query/include/matador/object/relation_completer.hpp

337 lines
16 KiB
C++

#ifndef RELATION_COMPLETER_HPP
#define RELATION_COMPLETER_HPP
#include "matador/object/internal/shadow_schema.hpp"
#include "matador/object/many_to_many_relation.hpp"
#include "matador/object/join_columns_collector.hpp"
#include "matador/object/object_ptr.hpp"
#include "matador/object/schema_node.hpp"
#include "matador/logger/log_manager.hpp"
#include <stack>
namespace matador::object {
/*
* 1. has_many (MM)
* no belongs to
* relation table is needed
* - element type is a foreign table (FT),
* then relation table must look like follows:
* relation_table<MM, FT>
* where MM and FT must be defined as belongs to
* - element type if a builtin type BT (i.e. string, int, etc.),
* then the relation table must look like follows:
* relation_table<MM, BT>
* where MM as belongs to and BT as given type
*
* 2. has_many_to_many (MM1, MM2)
* relation_table is needed
* relation_table<MM1, MM2>
* where MM1 and MM2 must be defined as belongs to
*
* 3. hans_many (MM) <-> belongs_to (BT)
* belongs_to has foreign key to the has_many side
* no relation table needed
*
* 4. has_one to belongs_to
* no relation table is needed
*
* 5. has_many (MM) <-> has_one (HO)
* invalid relation -> error
*
* 6. has_one
* no has_many or belongs_to
* invalid relation -> error
*/
template<typename Type>
class relation_completer final {
private:
using node_ptr = std::shared_ptr<schema_node>;
public:
using endpoint_ptr = std::shared_ptr<relation_endpoint>;
static void complete(const std::shared_ptr<schema_node> &node) {
internal::shadow_schema shadow(node->schema_);
relation_completer completer(shadow);
completer.complete_node_relations(node);
}
template<class PrimaryKeyType>
static void on_primary_key(const char * /*id*/, PrimaryKeyType &/*pk*/, std::enable_if_t<std::is_integral_v<PrimaryKeyType> && !std::is_same_v<bool, PrimaryKeyType>> * = nullptr) {}
static void on_primary_key(const char * /*id*/, std::string &/*pk*/, size_t /*size*/) {}
static void on_revision(const char * /*id*/, uint64_t &/*rev*/) {}
template<typename AttributeType>
static void on_attribute(const char * /*id*/, AttributeType &/*val*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
template<typename AttributeType>
static void on_attribute(const char * /*id*/, std::optional<AttributeType> &/*val*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
template<class ForeignPointerType>
void on_belongs_to(const char *id, ForeignPointerType &obj, const utils::foreign_attributes &attr);
template<class ForeignPointerType>
void on_has_one(const char * /*id*/, ForeignPointerType &/*obj*/, const utils::foreign_attributes &/*attr*/);
template<class CollectionType>
void on_has_many(const char *id, CollectionType &, const char *join_column, const utils::foreign_attributes &attr, std::enable_if_t<is_object_ptr<typename CollectionType::value_type>::value> * = nullptr);
template<class CollectionType>
void on_has_many(const char *id, CollectionType &, const char *join_column, const utils::foreign_attributes &attr, std::enable_if_t<!is_object_ptr<typename CollectionType::value_type>::value> * = nullptr);
template<class CollectionType>
void on_has_many_to_many(const char *id, CollectionType &collection, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr);
template<class CollectionType>
void on_has_many_to_many(const char *id, CollectionType &collection, const utils::foreign_attributes &attr);
private:
explicit relation_completer(internal::shadow_schema &shadow)
: schema_(shadow)
, log_(logger::create_logger("relation_completer")) {
}
void complete_node_relations(const std::shared_ptr<schema_node> &node) {
nodes_.push(node);
Type obj;
access::process(*this, obj);
nodes_.pop();
}
static void register_relation_endpoints(const endpoint_ptr &endpoint,
const endpoint_ptr &other_endpoint);
static void link_relation_endpoints(const endpoint_ptr &endpoint,
const endpoint_ptr &other_endpoint);
private:
std::stack<node_ptr> nodes_;
internal::shadow_schema &schema_;
logger::logger log_;
join_columns_collector join_columns_collector_{};
};
template<typename Type>
template<class CollectionType>
void relation_completer<Type>::on_has_many(const char *id, CollectionType &,
const char *join_column,
const utils::foreign_attributes &,
