in_flight: 0.into(),
             borrow_asset_borrowed: 0.into(),
+            collateral_asset_deposited: 0.into(),
             supply_positions: UnorderedMap::new(key!(SupplyPositions)),
             borrow_positions: UnorderedMap::new(key!(BorrowPositions)),
             current_snapshot,
@@ -117,13 +126,16 @@ impl Market {
             self.current_snapshot.update_active(
                 self.borrow_asset_deposited_active,
                 self.borrow_asset_borrowed,
+                self.collateral_asset_deposited,
                 &self.configuration.borrow_interest_rate_strategy,
             );
             self.current_snapshot.add_yield(yield_distribution);
-            self.current_snapshot.deposited_incoming = *self
-                .borrow_asset_deposited_incoming
-                .get(&self.finalized_snapshots.len())
-                .unwrap_or(&0.into());
+            self.current_snapshot.set_borrow_asset_deposited_incoming(
+                *self
+                    .borrow_asset_deposited_incoming
+                    .get(&self.finalized_snapshots.len())
+                    .unwrap_or(&0.into()),
+            );
         } else {
             // Otherwise, finalize the current snapshot and create a new one.
             let deposited_incoming = self
@@ -132,11 +144,12 @@ impl Market {
                 .unwrap_or(0.into());
             asset_op!(self.borrow_asset_deposited_active += deposited_incoming);
             let mut snapshot = Snapshot::new(time_chunk);
-            snapshot.yield_distribution = yield_distribution;
-            snapshot.deposited_incoming = deposited_incoming;
+            snapshot.set_yield_distribution(yield_distribution);
+            snapshot.set_borrow_asset_deposited_incoming(deposited_incoming);
             snapshot.update_active(
                 self.borrow_asset_deposited_active,
                 self.borrow_asset_borrowed,
+                self.collateral_asset_deposited,
                 &self.configuration.borrow_interest_rate_strategy,
             );
             std::mem::swap(&mut snapshot, &mut self.current_snapshot);

common/src/snapshot.rs

@@ -1,30 +1,35 @@
 use near_sdk::{env, json_types::U64, near};
 
 use crate::{
-    asset::BorrowAssetAmount, asset_op, interest_rate_strategy::InterestRateStrategy,
-    number::Decimal, time_chunk::TimeChunk,
+    asset::{BorrowAssetAmount, CollateralAssetAmount},
+    asset_op,
+    interest_rate_strategy::InterestRateStrategy,
+    number::Decimal,
+    time_chunk::TimeChunk,
 };
 
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 #[near(serializers = [borsh, json])]
 pub struct Snapshot {
-    pub time_chunk: TimeChunk,
-    pub end_timestamp_ms: U64,
-    deposited_active: BorrowAssetAmount,
-    pub deposited_incoming: BorrowAssetAmount,
-    borrowed: BorrowAssetAmount,
-    pub yield_distribution: BorrowAssetAmount,
+    pub(crate) time_chunk: TimeChunk,
+    pub(crate) end_timestamp_ms: U64,
+    pub(crate) borrow_asset_deposited_active: BorrowAssetAmount,
+    borrow_asset_deposited_incoming: BorrowAssetAmount,
+    borrow_asset_borrowed: BorrowAssetAmount,
+    collateral_asset_deposited: CollateralAssetAmount,
+    yield_distribution: BorrowAssetAmount,
     interest_rate: Decimal,
 }
 
 impl Snapshot {
     pub fn new(time_chunk: TimeChunk) -> Self {
         Self {
             time_chunk,
-            end_timestamp_ms: near_sdk::env::block_timestamp_ms().into(),
-            deposited_active: 0.into(),
-            deposited_incoming: 0.into(),
-            borrowed: 0.into(),
+            end_timestamp_ms: env::block_timestamp_ms().into(),
+            borrow_asset_deposited_active: 0.into(),
+            borrow_asset_deposited_incoming: 0.into(),
+            borrow_asset_borrowed: 0.into(),
+            collateral_asset_deposited: 0.into(),
             yield_distribution: BorrowAssetAmount::zero(),
             interest_rate: Decimal::ZERO,
         }
@@ -36,35 +41,70 @@ impl Snapshot {
 
     pub fn update_active(
         &mut self,
-        deposited_active: BorrowAssetAmount,
-        borrowed: BorrowAssetAmount,
+        borrow_asset_deposited_active: BorrowAssetAmount,
+        borrow_asset_borrowed: BorrowAssetAmount,
+        collateral_asset_deposited: CollateralAssetAmount,
         interest_rate_strategy: &InterestRateStrategy,
     ) {
         self.end_timestamp_ms = env::block_timestamp_ms().into();
-        self.deposited_active = deposited_active;
-        self.borrowed = borrowed;
+        self.borrow_asset_deposited_active = borrow_asset_deposited_active;
+        self.borrow_asset_borrowed = borrow_asset_borrowed;
+        self.collateral_asset_deposited = collateral_asset_deposited;
         self.interest_rate = interest_rate_strategy.at(self.usage_ratio());
     }
 
