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Diffstat (limited to 'odb/mssql/polymorphic-object-result.txx')
| -rw-r--r-- | odb/mssql/polymorphic-object-result.txx | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/odb/mssql/polymorphic-object-result.txx b/odb/mssql/polymorphic-object-result.txx new file mode 100644 index 0000000..be4a6ab --- /dev/null +++ b/odb/mssql/polymorphic-object-result.txx @@ -0,0 +1,304 @@ +// file : odb/mssql/polymorphic-object-result.txx +// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC +// license : ODB NCUEL; see accompanying LICENSE file + +#include <cassert> + +#include <odb/callback.hxx> +#include <odb/cache-traits.hxx> +#include <odb/exceptions.hxx> // result_not_cached + +#include <odb/mssql/exceptions.hxx> // long_data_reload +#include <odb/mssql/polymorphic-object-statements.hxx> + +namespace odb +{ + namespace mssql + { + template <typename T> + polymorphic_object_result_impl<T>:: + ~polymorphic_object_result_impl () + { + change_callback_type& cc ( + statements_.root_statements ().image ().change_callback_); + + if (cc.context == this) + { + cc.context = 0; + cc.callback = 0; + } + + if (image_copy_ != 0) + object_traits::free_image (image_copy_); + + if (!this->end_) + statement_->free_result (); + } + + template <typename T> + polymorphic_object_result_impl<T>:: + polymorphic_object_result_impl (const query&, + details::shared_ptr<select_statement> st, + statements_type& sts) + : base_type (sts.connection ().database ()), + statement_ (st), + statements_ (sts), + use_copy_ (false), + image_copy_ (0) + { + } + + template <typename T> + void polymorphic_object_result_impl<T>:: + load (object_type* pobj, bool) + { + if (!can_load_) + throw long_data_reload (); + + typename statements_type::root_statements_type& rsts ( + statements_.root_statements ()); + + // This is a top-level call so the statements cannot be locked. + // + assert (!rsts.locked ()); + typename statements_type::auto_lock l (rsts); + + odb::database& db (this->database ()); + image_type& i (use_copy_ ? *image_copy_ : statements_.image ()); + typename root_traits::image_type& ri ( + use_copy_ ? object_traits::root_image (i) : rsts.image ()); + + id_type id (root_traits::id (ri)); + + // Determine this object's dynamic type. + // + typedef typename root_traits::info_type info_type; + discriminator_type d (root_traits::discriminator (ri)); + + // Use the polymorphic_info() helper to get concrete_info if + // object_type is concrete and NULL if it is abstract. + // + const info_type* spi (polymorphic_info (object_traits::info)); + const info_type& pi ( + spi != 0 && spi->discriminator == d + ? *spi + : root_traits::map->find (d)); + + typedef typename root_traits::pointer_type root_pointer_type; + typedef typename root_traits::pointer_traits root_pointer_traits; + + typename object_traits::pointer_cache_traits::insert_guard ig; + + if (pobj == 0) + { + // Need to create a new instance of the dynamic type. + // + root_pointer_type rp (pi.create ()); + pointer_type p ( + root_pointer_traits::template static_pointer_cast<object_type> (rp)); + + // Insert it as a root pointer (for non-unique pointers, rp should + // still be valid and for unique pointers this is a no-op). + // + ig.reset (object_traits::pointer_cache_traits::insert (db, id, rp)); + + pobj = &pointer_traits::get_ref (p); + current (p); + } + else + { + // We are loading into an existing instance. If the static and + // dynamic types differ, then make sure the instance is at least + // of the dynamic type. + // + if (&pi != &object_traits::info) + { + const info_type& dpi (root_traits::map->find (typeid (*pobj))); + + if (&dpi != &pi && dpi.derived (pi)) + throw object_not_persistent (); // @@ type_mismatch ? + } + } + + callback_event ce (callback_event::pre_load); + pi.dispatch (info_type::call_callback, db, pobj, &ce); + + object_traits::init (*pobj, i, &db); + + // If we are using a copy, make sure the callback information for + // long data also comes from the copy. + // + can_load_ = !statement_->stream_result ( + use_copy_ ? &statements_.image () : 0, + use_copy_ ? image_copy_ : 0); + + // Initialize the id image and binding and load the rest of the object + // (containers, dynamic part, etc). + // + typename object_traits::id_image_type& idi (statements_.id_image ()); + root_traits::init (idi, id); + + binding& idb (statements_.id_image_binding ()); + if (idi.version != statements_.id_image_version () || idb.version == 0) + { + object_traits::bind (idb.bind, idi); + statements_.id_image_version (idi.version); + idb.version++; + } + + object_traits::load_ (statements_, *pobj); + + // Load the dynamic part of the object unless static and dynamic + // types are the same. + // + if (&pi != &object_traits::info) + { + std::size_t d (object_traits::depth); + pi.dispatch (info_type::call_load, db, pobj, &d); + }; + + rsts.load_delayed (); + l.unlock (); + + ce = callback_event::post_load; + pi.dispatch (info_type::call_callback, db, pobj, &ce); + ig.release (); + } + + template <typename T> + typename polymorphic_object_result_impl<T>::id_type + polymorphic_object_result_impl<T>:: + load_id () + { + typename root_traits::image_type& i ( + use_copy_ + ? object_traits::root_image (*image_copy_) + : statements_.root_statements ().image ()); + + return root_traits::id (i); + } + + template <typename T> + typename polymorphic_object_result_impl<T>::discriminator_type + polymorphic_object_result_impl<T>:: + load_discriminator () + { + typename root_traits::image_type& i ( + use_copy_ + ? object_traits::root_image (*image_copy_) + : statements_.root_statements ().image ()); + + return root_traits::discriminator (i); + } + + template <typename T, typename R> + struct polymorphic_image_rebind + { + // Derived type version. + // + typedef object_traits<T> traits; + + static void + rebind (typename traits::statements_type& sts) + { + typename traits::image_type& im (sts.image ()); + + if (traits::check_version (sts.select_image_versions (), im)) + { + binding& b (sts.select_image_binding (traits::depth)); + traits::bind (b.bind, 0, 0, im, statement_select); + traits::update_version ( + sts.select_image_versions (), im, sts.select_image_bindings ()); + } + } + }; + + template <typename R> + struct polymorphic_image_rebind<R, R> + { + // Root type version. + // + typedef object_traits<R> traits; + + static void + rebind (typename traits::statements_type& sts) + { + typename traits::image_type& im (sts.image ()); + + if (im.version != sts.select_image_version ()) + { + binding& b (sts.select_image_binding ()); + traits::bind (b.bind, im, statement_select); + sts.select_image_version (im.version); + b.version++; + } + } + }; + + template <typename T> + void polymorphic_object_result_impl<T>:: + next () + { + can_load_ = true; + this->current (pointer_type ()); + + change_callback_type& cc ( + statements_.root_statements ().image ().change_callback_); + + if (cc.context == this) + { + cc.callback = 0; + cc.context = 0; + } + + use_copy_ = false; + polymorphic_image_rebind<object_type, root_type>::rebind (statements_); + + if (statement_->fetch () == select_statement::no_data) + { + statement_->free_result (); + this->end_ = true; + } + else + { + cc.callback = &change_callback; + cc.context = this; + } + } + + template <typename T> + void polymorphic_object_result_impl<T>:: + cache () + { + } + + template <typename T> + std::size_t polymorphic_object_result_impl<T>:: + size () + { + throw result_not_cached (); + } + + template <typename T> + void polymorphic_object_result_impl<T>:: + change_callback (void* c) + { + polymorphic_object_result_impl<T>* r ( + static_cast<polymorphic_object_result_impl<T>*> (c)); + image_type& im (r->statements_.image ()); + + if (r->image_copy_ == 0) + r->image_copy_ = object_traits::clone_image (im); + else + object_traits::copy_image (*r->image_copy_, im); + + typename root_traits::image_type& rim ( + r->statements_.root_statements ().image ()); + + rim.change_callback_.callback = 0; + rim.change_callback_.context = 0; + + r->use_copy_ = true; + } + } +} |