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arangodb/arangod/Aql/SharedQueryState.h

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C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 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 Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_SHARED_QUERY_STATE_H
#define ARANGOD_AQL_SHARED_QUERY_STATE_H 1
#include "Basics/Common.h"
#include "Basics/ConditionLocker.h"
#include "Basics/ConditionVariable.h"
namespace arangodb {
namespace aql {
class SharedQueryState {
public:
SharedQueryState(SharedQueryState const&) = delete;
SharedQueryState& operator=(SharedQueryState const&) = delete;
SharedQueryState()
: _wasNotified(false),
_hasHandler(false),
_valid(true) {
}
~SharedQueryState() = default;
void invalidate();
bool execute(std::function<bool()> const& cb);
/// this has to stay for a backwards-compatible AQL HTTP API (hasMore).
void waitForAsyncResponse();
/// @brief setter for the continue callback:
/// We can either have a handler or a callback
void setContinueCallback() noexcept;
/// @brief setter for the continue handler:
/// We can either have a handler or a callback
void setContinueHandler(std::function<void()> const& handler);
private:
basics::ConditionVariable _condition;
/// @brief a callback function which is used to implement continueAfterPause.
/// Typically, the RestHandler using the Query object will put a closure
/// in here, which continueAfterPause simply calls.
std::function<void()> _continueCallback;
bool _wasNotified;
/// @brief decide if the _continueCallback needs to be pushed onto the ioservice
/// or if it has to be executed in this thread.
bool _hasHandler;
bool _valid;
};
}
}
#endif