/src/gdal/gcore/gdalarraybandblockcache.cpp

Source
/******************************************************************************
 *
 * Project:  GDAL Core
 * Purpose:  Store cached blocks in a array or a two-level array
 * Author:   Even Rouault, <even dot rouault at spatialys dot org>
 *
 ******************************************************************************
 * Copyright (c) 1998, Frank Warmerdam
 * Copyright (c) 2007-2015, Even Rouault <even dot rouault at spatialys dot org>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_port.h"
#include "gdal_priv.h"

#include <cassert>
#include <climits>
#include <cstddef>
#include <new>

#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_multiproc.h"
#include "cpl_vsi.h"

#include "gdal_abstractbandblockcache.h"

//! @cond Doxygen_Suppress

constexpr int SUBBLOCK_SIZE = 64;
#define TO_SUBBLOCK(x) ((x) >> 6)
#define WITHIN_SUBBLOCK(x) ((x)&0x3f)

/* ******************************************************************** */
/*                        GDALArrayBandBlockCache                       */
/* ******************************************************************** */

class GDALArrayBandBlockCache final : public GDALAbstractBandBlockCache
{
    bool bSubBlockingActive = false;
    int nSubBlocksPerRow = 0;
    int nSubBlocksPerColumn = 0;

    union u
    {
        GDALRasterBlock **papoBlocks;
        GDALRasterBlock ***papapoBlocks;

        u() : papoBlocks(nullptr)
        {
        }
    } u{};

    CPL_DISALLOW_COPY_ASSIGN(GDALArrayBandBlockCache)

  public:
    explicit GDALArrayBandBlockCache(GDALRasterBand *poBand);
    ~GDALArrayBandBlockCache() override;

    bool Init() override;
    bool IsInitOK() override;
    CPLErr FlushCache() override;
    CPLErr AdoptBlock(GDALRasterBlock *) override;
    GDALRasterBlock *TryGetLockedBlockRef(int nXBlockOff,
                                          int nYBlockYOff) override;
    CPLErr UnreferenceBlock(GDALRasterBlock *poBlock) override;
    CPLErr FlushBlock(int nXBlockOff, int nYBlockOff,
                      int bWriteDirtyBlock) override;
};

/************************************************************************/
/*                     GDALArrayBandBlockCacheCreate()                 */
/************************************************************************/

GDALAbstractBandBlockCache *
GDALArrayBandBlockCacheCreate(GDALRasterBand *poBand)
{
    return new (std::nothrow) GDALArrayBandBlockCache(poBand);
}

/************************************************************************/
/*                       GDALArrayBandBlockCache()                      */
/************************************************************************/

GDALArrayBandBlockCache::GDALArrayBandBlockCache(GDALRasterBand *poBandIn)
    : GDALAbstractBandBlockCache(poBandIn)
{
}

/************************************************************************/
/*                      ~GDALArrayBandBlockCache()                     */
/************************************************************************/

GDALArrayBandBlockCache::~GDALArrayBandBlockCache()
{
    GDALArrayBandBlockCache::FlushCache();

    if (!bSubBlockingActive)
        CPLFree(u.papoBlocks);
    else
        CPLFree(u.papapoBlocks);
}

/************************************************************************/
/*                                  Init()                              */
/************************************************************************/

bool GDALArrayBandBlockCache::Init()
{
    if (poBand->nBlocksPerRow < SUBBLOCK_SIZE / 2)
    {
        bSubBlockingActive = false;

        if (poBand->nBlocksPerRow < INT_MAX / poBand->nBlocksPerColumn)
        {
            u.papoBlocks = static_cast<GDALRasterBlock **>(VSICalloc(
                sizeof(void *), cpl::fits_on<int>(poBand->nBlocksPerRow *
                                                  poBand->nBlocksPerColumn)));
            if (u.papoBlocks == nullptr)
            {
                poBand->ReportError(CE_Failure, CPLE_OutOfMemory,
                                    "Out of memory in InitBlockInfo().");
                return false;
            }
        }
        else
        {
            poBand->ReportError(
                CE_Failure, CPLE_NotSupported, "Too many blocks : %d x %d",
                poBand->nBlocksPerRow, poBand->nBlocksPerColumn);
            return false;
        }
    }
    else
    {
        bSubBlockingActive = true;

