CPLErr VRTRawRasterBand::IRasterIO( GDALRWFlag eRWFlag,
int nXOff, int nYOff,
int nXSize, int nYSize,
void * pData, int nBufXSize, int nBufYSize,
GDALDataType eBufType,
GSpacing nPixelSpace,
GSpacing nLineSpace,
GDALRasterIOExtraArg* psExtraArg )
{
if( m_poRawRaster == NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"No raw raster band configured on VRTRawRasterBand." );
return CE_Failure;
}
if( eRWFlag == GF_Write && eAccess == GA_ReadOnly )
{
CPLError( CE_Failure, CPLE_NoWriteAccess,
"Attempt to write to read only dataset in"
"VRTRawRasterBand::IRasterIO()." );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Do we have overviews that would be appropriate to satisfy */
/* this request? */
/* -------------------------------------------------------------------- */
if( (nBufXSize < nXSize || nBufYSize < nYSize)
&& GetOverviewCount() > 0 )
{
if( OverviewRasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace,
nLineSpace, psExtraArg ) == CE_None )
return CE_None;
}
m_poRawRaster->SetAccess(eAccess);
return m_poRawRaster->RasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace,
nLineSpace, psExtraArg );
}
CPLErr RawRasterBand::IRasterIO( GDALRWFlag eRWFlag,
int nXOff, int nYOff, int nXSize, int nYSize,
void * pData, int nBufXSize, int nBufYSize,
GDALDataType eBufType,
int nPixelSpace, int nLineSpace )
{
int nBandDataSize = GDALGetDataTypeSize(eDataType) / 8;
int nBufDataSize = GDALGetDataTypeSize( eBufType ) / 8;
int nBytesToRW = nPixelOffset * nXSize;
/* -------------------------------------------------------------------- */
/* Use direct IO without caching if: */
/* */
/* GDAL_ONE_BIG_READ is enabled */
/* */
/* or */
/* */
/* the length of a scanline on disk is more than 50000 bytes, and the */
/* width of the requested chunk is less than 40% of the whole scanline */
/* and none of the requested scanlines are already in the cache. */
/* -------------------------------------------------------------------- */
if( nPixelOffset < 0 )
{
return GDALRasterBand::IRasterIO( eRWFlag, nXOff, nYOff,
nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType,
nPixelSpace, nLineSpace );
}
if ( !CSLTestBoolean( CPLGetConfigOption( "GDAL_ONE_BIG_READ", "NO") ) )
{
if ( nLineSize < 50000
|| nBytesToRW > nLineSize / 5 * 2
|| IsLineLoaded( nYOff, nYSize ) )
{
return GDALRasterBand::IRasterIO( eRWFlag, nXOff, nYOff,
nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType,
nPixelSpace, nLineSpace );
}
}
/* ==================================================================== */
/* Read data. */
/* ==================================================================== */
if ( eRWFlag == GF_Read )
{
/* -------------------------------------------------------------------- */
/* Do we have overviews that would be appropriate to satisfy */
/* this request? */
/* -------------------------------------------------------------------- */
if( (nBufXSize < nXSize || nBufYSize < nYSize)
&& GetOverviewCount() > 0 )
{
if( OverviewRasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace ) == CE_None )
return CE_None;
}
/* ==================================================================== */
/* 1. Simplest case when we should get contiguous block */
/* of uninterleaved pixels. */
/* ==================================================================== */
if ( nXSize == GetXSize()
&& nXSize == nBufXSize
&& nYSize == nBufYSize
&& eBufType == eDataType
&& nPixelOffset == nBandDataSize
&& nPixelSpace == nBufDataSize
&& nLineSpace == nPixelSpace * nXSize )
{
if ( AccessBlock( nImgOffset
+ (vsi_l_offset)nYOff * nLineOffset + nXOff,
nXSize * nYSize * nBandDataSize, pData ) != CE_None )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to read %d bytes at %lu.",
nXSize * nYSize * nBandDataSize,
(unsigned long)
(nImgOffset + (vsi_l_offset)nYOff * nLineOffset
+ nXOff) );
}
}
/* ==================================================================== */
/* 2. Case when we need deinterleave and/or subsample data. */
/* ==================================================================== */
else
{
GByte *pabyData;
double dfSrcXInc, dfSrcYInc;
int iLine;
dfSrcXInc = (double)nXSize / nBufXSize;
dfSrcYInc = (double)nYSize / nBufYSize;
pabyData = (GByte *) CPLMalloc( nBytesToRW );
for ( iLine = 0; iLine < nBufYSize; iLine++ )
{
if ( AccessBlock( nImgOffset
+ ((vsi_l_offset)nYOff
+ (int)(iLine * dfSrcYInc)) * nLineOffset
+ nXOff * nPixelOffset,
nBytesToRW, pabyData ) != CE_None )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to read %d bytes at %lu.",
nBytesToRW,
(unsigned long)(nImgOffset
+ ((vsi_l_offset)nYOff
+ (int)(iLine * dfSrcYInc)) * nLineOffset
+ nXOff * nPixelOffset) );
}
/* -------------------------------------------------------------------- */
/* Copy data from disk buffer to user block buffer and subsample, */
/* if needed. */
/* -------------------------------------------------------------------- */
if ( nXSize == nBufXSize && nYSize == nBufYSize )
{
GDALCopyWords( pabyData, eDataType, nPixelOffset,
(GByte *)pData + iLine * nLineSpace,
eBufType, nPixelSpace, nXSize );
}
else
{
int iPixel;
for ( iPixel = 0; iPixel < nBufXSize; iPixel++ )
{
GDALCopyWords( pabyData +
(int)(iPixel * dfSrcXInc) * nPixelOffset,
eDataType, 0,
(GByte *)pData + iLine * nLineSpace +
iPixel * nBufDataSize,
eBufType, nPixelSpace, 1 );
}
}
}
CPLFree( pabyData );
}
}
/* ==================================================================== */
/* Write data. */
/* ==================================================================== */
else
{
int nBytesActuallyWritten;
/* ==================================================================== */
/* 1. Simplest case when we should write contiguous block */
/* of uninterleaved pixels. */
/* ==================================================================== */
