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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by the Board of Trustees of the University of Illinois. *
* All rights reserved. *
* *
* This file is part of HDF5. The full HDF5 copyright notice, including *
* terms governing use, modification, and redistribution, is contained in *
* the files COPYING and Copyright.html. COPYING can be found at the root *
* of the source code distribution tree; Copyright.html can be found at the *
* root level of an installed copy of the electronic HDF5 document set and *
* is linked from the top-level documents page. It can also be found at *
* http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html. If you do not have *
* access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#include "hdf5.h"
#include <stdlib.h>
/*-------------------------------------------------------------------------
* Packet Table Variable-Length Example
*
* Example program that creates a variable-length packet table and performs
* writes and reads.
*
*-------------------------------------------------------------------------
*/
int main(void)
{
hid_t fid; /* File identifier */
hid_t ptable; /* Packet table identifier */
herr_t err; /* Function return status */
hsize_t count; /* Number of records in the table */
int x; /* Loop variable */
/* Buffers to hold data */
hvl_t writeBuffer[5];
hvl_t readBuffer[5];
/* This example has two different sizes of "record": longs and shorts */
long longBuffer[5];
short shortBuffer[5];
/* Initialize buffers */
for(x=0; x<5; x++)
{
longBuffer[x] = -x;
shortBuffer[x] = x;
}
/* Fill the write buffer with a mix of longs and shorts */
/* We need to supply the length of each record and a pointer to */
/* the beginning of each record. */
writeBuffer[0].len = sizeof(long);
writeBuffer[0].p = &(longBuffer[0]);
writeBuffer[1].len = sizeof(short);
writeBuffer[1].p = &(shortBuffer[1]);
writeBuffer[2].len = sizeof(long);
writeBuffer[2].p = &(longBuffer[2]);
writeBuffer[3].len = sizeof(long);
writeBuffer[3].p = &(longBuffer[3]);
writeBuffer[4].len = sizeof(short);
writeBuffer[4].p = &(shortBuffer[4]);
/* Create a file using default properties */
fid=H5Fcreate("packet_table_VLexample.h5",H5F_ACC_TRUNC,H5P_DEFAULT,H5P_DEFAULT);
/* Create a variable-length packet table within the file */
ptable = H5PTcreate_vl(fid, "Packet Test Dataset", 1);
if(ptable == H5I_INVALID_HID)
goto out;
/* Write the entire buffer to the packet table */
err = H5PTappend(ptable, 5, writeBuffer );
if(err < 0)
goto out;
/* Get the number of packets in the packet table. This should be five. */
err = H5PTget_num_packets(ptable, &count);
if(err < 0)
goto out;
printf("Number of packets in packet table after five appends: %d\n", count);
/* Read all five packets back */
err = H5PTread_packets(ptable, 0, 5, readBuffer );
if(err < 0)
goto out;
for(x=0; x<5; x++)
{
printf("Packet %d's length is %d\n", x, readBuffer[x].len);
if(readBuffer[x].len == sizeof(long))
printf("Packet %d's value is %d\n", x, *( (long *) readBuffer[x].p) );
else
printf("Packet %d's value is %d\n", x, *( (short *) readBuffer[x].p) );
}
/* Before we close the packet table, we must free the memory that */
/* the pointers in readBuffer point to. */
err = H5PTfree_vlen_readbuff(ptable, 5, readBuffer);
if(err < 0)
goto out;
/* Close the packet table */
err = H5PTclose(ptable);
if(err < 0)
goto out;
/* Close the file */
H5Fclose(fid);
return 0;
out: /* An error has occurred. Clean up and exit. */
fprintf(stderr, "An error has occurred!\n");
H5PTclose(ptable);
H5Fclose(fid);
return -1;
}
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