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+// file : odb/mysql/view-result.txx
+// license : GNU GPL v2; see accompanying LICENSE file
+
+#include <odb/callback.hxx>
+#include <odb/exceptions.hxx>
+
+#include <odb/mysql/view-statements.hxx>
+
+namespace odb
+{
+ namespace mysql
+ {
+ template <typename T>
+ view_result_impl<T>::
+ ~view_result_impl ()
+ {
+ if (!this->end_)
+ statement_->free_result ();
+ }
+
+ template <typename T>
+ void view_result_impl<T>::
+ invalidate ()
+ {
+ if (!this->end_)
+ {
+ statement_->free_result ();
+ this->end_ = true;
+ }
+
+ statement_.reset ();
+ }
+
+ template <typename T>
+ view_result_impl<T>::
+ view_result_impl (const query_base&,
+ details::shared_ptr<select_statement> statement,
+ statements_type& statements,
+ const schema_version_migration* svm)
+ : base_type (statements.connection ()),
+ statement_ (statement),
+ statements_ (statements),
+ tc_ (svm),
+ count_ (0)
+ {
+ }
+
+ template <typename T>
+ void view_result_impl<T>::
+ load (view_type& view)
+ {
+ if (count_ > statement_->fetched ())
+ fetch ();
+
+ view_traits::callback (this->db_, view, callback_event::pre_load);
+ tc_.init (view, statements_.image (), &this->db_);
+ view_traits::callback (this->db_, view, callback_event::post_load);
+ }
+
+ template <typename T>
+ void view_result_impl<T>::
+ next ()
+ {
+ this->current (pointer_type ());
+
+ if (this->end_)
+ return;
+
+ // If we are cached, simply increment the position and
+ // postpone the actual row fetching until later. This way
+ // if the same view is loaded in between iteration, the
+ // image won't be messed up.
+ //
+ count_++;
+
+ if (statement_->cached ())
+ this->end_ = count_ > statement_->result_size ();
+ else
+ fetch ();
+
+ if (this->end_)
+ statement_->free_result ();
+ }
+
+ template <typename T>
+ void view_result_impl<T>::
+ fetch ()
+ {
+ // If the result is cached, the image can grow between calls
+ // to fetch() as a result of other statements execution.
+ //
+ if (statement_->cached ())
+ {
+ typename view_traits::image_type& im (statements_.image ());
+
+ if (im.version != statements_.image_version ())
+ {
+ binding& b (statements_.image_binding ());
+ tc_.bind (b.bind, im);
+ statements_.image_version (im.version);
+ b.version++;
+ }
+ }
+
+ while (!this->end_ && count_ > statement_->fetched ())
+ {
+ select_statement::result r (statement_->fetch ());
+
+ switch (r)
+ {
+ case select_statement::truncated:
+ {
+ // Don't re-fetch data we are skipping.
+ //
+ if (count_ != statement_->fetched ())
+ continue;
+
+ typename view_traits::image_type& im (statements_.image ());
+
+ if (tc_.grow (im, statements_.image_truncated ()))
+ im.version++;
+
+ if (im.version != statements_.image_version ())
+ {
+ binding& b (statements_.image_binding ());
+ tc_.bind (b.bind, im);
+ statements_.image_version (im.version);
+ b.version++;
+ statement_->refetch ();
+ }
+ // Fall throught.
+ }
+ case select_statement::success:
+ {
+ break;
+ }
+ case select_statement::no_data:
+ {
+ this->end_ = true;
+ break;
+ }
+ }
+ }
+ }
+
+ template <typename T>
+ void view_result_impl<T>::
+ cache ()
+ {
+ if (!this->end_ && !statement_->cached ())
+ {
+ statement_->cache ();
+
+ if (count_ == statement_->result_size ())
+ {
+ statement_->free_result ();
+ count_++; // One past the result size.
+ this->end_ = true;
+ }
+ }
+ }
+
+ template <typename T>
+ std::size_t view_result_impl<T>::
+ size ()
+ {
+ if (!this->end_)
+ {
+ if (!statement_->cached ())
+ throw result_not_cached ();
+
+ return statement_->result_size ();
+ }
+ else
+ return count_ - 1; // One past the result size.
+ }
+ }
+}