Add new command line option to make replaying transactions easier: (#…

…5027)

* Add trap_tx_hash command line option

This new option can be used only if replay is also enabled. It takes a transaction hash from the ledger loaded for replay, and will cause a specific line to be hit in Transactor.cpp, right before the selected transaction is applied.

src/ripple/app/main/Application.cpp

@@ -225,6 +225,7 @@ class ApplicationImp : public Application, public BasicApp
     std::unique_ptr<RelationalDatabase> mRelationalDatabase;
     std::unique_ptr<DatabaseCon> mWalletDB;
     std::unique_ptr<Overlay> overlay_;
+    std::optional<uint256> trapTxID_;
 
     boost::asio::signal_set m_signals;
 
@@ -1254,6 +1255,12 @@ class ApplicationImp : public Application, public BasicApp
         return maxDisallowedLedger_;
     }
 
+    virtual const std::optional<uint256>&
+    trapTxID() const override
+    {
+        return trapTxID_;
+    }
+
 private:
     // For a newly-started validator, this is the greatest persisted ledger
     // and new validations must be greater than this.
@@ -1272,7 +1279,11 @@ class ApplicationImp : public Application, public BasicApp
     loadLedgerFromFile(std::string const& ledgerID);
 
     bool
-    loadOldLedger(std::string const& ledgerID, bool replay, bool isFilename);
+    loadOldLedger(
+        std::string const& ledgerID,
+        bool replay,
+        bool isFilename,
+        std::optional<uint256> trapTxID);
 
     void
     setMaxDisallowedLedger();
@@ -1404,7 +1415,8 @@ ApplicationImp::setup(boost::program_options::variables_map const& cmdline)
             if (!loadOldLedger(
                     config_->START_LEDGER,
                     startUp == Config::REPLAY,
-                    startUp == Config::LOAD_FILE))
+                    startUp == Config::LOAD_FILE,
+                    config_->TRAP_TX_HASH))
             {
                 JLOG(m_journal.error())
                     << "The specified ledger could not be loaded.";
@@ -2086,7 +2098,8 @@ bool
 ApplicationImp::loadOldLedger(
     std::string const& ledgerID,
     bool replay,
-    bool isFileName)
+    bool isFileName,
+    std::optional<uint256> trapTxID)
 {
     try
     {
@@ -2233,6 +2246,11 @@ ApplicationImp::loadOldLedger(
             {
                 (void)_;
                 auto txID = tx->getTransactionID();
+                if (trapTxID == txID)
+                {
+                    trapTxID_ = txID;
+                    JLOG(m_journal.debug()) << "Trap transaction set: " << txID;
+                }
 
                 auto s = std::make_shared<Serializer>();
                 tx->add(*s);
@@ -2247,6 +2265,14 @@ ApplicationImp::loadOldLedger(
             }
 
             m_ledgerMaster->takeReplay(std::move(replayData));
+
+            if (trapTxID && !trapTxID_)
+            {
+                JLOG(m_journal.fatal())
+                    << "Ledger " << replayLedger->info().seq
+                    << " does not contain the transaction hash " << *trapTxID;
+                return false;
+            }
         }
     }
     catch (SHAMapMissingNode const& mn)

src/ripple/app/main/Application.h

@@ -284,6 +284,9 @@ class Application : public beast::PropertyStream::Source
      * than the last ledger it persisted. */
     virtual LedgerIndex
     getMaxDisallowedLedger() = 0;
+
+    virtual const std::optional<uint256>&
+    trapTxID() const = 0;
 };
 
 std::unique_ptr<Application>

src/ripple/app/main/Main.cpp

@@ -400,6 +400,9 @@ run(int argc, char** argv)
         "net", "Get the initial ledger from the network.")(
         "nodetoshard", "Import node store into shards")(
         "replay", "Replay a ledger close.")(
+        "trap_tx_hash",
+        po::value<std::string>(),
+        "Trap a specific transaction during replay.")(
         "start", "Start from a fresh Ledger.")(
         "startReporting",
         po::value<std::string>(),
@@ -558,6 +561,7 @@ run(int argc, char** argv)
             argc,
             argv);
     }
+    // LCOV_EXCL_START
     else
     {
         if (vm.count("unittest-jobs"))
@@ -679,7 +683,25 @@ run(int argc, char** argv)
     {
         config->START_LEDGER = vm["ledger"].as<std::string>();
         if (vm.count("replay"))
+        {
             config->START_UP = Config::REPLAY;
+            if (vm.count("trap_tx_hash"))
+            {
+                uint256 tmp = {};
+                auto hash = vm["trap_tx_hash"].as<std::string>();
+                if (tmp.parseHex(hash))
+                {
+                    config->TRAP_TX_HASH = tmp;
+                }
+                else
+                {
+                    std::cerr << "Trap parameter was ill-formed, expected "
+                                 "valid transaction hash but received: "
+                              << hash << std::endl;
+                    return -1;
+                }
+            }
+        }
         else
             config->START_UP = Config::LOAD;
     }
@@ -693,6 +715,13 @@ run(int argc, char** argv)
         config->START_UP = Config::LOAD;
     }
 
+    if (vm.count("trap_tx_hash") && vm.count("replay") == 0)
+    {
+        std::cerr << "Cannot use trap option without replay option"
+                  << std::endl;
+        return -1;
+    }
+
     if (vm.count("net") && !config->FAST_LOAD)
     {
         if ((config->START_UP == Config::LOAD) ||
@@ -828,6 +857,7 @@ run(int argc, char** argv)
     beast::setCurrentThreadName("rippled: rpc");
     return RPCCall::fromCommandLine(
         *config, vm["parameters"].as<std::vector<std::string>>(), *logs);
+    // LCOV_EXCL_STOP
 }
 
 }  // namespace ripple

src/ripple/app/tx/impl/Transactor.cpp

@@ -854,6 +854,12 @@ Transactor::operator()()
     }
 #endif
 
+    if (auto const& trap = ctx_.app.trapTxID();
+        trap && *trap == ctx_.tx.getTransactionID())
+    {
+        JLOG(j_.debug()) << "Transaction trapped: " << *trap;
+    }
+
     auto result = ctx_.preclaimResult;
     if (result == tesSUCCESS)
         result = apply();

src/ripple/core/Config.h

@@ -162,6 +162,8 @@ class Config : public BasicConfig
 
     std::string START_LEDGER;
 
+    std::optional<uint256> TRAP_TX_HASH;
+
     // Network parameters
     uint32_t NETWORK_ID = 0;