Fix everything to make it work with real assethub westend

Author: dimartiro

crates/anvil-polkadot/Cargo.toml

@@ -163,5 +163,4 @@ op-alloy-rpc-types.workspace = true
 
 [features]
 default = []
-asm-keccak = ["alloy-primitives/asm-keccak"]
-forking-tests = []
+asm-keccak = ["alloy-primitives/asm-keccak"]

crates/anvil-polkadot/src/api_server/server.rs

@@ -87,9 +87,13 @@ use sqlx::sqlite::SqlitePoolOptions;
 use std::{collections::BTreeSet, sync::Arc, time::Duration};
 use substrate_runtime::{Balance, constants::NATIVE_TO_ETH_RATIO};
 use subxt::{
-    Metadata as SubxtMetadata, OnlineClient, backend::rpc::RpcClient,
-    client::RuntimeVersion as SubxtRuntimeVersion, config::substrate::H256,
-    ext::subxt_rpcs::LegacyRpcMethods, utils::H160,
+    Metadata as SubxtMetadata, OnlineClient,
+    backend::rpc::RpcClient,
+    client::RuntimeVersion as SubxtRuntimeVersion,
+    config::substrate::H256,
+    dynamic::{Value as DynamicValue, tx as dynamic_tx},
+    ext::subxt_rpcs::LegacyRpcMethods,
+    utils::H160,
 };
 use subxt_signer::eth::Keypair;
 use tokio::try_join;
@@ -113,6 +117,12 @@ pub struct ApiServer {
     /// Tracks all active filters
     filters: Filters,
     hardcoded_chain_id: u64,
+    /// RPC methods for submitting transactions
+    rpc: LegacyRpcMethods<SrcChainConfig>,
+    /// Subxt OnlineClient for dynamic transaction building.
+    /// When forking, the metadata comes from the forked chain's WASM (loaded via lazy loading),
+    /// so pallet indices will be correct for the forked runtime.
+    api: OnlineClient<SrcChainConfig>,
 }
 
 /// Fetch the chain ID from the substrate chain.
@@ -140,7 +150,7 @@ impl ApiServer {
         let eth_rpc_client = create_revive_rpc_client(
             api.clone(),
             rpc_client.clone(),
-            rpc,
+            rpc.clone(),
             block_provider.clone(),
             substrate_service.spawn_handle.clone(),
             revive_rpc_block_limit,
@@ -176,6 +186,8 @@ impl ApiServer {
             instance_id: B256::random(),
             filters,
             hardcoded_chain_id: chain_id,
+            rpc,
+            api,
         })
     }
 
@@ -797,8 +809,32 @@ impl ApiServer {
 
     async fn send_raw_transaction(&self, transaction: Bytes) -> Result<H256> {
         let hash = H256(keccak_256(&transaction.0));
-        let call = subxt_client::tx().revive().eth_transact(transaction.0);
-        self.eth_rpc_client.submit(call).await?;
+
+        // Prefetch storage keys for the sender to speed up transaction validation.
+        // This is especially important when forking from a remote chain, as each storage
+        // read would otherwise require a separate RPC call. When not forking, this is a no-op.
+        if let Ok(signed_tx) = TransactionSigned::decode(&transaction.0) {
+            if let Ok(sender) = recover_maybe_impersonated_address(&signed_tx) {
+                self.backend.prefetch_eth_transaction_keys(sender);
+            }
+        }
+
+        // Use dynamic transaction building to ensure the correct pallet index is used.
+        // The metadata in self.api comes from the runtime's WASM (via runtime API call),
+        // which is the forked chain's WASM when forking. This ensures correct pallet indices.
+        let payload_value = DynamicValue::from_bytes(transaction.0.clone());
+        let tx_payload = dynamic_tx("Revive", "eth_transact", vec![payload_value]);
+
+        let ext = self.api.tx().create_unsigned(&tx_payload).map_err(|e| {
+            Error::InternalError(format!("Failed to create unsigned extrinsic: {e}"))
+        })?;
+
+        // Submit the extrinsic to the transaction pool
+        self.rpc
+            .author_submit_extrinsic(ext.encoded())
+            .await
+            .map_err(|e| Error::InternalError(format!("Failed to submit transaction: {e}")))?;
+
         Ok(hash)
     }
 

crates/anvil-polkadot/src/substrate_node/lazy_loading/backend/blockchain.rs

@@ -156,10 +156,10 @@ impl<Block: BlockT + DeserializeOwned> Blockchain<Block> {
             storage.genesis_hash = hash;
         }
 
