deposit limit implementation rebased

Author: DaSichuan

token-lending/program/src/instruction.rs

@@ -408,7 +408,8 @@ impl LendingInstruction {
                 let (max_borrow_rate, rest) = Self::unpack_u8(rest)?;
                 let (borrow_fee_wad, rest) = Self::unpack_u64(rest)?;
                 let (flash_loan_fee_wad, rest) = Self::unpack_u64(rest)?;
-                let (host_fee_percentage, _rest) = Self::unpack_u8(rest)?;
+                let (host_fee_percentage, rest) = Self::unpack_u8(rest)?;
+                let (deposit_limit, _) = Self::unpack_u64(rest)?;
                 Self::InitReserve {
                     liquidity_amount,
                     config: ReserveConfig {
@@ -424,6 +425,7 @@ impl LendingInstruction {
                             flash_loan_fee_wad,
                             host_fee_percentage,
                         },
+                        deposit_limit,
                     },
                 }
             }
@@ -481,6 +483,7 @@ impl LendingInstruction {
                 let (borrow_fee_wad, _rest) = Self::unpack_u64(_rest)?;
                 let (flash_loan_fee_wad, _rest) = Self::unpack_u64(_rest)?;
                 let (host_fee_percentage, _rest) = Self::unpack_u8(_rest)?;
+                let (deposit_limit, _rest) = Self::unpack_u64(_rest)?;
 
                 Self::UpdateReserveConfig {
                     config: ReserveConfig {
@@ -496,6 +499,7 @@ impl LendingInstruction {
                             flash_loan_fee_wad,
                             host_fee_percentage,
                         },
+                        deposit_limit,
                     },
                 }
             }
@@ -591,6 +595,7 @@ impl LendingInstruction {
                                 flash_loan_fee_wad,
                                 host_fee_percentage,
                             },
+                        deposit_limit,
                     },
             } => {
                 buf.push(2);
@@ -605,6 +610,7 @@ impl LendingInstruction {
                 buf.extend_from_slice(&borrow_fee_wad.to_le_bytes());
                 buf.extend_from_slice(&flash_loan_fee_wad.to_le_bytes());
                 buf.extend_from_slice(&host_fee_percentage.to_le_bytes());
+                buf.extend_from_slice(&deposit_limit.to_le_bytes());
             }
             Self::RefreshReserve => {
                 buf.push(3);
@@ -667,6 +673,7 @@ impl LendingInstruction {
                 buf.extend_from_slice(&config.fees.borrow_fee_wad.to_le_bytes());
                 buf.extend_from_slice(&config.fees.flash_loan_fee_wad.to_le_bytes());
                 buf.extend_from_slice(&config.fees.host_fee_percentage.to_le_bytes());
+                buf.extend_from_slice(&config.deposit_limit.to_le_bytes());
             }
         }
         buf

token-lending/program/src/processor.rs

@@ -560,6 +560,15 @@ fn _deposit_reserve_liquidity<'a>(
         return Err(LendingError::InvalidMarketAuthority.into());
     }
 
+    if Decimal::from(liquidity_amount)
+        .try_add(reserve.liquidity.total_supply()?)?
+        .try_floor_u64()?
+        > reserve.config.deposit_limit
+    {
+        msg!("Cannot deposit liquidity above the reserve deposit limit");
+        return Err(LendingError::InvalidAmount.into());
+    }
+
     let collateral_amount = reserve.deposit_liquidity(liquidity_amount)?;
     reserve.last_update.mark_stale();
     Reserve::pack(reserve, &mut reserve_info.data.borrow_mut())?;

token-lending/program/src/state/reserve.rs

@@ -611,6 +611,8 @@ pub struct ReserveConfig {
     pub max_borrow_rate: u8,
     /// Program owner fees assessed, separate from gains due to interest accrual
     pub fees: ReserveFees,
+    /// Maximum deposit limit of liquidity in native units, u64::MAX for inf
+    pub deposit_limit: u64,
 }
 
 /// Additional fee information on a reserve
@@ -717,7 +719,7 @@ impl IsInitialized for Reserve {
     }
 }
 
-const RESERVE_LEN: usize = 603; // 1 + 8 + 1 + 32 + 32 + 1 + 32 + 32 + 32 + 32 + 8 + 16 + 16 + 16 + 32 + 8 + 32 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 8 + 8 + 1 + 248
+const RESERVE_LEN: usize = 611; // 1 + 8 + 1 + 32 + 32 + 1 + 32 + 32 + 32 + 32 + 8 + 16 + 16 + 16 + 32 + 8 + 32 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 8 + 8 + 1 + 8 + 248
 impl Pack for Reserve {
     const LEN: usize = RESERVE_LEN;
 
