Refactor rollback handling in dtor

taocpp · Jan 2, 2025 · 7374901 · 7374901
1 parent 1876501
commit 7374901
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Showing 5 changed files with 29 additions and 35 deletions.
diff --git a/include/tao/pq/connection.hpp b/include/tao/pq/connection.hpp
@@ -54,6 +54,7 @@ namespace tao::pq
       friend class connection_pool;
       friend class table_reader;
       friend class table_writer;
+      friend class transaction;
       friend class transaction_base;
 
       friend class internal::top_level_transaction;

diff --git a/include/tao/pq/log.hpp b/include/tao/pq/log.hpp
@@ -15,6 +15,7 @@
 namespace tao::pq
 {
    class connection;
+   class transaction;
 
    struct log
    {
@@ -120,7 +121,10 @@ namespace tao::pq
 
       struct transaction_t
       {
-         // TODO...
+         // check std::current_exception() for more information
+         using destructor_rollback_failed_t = std::function< void( transaction& ) >;  // noexcept
+
+         destructor_rollback_failed_t destructor_rollback_failed;
 
       } transaction;
    };

diff --git a/include/tao/pq/transaction.hpp b/include/tao/pq/transaction.hpp
@@ -32,6 +32,8 @@ namespace tao::pq
 
       virtual void v_reset() noexcept = 0;
 
+      void rollback_in_dtor() noexcept;
+
    public:
       [[nodiscard]] auto subtransaction() -> std::shared_ptr< transaction >;
       [[nodiscard]] auto pipeline() -> std::shared_ptr< pq::pipeline >;

diff --git a/src/lib/pq/connection.cpp b/src/lib/pq/connection.cpp
@@ -8,7 +8,6 @@
 #include <cctype>
 #include <chrono>
 #include <cstring>
-#include <exception>
 #include <format>
 #include <functional>
 #include <memory>
@@ -137,17 +136,7 @@ namespace tao::pq
          ~top_level_transaction() override
          {
             if( m_connection && m_connection->attempt_rollback() ) {
-               try {
-                  rollback();
-               }
-               // LCOV_EXCL_START
-               catch( const std::exception& ) {  // NOLINT(bugprone-empty-catch)
-                  // TAO_LOG( WARNING, "unable to rollback transaction, swallowing exception: " + std::string( e.what() ) );
-               }
-               catch( ... ) {  // NOLINT(bugprone-empty-catch)
-                  // TAO_LOG( WARNING, "unable to rollback transaction, swallowing unknown exception" );
-               }
-               // LCOV_EXCL_STOP
+               rollback_in_dtor();
             }
          }
 

diff --git a/src/lib/pq/transaction.cpp b/src/lib/pq/transaction.cpp
@@ -6,7 +6,6 @@
 
 #include <chrono>
 #include <cstdio>
-#include <exception>
 #include <memory>
 #include <stdexcept>
 #include <utility>
@@ -33,17 +32,7 @@ namespace tao::pq
          ~top_level_subtransaction() override
          {
             if( m_connection && m_connection->attempt_rollback() ) {
-               try {
-                  rollback();
-               }
-               // LCOV_EXCL_START
-               catch( const std::exception& ) {  // NOLINT(bugprone-empty-catch)
-                  // TAO_LOG( WARNING, "unable to rollback transaction, swallowing exception: " + std::string( e.what() ) );
-               }
-               catch( ... ) {  // NOLINT(bugprone-empty-catch)
-                  // TAO_LOG( WARNING, "unable to rollback transaction, swallowing unknown exception" );
-               }
-               // LCOV_EXCL_STOP
+               rollback_in_dtor();
             }
          }
 
@@ -79,14 +68,7 @@ namespace tao::pq
          ~nested_subtransaction() override
          {
             if( m_connection && m_connection->attempt_rollback() ) {
-               try {
-                  rollback();
-               }
-               // LCOV_EXCL_START
-               catch( ... ) {  // NOLINT(bugprone-empty-catch)
-                  // TODO: How to handle this case properly?
-               }
-               // LCOV_EXCL_STOP
+               rollback_in_dtor();
             }
          }
 
@@ -130,8 +112,8 @@ namespace tao::pq
 
    void transaction::commit()
    {
-      check_current_transaction();
       try {
+         check_current_transaction();
          v_commit();
       }
       // LCOV_EXCL_START
@@ -145,8 +127,8 @@ namespace tao::pq
 
    void transaction::rollback()
    {
-      check_current_transaction();
       try {
+         check_current_transaction();
          v_rollback();
       }
       // LCOV_EXCL_START
@@ -158,4 +140,20 @@ namespace tao::pq
       v_reset();
    }
 
+   void transaction::rollback_in_dtor() noexcept
+   {
+      try {
+         check_current_transaction();
+         v_rollback();
+      }
+      // LCOV_EXCL_START
+      catch( ... ) {
+         if( m_connection->m_log && m_connection->m_log->transaction.destructor_rollback_failed ) {
+            m_connection->m_log->transaction.destructor_rollback_failed( *this );
+         }
+      }
+      // LCOV_EXCL_STOP
+      v_reset();
+   }
+
 }  // namespace tao::pq