Add odb::connection class

This abstract class represents a connection to the database. One can
use it to start a transaction or to execute a native statement out
of a transaction.

Before we had concrete connection classes in the database runtime
libraries (e.g., odb::mysql::connection). Now these classes derive
from odb::connection.

1 files changed, 37 insertions, 0 deletions

diff --git a/odb/tracer/connection.cxx b/odb/tracer/connection.cxx
new file mode 100644
index 0000000..516e36a
--- /dev/null
+++ b/odb/tracer/connection.cxx
@@ -0,0 +1,37 @@
+// file      : odb/tracer/connection.cxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#include <odb/transaction.hxx>
+
+#include <odb/tracer/database.hxx>
+#include <odb/tracer/connection.hxx>
+
+namespace odb
+{
+  namespace tracer
+  {
+    connection::
+    connection (database_type& db)
+        : odb::connection (db)
+    {
+    }
+
+    unsigned long long connection::
+    execute (const char*, std::size_t)
+    {
+      return 0;
+    }
+
+    transaction_impl* connection::
+    begin ()
+    {
+      if (odb::transaction::has_current ())
+        throw already_in_transaction ();
+
+      return new transaction_impl (
+        connection_ptr (inc_ref (this)));
+    }
+  }
+}