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[opencl] Reduce memory footprint and optimize
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@elpaso
elpaso committed Aug 8, 2018
1 parent 95fa27f commit 66b02d6
Showing 1 changed file with 44 additions and 51 deletions.
95 changes: 44 additions & 51 deletions src/analysis/raster/qgsninecellfilter.cpp
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Expand Up @@ -52,8 +52,7 @@ int QgsNineCellFilter::processRaster( QgsFeedback *feedback )
}
catch ( cl::Error &e )
{
QString err = QObject::tr( "Error %1 running OpenCL program in %2" )
.arg( QgsOpenClUtils::errorText( e.err() ), QString::fromStdString( e.what() ) );
QString err = QObject::tr( "Error running OpenCL program: %1 - %2" ).arg( e.what( ) ).arg( QgsOpenClUtils::errorText( e.err( ) ) );
QgsMessageLog::logMessage( err, QgsOpenClUtils::LOGMESSAGE_TAG, Qgis::Critical );
throw QgsProcessingException( err );
}
Expand Down Expand Up @@ -209,17 +208,12 @@ int QgsNineCellFilter::processRasterGPU( const QString &source, QgsFeedback *fee

// Prepare context and queue
cl::Context ctx = QgsOpenClUtils::context();
cl::Context::setDefault( ctx );
cl::CommandQueue queue( ctx );

//keep only three scanlines in memory at a time, make room for initial and final nodata
QgsOpenClUtils::CPLAllocator<float> scanLine1( xSize + 2 );
QgsOpenClUtils::CPLAllocator<float> scanLine2( xSize + 2 );
QgsOpenClUtils::CPLAllocator<float> scanLine3( xSize + 2 );
QgsOpenClUtils::CPLAllocator<float> scanLine( xSize + 2 );
QgsOpenClUtils::CPLAllocator<float> resultLine( xSize );

cl_int errorCode = 0;

// Cast to float (because double just crashes on some GPUs)
std::vector<float> rasterParams;

Expand All @@ -231,12 +225,13 @@ int QgsNineCellFilter::processRasterGPU( const QString &source, QgsFeedback *fee

addExtraRasterParams( rasterParams );

std::size_t bufferSize( sizeof( float ) * ( xSize + 2 ) );

cl::Buffer rasterParamsBuffer( rasterParams.begin(), rasterParams.end(), true, false, &errorCode );
cl::Buffer scanLine1Buffer( CL_MEM_READ_ONLY, sizeof( float ) * ( xSize + 2 ), nullptr, &errorCode );
cl::Buffer scanLine2Buffer( CL_MEM_READ_ONLY, sizeof( float ) * ( xSize + 2 ), nullptr, &errorCode );
cl::Buffer scanLine3Buffer( CL_MEM_READ_ONLY, sizeof( float ) * ( xSize + 2 ), nullptr, &errorCode );
cl::Buffer resultLineBuffer( CL_MEM_WRITE_ONLY, sizeof( float ) * xSize, nullptr, &errorCode );
cl::Buffer rasterParamsBuffer( queue, rasterParams.begin(), rasterParams.end(), true, false, nullptr );
cl::Buffer scanLine1Buffer( ctx, CL_MEM_READ_ONLY, bufferSize, nullptr, nullptr );
cl::Buffer scanLine2Buffer( ctx, CL_MEM_READ_ONLY, bufferSize, nullptr, nullptr );
cl::Buffer scanLine3Buffer( ctx, CL_MEM_READ_ONLY, bufferSize, nullptr, nullptr );
cl::Buffer resultLineBuffer( ctx, CL_MEM_WRITE_ONLY, sizeof( float ) * xSize, nullptr, nullptr );

// Create a program from the kernel source
cl::Program program( QgsOpenClUtils::buildProgram( ctx, source, QgsOpenClUtils::ExceptionBehavior::Throw ) );
Expand All @@ -250,7 +245,7 @@ int QgsNineCellFilter::processRasterGPU( const QString &source, QgsFeedback *fee
cl::Buffer &
> ( program, "processNineCellWindow" );

//values outside the layer extent (if the 3x3 window is on the border) are sent to the processing method as (input) nodata values
// values outside the layer extent (if the 3x3 window is on the border) are sent to the processing method as (input) nodata values
for ( int i = 0; i < ySize; ++i )
{
if ( feedback && feedback->isCanceled() )
Expand All @@ -265,54 +260,51 @@ int QgsNineCellFilter::processRasterGPU( const QString &source, QgsFeedback *fee

if ( i == 0 )
{
//fill scanline 1 with (input) nodata for the values above the first row and feed scanline2 with the first row
// Fill scanline 1 with (input) nodata for the values above the first row and feed scanline2 with the first row
for ( int a = 0; a < xSize + 2 ; ++a )
{
scanLine1[a] = mInputNodataValue;
scanLine[a] = mInputNodataValue;
}
queue.enqueueWriteBuffer( scanLine1Buffer, CL_TRUE, 0, bufferSize, scanLine.get() );

// Read scanline2
if ( GDALRasterIO( rasterBand, GF_Read, 0, 0, xSize, 1, &scanLine2[1], xSize, 1, GDT_Float32, 0, 0 ) != CE_None )
if ( GDALRasterIO( rasterBand, GF_Read, 0, 0, xSize, 1, &scanLine[1], xSize, 1, GDT_Float32, 0, 0 ) != CE_None )
{
QgsDebugMsg( "Raster IO Error" );
}
}
else
{
//normally fetch only scanLine3 and release scanline 1 if we move forward one row
scanLine1.reset( scanLine2.release() );
scanLine2.reset( scanLine3.release() );
scanLine3.reset( xSize + 2 );
}
queue.enqueueWriteBuffer( scanLine2Buffer, CL_TRUE, 0, bufferSize, scanLine.get() );

