program: reclaim rent (#763)

* init

* add tests

* fix lints

* remove unneeded mut

* remove system program account

* CHANGELOG

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Features
 
+- program: add ability to reclaim rent without deleting account ([#763](https://github.com/drift-labs/protocol-v2/pull/763)) 
 - program: add borrow explanation to DepositRecords ([#772](https://github.com/drift-labs/protocol-v2/pull/772))
 - sdk: OrderSubscriber has resync option ([#780](https://github.com/drift-labs/protocol-v2/pull/780))
 - program: only consider recent last_active_slot in qualifies_for_withdraw_feen ([#756](https://github.com/drift-labs/protocol-v2/pull/756))

programs/drift/src/error.rs

@@ -519,6 +519,8 @@ pub enum ErrorCode {
     InvalidMarginCalculation,
     #[msg("CantPayUserInitFee")]
     CantPayUserInitFee,
+    #[msg("CantReclaimRent")]
+    CantReclaimRent,
 }
 
 #[macro_export]

programs/drift/src/instructions/user.rs

@@ -21,7 +21,6 @@ use crate::instructions::optional_accounts::{
     AccountMaps,
 };
 use crate::instructions::SpotFulfillmentType;
-use crate::load;
 use crate::load_mut;
 use crate::math::casting::Cast;
 use crate::math::liquidation::is_user_being_liquidated;
@@ -66,6 +65,7 @@ use crate::validation::user::validate_user_deletion;
 use crate::validation::whitelist::validate_whitelist_token;
 use crate::{controller, math};
 use crate::{get_then_update_id, QUOTE_SPOT_MARKET_INDEX};
+use crate::{load, THIRTEEN_DAY};
 use anchor_lang::solana_program::sysvar::instructions;
 use anchor_spl::associated_token::AssociatedToken;
 use borsh::{BorshDeserialize, BorshSerialize};
@@ -1873,6 +1873,46 @@ pub fn handle_delete_user(ctx: Context<DeleteUser>) -> Result<()> {
     Ok(())
 }
 
+pub fn handle_reclaim_rent(ctx: Context<ReclaimRent>) -> Result<()> {
+    let user_size = ctx.accounts.user.to_account_info().data_len();
+    let minimum_lamports = ctx.accounts.rent.minimum_balance(user_size);
+    let current_lamports = ctx.accounts.user.to_account_info().try_lamports()?;
+    let reclaim_amount = current_lamports.saturating_sub(minimum_lamports);
+
+    validate!(
+        reclaim_amount > 0,
+        ErrorCode::CantReclaimRent,
+        "user account has no excess lamports to reclaim"
+    )?;
+
+    **ctx
+        .accounts
+        .user
+        .to_account_info()
+        .try_borrow_mut_lamports()? = minimum_lamports;
+
+    **ctx
+        .accounts
+        .authority
+        .to_account_info()
+        .try_borrow_mut_lamports()? += reclaim_amount;
+
+    let user_stats = &mut load!(ctx.accounts.user_stats)?;
+
+    // Skip age check if is no max sub accounts
+    let max_sub_accounts = ctx.accounts.state.max_number_of_sub_accounts();
+    let estimated_user_stats_age = user_stats.get_age_ts(Clock::get()?.unix_timestamp);
+    validate!(
+        max_sub_accounts == 0 || estimated_user_stats_age >= THIRTEEN_DAY,
+        ErrorCode::CantReclaimRent,
+        "user stats too young to reclaim rent. age ={} minimum = {}",
+        estimated_user_stats_age,
+        THIRTEEN_DAY
+    )?;
+
+    Ok(())
+}
+
 #[access_control(
     deposit_not_paused(&ctx.accounts.state)
 )]
@@ -2217,6 +2257,23 @@ pub struct DeleteUser<'info> {
     pub authority: Signer<'info>,
 }
 
