diff options
Diffstat (limited to 'libodb-mysql/odb/mysql/simple-object-result.txx')
-rw-r--r-- | libodb-mysql/odb/mysql/simple-object-result.txx | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/libodb-mysql/odb/mysql/simple-object-result.txx b/libodb-mysql/odb/mysql/simple-object-result.txx new file mode 100644 index 0000000..5c6e198 --- /dev/null +++ b/libodb-mysql/odb/mysql/simple-object-result.txx @@ -0,0 +1,235 @@ +// file : odb/mysql/simple-object-result.txx +// license : GNU GPL v2; see accompanying LICENSE file + +#include <cassert> + +#include <odb/callback.hxx> +#include <odb/exceptions.hxx> // result_not_cached + +#include <odb/mysql/simple-object-statements.hxx> + +namespace odb +{ + namespace mysql + { + template <typename T> + object_result_impl<T>:: + ~object_result_impl () + { + if (!this->end_) + statement_->free_result (); + } + + template <typename T> + void object_result_impl<T>:: + invalidate () + { + if (!this->end_) + { + statement_->free_result (); + this->end_ = true; + } + + statement_.reset (); + } + + template <typename T> + object_result_impl<T>:: + object_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 object_result_impl<T>:: + load (object_type& obj, bool f) + { + if (count_ > statement_->fetched ()) + fetch (); + else if (f && statement_->cached ()) + { + // We have to re-load the image in case it has been overwritten + // between the last time we fetched and this call to load(). + // + fetch (false); + } + + // This is a top-level call so the statements cannot be locked. + // + assert (!statements_.locked ()); + typename statements_type::auto_lock l (statements_); + + object_traits::callback (this->db_, obj, callback_event::pre_load); + + typename object_traits::image_type& i (statements_.image ()); + tc_.init (obj, i, &this->db_); + + // Initialize the id image and binding and load the rest of the object + // (containers, etc). + // + typename object_traits::id_image_type& idi (statements_.id_image ()); + object_traits::init (idi, object_traits::id (i)); + + 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++; + } + + tc_.load_ (statements_, obj, false); + statements_.load_delayed (tc_.version ()); + l.unlock (); + object_traits::callback (this->db_, obj, callback_event::post_load); + } + + template <typename T> + typename object_result_impl<T>::id_type + object_result_impl<T>:: + load_id () + { + if (count_ > statement_->fetched ()) + fetch (); + else if (statement_->cached ()) + { + // We have to re-load the image in case it has been overwritten + // between the last time we fetched and this call to load_id(). + // + fetch (false); + } + + return object_traits::id (statements_.image ()); + } + + template <typename T> + void object_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 object 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 object_result_impl<T>:: + fetch (bool next) + { + // If the result is cached, the image can grow between calls + // to fetch() as a result of other statements execution. + // + if (statement_->cached ()) + { + typename object_traits::image_type& im (statements_.image ()); + + if (im.version != statements_.select_image_version ()) + { + binding& b (statements_.select_image_binding ()); + tc_.bind (b.bind, im, statement_select); + statements_.select_image_version (im.version); + b.version++; + } + } + + while (!this->end_ && (!next || count_ > statement_->fetched ())) + { + select_statement::result r (statement_->fetch (next)); + + switch (r) + { + case select_statement::truncated: + { + // Don't re-fetch data we are skipping. + // + if (next && count_ != statement_->fetched ()) + continue; + + typename object_traits::image_type& im (statements_.image ()); + + if (tc_.grow (im, statements_.select_image_truncated ())) + im.version++; + + if (im.version != statements_.select_image_version ()) + { + binding& b (statements_.select_image_binding ()); + tc_.bind (b.bind, im, statement_select); + statements_.select_image_version (im.version); + b.version++; + statement_->refetch (); + } + // Fall throught. + } + case select_statement::success: + { + break; + } + case select_statement::no_data: + { + this->end_ = true; + break; + } + } + + // If we are refetching the current row, then we are done. + // + if (!next) + break; + } + } + + template <typename T> + void object_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 object_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. + } + } +} |