std::enable_if_t<is_object_ptr<typename CollectionType::value_type>::value> * /*unused*/) {
// Shortcut to a value type of object_ptr::value_type in a collection
using value_type = typename CollectionType::value_type::value_type;
using relation_value_type = many_to_many_relation<value_type, Type>;
// Check if the object_ptr type is already inserted in the schema (by id)
auto result = schema_.find_node(typeid(value_type));
if (!result) {
// Todo: throw internal error or attach node
return;
}
if (const auto endpoint = nodes_.top()->info().find_relation_endpoint(typeid(relation_value_type)); endpoint == nodes_.top()->info().endpoint_end()) {
// Endpoint was not found
log_.debug("node '%s' has has many foreign keys '%s' mapped by '%s'", nodes_.top()->name().c_str(), id, join_column);
result = schema_node::make_relation_node<relation_value_type>(
schema_.schema(), id, [join_column] {
return std::make_unique<relation_value_type>("id", join_column);
});
if (!result) {
// Todo: throw internal error
return;
}
const auto local_endpoint = std::make_shared<relation_endpoint>(id, relation_type::HAS_MANY, nodes_.top());
const auto foreign_endpoint = std::make_shared<relation_endpoint>(join_column, relation_type::BELONGS_TO, result.value());
nodes_.top()->info_->register_relation_endpoint(typeid(value_type), local_endpoint);
foreign_endpoint->node_->info_->register_relation_endpoint(nodes_.top()->type_index(), foreign_endpoint);
link_relation_endpoints(local_endpoint, foreign_endpoint);
} else {
const auto &foreign_node = result.value();
if (const auto rit = foreign_node->info_->find_relation_endpoint(nodes_.top()->type_index());
rit != foreign_node->info().endpoint_end()) {
if (rit->second->is_belongs_to()) {
rit->second->node_ = foreign_node;
const auto localEndpoint = std::make_shared<relation_endpoint>(id, relation_type::HAS_MANY, nodes_.top());
nodes_.top()->info_->register_relation_endpoint(nodes_.top()->type_index(), localEndpoint);
link_relation_endpoints(localEndpoint, rit->second);
} else {
// Todo: throw internal error relation node has invalid type
}
} else {
// Todo: throw internal error couldn't find relation node
}
}
}
template<typename Type>
template<class CollectionType>
void relation_completer<Type>::on_has_many(const char *id, CollectionType &, const char *join_column,
const utils::foreign_attributes &,
std::enable_if_t<!is_object_ptr<typename CollectionType::value_type>::value>
* /*unused*/) {
using value_type = typename CollectionType::value_type;
using relation_value_type = many_to_relation<Type, value_type>;
const auto result = schema_node::make_relation_node<relation_value_type>(
schema_.schema(), id, [join_column] {
return std::make_unique<relation_value_type>(join_column, "value");
});
if (!result) {
// Todo: throw internal exception
}
const auto local_endpoint = std::make_shared<relation_endpoint>(id, relation_type::HAS_MANY, nodes_.top());
const auto foreign_endpoint = std::make_shared<relation_endpoint>(join_column, relation_type::BELONGS_TO, result.value());
nodes_.top()->info_->register_relation_endpoint(typeid(value_type), local_endpoint);
foreign_endpoint->node_->info_->register_relation_endpoint(nodes_.top()->type_index(), foreign_endpoint);
link_relation_endpoints(local_endpoint, foreign_endpoint);
}
template<typename Type>
template<class CollectionType>
void relation_completer<Type>::on_has_many_to_many(const char *id,
CollectionType &/*collection*/,
const char *join_column,
const char *inverse_join_column,
const utils::foreign_attributes &/*attr*/) {
using relation_value_type = many_to_many_relation<typename CollectionType::value_type::value_type, Type>;
auto result = schema_.find_node(typeid(relation_value_type));
if (result) {
// Found relation node.
// Complete relation links
const auto &foreign_node = result.value();
const auto local_endpoint = std::make_shared<relation_endpoint>(id, relation_type::HAS_MANY, nodes_.top());
nodes_.top()->info_->register_relation_endpoint(typeid(typename CollectionType::value_type::value_type), local_endpoint);
const auto it = foreign_node->info_->find_relation_endpoint(nodes_.top()->type_index());
if (it == foreign_node->info().endpoint_end()) {
// Todo: Throw error
return;
}
link_relation_endpoints(local_endpoint, it->second);
} else {
// Relation not found.
