From 50a3dbfd0fa9dbcdf542d64be26d6f44ba65998c Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Tue, 29 Dec 2015 05:16:51 +0000
Subject: Improve and centralise transaction handling logic

---
 libodbcpp/odbc-connection.cpp    | 100 +++++++++------------------------------
 libodbcpp/odbc-connection.h      |  14 ++----
 libodbcpp/odbc-modifycommand.cpp |   4 +-
 3 files changed, 29 insertions(+), 89 deletions(-)

(limited to 'libodbcpp')

diff --git a/libodbcpp/odbc-connection.cpp b/libodbcpp/odbc-connection.cpp
index 433acb5..c26af05 100644
--- a/libodbcpp/odbc-connection.cpp
+++ b/libodbcpp/odbc-connection.cpp
@@ -13,9 +13,7 @@ ODBC::Connection::Connection(const DSN& d) :
 	env(0),
 	conn(0),
 	thinkDelStyle(DB::BulkDeleteUsingUsing),
-	thinkUpdStyle(DB::BulkUpdateUsingFromSrc),
-	txDepth(0),
-	txAborted(false)
+	thinkUpdStyle(DB::BulkUpdateUsingFromSrc)
 {
 	connectPre();
 	RETCODE dberr = SQLConnect(conn, (SQLCHAR*)d.dsn.c_str(), SQL_NTS,
@@ -73,9 +71,7 @@ ODBC::Connection::Connection(const std::string & s) :
 	env(0),
 	conn(0),
 	thinkDelStyle(DB::BulkDeleteUsingUsing),
-	thinkUpdStyle(DB::BulkUpdateUsingFromSrc),
-	txDepth(0),
-	txAborted(false)
+	thinkUpdStyle(DB::BulkUpdateUsingFromSrc)
 {
 	connectPre();
 	RETCODE dberr = SQLDriverConnect(conn, NULL, (SQLCHAR*)s.c_str(), s.length(), NULL, 0, NULL, SQL_DRIVER_NOPROMPT);
@@ -97,88 +93,38 @@ ODBC::Connection::~Connection()
 }
 
 void
-ODBC::Connection::finish() const
+ODBC::Connection::beginTxInt()
 {
-	if (txDepth != 0) {
-		rollbackTx();
-		throw DB::TransactionStillOpen();
-	}
-}
-
-int
-ODBC::Connection::beginTx() const
-{
-	if (txDepth == 0) {
-		SQLRETURN dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF);
-		if (!SQL_SUCCEEDED(dberr)) {
-			throw Error(dberr, SQL_HANDLE_DBC, conn);
-		}
+	SQLRETURN dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF);
+	if (!SQL_SUCCEEDED(dberr)) {
+		throw Error(dberr, SQL_HANDLE_DBC, conn);
 	}
-	txDepth += 1;
-	return txDepth;
 }
 
-int
-ODBC::Connection::commitTx() const
+void
+ODBC::Connection::commitTxInt()
 {
-	if (txDepth > 0) {
-		if (txAborted) {
-			return rollbackTx();
-		}
-		txDepth -= 1;
-		if (txDepth == 0) {
-			SQLRETURN dberr = SQLEndTran(SQL_HANDLE_DBC, conn, SQL_COMMIT);
-			if (!SQL_SUCCEEDED(dberr)) {
-				throw Error(dberr, SQL_HANDLE_DBC, conn);
-			}
-			dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
-			if (!SQL_SUCCEEDED(dberr)) {
-				throw Error(dberr, SQL_HANDLE_DBC, conn);
-			}
-			txAborted = false;
-		}
-		return txDepth;
+	SQLRETURN dberr = SQLEndTran(SQL_HANDLE_DBC, conn, SQL_COMMIT);
+	if (!SQL_SUCCEEDED(dberr)) {
+		throw Error(dberr, SQL_HANDLE_DBC, conn);
 	}
-	throw DB::TransactionRequired();
-}
-
-int
-ODBC::Connection::rollbackTx() const
-{
-	if (txDepth > 0) {
-		txDepth -= 1;
-		if (txDepth == 0) {
-			SQLRETURN dberr = SQLEndTran(SQL_HANDLE_DBC, conn, SQL_ROLLBACK);
-			if (!SQL_SUCCEEDED(dberr)) {
-				throw Error(dberr, SQL_HANDLE_DBC, conn);
-			}
-			dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
-			if (!SQL_SUCCEEDED(dberr)) {
-			throw Error(dberr, SQL_HANDLE_DBC, conn);
-			}
-			txAborted = false;
-		}
-		return txDepth;
+	dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
+	if (!SQL_SUCCEEDED(dberr)) {
+		throw Error(dberr, SQL_HANDLE_DBC, conn);
 	}
-	throw DB::TransactionRequired();
 }
 
