rpcdaemon: remove db::chain read header hash (#2600)

silkworm/db/chain/chain_storage.hpp

@@ -90,6 +90,8 @@ class ChainStorage {
 
     virtual Task<std::optional<BlockNum>> read_block_num_by_transaction_hash(const evmc::bytes32& transaction_hash) const = 0;
     virtual Task<std::optional<Transaction>> read_transaction_by_idx_in_block(BlockNum block_num, uint64_t txn_id) const = 0;
+
+    virtual Task<std::pair<std::optional<BlockHeader>, std::optional<Hash>>> read_head_header_and_hash() const = 0;
 };
 
 }  // namespace silkworm::db::chain

silkworm/db/chain/local_chain_storage.cpp

@@ -149,4 +149,8 @@ Task<std::optional<Transaction>> LocalChainStorage::read_transaction_by_idx_in_b
     throw std::runtime_error{"not yet implemented"};
 }
 
+Task<std::pair<std::optional<BlockHeader>, std::optional<Hash>>> LocalChainStorage::read_head_header_and_hash() const {
+    co_return data_model_.read_head_header_and_hash();
+}
+
 }  // namespace silkworm::db::chain

silkworm/db/chain/local_chain_storage.hpp

@@ -69,6 +69,8 @@ class LocalChainStorage : public ChainStorage {
     Task<std::optional<BlockNum>> read_block_num_by_transaction_hash(const evmc::bytes32& transaction_hash) const override;
     Task<std::optional<Transaction>> read_transaction_by_idx_in_block(BlockNum block_num, uint64_t txn_id) const override;
 
+    Task<std::pair<std::optional<BlockHeader>, std::optional<Hash>>> read_head_header_and_hash() const override;
+
   private:
     db::DataModel data_model_;
 };

silkworm/db/chain/remote_chain_storage.cpp

@@ -19,13 +19,13 @@
 #include <utility>
 
 #include <silkworm/core/common/base.hpp>
+#include <silkworm/core/common/bytes_to_string.hpp>
 #include <silkworm/core/common/util.hpp>
+#include <silkworm/core/types/evmc_bytes32.hpp>
 #include <silkworm/db/tables.hpp>
 #include <silkworm/infra/common/log.hpp>
 #include <silkworm/infra/grpc/common/conversion.hpp>
 
-#include "chain.hpp"
-
 namespace silkworm::db::chain {
 
 RemoteChainStorage::RemoteChainStorage(kv::api::Transaction& tx, Providers providers)
@@ -239,4 +239,19 @@ Task<std::optional<Transaction>> RemoteChainStorage::read_transaction_by_idx_in_
     co_return body.transactions[txn_id];
 }
 
+Task<std::pair<std::optional<BlockHeader>, std::optional<Hash>>> RemoteChainStorage::read_head_header_and_hash() const {
+    const auto value = co_await tx_.get_one(table::kHeadHeaderName, string_to_bytes(table::kHeadHeaderName));
+    if (value.empty()) {
+        throw std::runtime_error{"empty head header hash value in read_head_header_hash"};
+    }
+    const auto head_header_hash{to_bytes32(value)};
+    SILK_DEBUG << "head header hash: " << to_hex(head_header_hash);
+
+    auto header = co_await read_header(head_header_hash);
+
+    Hash header_hash{head_header_hash};
+
+    co_return std::pair{std::move(header), std::move(header_hash)};
+}
+
 }  // namespace silkworm::db::chain

silkworm/db/chain/remote_chain_storage.hpp

@@ -16,6 +16,8 @@
 
 #pragma once
 
+#include <optional>
+
 #include <silkworm/db/chain/providers.hpp>
 #include <silkworm/db/kv/api/transaction.hpp>
 
@@ -69,6 +71,8 @@ class RemoteChainStorage : public ChainStorage {
     Task<std::optional<BlockNum>> read_block_num_by_transaction_hash(const evmc::bytes32& transaction_hash) const override;
     Task<std::optional<Transaction>> read_transaction_by_idx_in_block(BlockNum block_num, uint64_t txn_id) const override;
 
+    Task<std::pair<std::optional<BlockHeader>, std::optional<Hash>>> read_head_header_and_hash() const override;
+
   protected:
     Providers& providers() { return providers_; }
 

silkworm/db/test_util/mock_chain_storage.hpp

@@ -73,6 +73,8 @@ class MockChainStorage : public chain::ChainStorage {
 
     MOCK_METHOD((Task<std::optional<BlockNum>>), read_block_num_by_transaction_hash, (const evmc::bytes32&), (const, override));
     MOCK_METHOD((Task<std::optional<Transaction>>), read_transaction_by_idx_in_block, (BlockNum, uint64_t), (const, override));
+
+    MOCK_METHOD((Task<std::pair<std::optional<BlockHeader>, std::optional<Hash>>>), read_head_header_and_hash, (), (const, override));
 };
 
 }  // namespace silkworm::db::test_util

silkworm/rpc/commands/erigon_api.cpp

@@ -22,7 +22,6 @@
 
 #include <silkworm/core/common/base.hpp>
 #include <silkworm/core/types/evmc_bytes32.hpp>
-#include <silkworm/db/chain/chain.hpp>
 #include <silkworm/infra/common/async_binary_search.hpp>
 #include <silkworm/infra/common/ensure.hpp>
 #include <silkworm/infra/common/log.hpp>
@@ -123,10 +122,7 @@ Task<void> ErigonRpcApi::handle_erigon_get_block_by_timestamp(const nlohmann::js
         // Lookup the first and last block headers
         const auto first_header = co_await chain_storage->read_canonical_header(kEarliestBlockNum);
         ensure(first_header.has_value(), "cannot find earliest header");
-        const auto head_header_hash = co_await db::chain::read_head_header_hash(*tx);
-        const auto head_header_block_num = co_await chain_storage->read_block_num(head_header_hash);
-        ensure(head_header_block_num.has_value(), "cannot find head header hash");
-        const auto current_header = co_await chain_storage->read_header(*head_header_block_num, head_header_hash);
+        const auto [current_header, head_header_hash] = co_await chain_storage->read_head_header_and_hash();
         ensure(current_header.has_value(), "cannot find head header");
         const BlockNum current_block_num = current_header->number;
 

silkworm/rpc/core/logs_walker.cpp

@@ -22,7 +22,6 @@
 
 #include <silkworm/core/types/address.hpp>
 #include <silkworm/core/types/evmc_bytes32.hpp>
-#include <silkworm/db/chain/chain.hpp>
 #include <silkworm/db/kv/txn_num.hpp>
 #include <silkworm/db/tables.hpp>
 #include <silkworm/db/util.hpp>