[NeXus-code-tickets] [NeXusCode] #226: Save a NeXus file with chunking and no compression

[NeXus Data Format Library and Applications]

#226: Save a NeXus file with chunking and no compression
----------------------------+---------------------------
  Reporter:  Pedro.vicente  |      Owner:  Pedro.vicente
      Type:  enhancement    |     Status:  closed
  Priority:  major          |  Milestone:  4.3.0
 Component:  napi           |    Version:  trunk
Resolution:  fixed          |   Keywords:
----------------------------+---------------------------
Changes (by Freddie Akeroyd):

 * status:  assigned => closed
 * resolution:   => fixed


Old description:

> PROPOSED SOLUTION (HDF5)
>
> 1) define a new symbol  NX_CHUNK
>

> {{{
>
> /* Map NeXus compression methods to HDF compression methods */
> #define NX_CHUNK     0
> #define NX_COMP_NONE 100
> #define NX_COMP_LZW 200
> #define NX_COMP_RLE 300
> #define NX_COMP_HUF 400
> }}}
>

> 2) the same for the C++ binding
>

> {{{
> enum NXcompression {
>     CHUNK = NX_CHUNK,
>     NONE = NX_COMP_NONE,
>     LZW = NX_COMP_LZW,
>     RLE = NX_COMP_RLE,
>     HUF = NX_COMP_HUF
>   };
> }}}
>

>

> 3) modify NX5compmakedata  to handle this case
>
> {{{
> else if (compress_type == NX_CHUNK)
>       {
>           cparms = H5Pcreate(H5P_DATASET_CREATE);
>           iNew = H5Pset_chunk(cparms,rank,chunkdims);
>           if (iNew < 0)
>           {
>               NXIReportError (NXpData, "ERROR: Size of chunks could not
> be set!");
>               return NX_ERROR;
>           }
>           iRet = H5Dcreate (pFile->iCurrentG, (char*)name, datatype1,
> dataspace, cparms);
>
>       }
>

> }}}

New description:

 PROPOSED SOLUTION (HDF5)

 1) define a new symbol  NX_CHUNK


 {{{

 /* Map NeXus compression methods to HDF compression methods */
 #define NX_CHUNK     0
 #define NX_COMP_NONE 100
 #define NX_COMP_LZW 200
 #define NX_COMP_RLE 300
 #define NX_COMP_HUF 400
 }}}


 2) the same for the C++ binding


 {{{
 enum NXcompression {
     CHUNK = NX_CHUNK,
     NONE = NX_COMP_NONE,
     LZW = NX_COMP_LZW,
     RLE = NX_COMP_RLE,
     HUF = NX_COMP_HUF
   };
 }}}




 3) modify NX5compmakedata  to handle this case

 {{{
 else if (compress_type == NX_CHUNK)
       {
           cparms = H5Pcreate(H5P_DATASET_CREATE);
           iNew = H5Pset_chunk(cparms,rank,chunkdims);
           if (iNew < 0)
           {
               NXIReportError (NXpData, "ERROR: Size of chunks could not be
 set!");
               return NX_ERROR;
           }
           iRet = H5Dcreate (pFile->iCurrentG, (char*)name, datatype1,
 dataspace, cparms);

       }


 }}}

--

-- 
Ticket URL: <http://trac.nexusformat.org/code/ticket/226#comment:4>
NeXus Data Format Library and Applications <http://www.nexusformat.org/>
NeXus Data Format Library and Applications