Filter duplicate Eth logs at api level

Author: chetan-zilliqa

src/libServer/EthRpcMethods.cpp

@@ -1777,6 +1777,8 @@ Json::Value EthRpcMethods::GetEthTransactionReceipt(
         Eth::GetLogsFromReceipt(transactionBodyPtr->GetTransactionReceipt());
 
     logs = Eth::ConvertScillaEventsToEvm(logs);
+    Json::Value filteredLogs =
+        JSONUtils::GetInstance().FilterDuplicateLogs(logs);
 
     const auto [errors, exceptions] = Eth::GetErrorsAndExceptionsFromReceipt(
         transactionBodyPtr->GetTransactionReceipt());
@@ -1785,24 +1787,24 @@ Json::Value EthRpcMethods::GetEthTransactionReceipt(
         Eth::ConvertScillaExceptionsToEvm(exceptions);
 
     for (const auto &error : convertedErrors) {
-      logs.append(error);
+      filteredLogs.append(error);
     }
 
     for (const auto &exception : convertedExceptions) {
-      logs.append(exception);
+      filteredLogs.append(exception);
     }
 
     const auto baselogIndex =
         Eth::GetBaseLogIndexForReceiptInBlock(argHash, txBlock);
 
-    Eth::DecorateReceiptLogs(logs, txnhash, blockHash, blockNumber,
+    Eth::DecorateReceiptLogs(filteredLogs, txnhash, blockHash, blockNumber,
                              transactionIndex, baselogIndex);
     const auto bloomLogs = Eth::GetBloomFromReceiptHex(
         transactionBodyPtr->GetTransactionReceipt());
 
     auto res = Eth::populateReceiptHelper(
         hashId, success, sender, toAddr, cumGas, gasPrice, blockHash,
-        blockNumber, contractAddress, logs, bloomLogs, transactionIndex,
+        blockNumber, contractAddress, filteredLogs, bloomLogs, transactionIndex,
         transactionBodyPtr->GetTransaction());
 
     return res;

src/libUtils/JsonUtils.h

@@ -45,28 +45,30 @@ class JSONUtils {
         std::unique_ptr<Json::StreamWriter>(writeBuilder.newStreamWriter());
   }
 
-  ~JSONUtils(){};
+  ~JSONUtils() {};
 
  public:
   static JSONUtils& GetInstance() {
     static JSONUtils jsonutils;
     return jsonutils;
   }
 
-  bool getUint128FromObject(const Json::Value& obj, const std::string& key, uint128_t &result) const {
+  bool getUint128FromObject(const Json::Value& obj, const std::string& key,
+                            uint128_t& result) const {
     return this->getUint128FromObject(obj, key.c_str(), result);
   }
-  
+
   /// Get an object value as a uint128_t.
   /// @return false if we failed, true if we succeeded.
-  bool getUint128FromObject(const Json::Value& obj, const char* key, uint128_t &result) const {
-    if (obj.isObject() &&
-        obj.isMember(key)) {
+  bool getUint128FromObject(const Json::Value& obj, const char* key,
+                            uint128_t& result) const {
+    if (obj.isObject() && obj.isMember(key)) {
       Json::Value member = obj[key];
       if (member.isString()) {
         // Parse it.
         try {
-          result = DataConversion::ConvertStrToInt<uint128_t>(member.asString());
+          result =
+              DataConversion::ConvertStrToInt<uint128_t>(member.asString());
           return true;
         } catch (...) {
           return false;
@@ -118,6 +120,33 @@ class JSONUtils {
     std::lock_guard<std::mutex> g(m_mutexWriter);
     m_writer->write(_json, &os);
   }
+
+  static std::size_t hashJsonValue(const Json::Value& log) {
+    Json::StreamWriterBuilder writer;
+    std::string logStr = Json::writeString(writer, log);
+    return std::hash<std::string>{}(logStr);
+  }
+
+  static bool equalJsonValue(const Json::Value& lhs, const Json::Value& rhs) {
+    return lhs == rhs;
+  }
+
+  Json::Value FilterDuplicateLogs(const Json::Value& logs) {
+    using CustomHash = std::function<std::size_t(const Json::Value&)>;
+    using CustomEqual =
+        std::function<bool(const Json::Value&, const Json::Value&)>;
+
+    std::unordered_set<Json::Value, CustomHash, CustomEqual> uniqueLogs(
+        10, hashJsonValue, equalJsonValue);
+    Json::Value filteredLogs(Json::arrayValue);
+
+    for (const auto& log : logs) {
+      if (uniqueLogs.insert(log).second) {
+        filteredLogs.append(log);
+      }
+    }
+    return filteredLogs;
+  }
 };
 
 #endif  // ZILLIQA_SRC_LIBUTILS_JSONUTILS_H_

tests/EvmAcceptanceTests/contracts/Event.sol

@@ -32,4 +32,12 @@ contract Event {
         child.one_log();
         revert();
     }
+    function duplicate_one_log() public {
+        emit Log(msg.sender, "Hello World!");
+        emit Log(msg.sender, "Hello World!");
+        emit Log(msg.sender, "Hello World!");
+        emit Log(msg.sender, "Hello World!");
+        emit Log(msg.sender, "Hello World2!");
+        emit Log(msg.sender, "Hello World3!");
+    }
 }

tests/EvmAcceptanceTests/test/EventsLogs.ts

@@ -1,6 +1,6 @@
-import {expect} from "chai";
-import {Contract} from "ethers";
-import hre, {ethers} from "hardhat";
+import { expect } from "chai";
+import { Contract } from "ethers";
+import hre, { ethers } from "hardhat";
 
 const FUND = ethers.utils.parseUnits("1", "gwei");
 
@@ -28,9 +28,14 @@ describe("Events and logs #parallel", function () {
   });
 
   it("Should return log from child contract even if function failed @block-2", async function () {
-    const tx = await contract.one_log_and_fail({gasLimit: 250000});
+    const tx = await contract.one_log_and_fail({ gasLimit: 250000 });
     const receipt = await ethers.provider.getTransactionReceipt(tx.hash);
-    console.log("Receipt: " + JSON.stringify(receipt));
     expect(receipt.logs.length).to.be.eq(1);
   });
+  it("Should return 3 log whenever a function with duplicate one event is called @block-1", async function () {
+    const tx = await contract.duplicate_one_log();
+    const receipt = await ethers.provider.getTransactionReceipt(tx.hash);
+    //console.log("Receipt = ", JSON.stringify(receipt));
+    expect(receipt.logs.length).to.be.eq(3);
+  });
 });