Improve and centralise transaction handling logiclibdbpp-1.0.0

4 files changed, 122 insertions, 16 deletions

diff --git a/libdbpp/connection.cpp b/libdbpp/connection.cpp
index 979c30f..33ae543 100644
--- a/libdbpp/connection.cpp
+++ b/libdbpp/connection.cpp
@@ -18,6 +18,11 @@ DB::TransactionStillOpen::message() const throw()
 	return "A transaction is still open.";
 }
 
+DB::Connection::Connection() :
+	txOpenDepth(0)
+{
+}
+
 DB::Connection::~Connection()
 {
 }
@@ -42,6 +47,64 @@ DB::Connection::modify(const std::string & sql)
 }
 
 void
+DB::Connection::finish() const
+{
+	if (inTx()) {
+		throw TransactionStillOpen();
+	}
+}
+
+void
+DB::Connection::beginTx()
+{
+	if (inTx()) {
+		savepoint(stringbf("tx_sp_%p_%d", this, txOpenDepth));
+	}
+	else {
+		beginTxInt();
+	}
+	txOpenDepth += 1;
+}
+
+void
+DB::Connection::commitTx()
+{
+	switch (txOpenDepth) {
+		case 0:
+			throw TransactionRequired();
+		case 1:
+			commitTxInt();
+			break;
+		default:
+			releaseSavepoint(stringbf("tx_sp_%p_%d", this, txOpenDepth - 1));
+			break;
+	}
+	txOpenDepth -= 1;
+}
+
+void
+DB::Connection::rollbackTx()
+{
+	switch (txOpenDepth) {
+		case 0:
+			throw TransactionRequired();
+		case 1:
+			rollbackTxInt();
+			break;
+		default:
+			rollbackToSavepoint(stringbf("tx_sp_%p_%d", this, txOpenDepth - 1));
+			break;
+	}
+	txOpenDepth -= 1;
+}
+
+bool
+DB::Connection::inTx() const
+{
+	return txOpenDepth > 0;
+}
+
+void
 DB::Connection::executeScript(std::istream & f, const boost::filesystem::path & s)
 {
 	if (!f.good()) {
diff --git a/libdbpp/connection.h b/libdbpp/connection.h
index 700323b..0c03f0b 100644
--- a/libdbpp/connection.h
+++ b/libdbpp/connection.h
@@ -87,15 +87,15 @@ namespace DB {
 			virtual ~Connection();
 
 			/// Perform final checks before closing.
-			virtual void	finish() const = 0;
+			void finish() const;
 			/// Open a new transaction.
-			virtual int		beginTx() const = 0;
+			void beginTx();
 			/// Commit an open transaction.
-			virtual int		commitTx() const = 0;
+			void commitTx();
 			/// Rollback an open transaction.
-			virtual int		rollbackTx() const = 0;
+			void rollbackTx();
 			/// Test to see if a transaction is currently open.
-			virtual bool	inTx() const = 0;
+			bool inTx() const;
 			/// Create a named save point.
 			virtual void savepoint(const std::string &);
 			/// Rollback to a named save point.
@@ -103,7 +103,7 @@ namespace DB {
 			/// Release a named save point.
 			virtual void releaseSavepoint(const std::string &);
 			/// Test server connection availability.
-			virtual void	ping() const = 0;
+			virtual void ping() const = 0;
 			/// @cond
 			virtual BulkDeleteStyle bulkDeleteStyle() const = 0;
 			virtual BulkUpdateStyle bulkUpdateStyle() const = 0;
@@ -143,6 +143,16 @@ namespace DB {
 			static boost::optional<std::string> resolvePlugin(const std::type_info &, const std::string &);
 
 		protected:
+			/// Create a new connection.
+			Connection();
+
+			/// Internal begin transaction.
+			virtual void beginTxInt() = 0;
+			/// Internal commit transaction.
+			virtual void commitTxInt() = 0;
+			/// Internal rollbacj transaction.
+			virtual void rollbackTxInt() = 0;
+
 			/// Internal perform table patch delete operations.
 			virtual unsigned int patchDeletes(TablePatch * tp);
 			/// Internal perform table patch update operations.
@@ -151,6 +161,7 @@ namespace DB {
 			virtual unsigned int patchInserts(TablePatch * tp);
 
 		private:
+			unsigned int txOpenDepth;
 	};
 
