diff options
author | Boris Kolpackov <boris@codesynthesis.com> | 2011-09-05 10:20:47 +0200 |
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committer | Boris Kolpackov <boris@codesynthesis.com> | 2011-09-05 10:20:47 +0200 |
commit | 0979184f66b49440758b7fc2b81172af7fe47ad8 (patch) | |
tree | 212b703960772b904f42f08d12ed37abe86297b7 /odb/mysql/view-result.txx | |
parent | 141253ea17264e122e440cae441bf3d952329d35 (diff) |
Support for views; native part
Diffstat (limited to 'odb/mysql/view-result.txx')
-rw-r--r-- | odb/mysql/view-result.txx | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/odb/mysql/view-result.txx b/odb/mysql/view-result.txx new file mode 100644 index 0000000..51f3d6f --- /dev/null +++ b/odb/mysql/view-result.txx @@ -0,0 +1,152 @@ +// file : odb/mysql/view-result.txx +// author : Boris Kolpackov <boris@codesynthesis.com> +// copyright : Copyright (c) 2009-2011 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> + result_impl<T, class_view>:: + ~result_impl () + { + } + + template <typename T> + result_impl<T, class_view>:: + result_impl (const query&, + details::shared_ptr<select_statement> statement, + view_statements<view_type>& statements) + : base_type (statements.connection ().database ()), + statement_ (statement), + statements_ (statements), + count_ (0) + { + } + + template <typename T> + void result_impl<T, class_view>:: + load (view_type& view) + { + if (count_ > statement_->fetched ()) + fetch (); + + odb::database& db (this->database ()); + view_traits::callback (db, view, callback_event::pre_load); + + typename view_traits::image_type& i (statements_.image ()); + view_traits::init (view, i); + + view_traits::callback (db, view, callback_event::post_load); + } + + template <typename T> + void result_impl<T, class_view>:: + next () + { + this->current (pointer_type ()); + + // 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 (); + } + + template <typename T> + void result_impl<T, class_view>:: + 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 ()); + view_traits::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 (view_traits::grow (im, statements_.image_truncated ())) + im.version++; + + if (im.version != statements_.image_version ()) + { + binding& b (statements_.image_binding ()); + view_traits::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 result_impl<T, class_view>:: + cache () + { + if (!statement_->cached ()) + { + statement_->cache (); + + if (count_ >= statement_->result_size ()) + this->end_ = true; + } + } + + template <typename T> + std::size_t result_impl<T, class_view>:: + size () + { + if (!statement_->cached ()) + throw result_not_cached (); + + return statement_->result_size (); + } + } +} |