Rpc multiquery

README.md

@@ -137,6 +137,54 @@ obtained from the connected node when not explicitly specified. If you only need
 the signed transaction but don't intend to send it, you can use
 `client.signTransaction`.
 
+## Request with multiple querys
+
+As of JSON-RPC specification, one can make several queries in one http request.
+For using this feature, instead of using the common Web3Client, you have to instantiate
+a `MultiQueryWeb3Client`, which has the same functionality as ao  Web3Client, but adds the
+`client.multiQueryCall` method.
+For usability purposes, some helper classes have been implemented to ask for different required queries inside the same request.
+
+The `multiqueryCall` method requires a list of `ETHRpcQuery` instances
+You can easily construct them thanks to these useful custom constructors. For instance, to ask for the balance, you can use `ETHRpcQuery.getBalance`.
+
+All queries inside this list must satisfy a condition: either all of them or none of them should have an rpc query id assigned (to manage the responses id from the server).
+
+For any other not specified rpc method, you can construct it yourself using the normal `ETHRpcQuery` constructor. The trick here would be correctly parsing the result as desired with the `decodeFn` parameter.
+
+Example usage:
+
+```dart
+final client = MultiQueryWeb3Client(apiUrl, Client());
+final queries = [
+        EthRPCQuery.getBalance(
+          id: 2,
+          address: EthereumAddress.fromHex(
+            '0x81bEdCC7314baf7606b665909CeCDB4c68b180d6',
+          ),
+        ),
+        EthRPCQuery.callContract(
+          id: 1,
+          contractCallParams: EthContractCallParams(
+            contract: contract,
+            function: contract.function('balanceOf'),
+            params: [
+              EthereumAddress.fromHex(
+                '0x81bEdCC7314baf7606b665909CeCDB4c68b180d6',
+              ),
+            ],
+          ),
+        ),
+        EthRPCQuery.getBlockInformation(
+          block: BlockNum.exact(8302276),
+          id: 3,
+        )
+      ];
+
+      final responses = await client.multiQueryCall(queries);
+```
+
+
 ### Smart contracts
 
 The library can parse the abi of a smart contract and send data to it. It can also

lib/src/core/client.dart

@@ -1,4 +1,4 @@
-part of 'package:web3dart/web3dart.dart';
+part of '../../web3dart.dart';
 
 /// Signature for a function that opens a socket on which json-rpc operations
 /// can be performed.