 	/// Helper class for beginning/committing/rolling back transactions in accordance with scope and exceptions.
diff --git a/libdbpp/sqlParse.h b/libdbpp/sqlParse.h
index 87b1303..4e01482 100644
--- a/libdbpp/sqlParse.h
+++ b/libdbpp/sqlParse.h
@@ -45,7 +45,6 @@ namespace DB {
 			std::string statement;
 	};
 	/// @endcond
-
 }
 
 #endif
diff --git a/libdbpp/unittests/testConnection.cpp b/libdbpp/unittests/testConnection.cpp
index 42cecfd..d4b1610 100644
--- a/libdbpp/unittests/testConnection.cpp
+++ b/libdbpp/unittests/testConnection.cpp
@@ -12,14 +12,12 @@
 // LCOV_EXCL_START
 class MockDb : public DB::Connection {
 	public:
-		MockDb(const std::string &) : txDepth(0) {}
-
-		void	finish() const override {}
-		int		beginTx() const override { return ++txDepth; }
-		int		commitTx() const override { return --txDepth; }
-		int		rollbackTx() const override { return --txDepth; }
-		bool	inTx() const override { return txDepth > 0; }
-		void	ping() const override {}
+		MockDb(const std::string &) {}
+
+		void beginTxInt() override { }
+		void commitTxInt() override { }
+		void rollbackTxInt() override { }
+		void ping() const override {}
 		DB::BulkDeleteStyle bulkDeleteStyle() const override { return DB::BulkDeleteUsingUsing; }
 		DB::BulkUpdateStyle bulkUpdateStyle() const override { return DB::BulkUpdateUsingJoin; }
 
@@ -30,7 +28,6 @@ class MockDb : public DB::Connection {
 		DB::ModifyCommand * newModifyCommand(const std::string &) override { return nullptr; }
 
 		mutable std::vector<std::string> executed;
-		mutable unsigned int txDepth;
 };
 // LCOV_EXCL_STOP
 
@@ -123,6 +120,42 @@ BOOST_AUTO_TEST_CASE( parse2 )
 	s.close();
 }
 
+BOOST_AUTO_TEST_CASE( finish )
+{
+	auto mock = DB::ConnectionFactory::createNew("MockDb", "doesn't matter");
+	BOOST_REQUIRE(mock);
+	BOOST_REQUIRE_EQUAL(false, mock->inTx());
+	mock->beginTx();
+	BOOST_REQUIRE_THROW(mock->finish(), DB::TransactionStillOpen);
+	mock->rollbackTx();
+	mock->finish();
+	mock->beginTx();
+	BOOST_REQUIRE_THROW(mock->finish(), DB::TransactionStillOpen);
+	mock->commitTx();
+	mock->finish();
+	delete mock;
+}
+
+BOOST_AUTO_TEST_CASE( tx )
+{
+	auto mock = DB::ConnectionFactory::createNew("MockDb", "doesn't matter");
+	BOOST_REQUIRE(mock);
+	BOOST_REQUIRE_EQUAL(false, mock->inTx());
+	mock->beginTx(); // 1
+	BOOST_REQUIRE_EQUAL(true, mock->inTx());
+	mock->beginTx(); // 2
+	BOOST_REQUIRE_EQUAL(true, mock->inTx());
+	mock->commitTx(); // 1
+	BOOST_REQUIRE_EQUAL(true, mock->inTx());
+	mock->beginTx(); // 2
+	BOOST_REQUIRE_EQUAL(true, mock->inTx());
+	mock->rollbackTx(); // 1
+	BOOST_REQUIRE_EQUAL(true, mock->inTx());
+	mock->rollbackTx(); // 0
+	BOOST_REQUIRE_EQUAL(false, mock->inTx());
+	delete mock;
+}
+
 BOOST_AUTO_TEST_CASE( txscope )
 {
 	auto mock = DB::ConnectionFactory::createNew("MockDb", "doesn't matter");