        nSubBlocksPerRow = DIV_ROUND_UP(poBand->nBlocksPerRow, SUBBLOCK_SIZE);
        nSubBlocksPerColumn =
            DIV_ROUND_UP(poBand->nBlocksPerColumn, SUBBLOCK_SIZE);

        if (nSubBlocksPerRow < INT_MAX / nSubBlocksPerColumn)
        {
            u.papapoBlocks = static_cast<GDALRasterBlock ***>(VSICalloc(
                sizeof(void *),
                cpl::fits_on<int>(nSubBlocksPerRow * nSubBlocksPerColumn)));
            if (u.papapoBlocks == nullptr)
            {
                poBand->ReportError(CE_Failure, CPLE_OutOfMemory,
                                    "Out of memory in InitBlockInfo().");
                return false;
            }
        }
        else
        {
            poBand->ReportError(CE_Failure, CPLE_NotSupported,
                                "Too many subblocks : %d x %d",
                                nSubBlocksPerRow, nSubBlocksPerColumn);
            return false;
        }
    }

    return true;
}

/************************************************************************/
/*                             IsInitOK()                               */
/************************************************************************/

bool GDALArrayBandBlockCache::IsInitOK()
{
    return (!bSubBlockingActive) ? u.papoBlocks != nullptr
                                 : u.papapoBlocks != nullptr;
}

/************************************************************************/
/*                            AdoptBlock()                              */
/************************************************************************/

CPLErr GDALArrayBandBlockCache::AdoptBlock(GDALRasterBlock *poBlock)

{
    const int nXBlockOff = poBlock->GetXOff();
    const int nYBlockOff = poBlock->GetYOff();

    FreeDanglingBlocks();

    /* -------------------------------------------------------------------- */
    /*      Simple case without subblocking.                                */
    /* -------------------------------------------------------------------- */

    if (!bSubBlockingActive)
    {
        const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;

        CPLAssert(u.papoBlocks[nBlockIndex] == nullptr);
        u.papoBlocks[nBlockIndex] = poBlock;
    }
    else
    {
        /* --------------------------------------------------------------------
         */
        /*      Identify the subblock in which our target occurs, and create */
        /*      it if necessary. */
        /* --------------------------------------------------------------------
         */
        const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
                              TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;

        if (u.papapoBlocks[nSubBlock] == nullptr)
        {
            const int nSubGridSize =
                sizeof(GDALRasterBlock *) * SUBBLOCK_SIZE * SUBBLOCK_SIZE;

            u.papapoBlocks[nSubBlock] =
                static_cast<GDALRasterBlock **>(VSICalloc(1, nSubGridSize));
            if (u.papapoBlocks[nSubBlock] == nullptr)
            {
                poBand->ReportError(CE_Failure, CPLE_OutOfMemory,
                                    "Out of memory in AdoptBlock().");
                return CE_Failure;
            }
        }

        /* --------------------------------------------------------------------
         */
        /*      Check within subblock. */
        /* --------------------------------------------------------------------
         */
        GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];

        const int nBlockInSubBlock =
            WITHIN_SUBBLOCK(nXBlockOff) +
            WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;

        CPLAssert(papoSubBlockGrid[nBlockInSubBlock] == nullptr);
        papoSubBlockGrid[nBlockInSubBlock] = poBlock;
    }

    return CE_None;
}

/************************************************************************/
/*                            FlushCache()                              */
/************************************************************************/

CPLErr GDALArrayBandBlockCache::FlushCache()
{
    FreeDanglingBlocks();

    CPLErr eGlobalErr = poBand->eFlushBlockErr;

    StartDirtyBlockFlushingLog();