 void
-ODBC::Connection::abortTx() const
+ODBC::Connection::rollbackTxInt()
 {
-	txAborted = true;
-}
-
-bool
-ODBC::Connection::txIsAborted() const
-{
-	return txAborted;
-}
-
-bool
-ODBC::Connection::inTx() const
-{
-	return (txDepth > 0);
+	SQLRETURN dberr = SQLEndTran(SQL_HANDLE_DBC, conn, SQL_ROLLBACK);
+	if (!SQL_SUCCEEDED(dberr)) {
+		throw Error(dberr, SQL_HANDLE_DBC, conn);
+	}
+	dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
+	if (!SQL_SUCCEEDED(dberr)) {
+		throw Error(dberr, SQL_HANDLE_DBC, conn);
+	}
 }
 
 DB::BulkDeleteStyle
diff --git a/libodbcpp/odbc-connection.h b/libodbcpp/odbc-connection.h
index 7fe5c56..97305e1 100644
--- a/libodbcpp/odbc-connection.h
+++ b/libodbcpp/odbc-connection.h
@@ -21,14 +21,10 @@ namespace ODBC {
 			SQLHENV 		env;
 			SQLHDBC 		conn;
 
-			void			finish() const override;
-			int				beginTx() const override;
-			int				commitTx() const override;
-			int				rollbackTx() const override;
-			void			abortTx() const;
-			bool			txIsAborted() const;
-			bool			inTx() const override;
-			void			ping() const override;
+			void beginTxInt() override;
+			void commitTxInt() override;
+			void rollbackTxInt() override;
+			void ping() const override;
 			std::string		getAttrStr(SQLINTEGER) const;
 			SQLINTEGER		getAttrInt(SQLINTEGER) const;
 			DB::BulkDeleteStyle bulkDeleteStyle() const override;
@@ -43,8 +39,6 @@ namespace ODBC {
 
 			void			connectPre();
 			void			connectPost();
-			mutable unsigned int	txDepth;
-			mutable bool			txAborted;
 	};
 }
 
diff --git a/libodbcpp/odbc-modifycommand.cpp b/libodbcpp/odbc-modifycommand.cpp
index cb6d3c0..0c49f92 100644
--- a/libodbcpp/odbc-modifycommand.cpp
+++ b/libodbcpp/odbc-modifycommand.cpp
@@ -16,11 +16,11 @@ unsigned int
 ODBC::ModifyCommand::execute(bool anc)
 {
 	RETCODE rc = SQLExecute(hStmt); 
-    if (!SQL_SUCCEEDED(rc)) {
+	if (!SQL_SUCCEEDED(rc)) {
 		if (rc != SQL_NO_DATA || !anc) {
 			throw Error(rc, SQL_HANDLE_STMT, hStmt);
 		}
-    }
+	}
 	SQLLEN rows;
 	rc = SQLRowCount(hStmt, &rows);
 	if (!SQL_SUCCEEDED(rc)) {
-- 
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