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// file : odb/mysql/view-result.txx
// copyright : Copyright (c) 2009-2017 Code Synthesis Tools CC
// 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.
}
}
}
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