if ( nXSize == GetXSize()
&& nXSize == nBufXSize
&& nYSize == nBufYSize
&& eBufType == eDataType
&& nPixelOffset == nBandDataSize
&& nPixelSpace == nBufDataSize
&& nLineSpace == nPixelSpace * nXSize )
{
/* -------------------------------------------------------------------- */
/* Byte swap the data buffer, if required. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pData, nBandDataSize, nXSize, nPixelOffset );
}
/* -------------------------------------------------------------------- */
/* Seek to the right block. */
/* -------------------------------------------------------------------- */
if( Seek( nImgOffset + (vsi_l_offset)nYOff * nLineOffset + nXOff,
SEEK_SET) == -1 )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to seek to %lu to write data.\n",
(unsigned long)(nImgOffset + (vsi_l_offset)nYOff
* nLineOffset + nXOff) );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Write the block. */
/* -------------------------------------------------------------------- */
nBytesToRW = nXSize * nYSize * nBandDataSize;
nBytesActuallyWritten = Write( pData, 1, nBytesToRW );
if( nBytesActuallyWritten < nBytesToRW )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to write %d bytes to file. %d bytes written",
nBytesToRW, nBytesActuallyWritten );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Byte swap (if necessary) back into machine order so the */
/* buffer is still usable for reading purposes. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pData, nBandDataSize, nXSize, nPixelOffset );
}
}
/* ==================================================================== */
/* 2. Case when we need deinterleave and/or subsample data. */
/* ==================================================================== */
else
{
GByte *pabyData;
double dfSrcXInc, dfSrcYInc;
vsi_l_offset nBlockOff;
int iLine;
dfSrcXInc = (double)nXSize / nBufXSize;
dfSrcYInc = (double)nYSize / nBufYSize;
pabyData = (GByte *) CPLMalloc( nBytesToRW );
for ( iLine = 0; iLine < nBufYSize; iLine++ )
{
nBlockOff = nImgOffset
+ ((vsi_l_offset)nYOff + (int)(iLine*dfSrcYInc))*nLineOffset
+ nXOff * nPixelOffset;
/* -------------------------------------------------------------------- */
/* If the data for this band is completely contiguous we don't */
/* have to worry about pre-reading from disk. */
/* -------------------------------------------------------------------- */
if( nPixelOffset > nBandDataSize )
AccessBlock( nBlockOff, nBytesToRW, pabyData );
/* -------------------------------------------------------------------- */
/* Copy data from user block buffer to disk buffer and subsample, */
/* if needed. */
/* -------------------------------------------------------------------- */
if ( nXSize == nBufXSize && nYSize == nBufYSize )
{
GDALCopyWords( (GByte *)pData + iLine * nLineSpace,
eBufType, nPixelSpace,
pabyData, eDataType, nPixelOffset, nXSize );
}
else
{
int iPixel;
for ( iPixel = 0; iPixel < nBufXSize; iPixel++ )
{
GDALCopyWords( (GByte *)pData+iLine*nLineSpace +
iPixel * nBufDataSize,
eBufType, nPixelSpace,
pabyData +
(int)(iPixel * dfSrcXInc) * nPixelOffset,
eDataType, 0, 1 );
}
}
/* -------------------------------------------------------------------- */
/* Byte swap the data buffer, if required. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pabyData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pabyData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pabyData, nBandDataSize, nXSize,
nPixelOffset );
}
/* -------------------------------------------------------------------- */
/* Seek to the right line in block. */
/* -------------------------------------------------------------------- */
if( Seek( nBlockOff, SEEK_SET) == -1 )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to seek to %ld to read.\n",
(long)nBlockOff );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Write the line of block. */
/* -------------------------------------------------------------------- */
nBytesActuallyWritten = Write( pabyData, 1, nBytesToRW );
if( nBytesActuallyWritten < nBytesToRW )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to write %d bytes to file. %d bytes written",
nBytesToRW, nBytesActuallyWritten );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Byte swap (if necessary) back into machine order so the */
/* buffer is still usable for reading purposes. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pabyData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pabyData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pabyData, nBandDataSize, nXSize,
nPixelOffset );
}
}
bDirty = TRUE;
CPLFree( pabyData );
}
}
return CE_None;
}
/**
* Read/write a region of image data for this band.
*
* Each of the sources for this derived band will be read and passed to
* the derived band pixel function. The pixel function is responsible
* for applying whatever algorithm is necessary to generate this band's
* pixels from the sources.
*
* The sources will be read using the transfer type specified for sources
* using SetSourceTransferType(). If no transfer type has been set for
* this derived band, the band's data type will be used as the transfer type.
*
* @see gdalrasterband
*
* @param eRWFlag Either GF_Read to read a region of data, or GT_Write to
* write a region of data.
*
* @param nXOff The pixel offset to the top left corner of the region
* of the band to be accessed. This would be zero to start from the left side.
*
* @param nYOff The line offset to the top left corner of the region
* of the band to be accessed. This would be zero to start from the top.
*
* @param nXSize The width of the region of the band to be accessed in pixels.
*
* @param nYSize The height of the region of the band to be accessed in lines.