-        // Update leaves for non-genesis blocks
-        if storage.blocks.len() > 1 {
-            storage.leaves.import(hash, number, *header.parent_hash());
-        }
+        // Update leaves for all blocks including genesis.
+        // For genesis when forking, the parent_hash points to the previous block on the remote chain.
+        // That parent won't be in our leaf set, so this effectively adds genesis as a new leaf.
+        storage.leaves.import(hash, number, *header.parent_hash());
 
         // Finalize block only if explicitly requested via new_state
         if let NewBlockState::Final = new_state {
@@ -266,25 +266,43 @@ impl<Block: BlockT + DeserializeOwned> HeaderBackend<Block> for Blockchain<Block
 
         // If not found in local storage, fetch from RPC client
         let header = if let Some(rpc) = self.rpc() {
-            rpc.block(Some(hash)).ok().flatten().map(|full| {
-                let block = full.block.clone();
-                self.storage
-                    .write()
-                    .blocks
-                    .insert(hash, StoredBlock::Full(block.clone(), full.justifications));
-                block.header().clone()
-            })
+            match rpc.block(Some(hash)) {
+                Ok(Some(full)) => {
+                    let block = full.block.clone();
+                    self.storage
+                        .write()
+                        .blocks
+                        .insert(hash, StoredBlock::Full(block.clone(), full.justifications));
+                    Some(block.header().clone())
+                }
+                Ok(None) => {
+                    // Block not found on remote chain - this is expected for locally-built blocks
+                    tracing::debug!(
+                        target: LAZY_LOADING_LOG_TARGET,
+                        "Block {:?} not found in local storage or remote RPC",
+                        hash
+                    );
+                    None
+                }
+                Err(e) => {
+                    tracing::warn!(
+                        target: LAZY_LOADING_LOG_TARGET,
+                        "Failed to fetch block {:?} from RPC: {}",
+                        hash,
+                        e
+                    );
+                    None
+                }
+            }
         } else {
-            None
-        };
-
-        if header.is_none() {
-            tracing::warn!(
+            // No RPC configured - block simply doesn't exist locally
+            tracing::debug!(
                 target: LAZY_LOADING_LOG_TARGET,
-                "Expected block {:x?} to exist.",
-                &hash
+                "Block {:?} not found in local storage (no RPC configured)",
+                hash
             );
-        }
+            None
+        };
 
         Ok(header)
     }
@@ -418,19 +436,34 @@ impl<Block: BlockT + DeserializeOwned> sp_blockchain::Backend<Block> for Blockch
         Ok(leaves)
     }
 
-    fn children(&self, _parent_hash: Block::Hash) -> sp_blockchain::Result<Vec<Block::Hash>> {
-        unimplemented!("Not supported by the `lazy-loading` backend.")
+    fn children(&self, parent_hash: Block::Hash) -> sp_blockchain::Result<Vec<Block::Hash>> {
+        // Find all blocks whose parent_hash matches the given hash
+        let storage = self.storage.read();
+        let children: Vec<Block::Hash> = storage
+            .blocks
+            .iter()
+            .filter_map(|(hash, block)| {
+                if *block.header().parent_hash() == parent_hash {
+                    Some(*hash)
+                } else {
+                    None
+                }
+            })
+            .collect();
+        Ok(children)
     }
 
     fn indexed_transaction(&self, _hash: Block::Hash) -> sp_blockchain::Result<Option<Vec<u8>>> {
-        unimplemented!("Not supported by the `lazy-loading` backend.")
+        // Indexed transactions are not supported in the lazy-loading backend
+        Ok(None)
     }
 
     fn block_indexed_body(
         &self,
         _hash: Block::Hash,
     ) -> sp_blockchain::Result<Option<Vec<Vec<u8>>>> {
-        unimplemented!("Not supported by the `lazy-loading` backend.")
+        // Indexed block bodies are not supported in the lazy-loading backend
+        Ok(None)
     }
 }
 

crates/anvil-polkadot/src/substrate_node/lazy_loading/backend/forked_lazy_backend.rs

