Merge pull request #823 from multiversx/interface-hook

example hook impl

Cargo.toml

@@ -21,6 +21,9 @@ members = [
   "dex/pair-mock",
   "dex/pair-mock/meta",
 
+  "dex/sample-hooks/pair-hooks-sample",
+  "dex/sample-hooks/pair-hooks-sample/meta",
+
   "energy-integration/energy-factory-mock",
   "energy-integration/energy-factory-mock/meta",
   "energy-integration/energy-update",

dex/pair/src/pair_actions/add_liq.rs

@@ -79,7 +79,7 @@ pub trait AddLiquidityModule:
             (HookType::BeforeAddLiq, HookType::AfterAddLiq)
         };
         let payments_after_hook =
-            self.call_hook(hook_type_before, caller.clone(), payments_vec, args.clone());
+            self.call_hook(hook_type_before, caller.clone(), payments_vec, args);
         let first_payment = payments_after_hook.get(0);
         let second_payment = payments_after_hook.get(1);
 
@@ -133,7 +133,7 @@ pub trait AddLiquidityModule:
             hook_type_after,
             caller.clone(),
             ManagedVec::from_single_item(lp_payment),
-            args,
+            ManagedVec::new(),
         );
         lp_payment = lp_payment_after_hook.get(0);
 

dex/pair/src/pair_actions/remove_liq.rs

@@ -2,6 +2,7 @@ use crate::{
     contexts::remove_liquidity::RemoveLiquidityContext, pair_hooks::hook_type::HookType,
     StorageCache, SwapTokensOrder, ERROR_BAD_PAYMENT_TOKENS, ERROR_INVALID_ARGS,
     ERROR_K_INVARIANT_FAILED, ERROR_LP_TOKEN_NOT_ISSUED, ERROR_NOT_ACTIVE, ERROR_NOT_WHITELISTED,
+    ERROR_SLIPPAGE_ON_REMOVE,
 };
 
 use super::common_result_types::RemoveLiquidityResultType;
@@ -74,7 +75,7 @@ pub trait RemoveLiquidityModule:
             HookType::BeforeRemoveLiq,
             caller.clone(),
             ManagedVec::from_single_item(payment),
-            args.clone(),
+            ManagedVec::new(),
         );
         let payment = payments_after_hook.get(0);
 
@@ -105,6 +106,17 @@ pub trait RemoveLiquidityModule:
             args,
         );
 
+        let first_payment_after = output_payments_after_hook.get(0);
+        let second_payment_after = output_payments_after_hook.get(1);
+        require!(
+            first_payment_after.amount >= remove_liq_context.first_token_amount_min,
+            ERROR_SLIPPAGE_ON_REMOVE
+        );
+        require!(
+            second_payment_after.amount >= remove_liq_context.second_token_amount_min,
+            ERROR_SLIPPAGE_ON_REMOVE
+        );
+
         self.send_multiple_tokens_if_not_zero(&caller, &output_payments_after_hook);
 
         self.emit_remove_liquidity_event(&storage_cache, remove_liq_context);

dex/pair/src/pair_actions/swap.rs

@@ -127,8 +127,6 @@ pub trait SwapModule:
 
         let mut args = ManagedVec::new();
         self.encode_arg_to_vec(&SwapType::FixedInput, &mut args);
-        self.encode_arg_to_vec(&token_out, &mut args);
-        self.encode_arg_to_vec(&amount_out_min, &mut args);
 
         let payments_after_hook = self.call_hook(
             HookType::BeforeSwap,
@@ -138,6 +136,9 @@ pub trait SwapModule:
         );
         let payment = payments_after_hook.get(0);
 
+        self.encode_arg_to_vec(&token_out, &mut args);
+        self.encode_arg_to_vec(&amount_out_min, &mut args);
+
         let mut swap_context = SwapContext::new(
             payment.token_identifier,
             payment.amount,
@@ -167,6 +168,11 @@ pub trait SwapModule:
         let output_payments_after_hook =
             self.call_hook(HookType::AfterSwap, caller.clone(), output_payments, args);
 
