1
0
Fork 0
arangodb/arangod/Aql/IndexHint.h

75 lines
2.1 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2019 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dan Larkin-York
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_INDEX_HINT_H
#define ARANGOD_AQL_INDEX_HINT_H 1
#include <iosfwd>
#include <velocypack/Builder.h>
#include <velocypack/Slice.h>
#include <velocypack/velocypack-aliases.h>
#include "Aql/AstNode.h"
namespace arangodb {
namespace aql {
/// @brief container for index hint information
class IndexHint {
public:
enum HintType : uint8_t { Illegal, None, Simple };
public:
explicit IndexHint();
explicit IndexHint(AstNode const* node);
explicit IndexHint(VPackSlice const& slice);
public:
HintType type() const;
bool isForced() const;
std::vector<std::string> const& hint() const;
void toVelocyPack(VPackBuilder& builder) const;
std::string typeName() const;
std::string toString() const;
private:
HintType _type;
bool const _forced;
// actual hint is a recursive structure, with the data type determined by the
// _type above; in the case of a nested IndexHint, the value of isForced() is
// inherited
struct HintData {
std::vector<std::string> simple;
} _hint;
};
std::ostream& operator<<(std::ostream& stream, arangodb::aql::IndexHint const& hint);
} // namespace aql
} // namespace arangodb
#endif