    /* -------------------------------------------------------------------- */
    /*      Flush all blocks in memory ... this case is without subblocking.*/
    /* -------------------------------------------------------------------- */
    if (!bSubBlockingActive && u.papoBlocks != nullptr)
    {
        const int nBlocksPerColumn = poBand->nBlocksPerColumn;
        const int nBlocksPerRow = poBand->nBlocksPerRow;
        for (int iY = 0; iY < nBlocksPerColumn; iY++)
        {
            for (int iX = 0; iX < nBlocksPerRow; iX++)
            {
                if (u.papoBlocks[iX + iY * nBlocksPerRow] != nullptr)
                {
                    CPLErr eErr = FlushBlock(iX, iY, eGlobalErr == CE_None);

                    if (eErr != CE_None)
                        eGlobalErr = eErr;
                }
            }
        }
    }

    /* -------------------------------------------------------------------- */
    /*      With subblocking.  We can short circuit missing subblocks.      */
    /* -------------------------------------------------------------------- */
    else if (u.papapoBlocks != nullptr)
    {
        for (int iSBY = 0; iSBY < nSubBlocksPerColumn; iSBY++)
        {
            for (int iSBX = 0; iSBX < nSubBlocksPerRow; iSBX++)
            {
                const int nSubBlock = iSBX + iSBY * nSubBlocksPerRow;

                GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];

                if (papoSubBlockGrid == nullptr)
                    continue;

                for (int iY = 0; iY < SUBBLOCK_SIZE; iY++)
                {
                    for (int iX = 0; iX < SUBBLOCK_SIZE; iX++)
                    {
                        if (papoSubBlockGrid[iX + iY * SUBBLOCK_SIZE] !=
                            nullptr)
                        {
                            CPLErr eErr = FlushBlock(iX + iSBX * SUBBLOCK_SIZE,
                                                     iY + iSBY * SUBBLOCK_SIZE,
                                                     eGlobalErr == CE_None);
                            if (eErr != CE_None)
                                eGlobalErr = eErr;
                        }
                    }
                }

                // We might as well get rid of this grid chunk since we know
                // it is now empty.
                u.papapoBlocks[nSubBlock] = nullptr;
                CPLFree(papoSubBlockGrid);
            }
        }
    }

    EndDirtyBlockFlushingLog();

    WaitCompletionPendingTasks();

    return (eGlobalErr);
}

/************************************************************************/
/*                        UnreferenceBlock()                            */
/************************************************************************/

CPLErr GDALArrayBandBlockCache::UnreferenceBlock(GDALRasterBlock *poBlock)
{
    const int nXBlockOff = poBlock->GetXOff();
    const int nYBlockOff = poBlock->GetYOff();

    UnreferenceBlockBase();

    /* -------------------------------------------------------------------- */
    /*      Simple case for single level caches.                            */
    /* -------------------------------------------------------------------- */
    if (!bSubBlockingActive)
    {
        const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;

        u.papoBlocks[nBlockIndex] = nullptr;
    }

    /* -------------------------------------------------------------------- */
    /*      Identify our subblock.                                          */
    /* -------------------------------------------------------------------- */
    else
    {
        const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
                              TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;

        /* --------------------------------------------------------------------
         */
        /*      Check within subblock. */
        /* --------------------------------------------------------------------
         */
        GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
        if (papoSubBlockGrid == nullptr)
            return CE_None;

        const int nBlockInSubBlock =
            WITHIN_SUBBLOCK(nXBlockOff) +
            WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;

        papoSubBlockGrid[nBlockInSubBlock] = nullptr;
    }

    return CE_None;
}

/************************************************************************/
/*                            FlushBlock()                              */
/************************************************************************/

CPLErr GDALArrayBandBlockCache::FlushBlock(int nXBlockOff, int nYBlockOff,
                                           int bWriteDirtyBlock)

{
    GDALRasterBlock *poBlock = nullptr;

    /* -------------------------------------------------------------------- */
    /*      Simple case for single level caches.                            */
    /* -------------------------------------------------------------------- */
    if (!bSubBlockingActive)
    {
        const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;

        assert(u.papoBlocks);
        poBlock = u.papoBlocks[nBlockIndex];
        u.papoBlocks[nBlockIndex] = nullptr;
    }

    /* -------------------------------------------------------------------- */
    /*      Identify our subblock.                                          */
    /* -------------------------------------------------------------------- */
    else
    {
        const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
                              TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;