*
* @param pData The buffer into which the data should be read, or from which
* it should be written. This buffer must contain at least nBufXSize *
* nBufYSize words of type eBufType. It is organized in left to right,
* top to bottom pixel order. Spacing is controlled by the nPixelSpace,
* and nLineSpace parameters.
*
* @param nBufXSize The width of the buffer image into which the desired
* region is to be read, or from which it is to be written.
*
* @param nBufYSize The height of the buffer image into which the desired
* region is to be read, or from which it is to be written.
*
* @param eBufType The type of the pixel values in the pData data buffer. The
* pixel values will automatically be translated to/from the GDALRasterBand
* data type as needed.
*
* @param nPixelSpace The byte offset from the start of one pixel value in
* pData to the start of the next pixel value within a scanline. If defaulted
* (0) the size of the datatype eBufType is used.
*
* @param nLineSpace The byte offset from the start of one scanline in
* pData to the start of the next. If defaulted the size of the datatype
* eBufType * nBufXSize is used.
*
* @return CE_Failure if the access fails, otherwise CE_None.
*/
CPLErr VRTDerivedRasterBand::IRasterIO(GDALRWFlag eRWFlag,
int nXOff, int nYOff, int nXSize,
int nYSize, void * pData, int nBufXSize,
int nBufYSize, GDALDataType eBufType,
int nPixelSpace, int nLineSpace )
{
GDALDerivedPixelFunc pfnPixelFunc;
void **pBuffers;
CPLErr eErr = CE_None;
int iSource, ii, typesize, sourcesize;
GDALDataType eSrcType;
if( eRWFlag == GF_Write )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Writing through VRTSourcedRasterBand is not supported." );
return CE_Failure;
}
typesize = GDALGetDataTypeSize(eBufType) / 8;
if (GDALGetDataTypeSize(eBufType) % 8 > 0) typesize++;
eSrcType = this->eSourceTransferType;
if ((eSrcType == GDT_Unknown) || (eSrcType >= GDT_TypeCount)) {
eSrcType = eBufType;
}
sourcesize = GDALGetDataTypeSize(eSrcType) / 8;
/* -------------------------------------------------------------------- */
/* Initialize the buffer to some background value. Use the */
/* nodata value if available. */
/* -------------------------------------------------------------------- */
if ( nPixelSpace == typesize &&
(!bNoDataValueSet || dfNoDataValue == 0) ) {
memset( pData, 0, nBufXSize * nBufYSize * nPixelSpace );
}
else if ( !bEqualAreas || bNoDataValueSet )
{
double dfWriteValue = 0.0;
int iLine;
if( bNoDataValueSet )
dfWriteValue = dfNoDataValue;
for( iLine = 0; iLine < nBufYSize; iLine++ )
{
GDALCopyWords( &dfWriteValue, GDT_Float64, 0,
((GByte *)pData) + nLineSpace * iLine,
eBufType, nPixelSpace, nBufXSize );
}
}
/* -------------------------------------------------------------------- */
/* Do we have overviews that would be appropriate to satisfy */
/* this request? */
/* -------------------------------------------------------------------- */
if( (nBufXSize < nXSize || nBufYSize < nYSize)
&& GetOverviewCount() > 0 )
{
if( OverviewRasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace ) == CE_None )
return CE_None;
}
/* ---- Get pixel function for band ---- */
pfnPixelFunc = VRTDerivedRasterBand::GetPixelFunction(this->pszFuncName);
if (pfnPixelFunc == NULL) {
CPLError( CE_Failure, CPLE_IllegalArg,
"VRTDerivedRasterBand::IRasterIO:" \
"Derived band pixel function '%s' not registered.\n",
this->pszFuncName);
return CE_Failure;
}
/* TODO: It would be nice to use a MallocBlock function for each
individual buffer that would recycle blocks of memory from a
cache by reassigning blocks that are nearly the same size.
A corresponding FreeBlock might only truly free if the total size
of freed blocks gets to be too great of a percentage of the size
of the allocated blocks. */
/* ---- Get buffers for each source ---- */
pBuffers = (void **) CPLMalloc(sizeof(void *) * nSources);
for (iSource = 0; iSource < nSources; iSource++) {
pBuffers[iSource] = (void *)
VSIMalloc(sourcesize * nBufXSize * nBufYSize);
if (pBuffers[iSource] == NULL)
{
for (ii = 0; ii < iSource; ii++) {
VSIFree(pBuffers[iSource]);
}
CPLError( CE_Failure, CPLE_OutOfMemory,
"VRTDerivedRasterBand::IRasterIO:" \
"Out of memory allocating %d bytes.\n",
nPixelSpace * nBufXSize * nBufYSize);
return CE_Failure;
}
/* ------------------------------------------------------------ */
/* #4045: Initialize the newly allocated buffers before handing */
/* them off to the sources. These buffers are packed, so we */
/* don't need any special line-by-line handling when a nonzero */
/* nodata value is set. */
/* ------------------------------------------------------------ */
if ( !bNoDataValueSet || dfNoDataValue == 0 )
{
memset( pBuffers[iSource], 0, sourcesize * nBufXSize * nBufYSize );
}
else
{
GDALCopyWords( &dfNoDataValue, GDT_Float64, 0,
(GByte *) pBuffers[iSource], eSrcType, sourcesize,
nBufXSize * nBufYSize);
}
}
/* ---- Load values for sources into packed buffers ---- */
for(iSource = 0; iSource < nSources; iSource++) {
eErr = ((VRTSource *)papoSources[iSource])->RasterIO