@@ -9,8 +9,8 @@ use polkadot_sdk::{
         traits::{Block as BlockT, HashingFor},
     },
     sp_state_machine::{
-        self, BackendTransaction, InMemoryBackend, IterArgs, StorageCollection, StorageValue,
-        TrieBackend, backend::AsTrieBackend,
+        self, Backend as StateMachineBackend, BackendTransaction, InMemoryBackend, IterArgs,
+        StorageCollection, StorageValue, TrieBackend, backend::AsTrieBackend,
     },
     sp_storage::ChildInfo,
     sp_trie::{self, PrefixedMemoryDB},
@@ -99,6 +99,63 @@ impl<Block: BlockT + DeserializeOwned> ForkedLazyBackend<Block> {
     pub(crate) fn rpc(&self) -> Option<&dyn RPCClient<Block>> {
         self.rpc_client.as_deref()
     }
+
+    /// Prefetch multiple storage keys in a single RPC batch call.
+    /// This significantly reduces latency when we know which keys will be needed.
+    /// Keys that are already cached or marked as removed will be skipped.
+    /// Returns the number of keys actually fetched from remote.
+    pub fn prefetch_keys(&self, keys: &[Vec<u8>]) -> usize {
+        if keys.is_empty() {
+            return 0;
+        }
+
+        let rpc = match self.rpc() {
+            Some(rpc) => rpc,
+            None => return 0,
+        };
+
+        // Filter out keys that are already cached or removed
+        let db = self.db.read();
+        let removed = self.removed_keys.read();
+
+        let keys_to_fetch: Vec<polkadot_sdk::sp_storage::StorageKey> = keys
+            .iter()
+            .filter(|key| {
+                // Skip if already in cache
+                if StateMachineBackend::storage(&*db, key).ok().flatten().is_some() {
+                    return false;
+                }
+                // Skip if marked as removed
+                if removed.contains(*key) {
+                    return false;
+                }
+                true
+            })
+            .map(|key| polkadot_sdk::sp_storage::StorageKey(key.clone()))
+            .collect();
+
+        drop(db);
+        drop(removed);
+
+        if keys_to_fetch.is_empty() {
+            return 0;
+        }
+
+        let fetch_count = keys_to_fetch.len();
+
+        // Use the batch RPC call
+        let block_to_query = if self.before_fork { self.block_hash } else { self.fork_block };
+
+        match rpc.storage_batch(keys_to_fetch, block_to_query) {
+            Ok(results) => {
+                for (key, value) in results {
+                    self.update_storage(&key.0, &value.map(|v| v.0));
+                }
+                fetch_count
+            }
+            Err(_) => 0,
+        }
+    }
 }
 
 impl<Block: BlockT + DeserializeOwned> sp_state_machine::Backend<HashingFor<Block>>

crates/anvil-polkadot/src/substrate_node/lazy_loading/backend/mod.rs

@@ -12,8 +12,8 @@ mod tests;
 use parking_lot::RwLock;
 use polkadot_sdk::{
     sc_client_api::{
-        TrieCacheContext, UsageInfo,
-        backend::{self, AuxStore},
+        HeaderBackend, TrieCacheContext, UsageInfo,
+        backend::{self, AuxStore, Backend as ClientBackend},
     },
     sp_blockchain,
     sp_core::{H256, offchain::storage::InMemOffchainStorage},
@@ -59,6 +59,22 @@ impl<Block: BlockT + DeserializeOwned> Backend<Block> {
     fn fork_checkpoint(&self) -> Option<&Block::Header> {
         self.fork_config.as_ref().map(|(_, checkpoint)| checkpoint)
     }
+
+    /// Prefetch multiple storage keys in a single batch RPC call.
+    /// This significantly reduces latency when we know which keys will be needed
+    /// (e.g., before transaction validation).
+    /// Returns the number of keys actually fetched from remote.
+    pub fn prefetch_storage_keys(&self, keys: &[Vec<u8>]) -> usize {
+        // Get the best block hash to find the current state
+        let best_hash = HeaderBackend::info(&self.blockchain).best_hash;
+
+        // Try to get the state for the best block
+        if let Ok(state) = ClientBackend::state_at(self, best_hash, TrieCacheContext::Trusted) {
+            state.prefetch_keys(keys)
+        } else {
+            0
+        }
+    }
 }
 
 impl<Block: BlockT + DeserializeOwned> AuxStore for Backend<Block> {

crates/anvil-polkadot/src/substrate_node/lazy_loading/backend/tests.rs

@@ -2,7 +2,7 @@ use super::*;
 use mock_rpc::{Rpc, TestBlock, TestHeader};
 use parking_lot::RwLock;
 use polkadot_sdk::{
-    sc_client_api::{Backend as BackendT, HeaderBackend, StateBackend},
+    sc_client_api::{Backend as BackendT, StateBackend},
     sp_runtime::{
         OpaqueExtrinsic,
         traits::{BlakeTwo256, Header as HeaderT},
@@ -276,6 +276,22 @@ mod mock_rpc {
             let take = min(filtered.len(), count as usize);
             Ok(filtered.into_iter().take(take).map(|k| k.0).collect())
         }
+
+        fn storage_batch(
+            &self,
+            keys: Vec<StorageKey>,
+            at: Option<Block::Hash>,
+        ) -> Result<Vec<(StorageKey, Option<StorageData>)>, jsonrpsee::core::ClientError> {
+            // Simple implementation: just call storage for each key
+            let results = keys
+                .into_iter()
+                .map(|key| {
+                    let value = self.storage(key.clone(), at).ok().flatten();
+                    (key, value)
+                })
+                .collect();
+            Ok(results)
+        }
     }
 }