        /* --------------------------------------------------------------------
         */
        /*      Check within subblock. */
        /* --------------------------------------------------------------------
         */
        GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
        if (papoSubBlockGrid == nullptr)
            return CE_None;

        const int nBlockInSubBlock =
            WITHIN_SUBBLOCK(nXBlockOff) +
            WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;

        poBlock = papoSubBlockGrid[nBlockInSubBlock];
        papoSubBlockGrid[nBlockInSubBlock] = nullptr;
    }

    if (poBlock == nullptr)
        return CE_None;

    if (!poBlock->DropLockForRemovalFromStorage())
        return CE_None;

    /* -------------------------------------------------------------------- */
    /*      Is the target block dirty?  If so we need to write it.          */
    /* -------------------------------------------------------------------- */
    poBlock->Detach();

    CPLErr eErr = CE_None;

    if (!m_nWriteDirtyBlocksDisabled && bWriteDirtyBlock && poBlock->GetDirty())
    {
        UpdateDirtyBlockFlushingLog();

        eErr = poBlock->Write();
    }

    /* -------------------------------------------------------------------- */
    /*      Deallocate the block;                                           */
    /* -------------------------------------------------------------------- */
    delete poBlock;

    return eErr;
}

/************************************************************************/
/*                        TryGetLockedBlockRef()                        */
/************************************************************************/

GDALRasterBlock *GDALArrayBandBlockCache::TryGetLockedBlockRef(int nXBlockOff,
                                                               int nYBlockOff)

{
    /* -------------------------------------------------------------------- */
    /*      Simple case for single level caches.                            */
    /* -------------------------------------------------------------------- */
    if (!bSubBlockingActive)
    {
        const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;

        GDALRasterBlock *poBlock = u.papoBlocks[nBlockIndex];
        if (poBlock == nullptr || !poBlock->TakeLock())
            return nullptr;
        return poBlock;
    }
    else
    {
        /* --------------------------------------------------------------------
         */
        /*      Identify our subblock. */
        /* --------------------------------------------------------------------
         */
        const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
                              TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;

        /* --------------------------------------------------------------------
         */
        /*      Check within subblock. */
        /* --------------------------------------------------------------------
         */
        GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
        if (papoSubBlockGrid == nullptr)
            return nullptr;

        const int nBlockInSubBlock =
            WITHIN_SUBBLOCK(nXBlockOff) +
            WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;

        GDALRasterBlock *poBlock = papoSubBlockGrid[nBlockInSubBlock];
        if (poBlock == nullptr || !poBlock->TakeLock())
            return nullptr;
        return poBlock;
    }
}