(nXOff, nYOff, nXSize, nYSize,
pBuffers[iSource], nBufXSize, nBufYSize,
eSrcType, GDALGetDataTypeSize( eSrcType ) / 8,
(GDALGetDataTypeSize( eSrcType ) / 8) * nBufXSize);
}
/* ---- Apply pixel function ---- */
if (eErr == CE_None) {
eErr = pfnPixelFunc((void **)pBuffers, nSources,
pData, nBufXSize, nBufYSize,
eSrcType, eBufType, nPixelSpace, nLineSpace);
}
/* ---- Release buffers ---- */
for (iSource = 0; iSource < nSources; iSource++) {
VSIFree(pBuffers[iSource]);
}
CPLFree(pBuffers);
return eErr;
}
CPLErr VRTSourcedRasterBand::IRasterIO( GDALRWFlag eRWFlag,
int nXOff, int nYOff, int nXSize, int nYSize,
void * pData, int nBufXSize, int nBufYSize,
GDALDataType eBufType,
int nPixelSpace, int nLineSpace )
{
int iSource;
CPLErr eErr = CE_None;
if( eRWFlag == GF_Write )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Writing through VRTSourcedRasterBand is not supported." );
return CE_Failure;
}
/* When using GDALProxyPoolDataset for sources, the recusion will not be */
/* detected at VRT opening but when doing RasterIO. As the proxy pool will */
/* return the already opened dataset, we can just test a member variable. */
if ( bAlreadyInIRasterIO )
{
CPLError( CE_Failure, CPLE_AppDefined,
"VRTSourcedRasterBand::IRasterIO() called recursively on the same band. "
"It looks like the VRT is referencing itself." );
return CE_Failure;
}
/* ==================================================================== */
/* Do we have overviews that would be appropriate to satisfy */
/* this request? */
/* ==================================================================== */
if( (nBufXSize < nXSize || nBufYSize < nYSize)
&& GetOverviewCount() > 0 )
{
if( OverviewRasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace ) == CE_None )
return CE_None;
}
/* -------------------------------------------------------------------- */
/* Initialize the buffer to some background value. Use the */
/* nodata value if available. */
/* -------------------------------------------------------------------- */
if ( nPixelSpace == GDALGetDataTypeSize(eBufType)/8 &&
(!bNoDataValueSet || (!CPLIsNan(dfNoDataValue) && dfNoDataValue == 0)) )
{
if (nLineSpace == nBufXSize * nPixelSpace)
{
memset( pData, 0, nBufYSize * nLineSpace );
}
else
{
int iLine;
for( iLine = 0; iLine < nBufYSize; iLine++ )
{
memset( ((GByte*)pData) + iLine * nLineSpace, 0, nBufXSize * nPixelSpace );
}
}
}
else if ( !bEqualAreas || bNoDataValueSet )
{
double dfWriteValue = 0.0;
int iLine;
if( bNoDataValueSet )
dfWriteValue = dfNoDataValue;
for( iLine = 0; iLine < nBufYSize; iLine++ )
{
GDALCopyWords( &dfWriteValue, GDT_Float64, 0,
((GByte *)pData) + nLineSpace * iLine,
eBufType, nPixelSpace, nBufXSize );
}
}
/* -------------------------------------------------------------------- */
/* Do we have overviews that would be appropriate to satisfy */
/* this request? */
/* -------------------------------------------------------------------- */
if( (nBufXSize < nXSize || nBufYSize < nYSize)
&& GetOverviewCount() > 0 )
{
if( OverviewRasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace ) == CE_None )
return CE_None;
}
bAlreadyInIRasterIO = TRUE;
/* -------------------------------------------------------------------- */
/* Overlay each source in turn over top this. */
/* -------------------------------------------------------------------- */
for( iSource = 0; eErr == CE_None && iSource < nSources; iSource++ )
{
eErr =
papoSources[iSource]->RasterIO( nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace);
}
bAlreadyInIRasterIO = FALSE;
return eErr;
}
CPLErr RawRasterBand::IRasterIO( GDALRWFlag eRWFlag,
int nXOff, int nYOff, int nXSize, int nYSize,
void * pData, int nBufXSize, int nBufYSize,
GDALDataType eBufType,
int nPixelSpace, int nLineSpace )
{
int nBandDataSize = GDALGetDataTypeSize(eDataType) / 8;
int nBufDataSize = GDALGetDataTypeSize( eBufType ) / 8;
int nBytesToRW = nPixelOffset * nXSize;
if( !CanUseDirectIO(nXOff, nYOff, nXSize, nYSize, eBufType ) )
{
return GDALRasterBand::IRasterIO( eRWFlag, nXOff, nYOff,
nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType,
nPixelSpace, nLineSpace );
}
CPLDebug("RAW", "Using direct IO implementation");
/* ==================================================================== */
/* Read data. */
/* ==================================================================== */
if ( eRWFlag == GF_Read )
{
/* -------------------------------------------------------------------- */
/* Do we have overviews that would be appropriate to satisfy */
/* this request? */
/* -------------------------------------------------------------------- */
if( (nBufXSize < nXSize || nBufYSize < nYSize)
&& GetOverviewCount() > 0 )
{
if( OverviewRasterIO( eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace ) == CE_None )
return CE_None;
}
/* ==================================================================== */
/* 1. Simplest case when we should get contiguous block */
/* of uninterleaved pixels. */
/* ==================================================================== */
if ( nXSize == GetXSize()
