memgraph/include/utils/iterator/accessor.hpp
Kruno Tomola Fabro 5a42e15c4a Alpha version of label indexes.
Squashed messages from 9 commits:

9.
Properties now uses PropertyFamily and contained classes.
Fetching,seting,clearing properties can be done with PropertyFamilyKey or PropertyTypeKey.
Hierarchy of newly added clases is:
Vertices -n-> PropertyFamily {name: String} <-1-n-> PropertyType {type: Property::Flags}
Edges -n-> PropertyFamily {name: String} <-1-n-> PropertyType {type: Property::Flags}

PropertyFamilyKey -> PropertyType
PropertyTypeKey -> PropertyType

PropertyType t0,t1;
let t0!=t1 be true
let t0.family==t1.family be true

then next is true
PropertyTypeKey{&t0}!=PropertyTypeKey{&t1}
PropertyFamilyKey{&t0}==PropertyFamilyKey{&t1}
PropertyFamilyKey{&t0}==PropertyTypeKey{&t1}
PropertyTypeKey{&t0}==PropertyFamilyKey{&t1}

8.
Intermedate commit.
Noticed that integration queries throw SEGFAULT.

7.
Defined interface for indexes.
Fixed three memory leaks.
Fixed integration_queries test which now passes.

6.
Commit which return Xorshift128plus to valid shape.

5.
Tmp commit.

4.
Label Index is compiling.

3.
tmp

2.
Vertex::Accessor now updates Label index.

1.
Applied changes for code review.
2016-08-18 15:34:36 +01:00

36 lines
963 B
C++

#pragma once
#include "utils/iterator/range_iterator.hpp"
#include "utils/option.hpp"
namespace iter
{
// Class which turns ranged iterator with next() into accessor.
// T - type of return value
// I - iterator type
template <class T, class I>
class OneTimeAccessor
{
public:
OneTimeAccessor() : it(Option<RangeIterator<T, I>>()) {}
OneTimeAccessor(I &&it) : it(RangeIterator<T, I>(std::move(it))) {}
RangeIterator<T, I> begin() { return it.take(); }
RangeIterator<T, I> end() { return RangeIterator<T, I>(); }
private:
Option<RangeIterator<T, I>> it;
};
template <class I>
auto make_one_time_accessor(I &&iter)
{
// Because function isn't receving or in any way using type T from
// OneTimeAccessor compiler can't deduce it thats way there is decltype in
// construction of OneTimeAccessor. Resoulting type of iter.next().take() is
// T.
return OneTimeAccessor<decltype(iter.next().take()), I>(std::move(iter));
}
}