//! @endcond

Coverage Report

Created: 2025-11-16 06:25

Line	Count	Source
1		/******************************************************************************
2		*
3		* Project: GDAL Core
4		* Purpose: Store cached blocks in a array or a two-level array
5		* Author: Even Rouault, <even dot rouault at spatialys dot org>
6		*
7		******************************************************************************
8		* Copyright (c) 1998, Frank Warmerdam
9		* Copyright (c) 2007-2015, Even Rouault <even dot rouault at spatialys dot org>
10		*
11		* SPDX-License-Identifier: MIT
12		****************************************************************************/
13
14		#include "cpl_port.h"
15		#include "gdal_priv.h"
16
17		#include <cassert>
18		#include <climits>
19		#include <cstddef>
20		#include <new>
21
22		#include "cpl_conv.h"
23		#include "cpl_error.h"
24		#include "cpl_multiproc.h"
25		#include "cpl_vsi.h"
26
27		#include "gdal_abstractbandblockcache.h"
28
29		//! @cond Doxygen_Suppress
30
31		constexpr int SUBBLOCK_SIZE = 64;
32	0	#define TO_SUBBLOCK(x) ((x) >> 6)
33	0	#define WITHIN_SUBBLOCK(x) ((x)&0x3f)
34
35		/* ******************************************************************** */
36		/* GDALArrayBandBlockCache */
37		/* ******************************************************************** */
38
39		class GDALArrayBandBlockCache final : public GDALAbstractBandBlockCache
40		{
41		bool bSubBlockingActive = false;
42		int nSubBlocksPerRow = 0;
43		int nSubBlocksPerColumn = 0;
44
45		union u
46		{
47		GDALRasterBlock **papoBlocks;
48		GDALRasterBlock ***papapoBlocks;
49
50	0	u() : papoBlocks(nullptr)
51	0	{
52	0	}
53		} u{};
54
55		CPL_DISALLOW_COPY_ASSIGN(GDALArrayBandBlockCache)
56
57		public:
58		explicit GDALArrayBandBlockCache(GDALRasterBand *poBand);
59		~GDALArrayBandBlockCache() override;
60
61		bool Init() override;
62		bool IsInitOK() override;
63		CPLErr FlushCache() override;
64		CPLErr AdoptBlock(GDALRasterBlock *) override;
65		GDALRasterBlock *TryGetLockedBlockRef(int nXBlockOff,
66		int nYBlockYOff) override;
67		CPLErr UnreferenceBlock(GDALRasterBlock *poBlock) override;
68		CPLErr FlushBlock(int nXBlockOff, int nYBlockOff,
69		int bWriteDirtyBlock) override;
70		};
71
72		/************************************************************************/
73		/* GDALArrayBandBlockCacheCreate() */
74		/************************************************************************/
75
76		GDALAbstractBandBlockCache *
77		GDALArrayBandBlockCacheCreate(GDALRasterBand *poBand)
78	0	{
79	0	return new (std::nothrow) GDALArrayBandBlockCache(poBand);
80	0	}
81
82		/************************************************************************/
83		/* GDALArrayBandBlockCache() */
84		/************************************************************************/
85
86		GDALArrayBandBlockCache::GDALArrayBandBlockCache(GDALRasterBand *poBandIn)
87	0	: GDALAbstractBandBlockCache(poBandIn)
88	0	{
89	0	}
90
91		/************************************************************************/
92		/* ~GDALArrayBandBlockCache() */
93		/************************************************************************/
94
95		GDALArrayBandBlockCache::~GDALArrayBandBlockCache()
96	0	{
97	0	GDALArrayBandBlockCache::FlushCache();
98
99	0	if (!bSubBlockingActive)
100	0	CPLFree(u.papoBlocks);
101	0	else
102	0	CPLFree(u.papapoBlocks);
103	0	}
104
105		/************************************************************************/
106		/* Init() */
107		/************************************************************************/
108
109		bool GDALArrayBandBlockCache::Init()
110	0	{
111	0	if (poBand->nBlocksPerRow < SUBBLOCK_SIZE / 2)
112	0	{
113	0	bSubBlockingActive = false;
114
115	0	if (poBand->nBlocksPerRow < INT_MAX / poBand->nBlocksPerColumn)
116	0	{
117	0	u.papoBlocks = static_cast<GDALRasterBlock **>(VSICalloc(
118	0	sizeof(void ), cpl::fits_on<int>(poBand->nBlocksPerRow
119	0	poBand->nBlocksPerColumn)));
120	0	if (u.papoBlocks == nullptr)
121	0	{
122	0	poBand->ReportError(CE_Failure, CPLE_OutOfMemory,
123	0	"Out of memory in InitBlockInfo().");
124	0	return false;
125	0	}
126	0	}
127	0	else
128	0	{
129	0	poBand->ReportError(
130	0	CE_Failure, CPLE_NotSupported, "Too many blocks : %d x %d",
131	0	poBand->nBlocksPerRow, poBand->nBlocksPerColumn);
132	0	return false;
133	0	}
134	0	}
135	0	else
136	0	{
137	0	bSubBlockingActive = true;
138
139	0	nSubBlocksPerRow = DIV_ROUND_UP(poBand->nBlocksPerRow, SUBBLOCK_SIZE);
140	0	nSubBlocksPerColumn =
141	0	DIV_ROUND_UP(poBand->nBlocksPerColumn, SUBBLOCK_SIZE);
142
143	0	if (nSubBlocksPerRow < INT_MAX / nSubBlocksPerColumn)
144	0	{
145	0	u.papapoBlocks = static_cast<GDALRasterBlock ***>(VSICalloc(
146	0	sizeof(void *),
147	0	cpl::fits_on<int>(nSubBlocksPerRow * nSubBlocksPerColumn)));
148	0	if (u.papapoBlocks == nullptr)
149	0	{
150	0	poBand->ReportError(CE_Failure, CPLE_OutOfMemory,
151	0	"Out of memory in InitBlockInfo().");
152	0	return false;
153	0	}
154	0	}
155	0	else
156	0	{
157	0	poBand->ReportError(CE_Failure, CPLE_NotSupported,
158	0	"Too many subblocks : %d x %d",
159	0	nSubBlocksPerRow, nSubBlocksPerColumn);
160	0	return false;
161	0	}
162	0	}
163
164	0	return true;
165	0	}
166
167		/************************************************************************/
168		/* IsInitOK() */
169		/************************************************************************/
170
171		bool GDALArrayBandBlockCache::IsInitOK()
172	0	{
173	0	return (!bSubBlockingActive) ? u.papoBlocks != nullptr
174	0	: u.papapoBlocks != nullptr;
175	0	}
176
177		/************************************************************************/
178		/* AdoptBlock() */
179		/************************************************************************/
180
181		CPLErr GDALArrayBandBlockCache::AdoptBlock(GDALRasterBlock *poBlock)
182
183	0	{
184	0	const int nXBlockOff = poBlock->GetXOff();
185	0	const int nYBlockOff = poBlock->GetYOff();
186
187	0	FreeDanglingBlocks();
188
189		/* -------------------------------------------------------------------- */
190		/* Simple case without subblocking. */
191		/* -------------------------------------------------------------------- */
192
193	0	if (!bSubBlockingActive)
194	0	{
195	0	const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;
196
197	0	CPLAssert(u.papoBlocks[nBlockIndex] == nullptr);
198	0	u.papoBlocks[nBlockIndex] = poBlock;
199	0	}
200	0	else
201	0	{
202		/* --------------------------------------------------------------------
203		*/
204		/* Identify the subblock in which our target occurs, and create */
205		/* it if necessary. */
206		/* --------------------------------------------------------------------
207		*/
208	0	const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
209	0	TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;
210
211	0	if (u.papapoBlocks[nSubBlock] == nullptr)
212	0	{
213	0	const int nSubGridSize =
214	0	sizeof(GDALRasterBlock ) SUBBLOCK_SIZE * SUBBLOCK_SIZE;
215
216	0	u.papapoBlocks[nSubBlock] =
217	0	static_cast<GDALRasterBlock **>(VSICalloc(1, nSubGridSize));
218	0	if (u.papapoBlocks[nSubBlock] == nullptr)
219	0	{
220	0	poBand->ReportError(CE_Failure, CPLE_OutOfMemory,
221	0	"Out of memory in AdoptBlock().");
222	0	return CE_Failure;
223	0	}
224	0	}
225
226		/* --------------------------------------------------------------------
227		*/
228		/* Check within subblock. */
229		/* --------------------------------------------------------------------
230		*/
231	0	GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
232
233	0	const int nBlockInSubBlock =
234	0	WITHIN_SUBBLOCK(nXBlockOff) +
235	0	WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;
236
237	0	CPLAssert(papoSubBlockGrid[nBlockInSubBlock] == nullptr);
238	0	papoSubBlockGrid[nBlockInSubBlock] = poBlock;
239	0	}
240
241	0	return CE_None;
242	0	}
243
244		/************************************************************************/
245		/* FlushCache() */
246		/************************************************************************/
247
248		CPLErr GDALArrayBandBlockCache::FlushCache()
249	0	{
250	0	FreeDanglingBlocks();
251
252	0	CPLErr eGlobalErr = poBand->eFlushBlockErr;
253
254	0	StartDirtyBlockFlushingLog();