&& nXSize == nBufXSize
&& nYSize == nBufYSize
&& eBufType == eDataType
&& nPixelOffset == nBandDataSize
&& nPixelSpace == nBufDataSize
&& nLineSpace == nPixelSpace * nXSize )
{
vsi_l_offset nOffset = nImgOffset
+ (vsi_l_offset)nYOff * nLineOffset + nXOff;
if ( AccessBlock( nOffset,
nXSize * nYSize * nBandDataSize, pData ) != CE_None )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to read %d bytes at " CPL_FRMT_GUIB ".",
nXSize * nYSize * nBandDataSize, nOffset);
}
}
/* ==================================================================== */
/* 2. Case when we need deinterleave and/or subsample data. */
/* ==================================================================== */
else
{
GByte *pabyData;
double dfSrcXInc, dfSrcYInc;
int iLine;
dfSrcXInc = (double)nXSize / nBufXSize;
dfSrcYInc = (double)nYSize / nBufYSize;
pabyData = (GByte *) CPLMalloc( nBytesToRW );
for ( iLine = 0; iLine < nBufYSize; iLine++ )
{
vsi_l_offset nOffset = nImgOffset
+ ((vsi_l_offset)nYOff
+ (vsi_l_offset)(iLine * dfSrcYInc)) * nLineOffset
+ nXOff * nPixelOffset;
if ( AccessBlock( nOffset,
nBytesToRW, pabyData ) != CE_None )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to read %d bytes at " CPL_FRMT_GUIB ".",
nBytesToRW, nOffset );
}
/* -------------------------------------------------------------------- */
/* Copy data from disk buffer to user block buffer and subsample, */
/* if needed. */
/* -------------------------------------------------------------------- */
if ( nXSize == nBufXSize && nYSize == nBufYSize )
{
GDALCopyWords( pabyData, eDataType, nPixelOffset,
(GByte *)pData + (vsi_l_offset)iLine * nLineSpace,
eBufType, nPixelSpace, nXSize );
}
else
{
int iPixel;
for ( iPixel = 0; iPixel < nBufXSize; iPixel++ )
{
GDALCopyWords( pabyData +
(vsi_l_offset)(iPixel * dfSrcXInc) * nPixelOffset,
eDataType, nPixelOffset,
(GByte *)pData + (vsi_l_offset)iLine * nLineSpace +
(vsi_l_offset)iPixel * nPixelSpace,
eBufType, nPixelSpace, 1 );
}
}
}
CPLFree( pabyData );
}
}
/* ==================================================================== */
/* Write data. */
/* ==================================================================== */
else
{
int nBytesActuallyWritten;
/* ==================================================================== */
/* 1. Simplest case when we should write contiguous block */
/* of uninterleaved pixels. */
/* ==================================================================== */
if ( nXSize == GetXSize()
&& nXSize == nBufXSize
&& nYSize == nBufYSize
&& eBufType == eDataType
&& nPixelOffset == nBandDataSize
&& nPixelSpace == nBufDataSize
&& nLineSpace == nPixelSpace * nXSize )
{
/* -------------------------------------------------------------------- */
/* Byte swap the data buffer, if required. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pData, nBandDataSize, nXSize, nPixelOffset );
}
/* -------------------------------------------------------------------- */
/* Seek to the right block. */
/* -------------------------------------------------------------------- */
vsi_l_offset nOffset = nImgOffset + (vsi_l_offset)nYOff * nLineOffset + nXOff;
if( Seek( nOffset, SEEK_SET) == -1 )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to seek to " CPL_FRMT_GUIB " to write data.\n",
nOffset);
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Write the block. */
/* -------------------------------------------------------------------- */
nBytesToRW = nXSize * nYSize * nBandDataSize;
nBytesActuallyWritten = Write( pData, 1, nBytesToRW );
if( nBytesActuallyWritten < nBytesToRW )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to write %d bytes to file. %d bytes written",
nBytesToRW, nBytesActuallyWritten );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Byte swap (if necessary) back into machine order so the */
/* buffer is still usable for reading purposes. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pData, nBandDataSize, nXSize, nPixelOffset );
}
}
/* ==================================================================== */
/* 2. Case when we need deinterleave and/or subsample data. */
/* ==================================================================== */
else
{
GByte *pabyData;
double dfSrcXInc, dfSrcYInc;
vsi_l_offset nBlockOff;
int iLine;
dfSrcXInc = (double)nXSize / nBufXSize;
dfSrcYInc = (double)nYSize / nBufYSize;
pabyData = (GByte *) CPLMalloc( nBytesToRW );
for ( iLine = 0; iLine < nBufYSize; iLine++ )
{
nBlockOff = nImgOffset
+ ((vsi_l_offset)nYOff + (vsi_l_offset)(iLine*dfSrcYInc))*nLineOffset
+ nXOff * nPixelOffset;
/* -------------------------------------------------------------------- */
/* If the data for this band is completely contiguous we don't */
/* have to worry about pre-reading from disk. */
/* -------------------------------------------------------------------- */
if( nPixelOffset > nBandDataSize )
AccessBlock( nBlockOff, nBytesToRW, pabyData );
/* -------------------------------------------------------------------- */
/* Copy data from user block buffer to disk buffer and subsample, */