auto creator = [join_column, inverse_join_column] {
return std::make_unique<relation_value_type>(join_column, inverse_join_column);
};
result = schema_node::make_relation_node<relation_value_type>(schema_.schema(), id, std::move(creator));
if (!result) {
// Todo: throw internal error
return;
}
auto& node = result.value();
auto local_endpoint = std::make_shared<relation_endpoint>(id, relation_type::HAS_MANY, nodes_.top());
auto join_endpoint = std::make_shared<relation_endpoint>(join_column, relation_type::BELONGS_TO, node);
auto inverse_join_endpoint = std::make_shared<relation_endpoint>(inverse_join_column, relation_type::BELONGS_TO,
node);
nodes_.top()->info_->register_relation_endpoint(typeid(typename CollectionType::value_type::value_type), local_endpoint);
node->info_->register_relation_endpoint(nodes_.top()->type_index(), join_endpoint);
link_relation_endpoints(local_endpoint, join_endpoint);
node->info_->register_relation_endpoint(typeid(typename CollectionType::value_type::value_type),
inverse_join_endpoint);
}
}
template<typename Type>
template<class CollectionType>
void relation_completer<Type>::on_has_many_to_many(const char *id,
CollectionType &collection,
const utils::foreign_attributes &attr) {
const auto join_columns = join_columns_collector_.collect<typename CollectionType::value_type::value_type>();
on_has_many_to_many(
id,
collection,
join_columns.inverse_join_column.c_str(),
join_columns.join_column.c_str(),
attr);
}
template<typename Type>
template<class ForeignPointerType>
void relation_completer<Type>::on_has_one(const char *id,
ForeignPointerType &/*obj*/,
const utils::foreign_attributes &/*attr*/) {
const auto ti = std::type_index(typeid(typename ForeignPointerType::value_type));
if (const auto result = schema_.find_node(ti); !result) {
// Node was not found
// Create node without the foreign relation endpoint
log_.debug("node '%s' has foreign key '%s' has one '%s'", nodes_.top()->name().c_str(), id, ti.name());
nodes_.top()->info_->
register_relation_endpoint(ti, std::make_shared<relation_endpoint>(id, relation_type::HAS_ONE, nodes_.top()));
} else {
const auto &foreign_node = result.value();
if (const auto it = foreign_node->info().find_relation_endpoint(nodes_.top()->type_index());
it != foreign_node->info().endpoint_end()) {
if (it->second->is_belongs_to()) {
it->second->node_ = foreign_node;
const auto endpoint = std::make_shared<relation_endpoint>(id, relation_type::HAS_ONE, nodes_.top());
nodes_.top()->info_->register_relation_endpoint(ti, endpoint);
link_relation_endpoints(endpoint, it->second);
} else {
// Todo: Throw internal error
return;
}
}
}
}
template<typename Type>
template<class ForeignPointerType>
void relation_completer<Type>::on_belongs_to(const char *id,
ForeignPointerType & /*obj*/,
const utils::foreign_attributes & /*attr*/) {
using value_type = typename ForeignPointerType::value_type;
const auto ti = std::type_index(typeid(value_type));
if (auto result = schema_.find_node(ti); !result) {
// Type was not found
// Create node without the foreign relation endpoint
log_.debug("node '%s' has foreign key '%s' belongs to '%s'", nodes_.top()->name().c_str(), id, ti.name());
nodes_.top()->info_->register_relation_endpoint(
ti, std::make_shared<relation_endpoint>(id, relation_type::BELONGS_TO, node_ptr{}));
} else {
// Type was found
const auto &foreign_node = result.value();
// Check foreign node and relation endpoint
if (const auto it = foreign_node->info_->find_relation_endpoint(nodes_.top()->type_index());
it != foreign_node->info().endpoint_end()) {
// Found corresponding relation endpoint in the foreign node
if (it->second->is_has_one()) {
const auto endpoint = std::make_shared<relation_endpoint>(id, relation_type::BELONGS_TO, nodes_.top());
nodes_.top()->info_->register_relation_endpoint(ti, endpoint);
link_relation_endpoints(endpoint, it->second);
} else if (it->second->foreign_endpoint()->node().type_index() == typeid(many_to_many_relation<Type, value_type>)) {
// Endpoint is a "many_to_many_relation". This means there
// is a "many_to_many_relation" node attached. Because of being a
// "belongs_to"-relation the "many_to_many_relation" can be removed
// (detach), and the endpoints must be adjusted
const auto foreign_endpoint = it->second->foreign_endpoint();
const auto detach_result = schema_.detach_node(foreign_endpoint->node_);
foreign_endpoint->node_ = nodes_.top();
nodes_.top()->info_->register_relation_endpoint(nodes_.top()->type_index(), foreign_endpoint);
} else {
// check type
}
} else {
// Relation node was not found, create only endpoint.
const auto endpoint = std::make_shared<relation_endpoint>(id, relation_type::BELONGS_TO, nodes_.top());
nodes_.top()->info_->register_relation_endpoint(ti, endpoint);
}
}
}
template<typename Type>
void relation_completer<Type>::register_relation_endpoints(const endpoint_ptr &endpoint,
const endpoint_ptr &other_endpoint) {
endpoint->node_->info_->register_relation_endpoint(other_endpoint->node_->type_index(), endpoint);
other_endpoint->node_->info_->register_relation_endpoint(endpoint->node_->type_index(), other_endpoint);
link_relation_endpoints(endpoint, other_endpoint);
}
template<typename Type>
void relation_completer<Type>::link_relation_endpoints(const endpoint_ptr &endpoint, const endpoint_ptr &other_endpoint) {
endpoint->link_foreign_endpoint(other_endpoint);
other_endpoint->link_foreign_endpoint(endpoint);
}
}
#endif //RELATION_COMPLETER_HPP