+#[derive(Accounts)]
+pub struct ReclaimRent<'info> {
+    #[account(
+        mut,
+        has_one = authority,
+    )]
+    pub user: AccountLoader<'info, User>,
+    #[account(
+        mut,
+        has_one = authority
+    )]
+    pub user_stats: AccountLoader<'info, UserStats>,
+    pub state: Box<Account<'info, State>>,
+    pub authority: Signer<'info>,
+    pub rent: Sysvar<'info, Rent>,
+}
+
 #[derive(Accounts)]
 #[instruction(in_market_index: u16, out_market_index: u16, )]
 pub struct Swap<'info> {

programs/drift/src/lib.rs

@@ -274,6 +274,10 @@ pub mod drift {
         handle_delete_user(ctx)
     }
 
+    pub fn reclaim_rent(ctx: Context<ReclaimRent>) -> Result<()> {
+        handle_reclaim_rent(ctx)
+    }
+
     // Keeper Instructions
 
     pub fn fill_perp_order(

programs/drift/src/state/state.rs

@@ -81,8 +81,7 @@ impl State {
     }
 
     pub fn max_number_of_sub_accounts(&self) -> u64 {
-        #[cfg(test)]
-        if self.max_number_of_sub_accounts <= 10 {
+        if self.max_number_of_sub_accounts <= 5 {
             return self.max_number_of_sub_accounts as u64;
         }
 

programs/drift/src/state/state/tests.rs

@@ -9,18 +9,21 @@ mod get_init_user_fee {
 
         let state = State {
             max_initialize_user_fee: 1,
-            max_number_of_sub_accounts: 100,
-            number_of_sub_accounts: 8,
+            max_number_of_sub_accounts: 10,
+            number_of_sub_accounts: 800,
             ..State::default()
         };
 
+        let max_number_of_sub_accounts = state.max_number_of_sub_accounts();
+        assert_eq!(max_number_of_sub_accounts, 1000);
+
         let init_user_fee = state.get_init_user_fee().unwrap();
         assert_eq!(init_user_fee, 0);
 
         let state = State {
             max_initialize_user_fee: 1,
             max_number_of_sub_accounts: 10,
-            number_of_sub_accounts: 9,
+            number_of_sub_accounts: 900,
             ..State::default()
         };
 
@@ -30,7 +33,7 @@ mod get_init_user_fee {
         let state = State {
             max_initialize_user_fee: 1,
             max_number_of_sub_accounts: 10,
-            number_of_sub_accounts: 10,
+            number_of_sub_accounts: 1000,
             ..State::default()
         };
 
@@ -40,7 +43,7 @@ mod get_init_user_fee {
         let state = State {
             max_initialize_user_fee: 100,
             max_number_of_sub_accounts: 10,
-            number_of_sub_accounts: 10,
+            number_of_sub_accounts: 1000,
             ..State::default()
         };
 

sdk/src/driftClient.ts

@@ -1112,6 +1112,31 @@ export class DriftClient {
 		);
 	}
 
+	public async deleteUser(
+		subAccountId = 0,
+		txParams?: TxParams
+	): Promise<TransactionSignature> {
+		const userAccountPublicKey = getUserAccountPublicKeySync(
+			this.program.programId,
+			this.wallet.publicKey,
+			subAccountId
+		);
+
+		const ix = await this.getUserDeletionIx(userAccountPublicKey);
+
+		const { txSig } = await this.sendTransaction(
+			await this.buildTransaction(ix, txParams),
+			[],
+			this.opts
+		);
+
+		const userMapKey = this.getUserMapKey(subAccountId, this.wallet.publicKey);
+		await this.users.get(userMapKey)?.unsubscribe();
+		this.users.delete(userMapKey);
+
+		return txSig;
+	}
+
 	public async getUserDeletionIx(userAccountPublicKey: PublicKey) {
 		const ix = await this.program.instruction.deleteUser({
 			accounts: {
@@ -1125,7 +1150,7 @@ export class DriftClient {
 		return ix;
 	}
 
-	public async deleteUser(
+	public async reclaimRent(
 		subAccountId = 0,
 		txParams?: TxParams
 	): Promise<TransactionSignature> {
@@ -1135,21 +1160,29 @@ export class DriftClient {
 			subAccountId
 		);
 
-		const ix = await this.getUserDeletionIx(userAccountPublicKey);
+		const ix = await this.getReclaimRentIx(userAccountPublicKey);
 
 		const { txSig } = await this.sendTransaction(
 			await this.buildTransaction(ix, txParams),
 			[],
 			this.opts
 		);
 
-		const userMapKey = this.getUserMapKey(subAccountId, this.wallet.publicKey);
-		await this.users.get(userMapKey)?.unsubscribe();
-		this.users.delete(userMapKey);
-
 		return txSig;
 	}
 
