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arangodb/arangod/PriorityQueue/priorityqueue.h

188 lines
7.1 KiB
C

////////////////////////////////////////////////////////////////////////////////
/// @brief priorty queue
///
/// @file
///
///
/// DISCLAIMER
///
/// Copyright 2004-2013 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 triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Dr. Oreste Costa-Panaia
/// @author Martin Schoenert
/// @author Copyright 2009-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef TRIAGENS_PRIORITY_QUEUE_PRIORITYQUEUE_H
#define TRIAGENS_PRIORITY_QUEUE_PRIORITYQUEUE_H 1
#include "BasicsC/common.h"
#include "BasicsC/locks.h"
#include "BasicsC/vector.h"
#ifdef __cplusplus
extern "C" {
#endif
// -----------------------------------------------------------------------------
// --SECTION-- skiplist public types
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup PriorityQueue
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief The base structure of a priority queue (pq)
////////////////////////////////////////////////////////////////////////////////
typedef struct TRI_pqueue_base_s {
// ...........................................................................
// The current storage allocated to the pq. This is NOT the number of items
// in the queue.
// ...........................................................................
size_t _capacity;
// ...........................................................................
// The storage of the items as an array of element size
// ...........................................................................
char* _items;
// ...........................................................................
// Size of each item (element)
// ...........................................................................
uint32_t _itemSize;
// ...........................................................................
// The number of actual elements in the pq
// ...........................................................................
size_t _count;
// ...........................................................................
// A counter which indicates the number of removals which are invalid.
// ...........................................................................
size_t _nrFalseRemoves;
// ...........................................................................
// A counter which indicates the number of inserts which are invalid.
// ...........................................................................
size_t _nrFalseAdds;
// ...........................................................................
// by default (reverse = false), items are stored from lowest to highest
// so that the items which sort lowest are the ones which are removed first.
// When this is set to true, the ... reverse is true ...eh? This can also
// be achieved by the call back comparision function
// ...........................................................................
bool _reverse;
// ...........................................................................
// Additional hidden external structure used outside this priority queue
// This hidden structure is not available within this priority queue
// ...........................................................................
// char[n]
}
TRI_pqueue_base_t;
////////////////////////////////////////////////////////////////////////////////
/// @brief The structure of a priority queue (pq)
////////////////////////////////////////////////////////////////////////////////
typedef struct TRI_pqueue_s {
TRI_pqueue_base_t _base;
void (*clearStoragePQ) (struct TRI_pqueue_s*, void*);
uint64_t (*getStoragePQ) (struct TRI_pqueue_s*, void*);
bool (*isLessPQ) (struct TRI_pqueue_s*, void*, void*);
void (*updateStoragePQ) (struct TRI_pqueue_s*, void*, uint64_t pos);
// ...........................................................................
// default pq add, remove, top methods
// ...........................................................................
bool (*add) (struct TRI_pqueue_s*, void*);
bool (*remove) (struct TRI_pqueue_s*, uint64_t, bool);
void* (*top) (struct TRI_pqueue_s*);
}
TRI_pqueue_t;
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- Priority Queue constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup PriorityQueue
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief initialises a priority queue
////////////////////////////////////////////////////////////////////////////////
bool TRI_InitPQueue (TRI_pqueue_t*, size_t, size_t, bool,
void (*clearStoragePQ) (struct TRI_pqueue_s*, void*),
uint64_t (*getStoragePQ) (struct TRI_pqueue_s*, void*),
bool (*isLessPQ) (struct TRI_pqueue_s*, void*, void*),
void (*updateStoragePQ) (struct TRI_pqueue_s*, void*, uint64_t pos));
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a skip list, but does not free the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_DestroyPQueue (TRI_pqueue_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a skip list and frees the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_FreePQueue (TRI_pqueue_t*);
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
#ifdef __cplusplus
}
#endif
#endif
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @addtogroup\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: