memgraph/include/storage/record_accessor.hpp
Kruno Tomola Fabro df0bf6fa5f Database interface refactor.
DbAccessor:
 -Guarantees that access to Vertex and Edge is possible only through
 Vertex::Accessor and Edge::Accessor.
 -Guarantees that changing Vertex and Edge is possible only using
 Vertex::Accessor returned by vertex_insert() method and
 Edge::Accessor returned by edge_insert() method.
 -Offers CRUD for Vertex and Edge except iterating over all edges.

Squashed commit messages:

First step in database accessor refactoring done.
It's compiling.
All tests with exception of integration_querys pass

Tests now initialize logging facilities.

Refactored accessors.
RecordAccessor now has 3 states.
From,To,Out,In in there respecive Accessors return unfilled RecordAccessor.
Added iterator classes into utils/itearator/.
2016-08-15 00:09:58 +01:00

100 lines
2.4 KiB
C++

#pragma once
#include "database/db_transaction.hpp"
#include "mvcc/version_list.hpp"
#include "storage/model/properties/properties.hpp"
#include "storage/model/properties/property.hpp"
#include "transactions/transaction.hpp"
template <class T, class Derived, class vlist_t = mvcc::VersionList<T>>
class RecordAccessor
{
friend DbAccessor;
public:
RecordAccessor(vlist_t *vlist, DbTransaction &db) : vlist(vlist), db(db)
{
assert(vlist != nullptr);
}
RecordAccessor(T *t, vlist_t *vlist, DbTransaction &db)
: record(t), vlist(vlist), db(db)
{
assert(record != nullptr);
assert(vlist != nullptr);
}
RecordAccessor(RecordAccessor const &other) = default;
RecordAccessor(RecordAccessor &&other) = default;
bool empty() const { return record == nullptr; }
// Fills accessor and returns true if there is valid data for current
// transaction false otherwise.
bool fill() const
{
const_cast<RecordAccessor *>(this)->record = vlist->find(db.trans);
return record != nullptr;
}
const Id &id() const
{
assert(!empty());
return vlist->id;
}
Derived update() const
{
assert(!empty());
return Derived(vlist->update(db.trans), vlist, db);
}
bool remove() const
{
assert(!empty());
return vlist->remove(record, db.trans);
}
const Property &property(const std::string &key) const
{
return record->data.props.at(key);
}
template <class V, class... Args>
void property(const std::string &key, Args &&... args)
{
record->data.props.template set<V>(key, std::forward<Args>(args)...);
}
void property(const std::string &key, Property::sptr value)
{
record->data.props.set(key, std::move(value));
}
Properties &properties() const { return record->data.props; }
explicit operator bool() const { return record != nullptr; }
T const *operator->() const { return record; }
T *operator->() { return record; }
// Assumes same transaction
friend bool operator==(const RecordAccessor &a, const RecordAccessor &b)
{
return a.vlist == b.vlist;
}
// Assumes same transaction
friend bool operator!=(const RecordAccessor &a, const RecordAccessor &b)
{
return !(a == b);
}
protected:
T *record{nullptr};
vlist_t *const vlist;
DbTransaction &db;
};