Line data    Source code

       1             : /******************************************************************************
       2             :  *
       3             :  * Name:     gdal_abstractbandblockcache.h
       4             :  * Project:  GDAL Core
       5             :  * Purpose:  Declaration of GDALAbstractBandBlockCache base class
       6             :  * Author:   Frank Warmerdam, warmerdam@pobox.com
       7             :  *
       8             :  ******************************************************************************
       9             :  * Copyright (c) 1998, Frank Warmerdam
      10             :  * Copyright (c) 2007-2014, Even Rouault <even dot rouault at spatialys.com>
      11             :  *
      12             :  * SPDX-License-Identifier: MIT
      13             :  ****************************************************************************/
      14             : 
      15             : #ifndef GDALABSTRACTBANDBLOCKCACHE_H_INCLUDED
      16             : #define GDALABSTRACTBANDBLOCKCACHE_H_INCLUDED
      17             : 
      18             : #include "cpl_port.h"
      19             : #include "cpl_error.h"
      20             : 
      21             : typedef struct _CPLCond CPLCond;
      22             : typedef struct _CPLLock CPLLock;
      23             : typedef struct _CPLMutex CPLMutex;
      24             : 
      25             : class GDALRasterBand;
      26             : class GDALRasterBlock;
      27             : 
      28             : /* ******************************************************************** */
      29             : /*                       GDALAbstractBandBlockCache                     */
      30             : /* ******************************************************************** */
      31             : 
      32             : //! @cond Doxygen_Suppress
      33             : 
      34             : //! This manages how a raster band store its cached block.
      35             : // only used by GDALRasterBand implementation.
      36             : 
      37             : class GDALAbstractBandBlockCache /* non final */
      38             : {
      39             :     // List of blocks that can be freed or recycled, and its lock
      40             :     CPLLock *hSpinLock = nullptr;
      41             :     GDALRasterBlock *psListBlocksToFree = nullptr;
      42             : 
      43             :     // Band keep alive counter, and its lock & condition
      44             :     CPLCond *hCond = nullptr;
      45             :     CPLMutex *hCondMutex = nullptr;
      46             :     volatile int nKeepAliveCounter = 0;
      47             : 
      48             :     volatile int m_nDirtyBlocks = 0;
      49             : 
      50             :     CPL_DISALLOW_COPY_ASSIGN(GDALAbstractBandBlockCache)
      51             : 
      52             :   protected:
      53             :     explicit GDALAbstractBandBlockCache(GDALRasterBand *poBand);
      54             : 
      55             :     GDALRasterBand *poBand;
      56             : 
      57             :     int m_nInitialDirtyBlocksInFlushCache = 0;
      58             :     int m_nLastTick = -1;
      59             :     size_t m_nWriteDirtyBlocksDisabled = 0;
      60             : 
      61             :     void FreeDanglingBlocks();
      62             :     void UnreferenceBlockBase();
      63             : 
      64             :     void StartDirtyBlockFlushingLog();
      65             :     void UpdateDirtyBlockFlushingLog();
      66             :     void EndDirtyBlockFlushingLog();
      67             : 
      68             :   public:
      69             :     virtual ~GDALAbstractBandBlockCache();
      70             : 
      71             :     GDALRasterBlock *CreateBlock(int nXBlockOff, int nYBlockOff);
      72             :     void AddBlockToFreeList(GDALRasterBlock *poBlock);
      73             :     void IncDirtyBlocks(int nInc);
      74             :     void WaitCompletionPendingTasks();
      75             : 
      76           1 :     void EnableDirtyBlockWriting()
      77             :     {
      78           1 :         --m_nWriteDirtyBlocksDisabled;
      79           1 :     }
      80             : 
      81        3588 :     void DisableDirtyBlockWriting()
      82             :     {
      83        3588 :         ++m_nWriteDirtyBlocksDisabled;
      84        3588 :     }
      85             : 
      86           0 :     bool HasDirtyBlocks() const
      87             :     {
      88           0 :         return m_nDirtyBlocks > 0;
      89             :     }
      90             : 
      91             :     virtual bool Init() = 0;
      92             :     virtual bool IsInitOK() = 0;
      93             :     virtual CPLErr FlushCache() = 0;
      94             :     virtual CPLErr AdoptBlock(GDALRasterBlock *poBlock) = 0;
      95             :     virtual GDALRasterBlock *TryGetLockedBlockRef(int nXBlockOff,
      96             :                                                   int nYBlockYOff) = 0;
      97             :     virtual CPLErr UnreferenceBlock(GDALRasterBlock *poBlock) = 0;
      98             :     virtual CPLErr FlushBlock(int nXBlockOff, int nYBlockOff,
      99             :                               int bWriteDirtyBlock) = 0;
     100             : };
     101             : 
     102             : GDALAbstractBandBlockCache *
     103             : GDALArrayBandBlockCacheCreate(GDALRasterBand *poBand);
     104             : GDALAbstractBandBlockCache *
     105             : GDALHashSetBandBlockCacheCreate(GDALRasterBand *poBand);
     106             : 
     107             : //! @endcond
     108             : 
     109             : #endif