lib/src/core/eth_rpc_query/eth_rpc_query.dart

@@ -0,0 +1,255 @@
+part of '../../../web3dart.dart';
+
+/// D stands for decoded result
+/// R stands for raw result
+/// The idea is to maintain a stable typing when expecting raw results
+/// and when using functions to parsing them.
+/// Sadly Dart is not flexible with generic constructors nor factories,
+/// so all "factories" are static methods (view factories.dart file)
+typedef DecodableFunction<D, R> = D Function(R);
+
+class EthQueryResult<T> {
+  EthQueryResult(this.result, this.id);
+
+  final T result;
+  final int id;
+
+  @override
+  String toString() {
+    return '{"id": $id , "result": $result}';
+  }
+}
+
+class EthRPCQuery<D, R> extends RPCQuery {
+  EthRPCQuery._({
+    required String function,
+    List<dynamic> params = const [],
+    int? id,
+    required DecodableFunction<D, R> decodeFn,
+  })  : _decodeFunction = decodeFn,
+        super(function, params, id);
+
+  final DecodableFunction<D, R> _decodeFunction;
+
+  EthQueryResult decodeResult(R rawResult) =>
+      EthQueryResult(_decodeFunction(rawResult), id!);
+
+  EthRPCQuery copyWithId(
+    int id,
+  ) =>
+      EthRPCQuery<D, R>._(
+        id: id,
+        function: function,
+        params: this.params ?? [],
+        decodeFn: _decodeFunction,
+      );
+
+  /// Returns balance in Ether wei units of the address. (hex)
+  static EthRPCQuery getBalance({
+    required EthereumAddress address,
+    BlockNum atBlock = const BlockNum.current(),
+    int? id,
+  }) =>
+      EthRPCQuery<BigInt, String>._(
+        function: 'eth_getBalance',
+        params: [
+          address.with0x,
+          atBlock.toBlockParam(),
+        ],
+        id: id,
+        decodeFn: (r) => hexToInt(r),
+      );
+
+  /// Returns the amount of Ether in wei typically needed to pay for
+  /// one unit of gas. (hex)
+  static EthRPCQuery getGasPrice(int? id) => EthRPCQuery<EtherAmount, String>._(
+        function: 'eth_gasPrice',
+        id: id,
+        decodeFn: (r) => EtherAmount.fromHex(r),
+      );
+
+  static EthRPCQuery estimateGas(
+    int? id,
+  ) =>
+      EthRPCQuery<EtherAmount, String>._(
+        function: 'eth_estimateGas',
+        id: id,
+        decodeFn: (r) => EtherAmount.fromHex(r),
+      );
+
+  /// Returns the result of calling a contract as a List of returned results
+  static EthRPCQuery callContract({
+    required EthContractCallParams contractCallParams,
+    BlockNum block = const BlockNum.current(),
+    int? id,
+  }) =>
+      EthRPCQuery<List<dynamic>, String>._(
+        function: 'eth_call',
+        params: [
+          {
+            'to': contractCallParams.contract.address.with0x,
+            'data': bytesToHex(
+              contractCallParams.function.encodeCall(
+                contractCallParams.params,
+              ),
+              include0x: true,
+              padToEvenLength: true,
+            ),
+            if (contractCallParams.sender != null)
+              'from': contractCallParams.sender!.with0x,
+          },
+          block.toBlockParam(),
+        ],
+        id: id,
+        decodeFn: (r) {
+          return contractCallParams.function.decodeReturnValues(r);
+        },
+      );
+
+  /// Returns metadata of a certain block. [returnTransactionObjects]
+  /// parameter defines if txs details should be returned in this call,
+  /// or only the tx hashes. (map)
+  static EthRPCQuery getBlockInformation({
+    required BlockNum block,
+    bool returnTransactionObjects = false,
+    int? id,
+  }) =>
+      EthRPCQuery<BlockInformation, Map<String, dynamic>>._(
+        function: 'eth_getBlockByNumber',
+        params: [
+          block.toBlockParam(),
+          returnTransactionObjects,
+        ],
+        id: id,
+        decodeFn: (r) => BlockInformation.fromJson(r),
+      );
+
+  static EthRPCQuery getTransactionCount({
+    required EthereumAddress address,
+    BlockNum blockNum = const BlockNum.current(),
+    int? id,
+  }) =>
+      EthRPCQuery<int, String>._(
+        function: 'eth_getTransactionCount',
+        id: id,
+        decodeFn: (r) => hexToDartInt(r),
+      );
+
+  static EthRPCQuery sendRawTransaction(
+    Uint8List signedTransaction,
+    int? id,
+  ) =>
+      EthRPCQuery<String, String>._(
+        function: 'eth_sendRawTransaction',
+        params: [
+          bytesToHex(
+            signedTransaction,
+            include0x: true,
+            padToEvenLength: true,
+          ),
+        ],
+        id: id,
+        decodeFn: (r) => r,
+      );
+
+  /// Returns the information of a transaction
+  static EthRPCQuery getTransactionByHash(
+    String hash,
+    int? id,
+  ) =>
+      EthRPCQuery<TransactionInformation?, Map<String, dynamic>?>._(
+        function: 'eth_getTransactionByHash',
+        params: [hash],
+        id: id,
+        decodeFn: (r) => r != null ? TransactionInformation.fromMap(r) : null,
+      );
+
+  /// Returns a receipt of a transaction
+  static EthRPCQuery getTransactionReceipt(
+    String hash,
+    int? id,
+  ) =>
+      EthRPCQuery<TransactionReceipt?, Map<String, dynamic>?>._(
+        function: 'eth_getTransactionReceipt',
+        params: [hash],
+        id: id,
+        decodeFn: (r) => r != null ? TransactionReceipt.fromMap(r) : null,
+      );
+
+  // Returns version of the client (String)
+  static EthRPCQuery getClientVersion(int? id) => EthRPCQuery<String, String>._(
+        function: 'web3_clientVersion',
+        id: id,
+        decodeFn: (r) => r,
+      );
+
+  /// Returns network id (int)
+  static EthRPCQuery getNetworkId(int? id) => EthRPCQuery<int, String>._(
+        function: 'net_version',
+        id: id,
+        decodeFn: (r) => int.parse(r),
+      );
+
+  /// Returns chain id (hex)
+  /// https://chainid.network/chains.json
+  static EthRPCQuery getChainId(int? id) => EthRPCQuery<BigInt, String>._(
+        function: 'eth_chainId',
+        id: id,
+        decodeFn: (r) => hexToInt(r),
+      );
+
+  /// Returns the version of the Ethereum-protocol (hex)
+  static EthRPCQuery getEthProtocolVersion(int? id) =>
+      EthRPCQuery<int, String>._(
+        function: 'eth_protocolVersion',
+        id: id,
+        decodeFn: (r) => hexToDartInt(r),
+      );
+
+  /// Returns the coinbase address (hex)
+  static EthRPCQuery coinbaseAddress(int? id) =>
+      EthRPCQuery<EthereumAddress, String>._(
+        function: 'eth_coinbase',
+        id: id,
+        decodeFn: (r) => EthereumAddress.fromHex(r),
+      );
+
+  /// Returns if the client is currently mining (bool)
+  static EthRPCQuery isMining(int? id) => EthRPCQuery<bool, bool>._(
+        function: 'eth_mining',
+        id: id,
+        decodeFn: (r) => r,
+      );
+
+  /// Returns the amount of hashes per second the connected node is
+  /// mining with. (int)
+  static EthRPCQuery getMiningHashrate(int? id) => EthRPCQuery<int, String>._(
+        function: 'eth_hashrate',
+        id: id,
+        decodeFn: (r) => hexToDartInt(r),
+      );
+
+  /// Returns the number of the most recent mined block on the chain.
+  /// (int)
+  static EthRPCQuery getBlockNumber(int? id) => EthRPCQuery<int, String>._(
+        function: 'eth_blockNumber',
+        id: id,
+        decodeFn: (r) => hexToDartInt(r),
+      );
+
+  /// Return the code at a specific address (hex)
+  static EthRPCQuery getCode({
+    required EthereumAddress address,
+    BlockNum block = const BlockNum.current(),
+    int? id,
+  }) =>
+      EthRPCQuery<Uint8List, String>._(
+        function: 'eth_getCode',
+        params: [
+          address.with0x,
+          block.toBlockParam(),
+        ],
+        id: id,
+        decodeFn: (r) => hexToBytes(r),
+      );
+}

