From 3bc5964793f1700551b7db8107a939c98f1d1be1 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 13 Jun 2021 21:29:25 +0100
Subject: Add transaction support
---
lib/dbConn.cpp | 18 ++++++++++++++++++
lib/dbConn.h | 22 ++++++++++++++++++++++
lib/input/mysqlConn.cpp | 20 ++++++++++++++++++++
lib/input/mysqlConn.h | 4 ++++
lib/output/pq/pqConn.cpp | 18 ++++++++++++++++++
lib/output/pq/pqConn.h | 4 ++++
6 files changed, 86 insertions(+)
create mode 100644 lib/dbConn.cpp
(limited to 'lib')
diff --git a/lib/dbConn.cpp b/lib/dbConn.cpp
new file mode 100644
index 0000000..380910a
--- /dev/null
+++ b/lib/dbConn.cpp
@@ -0,0 +1,18 @@
+#include "dbConn.h"
+
+namespace MyGrate {
+ Tx::Tx(DbConn * c) : conn {c}
+ {
+ conn->beginTx();
+ }
+
+ Tx::~Tx()
+ {
+ if (std::uncaught_exceptions()) {
+ conn->rollbackTx();
+ }
+ else {
+ conn->commitTx();
+ }
+ }
+}
diff --git a/lib/dbConn.h b/lib/dbConn.h
index 3f14dcb..ffdd2e0 100644
--- a/lib/dbConn.h
+++ b/lib/dbConn.h
@@ -24,6 +24,28 @@ namespace MyGrate {
virtual void query(const char * const, const std::initializer_list<DbValue> &) = 0;
virtual DbPrepStmtPtr prepare(const char * const, std::size_t nParams) = 0;
+
+ virtual void beginTx() = 0;
+ virtual void commitTx() = 0;
+ virtual void rollbackTx() = 0;
+ };
+
+ class Tx {
+ public:
+ explicit Tx(DbConn *);
+ Tx(const Tx &) = delete;
+ Tx(Tx &&) = delete;
+ ~Tx();
+
+ template<typename C>
+ auto
+ operator()(C && callback)
+ {
+ return callback();
+ }
+
+ private:
+ DbConn * conn;
};
}
diff --git a/lib/input/mysqlConn.cpp b/lib/input/mysqlConn.cpp
index 362f9ea..99c2891 100644
--- a/lib/input/mysqlConn.cpp
+++ b/lib/input/mysqlConn.cpp
@@ -52,4 +52,24 @@ namespace MyGrate::Input {
{
return std::make_unique<MySQLPrepStmt>(q, this);
}
+
+ void
+ MySQLConn::beginTx()
+ {
+ verify<MySQLErr>(!mysql_autocommit(this, false), "Auto commit off", this);
+ }
+
+ void
+ MySQLConn::commitTx()
+ {
+ verify<MySQLErr>(!mysql_commit(this), "Commit", this);
+ verify<MySQLErr>(!mysql_autocommit(this, true), "Auto commit on", this);
+ }
+
+ void
+ MySQLConn::rollbackTx()
+ {
+ verify<MySQLErr>(!mysql_rollback(this), "Rollback", this);
+ verify<MySQLErr>(!mysql_autocommit(this, true), "Auto commit on", this);
+ }
}
diff --git a/lib/input/mysqlConn.h b/lib/input/mysqlConn.h
index dfb408f..bd53616 100644
--- a/lib/input/mysqlConn.h
+++ b/lib/input/mysqlConn.h
@@ -29,6 +29,10 @@ namespace MyGrate::Input {
void query(const char * const q, const std::initializer_list<DbValue> &) override;
DbPrepStmtPtr prepare(const char * const, std::size_t) override;
+
+ void beginTx() override;
+ void commitTx() override;
+ void rollbackTx() override;
};
}
diff --git a/lib/output/pq/pqConn.cpp b/lib/output/pq/pqConn.cpp
index 309b704..ba95cad 100644
--- a/lib/output/pq/pqConn.cpp
+++ b/lib/output/pq/pqConn.cpp
@@ -43,6 +43,24 @@ namespace MyGrate::Output::Pq {
return std::make_unique<PqPrepStmt>(q, n, this);
}
+ void
+ PqConn::beginTx()
+ {
+ query("BEGIN");
+ }
+
+ void
+ PqConn::commitTx()
+ {
+ query("COMMIT");
+ }
+
+ void
+ PqConn::rollbackTx()
+ {
+ query("ROLLBACK");
+ }
+
void
PqConn::notice_processor(void * p, const char * n)
{
diff --git a/lib/output/pq/pqConn.h b/lib/output/pq/pqConn.h
index 6db9bcf..3b27f97 100644
--- a/lib/output/pq/pqConn.h
+++ b/lib/output/pq/pqConn.h
@@ -32,6 +32,10 @@ namespace MyGrate::Output::Pq {
DbPrepStmtPtr prepare(const char * const, std::size_t nParams) override;
+ void beginTx() override;
+ void commitTx() override;
+ void rollbackTx() override;
+
const std::string connstr;
private:
--
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