Chain extension

Cargo.toml

@@ -18,4 +18,6 @@ exclude = [
   "fork-off",
   "benches/payout-stakers",
   "bin/cliain",
+  "contracts/snarcos-contract",
+  "contracts/snarcos-extension",
 ]

bin/runtime/src/lib.rs

@@ -20,14 +20,20 @@ pub use frame_support::{
     StorageValue,
 };
 use frame_support::{
+    log::error,
     sp_runtime::Perquintill,
     traits::{ConstU32, ConstU64, EqualPrivilegeOnly, SortedMembers, U128CurrencyToVote},
     weights::constants::WEIGHT_PER_MILLIS,
     PalletId,
 };
 use frame_system::{EnsureRoot, EnsureSignedBy};
 pub use pallet_balances::Call as BalancesCall;
-use pallet_contracts::weights::WeightInfo;
+use pallet_contracts::{
+    chain_extension::{
+        ChainExtension, Environment, Ext, InitState, RetVal, SysConfig, UncheckedFrom,
+    },
+    weights::WeightInfo,
+};
 use pallet_contracts_primitives::{
     CodeUploadResult, ContractExecResult, ContractInstantiateResult, GetStorageResult,
 };
@@ -51,7 +57,7 @@ use sp_runtime::{
         OpaqueKeys, Verify,
     },
     transaction_validity::{TransactionSource, TransactionValidity},
-    ApplyExtrinsicResult, MultiSignature, RuntimeAppPublic,
+    ApplyExtrinsicResult, DispatchError, MultiSignature, RuntimeAppPublic,
 };
 pub use sp_runtime::{FixedPointNumber, Perbill, Permill};
 use sp_staking::EraIndex;
@@ -640,6 +646,49 @@ impl pallet_utility::Config for Runtime {
     type PalletsOrigin = OriginCaller;
 }
 
+pub struct AlephChainExtension;
+impl ChainExtension<Runtime> for AlephChainExtension {
+    fn call<E: Ext>(func_id: u32, env: Environment<E, InitState>) -> Result<RetVal, DispatchError>
+    where
+        <E::T as SysConfig>::AccountId: UncheckedFrom<<E::T as SysConfig>::Hash> + AsRef<[u8]>,
+    {
+        match func_id {
+            41 => {
+                use pallet_snarcos::{Error, Pallet as Snarcos};
+
+                // The argument-passing-mode doesn't matter for now. All the data to runtime call
+                // are mocked now.
+                let mut env = env.buf_in_buf_out();
+                // After benchmarking is merged and `pallet_snarcos::WeightInfo` is available,
+                // use real weight here.
+                env.charge_weight(41)?;
+
+                match Snarcos::<Runtime>::bare_store_key([0u8; 4], [0u8; 8].to_vec()) {
+                    // In case `DispatchResultWithPostInfo` was returned (or some simpler
+                    // equivalent for `bare_store_key`), we could adjust weight. However, for the
+                    // storing key action it doesn't make sense.
+                    Ok(_) => {
+                        // Return status code for success.
+                        Ok(RetVal::Converging(0))
+                    }
+                    Err(Error::<Runtime>::VerificationKeyTooLong) => Ok(RetVal::Converging(1)),
+                    Err(Error::<Runtime>::IdentifierAlreadyInUse) => Ok(RetVal::Converging(2)),
+                    // Unknown error.
+                    _ => Ok(RetVal::Converging(3)),
+                }
+            }
+            _ => {
+                error!("Called an unregistered `func_id`: {}", func_id);
+                Err(DispatchError::Other("Unimplemented func_id"))
+            }
+        }
+    }
+
+    fn enabled() -> bool {
+        true
+    }
+}
+
 // Prints debug output of the `contracts` pallet to stdout if the node is started with `-lruntime::contracts=debug`.
 const CONTRACTS_DEBUG_OUTPUT: bool = true;
 
@@ -672,7 +721,7 @@ impl pallet_contracts::Config for Runtime {
     type DepositPerByte = DepositPerByte;
     type WeightPrice = pallet_transaction_payment::Pallet<Self>;
     type WeightInfo = pallet_contracts::weights::SubstrateWeight<Self>;
-    type ChainExtension = ();
+    type ChainExtension = AlephChainExtension;
     type DeletionQueueDepth = DeletionQueueDepth;
     type DeletionWeightLimit = DeletionWeightLimit;
     type Schedule = Schedule;