From 3a160a80c788d81e48acf19a2cf68f29cf125dae Mon Sep 17 00:00:00 2001 From: Karen Arutyunov Date: Thu, 25 Jan 2024 18:52:59 +0300 Subject: Turn libodb-mysql repository into package for muti-package repository --- libodb-mysql/odb/mysql/view-result.txx | 178 +++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+) create mode 100644 libodb-mysql/odb/mysql/view-result.txx (limited to 'libodb-mysql/odb/mysql/view-result.txx') diff --git a/libodb-mysql/odb/mysql/view-result.txx b/libodb-mysql/odb/mysql/view-result.txx new file mode 100644 index 0000000..c480920 --- /dev/null +++ b/libodb-mysql/odb/mysql/view-result.txx @@ -0,0 +1,178 @@ +// file : odb/mysql/view-result.txx +// license : GNU GPL v2; see accompanying LICENSE file + +#include +#include + +#include + +namespace odb +{ + namespace mysql + { + template + view_result_impl:: + ~view_result_impl () + { + if (!this->end_) + statement_->free_result (); + } + + template + void view_result_impl:: + invalidate () + { + if (!this->end_) + { + statement_->free_result (); + this->end_ = true; + } + + statement_.reset (); + } + + template + view_result_impl:: + view_result_impl (const query_base&, + details::shared_ptr statement, + statements_type& statements, + const schema_version_migration* svm) + : base_type (statements.connection ()), + statement_ (statement), + statements_ (statements), + tc_ (svm), + count_ (0) + { + } + + template + void view_result_impl:: + 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 + void view_result_impl:: + 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 + void view_result_impl:: + 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 + void view_result_impl:: + 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 + std::size_t view_result_impl:: + size () + { + if (!this->end_) + { + if (!statement_->cached ()) + throw result_not_cached (); + + return statement_->result_size (); + } + else + return count_ - 1; // One past the result size. + } + } +} -- cgit v1.1