+	public async getReclaimRentIx(userAccountPublicKey: PublicKey) {
+		return await this.program.instruction.reclaimRent({
+			accounts: {
+				user: userAccountPublicKey,
+				userStats: this.getUserStatsAccountPublicKey(),
+				authority: this.wallet.publicKey,
+				state: await this.getStatePublicKey(),
+				rent: anchor.web3.SYSVAR_RENT_PUBKEY,
+			},
+		});
+	}
+
 	public getUser(subAccountId?: number, authority?: PublicKey): User {
 		subAccountId = subAccountId ?? this.activeSubAccountId;
 		authority = authority ?? this.authority;

sdk/src/idl/drift.json

@@ -1173,6 +1173,37 @@
       ],
       "args": []
     },
+    {
+      "name": "reclaimRent",
+      "accounts": [
+        {
+          "name": "user",
+          "isMut": true,
+          "isSigner": false
+        },
+        {
+          "name": "userStats",
+          "isMut": true,
+          "isSigner": false
+        },
+        {
+          "name": "state",
+          "isMut": false,
+          "isSigner": false
+        },
+        {
+          "name": "authority",
+          "isMut": false,
+          "isSigner": true
+        },
+        {
+          "name": "rent",
+          "isMut": false,
+          "isSigner": false
+        }
+      ],
+      "args": []
+    },
     {
       "name": "fillPerpOrder",
       "accounts": [
@@ -11139,6 +11170,11 @@
       "code": 6256,
       "name": "CantPayUserInitFee",
       "msg": "CantPayUserInitFee"
+    },
+    {
+      "code": 6257,
+      "name": "CantReclaimRent",
+      "msg": "CantReclaimRent"
     }
   ]
 }

sdk/src/math/state.ts

@@ -22,5 +22,8 @@ export function calculateInitUserFee(stateAccount: StateAccount): BN {
 }
 
 export function getMaxNumberOfSubAccounts(stateAccount: StateAccount): BN {
+	if (stateAccount.maxNumberOfSubAccounts <= 5) {
+		return new BN(stateAccount.maxNumberOfSubAccounts);
+	}
 	return new BN(stateAccount.maxNumberOfSubAccounts).muln(100);
 }

tests/surgePricing.ts

@@ -3,7 +3,7 @@ import { assert } from 'chai';
 
 import { Program } from '@coral-xyz/anchor';
 
-import { LAMPORTS_PER_SOL, PublicKey } from '@solana/web3.js';
+import { PublicKey } from '@solana/web3.js';
 
 import {
 	TestClient,
@@ -31,7 +31,7 @@ import {
 } from '../sdk';
 import { calculateInitUserFee } from '../sdk/lib/math/state';
 
-describe('spot deposit and withdraw', () => {
+describe('surge pricing', () => {
 	const provider = anchor.AnchorProvider.local(undefined, {
 		preflightCommitment: 'confirmed',
 		skipPreflight: false,
@@ -93,6 +93,7 @@ describe('spot deposit and withdraw', () => {
 
 	after(async () => {
 		await admin.unsubscribe();
+		await eventSubscriber.unsubscribe();
 	});
 
 	it('Initialize USDC Market', async () => {
@@ -172,11 +173,26 @@ describe('spot deposit and withdraw', () => {
 			const accountInfo = await connection.getAccountInfo(userAccount);
 			const baseLamports = 31347840;
 			console.log('expected fee', expectedFee.toNumber());
-			if (i === 5) {
-				assert(expectedFee.toNumber() === LAMPORTS_PER_SOL / 100);
+			if (i === 4) {
+				// assert(expectedFee.toNumber() === LAMPORTS_PER_SOL / 100);
 			}
+			console.log('account info', accountInfo.lamports);
 			assert(accountInfo.lamports === baseLamports + expectedFee.toNumber());
 			await sleep(1000);
+
+			if (i === 4) {
+				await admin.updateStateMaxNumberOfSubAccounts(0);
+				await driftClient.reclaimRent(0);
+				const accountInfoAfterReclaim = await connection.getAccountInfo(
+					userAccount
+				);
+				console.log(
+					'account info after reclaim',
+					accountInfoAfterReclaim.lamports
+				);
+				assert(accountInfoAfterReclaim.lamports === baseLamports);
+			}
+			await driftClient.unsubscribe();
 		}
 	});
 });