lib/src/core/eth_rpc_query/params_classes.dart

@@ -0,0 +1,43 @@
+part of '../../../web3dart.dart';
+
+class EthContractCallParams {
+  EthContractCallParams({
+    this.sender,
+    required this.contract,
+    required this.function,
+    required this.params,
+    this.atBlock = const BlockNum.current(),
+    this.rpcId,
+  });
+
+  final EthereumAddress? sender;
+  final DeployedContract contract;
+  final ContractFunction function;
+  final List<dynamic> params;
+  final BlockNum? atBlock;
+  final String? rpcId;
+}
+
+class EthEstimateGasParams {
+  EthEstimateGasParams({
+    this.sender,
+    this.to,
+    this.value,
+    this.amountOfGas,
+    this.gasPrice,
+    this.maxPriorityFeePerGas,
+    this.maxFeePerGas,
+    this.data,
+    this.rpcId,
+  });
+
+  final EthereumAddress? sender;
+  final EthereumAddress? to;
+  final EtherAmount? value;
+  final BigInt? amountOfGas;
+  final EtherAmount? gasPrice;
+  final EtherAmount? maxPriorityFeePerGas;
+  final EtherAmount? maxFeePerGas;
+  final Uint8List? data;
+  final String? rpcId;
+}

lib/src/core/filters.dart

@@ -1,4 +1,4 @@
-part of 'package:web3dart/web3dart.dart';
+part of '../../web3dart.dart';
 
 class _FilterCreationParams {
   _FilterCreationParams(this.method, this.params);