// Read scanline 3
if ( i == ySize - 1 ) //fill the row below the bottom with nodata values
{
for ( int a = 0; a < xSize + 2; ++a )
// Read scanline3
if ( GDALRasterIO( rasterBand, GF_Read, 0, 0, xSize, 1, &scanLine[1], xSize, 1, GDT_Float32, 0, 0 ) != CE_None )
{
scanLine3[a] = mInputNodataValue;
QgsDebugMsg( "Raster IO Error" );
}
queue.enqueueWriteBuffer( scanLine3Buffer, CL_TRUE, 0, bufferSize, scanLine.get() );
}
else
{
if ( GDALRasterIO( rasterBand, GF_Read, 0, i + 1, xSize, 1, &scanLine3[1], xSize, 1, GDT_Float32, 0, 0 ) != CE_None )
// Normally fetch only scanLine3 and move forward one row
queue.enqueueCopyBuffer( scanLine2Buffer, scanLine1Buffer, 0, 0, bufferSize, nullptr, nullptr );
queue.enqueueCopyBuffer( scanLine3Buffer, scanLine2Buffer, 0, 0, bufferSize, nullptr, nullptr );

// Read scanline 3
if ( i == ySize - 1 ) //fill the row below the bottom with nodata values
{
QgsDebugMsg( "Raster IO Error" );
for ( int a = 0; a < xSize + 2; ++a )
{
scanLine[a] = mInputNodataValue;
}
queue.enqueueWriteBuffer( scanLine3Buffer, CL_TRUE, 0, bufferSize, scanLine.get() ); // row 0
}
else // Overwrite from input, skip first and last
{
if ( GDALRasterIO( rasterBand, GF_Read, 0, i + 1, xSize, 1, &scanLine[1], xSize, 1, GDT_Float32, 0, 0 ) != CE_None )
{
QgsDebugMsg( "Raster IO Error" );
}
queue.enqueueWriteBuffer( scanLine3Buffer, CL_TRUE, 0, bufferSize, scanLine.get() ); // row 0
}
}
// Set first and last extra colums to nodata
scanLine1[0] = scanLine1[xSize + 1] = mInputNodataValue;
scanLine2[0] = scanLine2[xSize + 1] = mInputNodataValue;
scanLine3[0] = scanLine3[xSize + 1] = mInputNodataValue;

// TODO: There is room for further optimization here: instead of replacing the buffers
// we could just replace just the new one (the top row) and switch the order
// of buffer arguments in the kernell call.
errorCode = cl::enqueueWriteBuffer( scanLine1Buffer, CL_TRUE, 0,
sizeof( float ) * ( xSize + 2 ), scanLine1.get() );
errorCode = cl::enqueueWriteBuffer( scanLine2Buffer, CL_TRUE, 0,
sizeof( float ) * ( xSize + 2 ), scanLine2.get() );
errorCode = cl::enqueueWriteBuffer( scanLine3Buffer, CL_TRUE, 0,
sizeof( float ) * ( xSize + 2 ), scanLine3.get() );

kernel( cl::EnqueueArgs(
queue,
Expand All @@ -325,7 +317,7 @@ int QgsNineCellFilter::processRasterGPU( const QString &source, QgsFeedback *fee
rasterParamsBuffer
);

cl::enqueueReadBuffer( resultLineBuffer, CL_TRUE, 0, xSize * sizeof( float ), resultLine.get() );
queue.enqueueReadBuffer( resultLineBuffer, CL_TRUE, 0, xSize * sizeof( float ), resultLine.get() );

if ( GDALRasterIO( outputRasterBand, GF_Write, 0, i, xSize, 1, resultLine.get(), xSize, 1, GDT_Float32, 0, 0 ) != CE_None )
{
Expand Down Expand Up @@ -393,9 +385,10 @@ int QgsNineCellFilter::processRasterCPU( QgsFeedback *feedback )
}

//keep only three scanlines in memory at a time, make room for initial and final nodata
float *scanLine1 = ( float * ) CPLMalloc( sizeof( float ) * ( xSize + 2 ) );
float *scanLine2 = ( float * ) CPLMalloc( sizeof( float ) * ( xSize + 2 ) );
float *scanLine3 = ( float * ) CPLMalloc( sizeof( float ) * ( xSize + 2 ) );
std::size_t bufferSize( sizeof( float ) * ( xSize + 2 ) );
float *scanLine1 = ( float * ) CPLMalloc( bufferSize );
float *scanLine2 = ( float * ) CPLMalloc( bufferSize );
float *scanLine3 = ( float * ) CPLMalloc( bufferSize );

float *resultLine = ( float * ) CPLMalloc( sizeof( float ) * xSize );

Expand Down Expand Up @@ -431,7 +424,7 @@ int QgsNineCellFilter::processRasterCPU( QgsFeedback *feedback )
CPLFree( scanLine1 );
scanLine1 = scanLine2;
scanLine2 = scanLine3;
scanLine3 = ( float * ) CPLMalloc( sizeof( float ) * ( xSize + 2 ) );
scanLine3 = ( float * ) CPLMalloc( bufferSize );
}

// Read scanline 3
Expand Down

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