/* if needed. */
/* -------------------------------------------------------------------- */
if ( nXSize == nBufXSize && nYSize == nBufYSize )
{
GDALCopyWords( (GByte *)pData + (vsi_l_offset)iLine * nLineSpace,
eBufType, nPixelSpace,
pabyData, eDataType, nPixelOffset, nXSize );
}
else
{
int iPixel;
for ( iPixel = 0; iPixel < nBufXSize; iPixel++ )
{
GDALCopyWords( (GByte *)pData+(vsi_l_offset)iLine*nLineSpace +
(vsi_l_offset)iPixel * nPixelSpace,
eBufType, nPixelSpace,
pabyData +
(vsi_l_offset)(iPixel * dfSrcXInc) * nPixelOffset,
eDataType, nPixelOffset, 1 );
}
}
/* -------------------------------------------------------------------- */
/* Byte swap the data buffer, if required. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pabyData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pabyData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pabyData, nBandDataSize, nXSize,
nPixelOffset );
}
/* -------------------------------------------------------------------- */
/* Seek to the right line in block. */
/* -------------------------------------------------------------------- */
if( Seek( nBlockOff, SEEK_SET) == -1 )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to seek to " CPL_FRMT_GUIB " to read.\n",
nBlockOff );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Write the line of block. */
/* -------------------------------------------------------------------- */
nBytesActuallyWritten = Write( pabyData, 1, nBytesToRW );
if( nBytesActuallyWritten < nBytesToRW )
{
CPLError( CE_Failure, CPLE_FileIO,
"Failed to write %d bytes to file. %d bytes written",
nBytesToRW, nBytesActuallyWritten );
return CE_Failure;
}
/* -------------------------------------------------------------------- */
/* Byte swap (if necessary) back into machine order so the */
/* buffer is still usable for reading purposes. */
/* -------------------------------------------------------------------- */
if( !bNativeOrder && eDataType != GDT_Byte )
{
if( GDALDataTypeIsComplex( eDataType ) )
{
int nWordSize;
nWordSize = GDALGetDataTypeSize(eDataType)/16;
GDALSwapWords( pabyData, nWordSize, nXSize, nPixelOffset );
GDALSwapWords( ((GByte *) pabyData) + nWordSize,
nWordSize, nXSize, nPixelOffset );
}
else
GDALSwapWords( pabyData, nBandDataSize, nXSize,
nPixelOffset );
}
}
bDirty = TRUE;
CPLFree( pabyData );
}
}
return CE_None;
}
CPLErr PostGISRasterRasterBand::IRasterIO(GDALRWFlag eRWFlag, int nXOff,
int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize,
int nBufYSize, GDALDataType eBufType, int nPixelSpace,
int nLineSpace)
{
PostGISRasterDataset * poRDS = (PostGISRasterDataset *)poDS;
CPLDebug("PostGIS_Raster",
"PostGISRasterRasterBand::IRasterIO(): Table %s.%s (%s), Srid : %d",
pszSchema, pszTable, pszColumn, poRDS->nSrid);
if (eRWFlag == GF_Write) {
/*
ReportError(CE_Failure, CPLE_NotSupported,
"Writing through PostGIS Raster band not supported yet");
return CE_Failure;
*/
// Delegate in generic IRasterIO to force IWriteBlock call.
// TODO: This is not a solution for UPDATE scenario, but it works
// for CREATE scenario.
return GDALRasterBand::IRasterIO(eRWFlag, nXOff, nYOff, nXSize,
nYSize, pData, nBufXSize, nBufYSize, eBufType, nPixelSpace,
nLineSpace);
}
/*******************************************************************
* Do we have overviews that would be appropriate to satisfy this
* request?
******************************************************************/
if( (nBufXSize < nXSize || nBufYSize < nYSize) &&
GetOverviewCount() > 0 && eRWFlag == GF_Read)
{
if(OverviewRasterIO(eRWFlag, nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize, eBufType, nPixelSpace,
nLineSpace) == CE_None)
return CE_None;
}
int bSameWindowAsOtherBand =
(nXOff == poRDS->nXOffPrev &&
nYOff == poRDS->nYOffPrev &&
nXSize == poRDS->nXSizePrev &&
nYSize == poRDS->nYSizePrev);
poRDS->nXOffPrev = nXOff;
poRDS->nYOffPrev = nYOff;
poRDS->nXSizePrev = nXSize;
poRDS->nYSizePrev = nYSize;
/* Logic to determine if bands are read in order 1, 2, ... N */
/* If so, then use multi-band caching, otherwise do just single band caching */
if( poRDS->bAssumeMultiBandReadPattern )
{
if( nBand != poRDS->nNextExpectedBand )
{
CPLDebug("PostGIS_Raster",
"Disabling multi-band caching since band access pattern does not match");
poRDS->bAssumeMultiBandReadPattern = false;
poRDS->nNextExpectedBand = 1;
}
else
{
poRDS->nNextExpectedBand ++;
if( poRDS->nNextExpectedBand > poRDS->GetRasterCount() )
poRDS->nNextExpectedBand = 1;
}
}
else
{
if( nBand == poRDS->nNextExpectedBand )
{
poRDS->nNextExpectedBand ++;
if( poRDS->nNextExpectedBand > poRDS->GetRasterCount() )
{
CPLDebug("PostGIS_Raster", "Re-enabling multi-band caching");
poRDS->bAssumeMultiBandReadPattern = true;
poRDS->nNextExpectedBand = 1;
}
}
}
#ifdef DEBUG_VERBOSE
CPLDebug("PostGIS_Raster",
"PostGISRasterRasterBand::IRasterIO: "
"nBand = %d, nXOff = %d, nYOff = %d, nXSize = %d, nYSize = %d, nBufXSize = %d, nBufYSize = %d",
nBand, nXOff, nYOff, nXSize, nYSize, nBufXSize, nBufYSize);
#endif
#ifdef notdef
/*******************************************************************
