diff options
Diffstat (limited to 'odb/relational/source.hxx')
| -rw-r--r-- | odb/relational/source.hxx | 317 |
1 files changed, 280 insertions, 37 deletions
diff --git a/odb/relational/source.hxx b/odb/relational/source.hxx index dcc9c23..cabb5c5 100644 --- a/odb/relational/source.hxx +++ b/odb/relational/source.hxx @@ -90,6 +90,17 @@ namespace relational line_.clear (); + // Version column (optimistic concurrency) requires special + // handling in the UPDATE statement. + // + // + if (sk_ == statement_update && version (m)) + { + string const& qname (quote_id (name)); + line_ = qname + "=" + qname + "+1"; + return true; + } + // Inverse object pointers come from a joined table. // if (im != 0) @@ -565,20 +576,22 @@ namespace relational os << "n += " << cc.total << "UL"; // select = total - // insert = total - inverse - // update = total - inverse - id - readonly + // insert = total - inverse - optimistic_managed + // update = total - inverse - optimistic_managed - id - readonly // - if (cc.inverse != 0 || (!ro && (cc.id != 0 || cc.readonly != 0))) + if (cc.inverse != 0 || + cc.optimistic_managed != 0 || + (!ro && (cc.id != 0 || cc.readonly != 0))) { os << " - (" << endl << "sk == statement_select ? 0 : "; - if (cc.inverse != 0) - os << cc.inverse << "UL" << endl; + if (cc.inverse != 0 || cc.optimistic_managed != 0) + os << (cc.inverse + cc.optimistic_managed) << "UL"; if (!ro && (cc.id != 0 || cc.readonly != 0)) { - if (cc.inverse != 0) + if (cc.inverse != 0 || cc.optimistic_managed != 0) os << " + "; os << "(" << endl @@ -2085,7 +2098,9 @@ namespace relational if (count_++ != 0) params_ += ','; - if (m.count ("id") && m.count ("auto")) + if (version (m)) + params_ += "1"; + else if (m.count ("id") && m.count ("auto")) params_ += qp_.auto_id (); else params_ += qp_.next (); @@ -2112,8 +2127,11 @@ namespace relational : grow_base_ (index_), grow_member_ (index_), bind_id_member_ ("id_"), + bind_version_member_ ("version_"), init_id_image_member_ ("id_", "id"), + init_version_image_member_ ("version_", "(*v)"), init_id_value_member_ ("id"), + init_version_value_member_ ("v"), stream_ (emitter_), drop_model_ (emitter_, stream_, format_embedded), drop_table_ (emitter_, stream_, format_embedded), @@ -2131,8 +2149,11 @@ namespace relational grow_base_ (index_), grow_member_ (index_), bind_id_member_ ("id_"), + bind_version_member_ ("version_"), init_id_image_member_ ("id_", "id"), + init_version_image_member_ ("version_", "(*v)"), init_id_value_member_ ("id"), + init_version_value_member_ ("v"), stream_ (emitter_), drop_model_ (emitter_, stream_, format_embedded), drop_table_ (emitter_, stream_, format_embedded), @@ -2266,13 +2287,16 @@ namespace relational bool auto_id (id ? id->count ("auto") : false); bool base_id (id ? &id->scope () != &c : false); // Comes from base. + semantics::data_member* optimistic (context::optimistic (c)); + bool grow (false); bool grow_id (false); if (generate_grow) { grow = context::grow (c); - grow_id = id ? context::grow (*id) : false; + grow_id = (id ? context::grow (*id) : false) || + (optimistic ? context::grow (*optimistic) : false); } column_count_type const& cc (column_count (c)); @@ -2345,6 +2369,18 @@ namespace relational << "}"; } + if (id != 0 && optimistic != 0 && !base_id) + { + os << traits << "::version_type" << endl + << traits << "::" << endl + << "version (const image_type& i)" + << "{" + << "version_type v;"; + init_version_value_member_->traverse (*optimistic); + os << "return v;" + << "}"; + } + // grow () // if (generate_grow) @@ -2397,7 +2433,17 @@ namespace relational << "bind (" << bind_vector << " b, id_image_type& i)" << "{" << "std::size_t n (0);"; + bind_id_member_->traverse (*id); + + if (optimistic != 0) + { + os << "n++;" //@@ composite id + << endl; + + bind_version_member_->traverse (*optimistic); + } + os << "}"; } @@ -2449,17 +2495,27 @@ namespace relational if (id != 0 && !base_id) { os << "void " << traits << "::" << endl - << "init (id_image_type& i, const id_type& id)" + << "init (id_image_type& i, const id_type& id" << + (optimistic != 0 ? ", const version_type* v" : "") << ")" << "{"; if (grow_id) - os << "bool grew (false);"; + os << "bool grew (false);" + << endl; init_id_image_member_->traverse (*id); + if (optimistic != 0) + { + // Here we rely on the fact that init_image_member + // always wraps the statements in a block. + // + os << "if (v != 0)"; + init_version_image_member_->traverse (*optimistic); + } + if (grow_id) - os << endl - << "if (grew)" << endl + os << "if (grew)" << endl << "i.version++;"; os << "}"; @@ -2564,7 +2620,13 @@ namespace relational instance<object_columns> t (statement_update, true, qp.get ()); t->traverse (c); - os << strlit (" WHERE " + id_col + "=" + qp->next ()) << ";" + string where (" WHERE " + id_col + "=" + qp->next ()); + + if (optimistic != 0) + where += " AND " + column_qname (*optimistic) + "=" + + qp->next (); + + os << strlit (where) << ";" << endl; } @@ -2577,6 +2639,20 @@ namespace relational << strlit (" WHERE " + id_col + "=" + qp->next ()) << ";" << endl; } + + if (optimistic != 0) + { + instance<query_parameters> qp; + + string where (" WHERE " + id_col + "=" + qp->next ()); + where += " AND " + column_qname (*optimistic) + "=" + qp->next (); + + os << "const char " << traits << + "::optimistic_erase_statement[] =" << endl + << strlit ("DELETE FROM " + table) << endl + << strlit (where) << ";" + << endl; + } } if (options.generate_query ()) @@ -2678,6 +2754,19 @@ namespace relational << endl; } + if (optimistic != 0) + { + // Set the version in the object member. + // + if (!auto_id || const_type (optimistic->type ())) + os << "const_cast< version_type& > (" << + "obj." << optimistic->name () << ") = 1;"; + else + os << "obj." << optimistic->name () << " = 1;"; + + os << endl; + } + if (straight_containers) { // Initialize id_image and binding. @@ -2718,9 +2807,15 @@ namespace relational { // Initialize object and id images. // - os << "id_image_type& i (sts.id_image ());" - << "init (i, obj." << id->name () << ");" - << endl + os << "id_image_type& i (sts.id_image ());"; + + if (optimistic == 0) + os << "init (i, obj." << id->name () << ");"; + else + os << "init (i, obj." << id->name () << ", &obj." << + optimistic->name () << ");"; + + os << endl << "image_type& im (sts.image ());" << "if (init (im, obj, statement_update))" << endl << "im.version++;" @@ -2748,18 +2843,33 @@ namespace relational << "if (i.version != sts.update_id_image_version () || " << "idb.version == 0)" << "{" + // If the id binding is up-to-date, then that means update + // binding is too and we just need to update the versions. + // + << "if (i.version != sts.id_image_version () || " << + "idb.version == 0)" + << "{" << "bind (idb.bind, i);" - << "sts.update_id_image_version (i.version);" - << "if (!u)" << endl - << "imb.version++;" - << endl - // Update the id binding versions since we rebound it. + // Update the id binding versions since we may use them later + // to update containers. // << "sts.id_image_version (i.version);" << "idb.version++;" + << "}" + << "sts.update_id_image_version (i.version);" + << endl + << "if (!u)" << endl + << "imb.version++;" << "}"; - os << "sts.update_statement ().execute ();"; + os << "if (sts.update_statement ().execute () == 0)" << endl; + + if (optimistic == 0) + os << "throw object_not_persistent ();"; + else + os << "throw object_changed ();"; + + os << endl; } else { @@ -2772,20 +2882,28 @@ namespace relational if (straight_readwrite_containers) os << endl - << "binding& idb (sts.id_image_binding ());"; + << "binding& idb (sts.id_image_binding ());" + << endl; } if (straight_readwrite_containers) { - os << endl; instance<container_calls> t (container_calls::update_call); t->traverse (c); } + if (optimistic != 0) + { + // Update version in the object member. + // + os << "const_cast< version_type& > (" << + "obj." << optimistic->name () << ")++;"; + } + os << "}"; } - // erase () + // erase (id_type) // if (id != 0) { @@ -2823,7 +2941,6 @@ namespace relational { instance<container_calls> t (container_calls::erase_call); t->traverse (c); - os << endl; } os << "if (sts.erase_statement ().execute () != 1)" << endl @@ -2832,6 +2949,91 @@ namespace relational os << "}"; } + // erase (object_type) + // + if (id != 0 && optimistic != 0) + { + os << "void " << traits << "::" << endl + << "erase (database&, const object_type& obj)" + << "{" + << "using namespace " << db << ";" + << endl + << db << "::connection& conn (" << endl + << db << "::transaction::current ().connection ());" + << object_statements_type << "& sts (" << endl + << "conn.statement_cache ().find_object<object_type> ());" + << endl; + + // Initialize id + managed column image. + // + os << "id_image_type& i (sts.id_image ());" + << "init (i, obj." << id->name () << ", &obj." << + optimistic->name () << ");" + << endl; + + // To update the id part of the optimistic id binding we have + // to do it indirectly via the id binding, since both id and + // optimistic id bindings just point to the suffix of the + // update bind array (see object_statements). + // + os << "binding& idb (sts.id_image_binding ());" + << "binding& oidb (sts.optimistic_id_image_binding ());" + << "if (i.version != sts.optimistic_id_image_version () || " << + "oidb.version == 0)" + << "{" + // If the id binding is up-to-date, then that means optimistic + // id binding is too and we just need to update the versions. + // + << "if (i.version != sts.id_image_version () || idb.version == 0)" + << "{" + << "bind (idb.bind, i);" + // Update the id binding versions since we may use them later + // to delete containers. + // + << "sts.id_image_version (i.version);" + << "idb.version++;" + << "}" + << "sts.optimistic_id_image_version (i.version);" + << "oidb.version++;" + << "}"; + + // Erase containers first so that there are no reference + // violations (we don't want to rely on ON DELETE CASCADE + // here since in case of a custom schema, it might not be + // there). + // + if (straight_containers) + { + // Things get complicated here: we don't want to trash the + // containers and then find out that the versions don't match + // and we therefore cannot delete the object. After all, there + // is no guarantee that the user will abort the transaction. + // In fact, a perfectly reasonable scenario is to reload the + // object, re-apply the changes, and commit the transaction. + // + // There doesn't seem to be anything better than first making + // sure we can delete the object, then deleting the container + // data, and then deleting the object. To check that we can + // delete the object we are going to use find_() and then + // compare the versions. A special-purpose SELECT query would + // have been more efficient but it would complicated and bloat + // things significantly. + // + os << "if (!find_ (sts, obj." << id->name () << ") ||" << endl + << "version (sts.image ()) != obj." << optimistic->name () << + ")" << endl + << "throw object_changed ();" + << endl; + + instance<container_calls> t (container_calls::erase_call); + t->traverse (c); + } + + os << "if (sts.optimistic_erase_statement ().execute () != 1)" << endl + << "throw object_changed ();" + << "}"; + } + // find (id) // if (id != 0 && c.default_ctor ()) @@ -2895,18 +3097,18 @@ namespace relational << db << "::transaction::current ().connection ());" << object_statements_type << "& sts (" << endl << "conn.statement_cache ().find_object<object_type> ());" - << object_statements_type << "::auto_lock l (sts);" << endl - << "if (l.locked ())" - << "{" - << "if (!find_ (sts, id))" << endl + // This can only be top-level call so auto_lock must succeed. + // + << object_statements_type << "::auto_lock l (sts);" + << endl; + + os << "if (!find_ (sts, id))" << endl << "return false;" - << "}" + << endl << "reference_cache_traits< object_type >::insert_guard ig (" << endl << "reference_cache_traits< object_type >::insert (db, id, obj));" << endl - << "if (l.locked ())" - << "{" << "callback (db, obj, callback_event::pre_load);" << "init (obj, sts.image (), db);"; @@ -2916,12 +3118,49 @@ namespace relational << "sts.load_delayed ();" << "l.unlock ();" << "callback (db, obj, callback_event::post_load);" - << "}" - << "else" << endl - << "sts.delay_load (id, obj, ig.position ());" + << "ig.release ();" + << "return true;" + << "}"; + } + + // reload() + // + if (id != 0) + { + os << "bool " << traits << "::" << endl + << "reload (database& db, object_type& obj)" + << "{" + << "using namespace " << db << ";" + << endl + << db << "::connection& conn (" << endl + << db << "::transaction::current ().connection ());" + << object_statements_type << "& sts (" << endl + << "conn.statement_cache ().find_object<object_type> ());" + << endl + // This can only be top-level call so auto_lock must succeed. + // + << object_statements_type << "::auto_lock l (sts);" << endl; - os << "ig.release ();" + os << "if (!find_ (sts, obj." << id->name () << "))" << endl + << "return false;" + << endl; + + if (optimistic != 0) + os << "if (version (sts.image ()) == obj." << + optimistic->name () << ")" << endl + << "return true;" + << endl; + + os << "callback (db, obj, callback_event::pre_load);" + << "init (obj, sts.image (), db);"; + + init_value_extra (); + + os << "load_ (sts, obj);" + << "sts.load_delayed ();" + << "l.unlock ();" + << "callback (db, obj, callback_event::post_load);" << "return true;" << "}"; } @@ -4126,6 +4365,7 @@ namespace relational instance<bind_member> bind_member_; traversal::names bind_member_names_; instance<bind_member> bind_id_member_; + instance<bind_member> bind_version_member_; instance<init_image_base> init_image_base_; traversal::inherits init_image_base_inherits_; @@ -4133,12 +4373,15 @@ namespace relational traversal::names init_image_member_names_; instance<init_image_member> init_id_image_member_; + instance<init_image_member> init_version_image_member_; instance<init_value_base> init_value_base_; traversal::inherits init_value_base_inherits_; instance<init_value_member> init_value_member_; traversal::names init_value_member_names_; + instance<init_value_member> init_id_value_member_; + instance<init_value_member> init_version_value_member_; schema_emitter emitter_; emitter_ostream stream_; |