255
256		/* -------------------------------------------------------------------- */
257		/* Flush all blocks in memory ... this case is without subblocking.*/
258		/* -------------------------------------------------------------------- */
259	0	if (!bSubBlockingActive && u.papoBlocks != nullptr)
260	0	{
261	0	const int nBlocksPerColumn = poBand->nBlocksPerColumn;
262	0	const int nBlocksPerRow = poBand->nBlocksPerRow;
263	0	for (int iY = 0; iY < nBlocksPerColumn; iY++)
264	0	{
265	0	for (int iX = 0; iX < nBlocksPerRow; iX++)
266	0	{
267	0	if (u.papoBlocks[iX + iY * nBlocksPerRow] != nullptr)
268	0	{
269	0	CPLErr eErr = FlushBlock(iX, iY, eGlobalErr == CE_None);
270
271	0	if (eErr != CE_None)
272	0	eGlobalErr = eErr;
273	0	}
274	0	}
275	0	}
276	0	}
277
278		/* -------------------------------------------------------------------- */
279		/* With subblocking. We can short circuit missing subblocks. */
280		/* -------------------------------------------------------------------- */
281	0	else if (u.papapoBlocks != nullptr)
282	0	{
283	0	for (int iSBY = 0; iSBY < nSubBlocksPerColumn; iSBY++)
284	0	{
285	0	for (int iSBX = 0; iSBX < nSubBlocksPerRow; iSBX++)
286	0	{
287	0	const int nSubBlock = iSBX + iSBY * nSubBlocksPerRow;
288
289	0	GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
290
291	0	if (papoSubBlockGrid == nullptr)
292	0	continue;
293
294	0	for (int iY = 0; iY < SUBBLOCK_SIZE; iY++)
295	0	{
296	0	for (int iX = 0; iX < SUBBLOCK_SIZE; iX++)
297	0	{
298	0	if (papoSubBlockGrid[iX + iY * SUBBLOCK_SIZE] !=
299	0	nullptr)
300	0	{
301	0	CPLErr eErr = FlushBlock(iX + iSBX * SUBBLOCK_SIZE,
302	0	iY + iSBY * SUBBLOCK_SIZE,
303	0	eGlobalErr == CE_None);
304	0	if (eErr != CE_None)
305	0	eGlobalErr = eErr;
306	0	}
307	0	}
308	0	}
309
310		// We might as well get rid of this grid chunk since we know
311		// it is now empty.
312	0	u.papapoBlocks[nSubBlock] = nullptr;
313	0	CPLFree(papoSubBlockGrid);
314	0	}
315	0	}
316	0	}
317
318	0	EndDirtyBlockFlushingLog();
319
320	0	WaitCompletionPendingTasks();
321
322	0	return (eGlobalErr);
323	0	}
324
325		/************************************************************************/
326		/* UnreferenceBlock() */
327		/************************************************************************/
328
329		CPLErr GDALArrayBandBlockCache::UnreferenceBlock(GDALRasterBlock *poBlock)
330	0	{
331	0	const int nXBlockOff = poBlock->GetXOff();
332	0	const int nYBlockOff = poBlock->GetYOff();
333
334	0	UnreferenceBlockBase();
335
336		/* -------------------------------------------------------------------- */
337		/* Simple case for single level caches. */
338		/* -------------------------------------------------------------------- */
339	0	if (!bSubBlockingActive)
340	0	{
341	0	const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;
342
343	0	u.papoBlocks[nBlockIndex] = nullptr;
344	0	}
345
346		/* -------------------------------------------------------------------- */
347		/* Identify our subblock. */
348		/* -------------------------------------------------------------------- */
349	0	else
350	0	{
351	0	const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
352	0	TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;
353
354		/* --------------------------------------------------------------------
355		*/
356		/* Check within subblock. */
357		/* --------------------------------------------------------------------
358		*/
359	0	GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
360	0	if (papoSubBlockGrid == nullptr)
361	0	return CE_None;
362
363	0	const int nBlockInSubBlock =
364	0	WITHIN_SUBBLOCK(nXBlockOff) +
365	0	WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;
366
367	0	papoSubBlockGrid[nBlockInSubBlock] = nullptr;
368	0	}
369
370	0	return CE_None;
371	0	}
372
373		/************************************************************************/
374		/* FlushBlock() */
375		/************************************************************************/
376
377		CPLErr GDALArrayBandBlockCache::FlushBlock(int nXBlockOff, int nYBlockOff,
378		int bWriteDirtyBlock)
379
380	0	{