* Optimization: We just have one tile. So, we can read it with
* IReadBlock
*
* TODO: Review it. It's not working (see comment in
* PostGISRasterDataset::ConstructOneDatasetFromTiles)
******************************************************************/
if (poRDS->nTiles == 1) {
return GDALRasterBand::IRasterIO(eRWFlag, nXOff, nYOff, nXSize,
nYSize, pData, nBufXSize, nBufYSize, eBufType, nPixelSpace,
nLineSpace);
}
#endif
/*******************************************************************
* Several tiles: we first look in all our sources caches. Missing
* blocks are queried
******************************************************************/
double adfProjWin[8];
int nFeatureCount = 0;
CPLRectObj sAoi;
poRDS->PolygonFromCoords(nXOff, nYOff, nXOff + nXSize, nYOff + nYSize, adfProjWin);
// (p[6], p[7]) is the minimum (x, y), and (p[2], p[3]) the max
sAoi.minx = adfProjWin[6];
sAoi.maxx = adfProjWin[2];
if( adfProjWin[7] < adfProjWin[3] )
{
sAoi.miny = adfProjWin[7];
sAoi.maxy = adfProjWin[3];
}
else
{
sAoi.maxy = adfProjWin[7];
sAoi.miny = adfProjWin[3];
}
#ifdef DEBUG_VERBOSE
CPLDebug("PostGIS_Raster",
"PostGISRasterRasterBand::IRasterIO: "
"Intersection box: (%f, %f) - (%f, %f)", sAoi.minx,
sAoi.miny, sAoi.maxx, sAoi.maxy);
#endif
if (poRDS->hQuadTree == NULL)
{
ReportError(CE_Failure, CPLE_AppDefined,
"Could not read metadata index.");
return CE_Failure;
}
NullBuffer(pData, nBufXSize, nBufYSize, eBufType, nPixelSpace, nLineSpace);
if( poRDS->bBuildQuadTreeDynamically && !bSameWindowAsOtherBand )
{
if( !(poRDS->LoadSources(nXOff, nYOff, nXSize, nYSize, nBand)) )
return CE_Failure;
}
// Matching sources, to avoid a dumb for loop over the sources
PostGISRasterTileDataset ** papsMatchingTiles =
(PostGISRasterTileDataset **)
CPLQuadTreeSearch(poRDS->hQuadTree, &sAoi, &nFeatureCount);
// No blocks found. This is not an error (the raster may have holes)
if (nFeatureCount == 0) {
CPLFree(papsMatchingTiles);
return CE_None;
}
int i;
/**
* We need to store the max, min coords for the missing tiles in
* any place. This is as good as any other
**/
sAoi.minx = 0.0;
sAoi.miny = 0.0;
sAoi.maxx = 0.0;
sAoi.maxy = 0.0;
GIntBig nMemoryRequiredForTiles = 0;
CPLString osIDsToFetch;
int nTilesToFetch = 0;
int nBandDataTypeSize = GDALGetDataTypeSize(eDataType) / 8;
// Loop just over the intersecting sources
for(i = 0; i < nFeatureCount; i++) {
PostGISRasterTileDataset *poTile = papsMatchingTiles[i];
PostGISRasterTileRasterBand* poTileBand =
(PostGISRasterTileRasterBand *)poTile->GetRasterBand(nBand);
nMemoryRequiredForTiles += poTileBand->GetXSize() * poTileBand->GetYSize() *
nBandDataTypeSize;
// Missing tile: we'll need to query for it
if (!poTileBand->IsCached()) {
// If we have a PKID, add the tile PKID to the list
if (poTile->pszPKID != NULL)
{
if( osIDsToFetch.size() != 0 )
osIDsToFetch += ",";
osIDsToFetch += "'";
osIDsToFetch += poTile->pszPKID;
osIDsToFetch += "'";
}
double dfTileMinX, dfTileMinY, dfTileMaxX, dfTileMaxY;
poTile->GetExtent(&dfTileMinX, &dfTileMinY,
&dfTileMaxX, &dfTileMaxY);
/**
* We keep the general max and min values of all the missing
* tiles, to raise a query that intersect just that area.
*
* TODO: In case of just a few tiles and very separated,
* this strategy is clearly suboptimal. We'll get our
* missing tiles, but with a lot of other not needed tiles.
*
* A possible optimization will be to simply rely on the
* I/O method of the source (must be implemented), in case
* we have minus than a reasonable amount of tiles missing.
* Another criteria to decide would be how separated the
* tiles are. Two queries for just two adjacent tiles is
* also a dumb strategy.
**/
if( nTilesToFetch == 0 )
{
sAoi.minx = dfTileMinX;
sAoi.miny = dfTileMinY;
sAoi.maxx = dfTileMaxX;
sAoi.maxy = dfTileMaxY;
}
else
{
if (dfTileMinX < sAoi.minx)
sAoi.minx = dfTileMinX;
if (dfTileMinY < sAoi.miny)
sAoi.miny = dfTileMinY;
if (dfTileMaxX > sAoi.maxx)
sAoi.maxx = dfTileMaxX;
if (dfTileMaxY > sAoi.maxy)
sAoi.maxy = dfTileMaxY;
}
nTilesToFetch ++;
}
}
/* Determine caching strategy */
int bAllBandCaching = FALSE;
if (nTilesToFetch > 0)
{
GIntBig nCacheMax = (GIntBig) GDALGetCacheMax64();
if( nMemoryRequiredForTiles > nCacheMax )
{
CPLDebug("PostGIS_Raster",
"For best performance, the block cache should be able to store " CPL_FRMT_GIB
" bytes for the tiles of the requested window, "
"but it is only " CPL_FRMT_GIB " byte large",
nMemoryRequiredForTiles, nCacheMax );
nTilesToFetch = 0;
}
if( poRDS->GetRasterCount() > 1 && poRDS->bAssumeMultiBandReadPattern )
{
GIntBig nMemoryRequiredForTilesAllBands =
nMemoryRequiredForTiles * poRDS->GetRasterCount();
if( nMemoryRequiredForTilesAllBands <= nCacheMax )
{
bAllBandCaching = TRUE;
}
else
{
CPLDebug("PostGIS_Raster", "Caching only this band, but not all bands. "
"Cache should be " CPL_FRMT_GIB " byte large for that",
nMemoryRequiredForTilesAllBands);
}
}
}
// Raise a query for missing tiles and cache them
if (nTilesToFetch > 0) {
/**
* There are several options here, to raise the query.
