Implement support for database operations callbacks

New object pragma: callback. New test: common/callback. New manual
section: 10.1.4, "callback".

3 files changed, 84 insertions, 21 deletions

diff --git a/odb/callback.hxx b/odb/callback.hxx
new file mode 100644
index 0000000..16d89ef
--- /dev/null
+++ b/odb/callback.hxx
@@ -0,0 +1,44 @@
+// file      : odb/callback.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef ODB_CALLBACK_HXX
+#define ODB_CALLBACK_HXX
+
+#include <odb/pre.hxx>
+
+#include <odb/details/export.hxx>
+
+namespace odb
+{
+  struct LIBODB_EXPORT callback_event
+  {
+    enum value
+    {
+      pre_persist,
+      post_persist,
+      pre_load,
+      post_load,
+      pre_update,
+      post_update,
+      pre_erase,
+      post_erase
+    };
+
+    callback_event (value v): v_ (v) {}
+    operator value () const {return v_;}
+
+  private:
+    value v_;
+  };
+
+  namespace core
+  {
+    using odb::callback_event;
+  }
+}
+
+#include <odb/post.hxx>
+
+#endif // ODB_CALLBACK_HXX
diff --git a/odb/database.ixx b/odb/database.ixx
index 252f866..bd3fb44 100644
--- a/odb/database.ixx
+++ b/odb/database.ixx
@@ -104,18 +104,6 @@ namespace odb
 
   template <typename T>
   inline void database::
-  erase (T& obj)
-  {
-    // T can be const T while object_type will always be T.
-    //
-    typedef typename odb::object_traits<T>::object_type object_type;
-    typedef odb::object_traits<object_type> object_traits;
-
-    erase<T> (object_traits::id (obj));
-  }
-
-  template <typename T>
-  inline void database::
   erase (T* p)
   {
     typedef typename object_traits<T>::pointer_type object_pointer;
@@ -163,15 +151,10 @@ namespace odb
   inline void database::
   erase_ (const typename object_traits<T>::pointer_type& pobj)
   {
-    // T can be const T while object_type will always be T.
-    //
-    typedef typename odb::object_traits<T>::object_type object_type;
-    typedef odb::object_traits<object_type> object_traits;
-
-    typedef typename odb::object_traits<T>::pointer_type pointer_type;
-    typedef odb::pointer_traits<pointer_type> pointer_traits;
+    typedef typename object_traits<T>::pointer_type pointer_type;
+    typedef pointer_traits<pointer_type> pointer_traits;
 
-    erase<T> (object_traits::id (pointer_traits::get_ref (pobj)));
+    erase<T> (pointer_traits::get_ref (pobj));
   }
 
   template <typename T>
diff --git a/odb/database.txx b/odb/database.txx
index b79c6f8..832c7ad 100644
--- a/odb/database.txx
+++ b/odb/database.txx
@@ -6,6 +6,7 @@
 #include <odb/exceptions.hxx>
 #include <odb/transaction.hxx>
 #include <odb/session.hxx>
+#include <odb/callback.hxx>
 #include <odb/cache-traits.hxx>
 #include <odb/pointer-traits.hxx>
 
@@ -23,7 +24,10 @@ namespace odb
     if (!transaction::has_current ())
       throw not_in_transaction ();
 
+    object_traits::callback (*this, obj, callback_event::pre_persist);
     object_traits::persist (*this, obj);
+    object_traits::callback (*this, obj, callback_event::post_persist);
+
     const typename object_traits::id_type& id (object_traits::id (obj));
     reference_cache_traits<T>::insert (*this, id, obj);
     return id;
@@ -45,7 +49,11 @@ namespace odb
       throw not_in_transaction ();
 
     T& obj (pointer_traits::get_ref (pobj));
+
+    object_traits::callback (*this, obj, callback_event::pre_persist);
     object_traits::persist (*this, obj);
+    object_traits::callback (*this, obj, callback_event::post_persist);
+
     const typename object_traits::id_type& id (object_traits::id (obj));
     pointer_cache_traits<pointer_type>::insert (*this, id, pobj);
     return id;
@@ -132,7 +140,9 @@ namespace odb
     if (!transaction::has_current ())
       throw not_in_transaction ();
 
+    object_traits::callback (*this, obj,callback_event::pre_update);
     object_traits::update (*this, obj);
+    object_traits::callback (*this, obj, callback_event::post_update);
   }
 
   template <typename T>
@@ -150,7 +160,11 @@ namespace odb
     if (!transaction::has_current ())
       throw not_in_transaction ();
 
-    object_traits::update (*this, pointer_traits::get_ref (pobj));
+    T& obj (pointer_traits::get_ref (pobj));
+
+    object_traits::callback (*this, obj, callback_event::pre_update);
+    object_traits::update (*this, obj);
+    object_traits::callback (*this, obj, callback_event::post_update);
   }
 
   template <typename T>
@@ -172,6 +186,28 @@ namespace odb
   }
 
   template <typename T>
+  void database::
+  erase (T& obj)
+  {
+    // T can be const T while object_type will always be T.
+    //
+    typedef typename odb::object_traits<T>::object_type object_type;
+    typedef odb::object_traits<object_type> object_traits;
+
+    typedef typename odb::object_traits<T>::pointer_type pointer_type;
+
+    if (!transaction::has_current ())
+      throw not_in_transaction ();
+
+    typename object_traits::id_type id (object_traits::id (obj));
+
+    object_traits::callback (*this, obj, callback_event::pre_erase);
+    object_traits::erase (*this, id);
+    pointer_cache_traits<pointer_type>::erase (*this, id);
+    object_traits::callback (*this, obj, callback_event::post_erase);
+  }
+
+  template <typename T>
   result<T> database::
   query (const odb::query<typename object_traits<T>::object_type>& q,
          bool cache)