#include "mfhdf.h"
#define FILE_NAME "SDSchunked.hdf"
#define SDS_NAME "ChunkedData"
#define RANK 2
int main()
{
/************************* Variable declaration **************************/
int32 sd_id, sds_id, sds_index;
intn status;
int32 flag, maxcache, new_maxcache;
int32 dim_sizes[2], origin[2];
HDF_CHUNK_DEF c_def, c_def_out; /* Chunking definitions */
int32 comp_flag, c_flags;
int16 all_data[9][4];
int32 start[2], edges[2];
int16 chunk_out[3][2];
int16 row[2] = { 5, 5 };
int16 column[3] = { 4, 4, 4 };
int16 fill_value = 0; /* Fill value */
int i,j;
/*
* Declare chunks data type and initialize some of them.
*/
int16 chunk1[3][2] = { {1, 1},
{1, 1},
{1, 1} };
int16 chunk2[3][2] = { {2, 2},
{2, 2},
{2, 2} };
int16 chunk3[3][2] = { {3, 3},
{3, 3},
{3, 3} };
int16 chunk6[3][2] = { {6, 6},
{6, 6},
{6, 6} };
/********************* End of variable declaration ***********************/
/*
* Define chunk's dimensions.
*
* In this example we do not use compression.
* To use chunking with RLE, Skipping Huffman, and GZIP
* compression, initialize
*
* c_def.comp.chunk_lengths[0] = 3;
* c_def.comp.chunk_lengths[1] = 2;
*
* To use chunking with NBIT, initialize
*
* c_def.nbit.chunk_lengths[0] = 3;
* c_def.nbit.chunk_lengths[1] = 2;
*
*/
c_def.chunk_lengths[0] = 3;
c_def.chunk_lengths[1] = 2;
/*
* Create the file and initialize SD interface.
*/
sd_id = SDstart (FILE_NAME, DFACC_CREATE);
/*
* Create 9x4 SDS.
*/
dim_sizes[0] = 9;
dim_sizes[1] = 4;
sds_id = SDcreate (sd_id, SDS_NAME,DFNT_INT16, RANK, dim_sizes);
/*
* Fill the SDS array with the fill value.
*/
status = SDsetfillvalue (sds_id, (VOIDP)&fill_value);
/*
* Create chunked SDS.
* In this example we do not use compression ( third
* parameter of SDsetchunk is set to HDF_CHUNK).
*
* To use RLE compresssion, set compression type and flag
*
* c_def.comp.comp_type = COMP_CODE_RLE;
* comp_flag = HDF_CHUNK | HDF_COMP;
*
* To use Skipping Huffman compression, set compression type, flag
* and skipping size skp_size
*
* c_def.comp.comp_type = COMP_CODE_SKPHUFF;
* c_def.comp.cinfo.skphuff.skp_size = value;
* comp_flag = HDF_CHUNK | HDF_COMP;
*
* To use GZIP compression, set compression type, flag and
* deflate level
*
* c_def.comp.comp_type = COMP_CODE_DEFLATE;
* c_def.comp.cinfo.deflate.level = value;
* comp_flag = HDF_CHUNK | HDF_COMP;
*
* To use NBIT compression, set compression flag and
* compression parameters
*
* comp_flag = HDF_CHUNK | HDF_NBIT;
* c_def.nbit.start_bit = value1;
* c_def.nbit.bit_len = value2;
* c_def.nbit.sign_ext = value3;
* c_def.nbit.fill_one = value4;
*/
comp_flag = HDF_CHUNK;
status = SDsetchunk (sds_id, c_def, comp_flag);
/*
* Set chunk cache to hold maximum of 3 chunks.
*/
maxcache = 3;
flag = 0;
new_maxcache = SDsetchunkcache (sds_id, maxcache, flag);
/*
* Write chunks using SDwritechunk function.
* Chunks can be written in any order.
*/
/*
* Write the chunk with the coordinates (0,0).
*/
origin[0] = 0;
origin[1] = 0;
status = SDwritechunk (sds_id, origin, (VOIDP) chunk1);
/*
* Write the chunk with the coordinates (1,0).
*/
origin[0] = 1;
origin[1] = 0;
status = SDwritechunk (sds_id, origin, (VOIDP) chunk3);
/*
* Write the chunk with the coordinates (0,1).