* - Get all the tiles which PKID is in a list of missing
* PKIDs.
* - Get all the tiles that intersect a polygon constructed
* based on the (min - max) values calculated before.
* - Get all the tiles with upper left pixel included in the
* range (min - max) calculated before.
*
* The first option is the most efficient one when a PKID exists.
* After that, the second one is the most efficient one when a
* spatial index exists.
* The third one is the only one available when neither a PKID or spatial
* index exist.
**/
CPLString osCommand;
PGresult * poResult;
CPLString osRasterToFetch;
if (bAllBandCaching)
osRasterToFetch = pszColumn;
else
osRasterToFetch.Printf("ST_Band(%s, %d)", pszColumn, nBand);
int bHasWhere = FALSE;
if (osIDsToFetch.size() && (poRDS->bIsFastPK || !(poRDS->HasSpatialIndex())) ) {
osCommand.Printf("SELECT %s, "
"ST_Metadata(%s), %s FROM %s.%s",
osRasterToFetch.c_str(), pszColumn,
poRDS->GetPrimaryKeyRef(), pszSchema, pszTable);
if( nTilesToFetch < poRDS->nTiles || poRDS->bBuildQuadTreeDynamically )
{
bHasWhere = TRUE;
osCommand += " WHERE ";
osCommand += poRDS->pszPrimaryKeyName;
osCommand += " IN (";
osCommand += osIDsToFetch;
osCommand += ")";
}
}
else {
CPLLocaleC oCLocale; // Force C locale to avoid commas instead of decimal points (for QGIS e.g.)
bHasWhere = TRUE;
osCommand.Printf("SELECT %s, ST_Metadata(%s), %s FROM %s.%s WHERE ",
osRasterToFetch.c_str(), pszColumn,
(poRDS->GetPrimaryKeyRef()) ? poRDS->GetPrimaryKeyRef() : "'foo'",
pszSchema, pszTable);
if( poRDS->HasSpatialIndex() )
{
osCommand += CPLSPrintf("%s && "
"ST_GeomFromText('POLYGON((%.18f %.18f,%.18f %.18f,%.18f %.18f,%.18f %.18f,%.18f %.18f))')",
pszColumn,
adfProjWin[0], adfProjWin[1],
adfProjWin[2], adfProjWin[3],
adfProjWin[4], adfProjWin[5],
adfProjWin[6], adfProjWin[7],
adfProjWin[0], adfProjWin[1]);
}
else
{
#define EPS 1e-5
osCommand += CPLSPrintf("ST_UpperLeftX(%s)"
" BETWEEN %f AND %f AND ST_UpperLeftY(%s) BETWEEN "
"%f AND %f", pszColumn, sAoi.minx-EPS, sAoi.maxx+EPS,
pszColumn, sAoi.miny-EPS, sAoi.maxy+EPS);
}
}
if( poRDS->pszWhere != NULL )
{
if( bHasWhere )
osCommand += " AND (";
else
osCommand += " WHERE (";
osCommand += poRDS->pszWhere;
osCommand += ")";
}
poResult = PQexec(poRDS->poConn, osCommand.c_str());
#ifdef DEBUG_QUERY
CPLDebug("PostGIS_Raster",
"PostGISRasterRasterBand::IRasterIO(): Query = \"%s\" --> number of rows = %d",
osCommand.c_str(), poResult ? PQntuples(poResult) : 0 );
#endif
if (poResult == NULL ||
PQresultStatus(poResult) != PGRES_TUPLES_OK ||
PQntuples(poResult) < 0) {
if (poResult)
PQclear(poResult);
CPLError(CE_Failure, CPLE_AppDefined,
"PostGISRasterRasterBand::IRasterIO(): %s",
PQerrorMessage(poRDS->poConn));
// Free the object that holds pointers to matching tiles
CPLFree(papsMatchingTiles);
return CE_Failure;
}
/**
* No data. Return the buffer filled with nodata values
**/
else if (PQntuples(poResult) == 0) {
PQclear(poResult);
// Free the object that holds pointers to matching tiles
CPLFree(papsMatchingTiles);
return CE_None;
}
/**
* Ok, we loop over the results
**/
int nTuples = PQntuples(poResult);
for(i = 0; i < nTuples; i++)
{
const char* pszMetadata = PQgetvalue(poResult, i, 1);
const char* pszRaster = PQgetvalue(poResult, i, 0);
const char *pszPKID = (poRDS->GetPrimaryKeyRef() != NULL) ? PQgetvalue(poResult, i, 2) : NULL;
poRDS->CacheTile(pszMetadata, pszRaster, pszPKID, nBand, bAllBandCaching);
} // All tiles have been added to cache
PQclear(poResult);
} // End missing tiles
/* -------------------------------------------------------------------- */
/* Overlay each source in turn over top this. */
/* -------------------------------------------------------------------- */
CPLErr eErr = CE_None;
/* Sort tiles by ascending PKID, so that the draw order is determinist */
if( poRDS->GetPrimaryKeyRef() != NULL )
{
qsort(papsMatchingTiles, nFeatureCount, sizeof(PostGISRasterTileDataset*),
SortTilesByPKID);
}
for(i = 0; i < nFeatureCount && eErr == CE_None; i++)
{
PostGISRasterTileDataset *poTile = papsMatchingTiles[i];
PostGISRasterTileRasterBand* poTileBand =
(PostGISRasterTileRasterBand *)poTile->GetRasterBand(nBand);
eErr =
poTileBand->poSource->RasterIO( nXOff, nYOff, nXSize, nYSize,
pData, nBufXSize, nBufYSize,
eBufType, nPixelSpace, nLineSpace);
}
// Free the object that holds pointers to matching tiles
CPLFree(papsMatchingTiles);
return eErr;
}