Merge pull request #818 from multiversx/hooks

hooks definition

common/modules/utils/src/lib.rs

@@ -126,4 +126,8 @@ pub trait UtilsModule {
             "Invalid SC address"
         );
     }
+
+    fn require_not_empty_buffer(&self, buffer: &ManagedBuffer) {
+        require!(!buffer.is_empty(), "Empty buffer");
+    }
 }

dex/pair/Cargo.toml

@@ -29,6 +29,9 @@ path = "../../locked-asset/simple-lock"
 [dependencies.fees-collector]
 path = "../../energy-integration/fees-collector"
 
+[dependencies.utils]
+path = "../../common/modules/utils"
+
 [dependencies.itertools]
 version = "0.10.1"
 default-features = false

dex/pair/src/lib.rs

@@ -12,6 +12,7 @@ pub mod fee;
 mod liquidity_pool;
 pub mod locking_wrapper;
 pub mod pair_actions;
+pub mod pair_hooks;
 pub mod safe_price;
 pub mod safe_price_view;
 
@@ -45,6 +46,10 @@ pub trait Pair<ContractReader>:
     + pair_actions::swap::SwapModule
     + pair_actions::views::ViewsModule
     + pair_actions::common_methods::CommonMethodsModule
+    + pair_hooks::banned_address::BannedAddressModule
+    + pair_hooks::change_hooks::ChangeHooksModule
+    + pair_hooks::call_hook::CallHookModule
+    + utils::UtilsModule
 {
     #[init]
     fn init(
@@ -96,6 +101,9 @@ pub trait Pair<ContractReader>:
             );
             self.add_permissions_for_all(admins, Permissions::ADMIN);
         };
+
+        let sc_address = self.blockchain().get_sc_address();
+        self.banned_addresses().add(&sc_address);
     }
 
     #[endpoint]

dex/pair/src/pair_hooks/banned_address.rs

@@ -0,0 +1,34 @@
+multiversx_sc::imports!();
+
+#[multiversx_sc::module]
+pub trait BannedAddressModule: permissions_module::PermissionsModule {
+    #[endpoint(addBannedAddress)]
+    fn add_banned_address(&self, addresses: MultiValueEncoded<ManagedAddress>) {
+        self.require_caller_has_owner_or_admin_permissions();
+
+        let mapper = self.banned_addresses();
+        for address in addresses {
+            mapper.add(&address);
+        }
+    }
+
+    #[endpoint(removeBannedAddress)]
+    fn remove_banned_address(&self, addresses: MultiValueEncoded<ManagedAddress>) {
+        self.require_caller_has_owner_or_admin_permissions();
+
+        let mapper = self.banned_addresses();
+        for address in addresses {
+            mapper.remove(&address);
+        }
+    }
+
+    fn require_not_banned_address(&self, address: &ManagedAddress) {
+        require!(
+            !self.banned_addresses().contains(address),
+            "Cannot add hook for this address"
+        );
+    }
+
+    #[storage_mapper("bannedAddresses")]
+    fn banned_addresses(&self) -> WhitelistMapper<ManagedAddress>;
+}

dex/pair/src/pair_hooks/call_hook.rs

@@ -0,0 +1,47 @@
+use common_structs::PaymentsVec;
+
+use super::hook_type::{Hook, HookType};
+
+multiversx_sc::imports!();
+
+#[multiversx_sc::module]
+pub trait CallHookModule {
+    fn call_hook(
+        &self,
+        hook_type: HookType,
+        caller: ManagedAddress,
+        input_payments: PaymentsVec<Self::Api>,
+        args: ManagedVec<ManagedBuffer>,
+    ) -> PaymentsVec<Self::Api> {
+        let hooks = self.hooks(hook_type).get();
+        if hooks.is_empty() {
+            return input_payments;
+        }
+
+        let mut call_args = ManagedArgBuffer::new();
+        call_args.push_arg(caller);
+
+        for arg in &args {
+            call_args.push_arg(arg);
+        }
+
+        let mut output_payments = input_payments;
+        for hook in &hooks {
+            let (_, back_transfers) =
+                ContractCallNoPayment::<_, MultiValueEncoded<ManagedBuffer>>::new(
+                    hook.dest_address,
+                    hook.endpoint_name,
+                )
+                .with_raw_arguments(call_args.clone())
+                .with_multi_token_transfer(output_payments)
+                .execute_on_dest_context_with_back_transfers::<MultiValueEncoded<ManagedBuffer>>();
+
+            output_payments = back_transfers.esdt_payments;
+        }
+
+        output_payments
+    }
+
+    #[storage_mapper("hooks")]
+    fn hooks(&self, hook_type: HookType) -> SingleValueMapper<ManagedVec<Hook<Self::Api>>>;
+}

