Initial implementation

1 files changed, 139 insertions, 0 deletions

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+// file      : odb/transaction.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009-2010 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef ODB_TRANSACTION_HXX
+#define ODB_TRANSACTION_HXX
+
+#include <new> // placement new
+
+#include <odb/forward.hxx>
+
+namespace odb
+{
+  class transaction_impl;
+
+  class transaction
+  {
+  public:
+    typedef odb::session session_type;
+    typedef odb::database database_type;
+
+    explicit
+    transaction (transaction_impl*);
+
+    // Unless the transaction has been already been finilized (explicitly
+    // committed or rolled back), the destructor will roll it back.
+    //
+    ~transaction ();
+
+    void
+    commit ();
+
+    void
+    rollback ();
+
+    // Return the database this transaction is on.
+    //
+    database_type&
+    database ();
+
+    // Return the session this transaction is part of.
+    //
+    session_type&
+    session ();
+
+    // Return current transaction or throw if there is no transaction
+    // in effect.
+    //
+    static transaction&
+    current ();
+
+    // Return true if there is a transaction in effect.
+    //
+    static bool
+    has_current ();
+
+  public:
+    transaction_impl&
+    implementation ();
+
+  private:
+    // Copying or assignment of transactions is not supported.
+    //
+    transaction (const transaction&);
+    transaction& operator= (const transaction&);
+
+  protected:
+    bool finilized_;
+    transaction_impl* impl_;
+  };
+}
+
+#include <odb/session.hxx>
+
+namespace odb
+{
+  class transaction_impl
+  {
+  protected:
+    friend class transaction;
+
+    typedef odb::session session_type;
+    typedef odb::database database_type;
+
+    transaction_impl (database_type& db, session_type& s)
+        : database_ (db), session_ (s)
+    {
+    }
+
+    transaction_impl (database_type& db)
+        : database_ (db),
+          session_ (*reinterpret_cast<session_type*> (&session_mem_))
+    {
+      new (&session_mem_) session_type ();
+    }
+
+    virtual
+    ~transaction_impl ();
+
+    virtual void
+    commit () = 0;
+
+    virtual void
+    rollback () = 0;
+
+    session_type&
+    session ()
+    {
+      return session_;
+    }
+
+    database_type&
+    database ()
+    {
+      return database_;
+    }
+
+    bool
+    own_session () const
+    {
+      return &session_ == reinterpret_cast<const session_type*> (&session_mem_);
+    }
+
+  protected:
+    database_type& database_;
+    session_type& session_;
+
+    union
+    {
+      void* align_;
+      char data_[sizeof (session_type)];
+    } session_mem_;
+  };
+}
+
+#include <odb/transaction.ixx>
+
+#endif // ODB_TRANSACTION_HXX