Compress the lossless part of MGARD data with Zstd. It was uncompress…

…ed until now. (#4339)

$ ctest -R MGARD.*/.*BP5.Serial
$ find testing/adios2/engine/bp/operations/bp5 -name "*bp" -exec du -sh {} \;
48K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.00001.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.00001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.01.bp
36K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.00001.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.0001.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.00001.bp
36K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.0001.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.0001.bp
32K     testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.01.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.00001.bp
32K     testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.001.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.01.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.001.bp
32K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.001.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.001.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.0001.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.01.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.001.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.01.bp
32K     testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.0001.bp
32K     testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.00001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.0001.bp
32K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.01.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.00001.bp
40K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.01.bp
44K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.0001.bp

Before this commit:

$ find testing/adios2/engine/bp/operations/bp5 -name "*bp" -exec du -sh {} \;
352K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.00001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.00001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.01.bp
96K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.00001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.0001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.00001.bp
96K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.0001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.0001.bp
100K    testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.01.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.00001.bp
100K    testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.01.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.001.bp
96K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.0001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1D_0.01.bp
352K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.001.bp
344K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.01.bp
100K    testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.0001.bp
100K    testing/adios2/engine/bp/operations/bp5/BPWRMGARDNull_0.00001.bp
60K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD2D_0.0001.bp
96K     testing/adios2/engine/bp/operations/bp5/BPWRMGARD3D_0.01.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD2DSel_0.00001.bp
176K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD1DSel_0.01.bp
352K    testing/adios2/engine/bp/operations/bp5/BPWRMGARD3DSel_0.0001.bp

source/adios2/operator/compress/CompressMGARD.cpp

@@ -151,10 +151,13 @@ size_t CompressMGARD::Operate(const char *dataIn, const Dims &blockStart, const
         return 0;
     }
 
+    mgard_x::Config config;
+    config.lossless = mgard_x::lossless_type::Huffman_Zstd;
+
     PutParameter(bufferOut, bufferOutOffset, true);
     void *compressedData = bufferOut + bufferOutOffset;
     mgard_x::compress(mgardDim, mgardType, mgardCount, tolerance, s, errorBoundType, dataIn,
-                      compressedData, sizeOut, true);
+                      compressedData, sizeOut, config, true);
     bufferOutOffset += sizeOut;
 
     return bufferOutOffset;