Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page dlabns_c

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Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       dlabns_c ( DLA, begin new segment )

       void dlabns_c ( SpiceInt            handle )

#### Abstract

       Begin a new segment in a DLA file.

#### Required_Reading

       DAS
       DLA

#### Keywords

       DAS
       DLA
       FILES

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       handle     I   Handle of open DLA file.

#### Detailed_Input

       handle      is the integer handle associated with the DLA file to
                   be updated. This handle is used to identify the file
                   in subsequent calls to other DLA or DAS routines.

                   The DLA file must be open for write access. A new DLA
                   segment is started in the indicated file. The file
                   is left open, since normally data will be written to
                   the file following a call to this routine.

#### Detailed_Output

       None. See the -Particulars and -Examples header sections for
       a description of the actions performed by this routine.

#### Parameters

       None.

#### Exceptions

       1)  If the input file handle does not refer to a DAS file that is
           open for write access, an error is signaled by a routine
           in the call tree of this routine.

       2)  If an error occurs while reading or writing to the DLA file,
           the error is signaled by a routine in the call tree of
           this routine.

#### Files

       See description of input argument `handle'.

#### Particulars

       DLA files are built using the DAS low-level format; DLA files are
       a specialized type of DAS file in which data are organized as a
       doubly linked list of segments. Each segment's data belong to
       contiguous components of character, double precision, and integer
       type.

       This routine supports creation of a DLA segment. DLA segments
       are created by appending data to the DAS integer, double
       precision, and character address spaces of a DLA file. The new
       segment's descriptor is located immediately before the integer
       component of the segment's data.

       When a new segment is added to a DLA file, the segment is
       inserted into the file's doubly linked segment list. If the new
       segment is the first, the DLA file's first and last list entry
       pointers are updated to point to the new segment; specifically,
       these pointers point to the first integer of the new segment's
       descriptor. The backward pointer of the new segment is set to
       null in this case.

       If the new segment is not the first, the DLA file's list end
       pointer is updated to point to the new segment, and the forward
       pointer of the previous segment also is updated to point to the
       first integer of the new segment's descriptor. The backward
       pointer of the new segment points to the first integer of the
       previous segment's descriptor.

       The normal sequence of operations required to create a DLA
       segment is as follows:

          Call dlaopn_c to create a new, empty DLA file.

          For each segment to be created,

             Call dlabns_c to begin a segment.

             Use the DAS "add" and "update" routines to populate
             the segment with data.

             Call dlaens_c to end the segment.

          Call dascls_c to segregate and close the DLA file.

#### Examples

       The numerical results shown for this example may differ across
       platforms. The results depend on the SPICE kernels used as
       input, the compiler and supporting libraries, and the machine
       specific arithmetic implementation.

       1) Create a DLA file containing one segment; the segment
          contains character, double precision, and integer data.
          After writing and closing the file, open the file for
          read access; dump the data to standard output.

          Example code begins here.

          /.
             Program dlabns_ex1
          ./
          #include <stdio.h>
          #include <string.h>
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Local parameters
             ./
             #define DLA          "dlabns_ex1.dla"
             #define LNSIZE       61
             #define MAXC         5
             #define MAXD         50
             #define MAXI         100

             /.
             Local variables
             ./
             SpiceChar            buffer [2];
             SpiceChar            cvals  [MAXC][LNSIZE];
             SpiceChar            cvals2 [MAXC][LNSIZE];
             SpiceChar            cvastr [LNSIZE+1];
             SpiceChar          * ifname;

             SpiceDouble          dvals  [MAXD];
             SpiceDouble          dvals2 [MAXD];

             SpiceDLADescr        descr;

             SpiceInt             base;
             SpiceInt             handle;
             SpiceInt             i;
             SpiceInt             ivals  [MAXI];
             SpiceInt             ivals2 [MAXI];
             SpiceInt             j;
             SpiceInt             k;
             SpiceInt             n;
             SpiceInt             ncomch;

             SpiceBoolean         found;

             /.
             Set the internal file name.  Don't reserve characters in
             the DAS comment area.
             ./
             ifname = "Example DLA file for testing";
             ncomch = 0;

             /.
             Open a new DLA file.
             ./
             dlaopn_c ( DLA, "DLA", ifname, ncomch, &handle );

             /.
             Begin a new segment.
             ./
             dlabns_c ( handle );

             /.
             Add character data to the segment.
             ./
             for ( i = 0; i < MAXC; i++ )
             {
                for ( j = 0; j < LNSIZE; j++ )
                {

                   /.
                   Remove null-terminating character added to `buffer' in order to
                   add it to the DLA file.
                   ./
                   k = ( (j+i+1) % 10 );
                   snprintf(buffer, 2, "%d", k);
                   cvals[i][j] = buffer[0];
                }
             }

             dasadc_c ( handle, MAXC*LNSIZE, 0, LNSIZE-1, LNSIZE, cvals );

             /.
             Add integer and double precision data to the segment.
             ./
             for ( i = 0; i < MAXI; i++ )
             {
                ivals[i] = i+1;
             }

             dasadi_c ( handle, MAXI, ivals );

             for ( i = 0; i < MAXD; i++ )
             {
                dvals[i] = (double)i+1;
             }

             dasadd_c ( handle, MAXD, dvals );

             /.
             End the segment.
             ./
             dlaens_c ( handle );

             /.
             Close the file.  The routine dascls_c flushes the DAS
             buffers and segregates the file before closing it.
             ./
             dascls_c ( handle );

             /.
             Now read the file and check the data.
             ./
             dasopr_c ( DLA, &handle );

             /.
             Obtain the segment descriptor for the sole segment
             in the file. We need not check the found flag
             in this case because we know there is one segment
             in the file.
             ./
             dlabfs_c ( handle, &descr, &found );

             /.
             Fetch character data from the segment.  Obtain the
             base address of the character data and the
             character count from the descriptor.
             ./
             base = descr.cbase;
             n    = descr.csize;

             dasrdc_c ( handle, base+1, base+n, 0, LNSIZE-1, LNSIZE, cvals2 );

             /.
             Display the character data.
             ./
             printf( "\n" );
             printf( "Character array:\n" );

             for ( i = 0; i < n/LNSIZE; i++ )
             {
                /.
                Add null-terminating character to `cvals2[i]' in order to
                print it to the screen.
                ./
                strncpy( cvastr, cvals2[i], LNSIZE );
                cvastr[LNSIZE] = '\0';

                printf( "%s\n", cvastr );
             }

             /.
             Fetch and display the integer and double precision data.
             ./
             base = descr.ibase;
             n    = descr.isize;

             dasrdi_c ( handle, base+1, base+n, ivals2 );

             printf( "\n" );
             printf( "Integer array:\n" );
             for ( i = 0; i < n/10; i++ )
             {
                for ( j = 0; j < 10; j++ )
                {
                   printf( "%6d", ivals2[i*10+j] );
                }
                printf( "\n" );
             }

             base = descr.dbase;
             n    = descr.dsize;

             dasrdd_c ( handle, base+1, base+n, dvals2 );

             printf( "\n" );
             printf( "Double precision array:\n" );
             for ( i = 0; i < n/10; i++ )
             {
                for ( j = 0; j < 10; j++ )
                {
                   printf( "%6.1f", dvals2[i*10+j] );
                }
                printf( "\n" );
             }

             /.
             Close the file.  This step is unnecessary in this
             program, but is a good practice in general
             because closing the file frees resources.
             ./
             dascls_c ( handle );

             return ( 0 );
          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

          Character array:
          1234567890123456789012345678901234567890123456789012345678901
          2345678901234567890123456789012345678901234567890123456789012
          3456789012345678901234567890123456789012345678901234567890123
          4567890123456789012345678901234567890123456789012345678901234
          5678901234567890123456789012345678901234567890123456789012345

          Integer array:
               1     2     3     4     5     6     7     8     9    10
              11    12    13    14    15    16    17    18    19    20
              21    22    23    24    25    26    27    28    29    30
              31    32    33    34    35    36    37    38    39    40
              41    42    43    44    45    46    47    48    49    50
              51    52    53    54    55    56    57    58    59    60
              61    62    63    64    65    66    67    68    69    70
              71    72    73    74    75    76    77    78    79    80
              81    82    83    84    85    86    87    88    89    90
              91    92    93    94    95    96    97    98    99   100

          Double precision array:
             1.0   2.0   3.0   4.0   5.0   6.0   7.0   8.0   9.0  10.0
            11.0  12.0  13.0  14.0  15.0  16.0  17.0  18.0  19.0  20.0
            21.0  22.0  23.0  24.0  25.0  26.0  27.0  28.0  29.0  30.0
            31.0  32.0  33.0  34.0  35.0  36.0  37.0  38.0  39.0  40.0
            41.0  42.0  43.0  44.0  45.0  46.0  47.0  48.0  49.0  50.0

          Note that after run completion, a new DLA file exists in the
          output directory.

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

       J. Diaz del Rio     (ODC Space)

#### Version

       -CSPICE Version 1.0.0, 14-JUN-2021 (JDR)

#### Index_Entries

       begin new segment in DLA file

#### Link to routine dlabns_c source file dlabns_c.c

    Fri Dec 31 18:41:04 2021