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arangodb/arangod/Utils/CursorRepository.h

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////////////////////////////////////////////////////////////////////////////////
/// @brief list of cursors present in database
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 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
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGODB_ARANGO_CURSORS_H
#define ARANGODB_ARANGO_CURSORS_H 1
#include "Basics/Common.h"
#include "Basics/Mutex.h"
#include "Utils/Cursor.h"
#include "VocBase/voc-types.h"
struct TRI_json_t;
struct TRI_vocbase_t;
namespace triagens {
namespace arango {
class CollectionExport;
// -----------------------------------------------------------------------------
// --SECTION-- class CursorRepository
// -----------------------------------------------------------------------------
class CursorRepository {
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief create a cursors repository
////////////////////////////////////////////////////////////////////////////////
explicit CursorRepository (TRI_vocbase_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief destroy a cursors repository
////////////////////////////////////////////////////////////////////////////////
~CursorRepository ();
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief creates a cursor and stores it in the registry
/// the cursor will be returned with the usage flag set to true. it must be
/// returned later using release()
/// the cursor will take ownership of both json and extra
////////////////////////////////////////////////////////////////////////////////
JsonCursor* createFromJson (struct TRI_json_t*,
size_t,
struct TRI_json_t*,
double,
bool,
bool);
////////////////////////////////////////////////////////////////////////////////
/// @brief creates a cursor and stores it in the registry
////////////////////////////////////////////////////////////////////////////////
ExportCursor* createFromExport (triagens::arango::CollectionExport*,
size_t,
double,
bool);
////////////////////////////////////////////////////////////////////////////////
/// @brief remove a cursor by id
////////////////////////////////////////////////////////////////////////////////
bool remove (CursorId);
////////////////////////////////////////////////////////////////////////////////
/// @brief find an existing cursor by id
/// if found, the cursor will be returned with the usage flag set to true.
/// it must be returned later using release()
////////////////////////////////////////////////////////////////////////////////
Cursor* find (CursorId,
bool&);
////////////////////////////////////////////////////////////////////////////////
/// @brief return a cursor
////////////////////////////////////////////////////////////////////////////////
void release (Cursor*);
////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not the repository contains a used cursor
////////////////////////////////////////////////////////////////////////////////
bool containsUsedCursor ();
////////////////////////////////////////////////////////////////////////////////
/// @brief run a garbage collection on the cursors
////////////////////////////////////////////////////////////////////////////////
bool garbageCollect (bool);
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief vocbase
////////////////////////////////////////////////////////////////////////////////
TRI_vocbase_t* _vocbase;
////////////////////////////////////////////////////////////////////////////////
/// @brief mutex for the cursors repository
////////////////////////////////////////////////////////////////////////////////
triagens::basics::Mutex _lock;
////////////////////////////////////////////////////////////////////////////////
/// @brief list of current cursors
////////////////////////////////////////////////////////////////////////////////
std::unordered_map<CursorId, Cursor*> _cursors;
////////////////////////////////////////////////////////////////////////////////
/// @brief maximum number of cursors to garbage-collect in one go
////////////////////////////////////////////////////////////////////////////////
static size_t const MaxCollectCount;
};
}
}
#endif
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: