GDAL processing output to memory in Pyqgis

Question

How do I save GDAL processing output rasters to a temporary layer? Using 'memory:' for vector processes works fine, but I couldn't get it to work for GDAL processes.

output_rast = self.parameterAsOutputLayer(parameters,self.OUTPUTR,context)
if True:
 magnitude_rast = processing.run("gdal:rasterize", {
 'INPUT':buffer_extent,
 'BURN': magnitude,
 'UNITS': 1,
 'WIDTH': 1.0,
 'HEIGHT': 1.0,
 'EXTENT': buffer_extent,
 'OUTPUT': 'memory:'
 }, context=context, feedback=feedback)['OUTPUT']
if True:
 source_rast = processing.run("gdal:rasterize", {
 'INPUT':parameters['SOURCE'],
 'BURN': 100,
 'UNITS': 1,
 'WIDTH': 1.0,
 'HEIGHT': 1.0,
 'EXTENT': buffer_extent,
 'OUTPUT': 'memory:'
 }, context=context, feedback=feedback)['OUTPUT']
if True:
 proximity_rast = processing.run("gdal:proximity", {
 'INPUT':source_rast,
 'BAND': 1,
 'VALUES': 100,
 'UNITS': 0,
 'DATA_TYPE': 5,
 'OUTPUT': output_rast
 }, context=context, feedback=feedback)['OUTPUT']
return {self.OUTPUTR: output_rast}

I've also tried using None for the output parameter as recommended here but I get an incorrect parameter value error.

Answer 1

You can use "OUTPUT": QgsProcessing.TEMPORARY_OUTPUT but this will "just" write the data to a file in your operating system's temporary directory. This is not necessarily stored in volatile memory (RAM).

I am not aware of an easy way to make GDAL Processing algorithms store their output in a RAM-backed location. Maybe one could use https://gdal.org/drivers/raster/mem.html ?