381	0	GDALRasterBlock *poBlock = nullptr;
382
383		/* -------------------------------------------------------------------- */
384		/* Simple case for single level caches. */
385		/* -------------------------------------------------------------------- */
386	0	if (!bSubBlockingActive)
387	0	{
388	0	const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;
389
390	0	assert(u.papoBlocks);
391	0	poBlock = u.papoBlocks[nBlockIndex];
392	0	u.papoBlocks[nBlockIndex] = nullptr;
393	0	}
394
395		/* -------------------------------------------------------------------- */
396		/* Identify our subblock. */
397		/* -------------------------------------------------------------------- */
398	0	else
399	0	{
400	0	const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
401	0	TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;
402
403		/* --------------------------------------------------------------------
404		*/
405		/* Check within subblock. */
406		/* --------------------------------------------------------------------
407		*/
408	0	GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
409	0	if (papoSubBlockGrid == nullptr)
410	0	return CE_None;
411
412	0	const int nBlockInSubBlock =
413	0	WITHIN_SUBBLOCK(nXBlockOff) +
414	0	WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;
415
416	0	poBlock = papoSubBlockGrid[nBlockInSubBlock];
417	0	papoSubBlockGrid[nBlockInSubBlock] = nullptr;
418	0	}
419
420	0	if (poBlock == nullptr)
421	0	return CE_None;
422
423	0	if (!poBlock->DropLockForRemovalFromStorage())
424	0	return CE_None;
425
426		/* -------------------------------------------------------------------- */
427		/* Is the target block dirty? If so we need to write it. */
428		/* -------------------------------------------------------------------- */
429	0	poBlock->Detach();
430
431	0	CPLErr eErr = CE_None;
432
433	0	if (!m_nWriteDirtyBlocksDisabled && bWriteDirtyBlock && poBlock->GetDirty())
434	0	{
435	0	UpdateDirtyBlockFlushingLog();
436
437	0	eErr = poBlock->Write();
438	0	}
439
440		/* -------------------------------------------------------------------- */
441		/* Deallocate the block; */
442		/* -------------------------------------------------------------------- */
443	0	delete poBlock;
444
445	0	return eErr;
446	0	}
447
448		/************************************************************************/
449		/* TryGetLockedBlockRef() */
450		/************************************************************************/
451
452		GDALRasterBlock *GDALArrayBandBlockCache::TryGetLockedBlockRef(int nXBlockOff,
453		int nYBlockOff)
454
455	0	{
456		/* -------------------------------------------------------------------- */
457		/* Simple case for single level caches. */
458		/* -------------------------------------------------------------------- */
459	0	if (!bSubBlockingActive)
460	0	{
461	0	const int nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;
462
463	0	GDALRasterBlock *poBlock = u.papoBlocks[nBlockIndex];
464	0	if (poBlock == nullptr \|\| !poBlock->TakeLock())
465	0	return nullptr;
466	0	return poBlock;
467	0	}
468	0	else
469	0	{
470		/* --------------------------------------------------------------------
471		*/
472		/* Identify our subblock. */
473		/* --------------------------------------------------------------------
474		*/
475	0	const int nSubBlock = TO_SUBBLOCK(nXBlockOff) +
476	0	TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;
477
478		/* --------------------------------------------------------------------
479		*/
480		/* Check within subblock. */
481		/* --------------------------------------------------------------------
482		*/
483	0	GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
484	0	if (papoSubBlockGrid == nullptr)
485	0	return nullptr;
486
487	0	const int nBlockInSubBlock =
488	0	WITHIN_SUBBLOCK(nXBlockOff) +
489	0	WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;
490
491	0	GDALRasterBlock *poBlock = papoSubBlockGrid[nBlockInSubBlock];
492	0	if (poBlock == nullptr \|\| !poBlock->TakeLock())
493	0	return nullptr;
494	0	return poBlock;
495	0	}
496	0	}
497
498		//! @endcond