EthConnector: add view function to check whether the proof is used.

src/connector.rs

@@ -8,7 +8,7 @@ use crate::deposit_event::*;
 use crate::engine::Engine;
 use crate::json::parse_json;
 use crate::prelude::*;
-use crate::prover::validate_eth_address;
+use crate::prover::{validate_eth_address, Proof};
 use crate::storage::{self, EthConnectorStorageId, KeyPrefix};
 #[cfg(feature = "log")]
 use alloc::format;
@@ -181,7 +181,6 @@ impl EthConnectorContract {
     pub fn deposit(&self) {
         self.assert_not_paused(PAUSE_DEPOSIT);
 
-        use crate::prover::Proof;
         #[cfg(feature = "log")]
         sdk::log("[Deposit tokens]");
 
@@ -643,6 +642,11 @@ impl EthConnectorContract {
         sdk::storage_has_key(&self.used_event_key(key))
     }
 
+    /// Checks whether the provided proof was already used
+    pub fn is_used_proof(&self, proof: Proof) -> bool {
+        self.check_used_event(&proof.get_key())
+    }
+
     /// Get Eth connector paused flags
     pub fn get_paused_flags(&self) -> PausedMask {
         self.get_paused()

src/lib.rs

@@ -86,8 +86,9 @@ mod contract {
     #[cfg(feature = "evm_bully")]
     use crate::parameters::{BeginBlockArgs, BeginChainArgs};
     use crate::parameters::{
-        ExpectUtf8, FunctionCallArgs, GetStorageAtArgs, InitCallArgs, NewCallArgs,
-        PauseEthConnectorCallArgs, SetContractDataCallArgs, TransferCallCallArgs, ViewCallArgs,
+        ExpectUtf8, FunctionCallArgs, GetStorageAtArgs, InitCallArgs, IsUsedProofCallArgs,
+        NewCallArgs, PauseEthConnectorCallArgs, SetContractDataCallArgs, TransferCallCallArgs,
+        ViewCallArgs,
     };
     use crate::prelude::{Address, H256, U256};
     use crate::sdk;
@@ -401,6 +402,15 @@ mod contract {
         EthConnectorContract::get_instance().finish_deposit_near();
     }
 
+    #[no_mangle]
+    pub extern "C" fn is_used_proof() {
+        let args = IsUsedProofCallArgs::try_from_slice(&sdk::read_input()).expect(ERR_FAILED_PARSE);
+
+        let is_used_proof = EthConnectorContract::get_instance().is_used_proof(args.proof);
+        let res = is_used_proof.try_to_vec().unwrap();
+        sdk::return_output(&res[..]);
+    }
+
     #[no_mangle]
     pub extern "C" fn ft_total_supply() {
         EthConnectorContract::get_instance().ft_total_supply();

src/parameters.rs

@@ -145,6 +145,14 @@ pub struct DepositCallArgs {
     pub relayer_eth_account: Option<EthAddress>,
 }
 
+/// Eth-connector isUsedProof arguments
+#[cfg(feature = "engine")]
+#[derive(BorshSerialize, BorshDeserialize)]
+pub struct IsUsedProofCallArgs {
+    /// Proof data
+    pub proof: Proof,
+}
+
 /// withdraw result for eth-connector
 #[cfg(feature = "engine")]
 #[derive(BorshSerialize)]