@@ -753,6 +755,7 @@ impl Pack for Reserve {
             config_fees_borrow_fee_wad,
             config_fees_flash_loan_fee_wad,
             config_fees_host_fee_percentage,
+            config_deposit_limit,
             _padding,
         ) = mut_array_refs![
             output,
@@ -783,6 +786,7 @@ impl Pack for Reserve {
             8,
             8,
             1,
+            8,
             248
         ];
 
@@ -827,6 +831,7 @@ impl Pack for Reserve {
         *config_fees_borrow_fee_wad = self.config.fees.borrow_fee_wad.to_le_bytes();
         *config_fees_flash_loan_fee_wad = self.config.fees.flash_loan_fee_wad.to_le_bytes();
         *config_fees_host_fee_percentage = self.config.fees.host_fee_percentage.to_le_bytes();
+        *config_deposit_limit = self.config.deposit_limit.to_le_bytes();
     }
 
     /// Unpacks a byte buffer into a [ReserveInfo](struct.ReserveInfo.html).
@@ -861,6 +866,7 @@ impl Pack for Reserve {
             config_fees_borrow_fee_wad,
             config_fees_flash_loan_fee_wad,
             config_fees_host_fee_percentage,
+            config_deposit_limit,
             _padding,
         ) = array_refs![
             input,
@@ -891,6 +897,7 @@ impl Pack for Reserve {
             8,
             8,
             1,
+            8,
             248
         ];
 
@@ -939,6 +946,7 @@ impl Pack for Reserve {
                     flash_loan_fee_wad: u64::from_le_bytes(*config_fees_flash_loan_fee_wad),
                     host_fee_percentage: u8::from_le_bytes(*config_fees_host_fee_percentage),
                 },
+                deposit_limit: u64::from_le_bytes(*config_deposit_limit),
             },
         })
     }

token-lending/program/tests/deposit_reserve_liquidity.rs

@@ -16,7 +16,7 @@ async fn test_success() {
     );
 
     // limit to track compute unit increase
-    test.set_bpf_compute_max_units(27_000);
+    test.set_bpf_compute_max_units(30_000);
 
     let user_accounts_owner = Keypair::new();
     let lending_market = add_lending_market(&mut test);

token-lending/program/tests/helpers/mod.rs

@@ -54,6 +54,7 @@ pub const TEST_RESERVE_CONFIG: ReserveConfig = ReserveConfig {
         flash_loan_fee_wad: 3_000_000_000_000_000,
         host_fee_percentage: 20,
     },
+    deposit_limit: 100_000_000_000,
 };
 
 pub const SOL_PYTH_PRODUCT: &str = "3Mnn2fX6rQyUsyELYms1sBJyChWofzSNRoqYzvgMVz5E";
@@ -883,7 +884,6 @@ impl TestReserve {
             ],
             Some(&payer.pubkey()),
         );
-
         let recent_blockhash = banks_client.get_recent_blockhash().await.unwrap();
         transaction.sign(
             &vec![
@@ -901,16 +901,15 @@ impl TestReserve {
             ],
             recent_blockhash,
         );
-
         banks_client
             .process_transaction(transaction)
             .await
             .map(|_| Self {
-                name,
+                name: name,
                 pubkey: reserve_pubkey,
                 lending_market_pubkey: lending_market.pubkey,
-                config,
-                liquidity_mint_pubkey,
+                config: config,
+                liquidity_mint_pubkey: liquidity_mint_pubkey,
                 liquidity_mint_decimals: liquidity_mint.decimals,
                 liquidity_supply_pubkey: liquidity_supply_keypair.pubkey(),
                 liquidity_fee_receiver_pubkey: liquidity_fee_receiver_keypair.pubkey(),
@@ -919,7 +918,7 @@ impl TestReserve {
                 liquidity_switchboard_oracle_pubkey: oracle.switchboard_feed_pubkey,
                 collateral_mint_pubkey: collateral_mint_keypair.pubkey(),
                 collateral_supply_pubkey: collateral_supply_keypair.pubkey(),
-                user_liquidity_pubkey,
+                user_liquidity_pubkey: user_liquidity_pubkey,
                 user_collateral_pubkey: user_collateral_token_keypair.pubkey(),
                 market_price: oracle.price,
             })

token-lending/program/tests/init_reserve.rs

@@ -313,6 +313,7 @@ async fn test_update_reserve_config() {
         min_borrow_rate: 1,
         optimal_borrow_rate: 5,
         max_borrow_rate: 45,
+        deposit_limit: 1_000_000,
         fees: ReserveFees {
             borrow_fee_wad: 200_000_000_000,
             flash_loan_fee_wad: 5_000_000_000_000_000,