*/
origin[0] = 0;
origin[1] = 1;
status = SDwritechunk (sds_id, origin, (VOIDP) chunk2);
/*
* Write chunk with the coordinates (1,2) using
* SDwritedata function.
*/
start[0] = 6;
start[1] = 2;
edges[0] = 3;
edges[1] = 2;
status = SDwritedata (sds_id, start, NULL, edges, (VOIDP) chunk6);
/*
* Fill second column in the chunk with the coordinates (1,1)
* using SDwritedata function.
*/
start[0] = 3;
start[1] = 3;
edges[0] = 3;
edges[1] = 1;
status = SDwritedata (sds_id, start, NULL, edges, (VOIDP) column);
/*
* Fill second row in the chunk with the coordinates (0,2)
* using SDwritedata function.
*/
start[0] = 7;
start[1] = 0;
edges[0] = 1;
edges[1] = 2;
status = SDwritedata (sds_id, start, NULL, edges, (VOIDP) row);
/*
* Terminate access to the data set.
*/
status = SDendaccess (sds_id);
/*
* Terminate access to the SD interface and close the file.
*/
status = SDend (sd_id);
/*
* Reopen the file and access the first data set.
*/
sd_id = SDstart (FILE_NAME, DFACC_READ);
sds_index = 0;
sds_id = SDselect (sd_id, sds_index);
/*
* Get information about the SDS. Only chunk lengths and compression
* flag can be returned. Compression information is not available if
* NBIT, Skipping Huffman, or GZIP compression is used.
*/
status = SDgetchunkinfo (sds_id, &c_def_out, &c_flags);
if (c_flags == HDF_CHUNK )
printf(" SDS is chunked\nChunk's dimensions %dx%d\n",
c_def_out.chunk_lengths[0],
c_def_out.chunk_lengths[1]);
else if (c_flags == (HDF_CHUNK | HDF_COMP))
printf("SDS is chunked and compressed\nChunk's dimensions %dx%d\n",
c_def_out.comp.chunk_lengths[0],
c_def_out.comp.chunk_lengths[1]);
else if (c_flags == (HDF_CHUNK | HDF_NBIT))
printf ("SDS is chunked (NBIT)\nChunk's dimensions %dx%d\n",
c_def_out.nbit.chunk_lengths[0],
c_def_out.nbit.chunk_lengths[1]);
/*
* Read the entire data set using SDreaddata function.
*/
start[0] = 0;
start[1] = 0;
edges[0] = 9;
edges[1] = 4;
status = SDreaddata (sds_id, start, NULL, edges, (VOIDP)all_data);
/*
* Print out what we have read.
* The following information should be displayed:
*
* SDS is chunked
* Chunk's dimensions 3x2
* 1 1 2
* 1 1 2 2
* 1 1 2 2
* 3 3 0 4
* 3 3 0 4
* 3 3 0 4
* 0 0 6 6
* 5 5 6 6
* 0 0 6 6
*/
for (j=0; j<9; j++)
{
for (i=0; i<4; i++) printf (" %d", all_data[j][i]);
printf ("\n");
}
/*
* Read chunk with the coordinates (2,0) and display it.
*/
origin[0] = 2;
origin[1] = 0;
status = SDreadchunk (sds_id, origin, chunk_out);
printf (" Chunk (2,0) \n");
for (j=0; j<3; j++)
{
for (i=0; i<2; i++) printf (" %d", chunk_out[j][i]);
printf ("\n");
}
/*
* Read chunk with the coordinates (1,1) and display it.
*/
origin[0] = 1;
origin[1] = 1;
status = SDreadchunk (sds_id, origin, chunk_out);
printf (" Chunk (1,1) \n");
for (j=0; j<3; j++)
{
for (i=0; i<2; i++) printf (" %d", chunk_out[j][i]);
printf ("\n");
}
/* The following information is displayed:
*
* Chunk (2,0)
* 0 0
* 5 5
* 0 0
* Chunk (1,1)
* 0 4
* 0 4
* 0 4
*/
/*
* Terminate access to the data set.
*/
status = SDendaccess (sds_id);
/*
* Terminate access to the SD interface and close the file.
*/
status = SDend (sd_id);
return 0;
}