+        require!(
+            output_payments_after_hook.get(0).amount >= swap_context.output_token_amount,
+            ERROR_SLIPPAGE_EXCEEDED
+        );
+
         self.send_multiple_tokens_if_not_zero(&caller, &output_payments_after_hook);
 
         self.emit_swap_event(&storage_cache, swap_context);
@@ -209,8 +215,6 @@ pub trait SwapModule:
 
         let mut args = ManagedVec::new();
         self.encode_arg_to_vec(&SwapType::FixedOutput, &mut args);
-        self.encode_arg_to_vec(&token_out, &mut args);
-        self.encode_arg_to_vec(&amount_out, &mut args);
 
         let payments_after_hook = self.call_hook(
             HookType::BeforeSwap,
@@ -220,6 +224,9 @@ pub trait SwapModule:
         );
         let payment = payments_after_hook.get(0);
 
+        self.encode_arg_to_vec(&token_out, &mut args);
+        self.encode_arg_to_vec(&amount_out, &mut args);
+
         let mut swap_context = SwapContext::new(
             payment.token_identifier,
             payment.amount,

dex/pair/src/pair_hooks/hook_type.rs

@@ -1,3 +1,5 @@
+use crate::pair_actions::swap::SwapType;
+
 multiversx_sc::imports!();
 multiversx_sc::derive_imports!();
 
@@ -21,3 +23,66 @@ pub struct Hook<M: ManagedTypeApi> {
     pub dest_address: ManagedAddress<M>,
     pub endpoint_name: ManagedBuffer<M>,
 }
+
+pub trait PairHook {
+    type Sc: ContractBase;
+
+    fn before_add_initial_liq(
+        sc: &Self::Sc,
+        first_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        second_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    );
+
+    fn after_add_initial_liq(
+        sc: &Self::Sc,
+        lp_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    );
+
+    fn before_add_liq(
+        sc: &Self::Sc,
+        first_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        second_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        first_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+        second_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+    );
+
+    fn after_add_liq(
+        sc: &Self::Sc,
+        lp_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    );
+
+    fn before_remove_liq(
+        sc: &Self::Sc,
+        lp_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    );
+
+    fn after_remove_liq(
+        sc: &Self::Sc,
+        first_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        second_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        first_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+        second_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+    );
+
+    fn before_swap(
+        sc: &Self::Sc,
+        payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        swap_type: SwapType,
+    );
+
+    fn after_swap(
+        sc: &Self::Sc,
+        payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        swap_type: SwapType,
+        token_out: TokenIdentifier<<Self::Sc as ContractBase>::Api>,
+        amount_out: BigUint<<Self::Sc as ContractBase>::Api>,
+    );
+}

dex/sample-hooks/pair-hooks-sample/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "pair-hooks-sample"
+version = "0.0.0"
+authors = ["you"]
+edition = "2021"
+publish = false
+
+[lib]
+path = "src/lib.rs"
+
+[dependencies.multiversx-sc]
+version = "=0.46.1"
+
+[dependencies.pair]
+path = "../../pair"
+
+[dev-dependencies]
+num-bigint = "0.4.2"
+
+[dev-dependencies.multiversx-sc-scenario]
+version = "=0.46.1"

dex/sample-hooks/pair-hooks-sample/meta/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "pair-hooks-sample-meta"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies.pair-hooks-sample]
+path = ".."
+
+[dependencies.multiversx-sc-meta]
+version = "=0.46.1"
+default-features = false

dex/sample-hooks/pair-hooks-sample/meta/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    multiversx_sc_meta::cli_main::<pair_hooks_sample::AbiProvider>();
+}

dex/sample-hooks/pair-hooks-sample/multiversx.json

@@ -0,0 +1,3 @@
+{
+    "language": "rust"
+}

dex/sample-hooks/pair-hooks-sample/src/lib.rs

@@ -0,0 +1,140 @@
+#![no_std]
+
+use core::marker::PhantomData;
+
+use pair::pair_hooks::hook_type::PairHook;
+
+multiversx_sc::imports!();
+
+#[multiversx_sc::contract]
+pub trait PairHooksSample {
+    #[init]
+    fn init(&self, known_pairs: MultiValueEncoded<ManagedAddress>) {
+        let mapper = self.known_pairs();
+        for pair in known_pairs {
+            mapper.add(&pair);
+        }
+    }
+
+    #[payable("*")]
+    #[endpoint(beforeAddInitialLiqHook)]
+    fn before_add_initial_liq_hook(&self, original_caller: ManagedAddress) {
+        self.require_known_pair();
+
+        let [first_payment, second_payment] = self.call_value().multi_esdt();
+        Wrapper::<Self>::before_add_initial_liq(
+            self,
+            first_payment,
+            second_payment,
+            original_caller,
+        );
+    }
+
+    #[payable("*")]
+    #[endpoint(afterAddInitialLiqHook)]
+    fn after_add_initial_liq_hook(&self, original_caller: ManagedAddress) {
+        self.require_known_pair();
+
+        let lp_payment = self.call_value().single_esdt();
+        Wrapper::<Self>::after_add_initial_liq(self, lp_payment, original_caller);
+    }
+
+    fn require_known_pair(&self) {
+        let caller = self.blockchain().get_caller();
+        require!(
+            self.known_pairs().contains(&caller),
+            "Only known pairs may call this endpoint"
+        );
+    }
+
+    #[storage_mapper("knownPairs")]
+    fn known_pairs(&self) -> WhitelistMapper<ManagedAddress>;
+}
+
+pub struct Wrapper<T: PairHooksSample> {
+    _phantom: PhantomData<T>,
+}
+
+impl<T: PairHooksSample> PairHook for Wrapper<T> {
+    type Sc = T;
+
+    fn before_add_initial_liq(
+        sc: &Self::Sc,
+        first_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        second_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    ) {
+        let caller = sc.blockchain().get_caller();
+        sc.send()
+            .direct_non_zero_esdt_payment(&caller, &first_payment);
+        sc.send()
+            .direct_non_zero_esdt_payment(&caller, &second_payment);
+    }
+
+    fn after_add_initial_liq(
+        sc: &Self::Sc,
+        lp_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    ) {
+        let caller = sc.blockchain().get_caller();
+        sc.send().direct_non_zero_esdt_payment(&caller, &lp_payment);
+    }
+
+    fn before_add_liq(
+        _sc: &Self::Sc,
+        _first_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _second_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        _first_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+        _second_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+    ) {
+        todo!()
+    }
+
+    fn after_add_liq(
+        _sc: &Self::Sc,
+        _lp_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    ) {
+        todo!()
+    }
+
+    fn before_remove_liq(
+        _sc: &Self::Sc,
+        _lp_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+    ) {
+        todo!()
+    }
+
+    fn after_remove_liq(
+        _sc: &Self::Sc,
+        _first_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _second_payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        _first_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+        _second_token_amount_min: BigUint<<Self::Sc as ContractBase>::Api>,
+    ) {
+        todo!()
+    }
+
+    fn before_swap(
+        _sc: &Self::Sc,
+        _payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        _swap_type: pair::pair_actions::swap::SwapType,
+    ) {
+        todo!()
+    }
+
+    fn after_swap(
+        _sc: &Self::Sc,
+        _payment: EsdtTokenPayment<<Self::Sc as ContractBase>::Api>,
+        _original_caller: ManagedAddress<<Self::Sc as ContractBase>::Api>,
+        _swap_type: pair::pair_actions::swap::SwapType,
+        _token_out: TokenIdentifier<<Self::Sc as ContractBase>::Api>,
+        _amount_out: BigUint<<Self::Sc as ContractBase>::Api>,
+    ) {
+        todo!()
+    }
+}