     pub fn usage_ratio(&self) -> Decimal {
-        if self.deposited_active.is_zero() || self.borrowed.is_zero() {
+        if self.borrow_asset_deposited_active.is_zero() || self.borrow_asset_borrowed.is_zero() {
             Decimal::ZERO
-        } else if self.borrowed >= self.deposited_active {
+        } else if self.borrow_asset_borrowed >= self.borrow_asset_deposited_active {
             Decimal::ONE
         } else {
-            Decimal::from(self.borrowed) / Decimal::from(self.deposited_active)
+            Decimal::from(self.borrow_asset_borrowed)
+                / Decimal::from(self.borrow_asset_deposited_active)
         }
     }
 
+    pub fn set_time_chunk(&mut self, time_chunk: TimeChunk) {
+        self.time_chunk = time_chunk;
+    }
+
+    pub fn set_borrow_asset_deposited_incoming(&mut self, amount: BorrowAssetAmount) {
+        self.borrow_asset_deposited_incoming = amount;
+    }
+
+    pub fn set_yield_distribution(&mut self, amount: BorrowAssetAmount) {
+        self.yield_distribution = amount;
+    }
+
+    pub fn time_chunk(&self) -> &TimeChunk {
+        &self.time_chunk
+    }
+
+    pub fn end_timestamp_ms(&self) -> U64 {
+        self.end_timestamp_ms
+    }
+
+    pub fn borrow_asset_deposited_incoming(&self) -> BorrowAssetAmount {
+        self.borrow_asset_deposited_incoming
+    }
+
+    pub fn collateral_asset_deposited(&self) -> CollateralAssetAmount {
+        self.collateral_asset_deposited
+    }
+
+    pub fn yield_distribution(&self) -> BorrowAssetAmount {
+        self.yield_distribution
+    }
+
     pub fn interest_rate(&self) -> Decimal {
         self.interest_rate
     }
 
-    pub fn deposited_active(&self) -> BorrowAssetAmount {
-        self.deposited_active
+    pub fn borrow_asset_deposited_active(&self) -> BorrowAssetAmount {
+        self.borrow_asset_deposited_active
     }
 
-    pub fn borrowed(&self) -> BorrowAssetAmount {
-        self.borrowed
+    pub fn borrow_asset_borrowed(&self) -> BorrowAssetAmount {
+        self.borrow_asset_borrowed
     }
 }

common/src/supply.rs

@@ -162,9 +162,9 @@ impl<M: Deref<Target = Market>> SupplyPositionRef<M> {
                 amount += u128::from(incoming.amount);
             }
 
-            if !snapshot.deposited_active().is_zero() {
-                accumulated += amount * Decimal::from(snapshot.yield_distribution)
-                    / Decimal::from(snapshot.deposited_active());
+            if !snapshot.borrow_asset_deposited_active.is_zero() {
+                accumulated += amount * Decimal::from(snapshot.yield_distribution())
+                    / Decimal::from(snapshot.borrow_asset_deposited_active);
             }
 
             next_snapshot_index = i as u32 + 1;

contract/market/src/impl_market_external.rs

@@ -292,11 +292,11 @@ impl MarketExternalInterface for Contract {
     }
 
     fn get_last_yield_rate(&self) -> Decimal {
-        let deposited: Decimal = self.current_snapshot.deposited_active().into();
+        let deposited: Decimal = self.current_snapshot.borrow_asset_deposited_active().into();
         if deposited.is_zero() {
             return Decimal::ZERO;
         }
-        let borrowed: Decimal = self.current_snapshot.borrowed().into();
+        let borrowed: Decimal = self.current_snapshot.borrow_asset_borrowed().into();
         let supply_weight: Decimal = self.configuration.yield_weights.supply.get().into();
         let total_weight: Decimal = self.configuration.yield_weights.total_weight().get().into();
 

contract/market/tests/happy_path.rs

@@ -81,9 +81,9 @@ async fn test_happy(#[case] borrow_mt: bool, #[case] collateral_mt: bool) {
 
     let snapshots = c.list_finalized_snapshots(None, None).await;
     assert_eq!(snapshots.len(), 1);
-    assert!(snapshots[0].yield_distribution.is_zero());
-    assert!(snapshots[0].deposited_active().is_zero());
-    assert!(snapshots[0].borrowed().is_zero());
+    assert!(snapshots[0].yield_distribution().is_zero());
+    assert!(snapshots[0].borrow_asset_deposited_active().is_zero());
+    assert!(snapshots[0].borrow_asset_borrowed().is_zero());
 
     // Step 1: Supply user sends tokens to contract to use for borrows.
     c.supply(&supply_user, 1100).await;