dex/pair/src/pair_hooks/change_hooks.rs

@@ -0,0 +1,43 @@
+use super::hook_type::{Hook, HookType};
+
+multiversx_sc::imports!();
+
+#[multiversx_sc::module]
+pub trait ChangeHooksModule:
+    super::call_hook::CallHookModule
+    + super::banned_address::BannedAddressModule
+    + permissions_module::PermissionsModule
+    + utils::UtilsModule
+{
+    #[endpoint(addHook)]
+    fn add_hook(&self, hook_type: HookType, to: ManagedAddress, endpoint_name: ManagedBuffer) {
+        self.require_caller_has_owner_or_admin_permissions();
+        self.require_not_banned_address(&to);
+        self.require_sc_address(&to);
+        self.require_not_empty_buffer(&endpoint_name);
+
+        self.hooks(hook_type).update(|hooks| {
+            hooks.push(Hook {
+                dest_address: to,
+                endpoint_name,
+            })
+        });
+    }
+
+    #[endpoint(removeHook)]
+    fn remove_hook(&self, hook_type: HookType, to: ManagedAddress, endpoint_name: ManagedBuffer) {
+        self.require_caller_has_owner_or_admin_permissions();
+
+        self.hooks(hook_type).update(|hooks| {
+            let opt_index = hooks.find(&Hook {
+                dest_address: to,
+                endpoint_name,
+            });
+
+            require!(opt_index.is_some(), "Item not found");
+
+            let index = unsafe { opt_index.unwrap_unchecked() };
+            hooks.remove(index);
+        })
+    }
+}

dex/pair/src/pair_hooks/hook_type.rs

@@ -0,0 +1,23 @@
+multiversx_sc::imports!();
+multiversx_sc::derive_imports!();
+
+#[derive(TypeAbi, TopEncode, TopDecode, NestedEncode, NestedDecode, Clone, Copy)]
+pub enum HookType {
+    // can't be done, execute_on_dest does not work on init
+    _BeforeInitialize,
+    _AfterInitialize,
+    BeforeAddInitialLiq,
+    AfterAddInitialLiq,
+    BeforeAddLiq,
+    AfterAddLiq,
+    BeforeRemoveLiq,
+    AfterRemoveLiq,
+    BeforeSwap,
+    AfterSwap,
+}
+
+#[derive(TypeAbi, TopEncode, TopDecode, NestedEncode, NestedDecode, ManagedVecItem, PartialEq)]
+pub struct Hook<M: ManagedTypeApi> {
+    pub dest_address: ManagedAddress<M>,
+    pub endpoint_name: ManagedBuffer<M>,
+}

dex/pair/src/pair_hooks/mod.rs

@@ -0,0 +1,4 @@
+pub mod banned_address;
+pub mod call_hook;
+pub mod change_hooks;
+pub mod hook_type;

dex/pair/wasm-pair-full/src/lib.rs

@@ -5,9 +5,9 @@
 ////////////////////////////////////////////////////
 
 // Init:                                 1
-// Endpoints:                           64
+// Endpoints:                           68
 // Async Callback (empty):               1
-// Total number of exported functions:  66
+// Total number of exported functions:  70
 
 #![no_std]
 #![allow(internal_features)]
@@ -75,6 +75,10 @@ multiversx_sc_wasm_adapter::endpoints! {
         getAmountOut => get_amount_out_view
         getAmountIn => get_amount_in_view
         getEquivalent => get_equivalent
+        addBannedAddress => add_banned_address
+        removeBannedAddress => remove_banned_address
+        addHook => add_hook
+        removeHook => remove_hook
         getLpTokensSafePriceByDefaultOffset => get_lp_tokens_safe_price_by_default_offset
         getLpTokensSafePriceByRoundOffset => get_lp_tokens_safe_price_by_round_offset
         getLpTokensSafePriceByTimestampOffset => get_lp_tokens_safe_price_by_timestamp_offset

dex/pair/wasm/src/lib.rs

@@ -5,9 +5,9 @@
 ////////////////////////////////////////////////////
 
 // Init:                                 1
-// Endpoints:                           55
+// Endpoints:                           59
 // Async Callback (empty):               1
-// Total number of exported functions:  57
+// Total number of exported functions:  61
 
 #![no_std]
 #![allow(internal_features)]
@@ -75,6 +75,10 @@ multiversx_sc_wasm_adapter::endpoints! {
         getAmountOut => get_amount_out_view
         getAmountIn => get_amount_in_view
         getEquivalent => get_equivalent
+        addBannedAddress => add_banned_address
+        removeBannedAddress => remove_banned_address
+        addHook => add_hook
+        removeHook => remove_hook
     )
 }