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arangodb/PriorityQueue/priorityqueue.h

205 lines
8.0 KiB
C
Executable File

////////////////////////////////////////////////////////////////////////////////
/// @brief priorty queue
///
/// @file
///
///
/// DISCLAIMER
///
/// Copyright by triAGENS GmbH - All rights reserved.
///
/// The Programs (which include both the software and documentation)
/// contain proprietary information of triAGENS GmbH; they are
/// provided under a license agreement containing restrictions on use and
/// disclosure and are also protected by copyright, patent and other
/// intellectual and industrial property laws. Reverse engineering,
/// disassembly or decompilation of the Programs, except to the extent
/// required to obtain interoperability with other independently created
/// software or as specified by law, is prohibited.
///
/// The Programs are not intended for use in any nuclear, aviation, mass
/// transit, medical, or other inherently dangerous applications. It shall
/// be the licensee's responsibility to take all appropriate fail-safe,
/// backup, redundancy, and other measures to ensure the safe use of such
/// applications if the Programs are used for such purposes, and triAGENS
/// GmbH disclaims liability for any damages caused by such use of
/// the Programs.
///
/// This software is the confidential and proprietary information of
/// triAGENS GmbH. You shall not disclose such confidential and
/// proprietary information and shall use it only in accordance with the
/// terms of the license agreement you entered into with triAGENS GmbH.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Dr. O
/// @author Martin Schoenert
/// @author Copyright 2009-2012, triagens GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef TRIAGENS_BASICS_C_PRIORITY_QUEUE_H
#define TRIAGENS_BASICS_C_PRIORITY_QUEUE_H 1
#include "BasicsC/common.h"
#include "BasicsC/locks.h"
#include "BasicsC/vector.h"
#ifdef __cplusplus
extern "C" {
#endif
// -----------------------------------------------------------------------------
// Currently only double values are supported.
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --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 extenral 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\\|// --SECTION--\\|/// @\\}\\)"
// End: