Index Page ekaclc_c

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

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

       void ekaclc_c ( SpiceInt                handle,
                       SpiceInt                segno,
                       ConstSpiceChar        * column,
                       SpiceInt                vallen,
                       const void            * cvals,
                       ConstSpiceInt         * entszs,
                       ConstSpiceBoolean     * nlflgs,
                       ConstSpiceInt         * rcptrs,
                       SpiceInt              * wkindx  )

#### Abstract

       Add an entire character column to an EK segment.

#### Required_Reading

       EK

#### Keywords

       EK

#### Brief_I/O

       Variable  I/O  Description
       --------  ---  --------------------------------------------------
       handle     I   EK file handle.
       segno      I   Number of segment to add column to.
       column     I   Column name.
       vallen     I   Length of character values.
       cvals      I   Character values to add to column.
       entszs     I   Array of sizes of column entries.
       nlflgs     I   Array of null flags for column entries.
       rcptrs     I   Record pointers for segment.
       wkindx    I-O  Work space for column index.

#### Detailed_Input

       handle         the handle of an EK file that is open for writing.
                      A "begin segment for fast write" operation must
                      have already been performed for the designated
                      segment.

       segno          is the number of the segment to which data is to be
                      added. Segments are numbered from 0 to nseg-1, where
                      nseg is the count of segments in the file.

       column         is the name of the column to be added.  All of
                      the data for the named column will be added in
                      one shot.

       vallen         is the length of the strings in the cvals array.
                      The array should be declared with dimensions

                         [nrows][vallen]

                      where nrows is the number of rows in the column.

       cvals          is an array containing the entire set of column
                      entries for the specified column.  The entries
                      are listed in row-order:  the column entry for the
                      first row of the segment is first, followed by the
                      column entry for the second row, and so on.  The
                      number of column entries must match the declared
                      number of rows in the segment.  For columns having
                      fixed-size entries, a null entry must be allocated
                      the same amount of space occupied by a non-null
                      entry in the array cvals.  For columns having
                      variable-size entries, null entries do not require
                      any space in the cvals* array, but in any case must
                      have their allocated space described correctly by
                      the corresponding element of the entszs array
                      (described below).

       entszs         is an array containing sizes of column entries.
                      The Ith element of entszs gives the size of the
                      Ith column entry.  entszs is used only for columns
                      having variable-size entries.  For such columns,
                      the dimension of entszs must be at least nrows.
                      The size of null entries should be set to zero.

                      For columns having fixed-size entries, the
                      dimension of this array may be any positive value.

       nlflgs         is an array of logical flags indicating whether
                      the corresponding entries are null.  If the Ith
                      element of nlflgs is SPICEFALSE, the Ith column entry
                      defined by cvals and entszs is added to the
                      current segment in the specified kernel file.

                      If the Ith element of nlfgls is SPICETRUE, the
                      contents of the Ith column entry are undefined.

                      nlflgs is used only for columns that allow null
                      values; it's ignored for other columns.

       rcptrs         is an array of record pointers for the input
                      segment.  This array is obtained as an output
                      from ekifld_c, the routine called to initiate a
                      fast write.

       wkindx         is a work space array used for building a column
                      index.  If the column is indexed, the dimension of
                      wkindx_c must be at nrows, where nrows is the number
                      of rows in the column.  If the column is not
                      indexed, this work space is not used, so the
                      dimension may be any positive value.

#### Detailed_Output

       None.  See $Particulars for a description of the effect of this
       routine.

#### Parameters

       None.

#### Exceptions

       1)  If handle is invalid, the error will be diagnosed by routines
           called by this routine.

       2)  If column is not the name of a declared column, the error
           SPICE(NOCOLUMN) will be signaled.

       3)  If column specifies a column of whose data type is not
           character, the error SPICE(WRONGDATATYPE) will be
           signalled.

       4)  If the specified column already contains ANY entries, the
           error will be diagnosed by routines called by this routine.

       5)  If an I/O error occurs while reading or writing the indicated
           file, the error will be diagnosed by routines called by this
           routine.

       6) If the string pointer for column is null, the error
          SPICE(NULLPOINTER) will be signaled.

       7) If the input string column has length zero, the error
          SPICE(EMPTYSTRING) will be signaled.

       8) If the string pointer for cvals is null, the error
          SPICE(NULLPOINTER) will be signaled.

       9) If the string length vallen is less than 2, the error
          SPICE(STRINGTOOSHORT) will be signaled.

#### Files

       See the EK Required Reading for a discussion of the EK file
       format.

#### Particulars

       This routine operates by side effects:  it modifies the named
       EK file by adding data to the specified column.  This routine
       writes the entire contents of the specified column in one shot.
       This routine creates columns much more efficiently than can be
       done by sequential calls to ekacec_c, but has the drawback that
       the caller must use more memory for the routine's inputs.  This
       routine cannot be used to add data to a partially completed
       column.

#### Examples

       1)  Suppose we have an E-kernel named order_db.ek which contains
           records of orders for data products.  The E-kernel has a
           table called DATAORDERS that consists of the set of columns
           listed below:

              DATAORDERS

                 Column Name     Data Type
                 -----------     ---------
                 ORDER_ID        INTEGER
                 CUSTOMER_ID     INTEGER
                 LAST_NAME       CHARACTER*(*)
                 FIRST_NAME      CHARACTER*(*)
                 ORDER_DATE      TIME
                 COST            DOUBLE PRECISION

           The order database also has a table of items that have been
           ordered.  The columns of this table are shown below:

              DATAITEMS

                 Column Name     Data Type
                 -----------     ---------
                 ITEM_ID         INTEGER
                 ORDER_ID        INTEGER
                 ITEM_NAME       CHARACTER*(*)
                 DESCRIPTION     CHARACTER*(*)
                 PRICE           DOUBLE PRECISION

           We'll suppose that the file ORDER_DB.EK contains two segments,
           the first containing the DATAORDERS table and the second
           containing the DATAITEMS table.

           Below, we show how we'd open a new EK file and create the
           first of the segments described above.

           #include "SpiceUsr.h"
           #include <stdio.h>

           void main()
           {
              /.
              Constants
              ./
              #define  CNMLEN      ( CSPICE_EK_COL_NAM_LEN + 1 )
              #define  DECLEN        201
              #define  EKNAME        "order_db.ek"
              #define  FNMLEN        50
              #define  IFNAME        "Test EK/Created 20-SEP-1995"
              #define  LNMLEN        50
              #define  LSK           "leapseconds.ker"
              #define  NCOLS         6
              #define  NRESVC        0
              #define  NROWS         9
              #define  TABLE         "DATAORDERS"
              #define  TNMLEN        CSPICE_EK_TAB_NAM_LEN
              #define  UTCLEN        30

              /.
              Local variables
              ./
              SpiceBoolean            nlflgs [ NROWS  ];

              SpiceChar               cdecls  [ NCOLS ] [ DECLEN ];
              SpiceChar               cnames  [ NCOLS ] [ CNMLEN ];
              SpiceChar               fnames  [ NROWS ] [ FNMLEN ];
              SpiceChar               lnames  [ NROWS ] [ LNMLEN ];
              SpiceChar               dateStr [ UTCLEN ];

              SpiceDouble             costs  [ NROWS ];
              SpiceDouble             ets    [ NROWS ];

              SpiceInt                cstids [ NROWS ];
              SpiceInt                ordids [ NROWS ];
              SpiceInt                handle;
              SpiceInt                i;
              SpiceInt                rcptrs [ NROWS ];
              SpiceInt                segno;
              SpiceInt                sizes  [ NROWS ];
              SpiceInt                wkindx [ NROWS ];

              /.
              Load a leapseconds kernel for UTC/ET conversion.
              ./
              furnsh_c ( LSK );

              /.
              Open a new EK file.  For simplicity, we will not
              reserve any space for the comment area, so the
              number of reserved comment characters is zero.
              The constant IFNAME is the internal file name.
              ./
              ekopn_c ( EKNAME, IFNAME, NRESVC, &handle );

              /.
              Set up the table and column names and declarations
              for the DATAORDERS segment.  We'll index all of
              the columns.  All columns are scalar, so we omit
              the size declaration.  Only the COST column may take
              null values.
              ./
              strcpy ( cnames[0], "ORDER_ID"                           );
              strcpy ( cdecls[0], "DATATYPE = INTEGER, INDEXED = TRUE" );

              strcpy ( cnames[1], "CUSTOMER_ID"                        );
              strcpy ( cdecls[1], "DATATYPE = INTEGER, INDEXED = TRUE" );

              strcpy ( cnames[2], "LAST_NAME"                          );
              strcpy ( cdecls[2], "DATATYPE = CHARACTER*(*),"
                                  "INDEXED  = TRUE"                    );

              strcpy ( cnames[3], "FIRST_NAME"                         );
              strcpy ( cdecls[3], "DATATYPE = CHARACTER*(*),"
                                  "INDEXED  = TRUE"                    );

              strcpy ( cnames[4], "ORDER_DATE"                         );
              strcpy ( cdecls[4], "DATATYPE = TIME, INDEXED  = TRUE"   );

              strcpy ( cnames[5], "COST"                               );
              strcpy ( cdecls[5], "DATATYPE = DOUBLE PRECISION,"
                                  "INDEXED  = TRUE,"
                                  "NULLS_OK = TRUE"                    );

              /.
              Start the segment.  We presume the number of  rows
              of data is known in advance.
              ./
              ekifld_c ( handle,  TABLE,   NCOLS,  NROWS,   CNMLEN,
                         cnames,  DECLEN,  cdecls, &segno,  rcptrs );

              /.
              At this point, arrays containing data for the
              segment's columns may be filled in.  The names
              of the data arrays are shown below.

                 Column           Data array

                 "ORDER_ID"       ordids
                 "CUSTOMER_ID"    cstids
                 "LAST_NAME"      lnames
                 "FIRST_NAME"     fnames
                 "ORDER_DATE"     odates
                 "COST"           costs

              The null flags array indicates which entries are null.
              It is ignored for columns that don't allow null
              values.  In this case, only the COST column allows
              nulls.

              Fill in data arrays and null flag arrays here.  This code
              section would normally be replaced by calls to user functions
              returning column values.
              ./

              for ( i = 0;  i < NROWS;  i++ )
              {
                 ordids[i]  =  i;
                 cstids[i]  =  i*100;
                 costs [i]  =  (SpiceDouble) 100*i;

                 sprintf  ( fnames[i], "Order %d Customer first name", i );
                 sprintf  ( lnames[i], "Order %d Customer last name",  i );
                 sprintf  ( dateStr,   "1998 Mar %d",                  i );

                 utc2et_c ( dateStr, ets+i );

                 nlflgs[i]  =  SPICEFALSE;
              }

              nlflgs[1] = SPICETRUE;

              /.
              The sizes array shown below is ignored for scalar
              and fixed-size array columns, so we need not
              initialize it.  For variable-size arrays, the
              Ith element of the sizes array must contain the size
              of the Ith column entry in the column being written.
              Normally, the sizes array would be reset for each
              variable-size column.

              Add the columns of data to the segment.  All of the
              data for each column is written in one shot.
              ./
              ekacli_c ( handle,  segno,   "order_id",    ordids,
                         sizes,   nlflgs,  rcptrs,        wkindx );

              ekacli_c ( handle,  segno,   "customer_id", cstids,
                         sizes,   nlflgs,  rcptrs,        wkindx );

              ekaclc_c ( handle,  segno,   "last_name",   LNMLEN,
                         lnames,  sizes,   nlflgs,        rcptrs,  wkindx );

              ekaclc_c ( handle,  segno,   "first_name",  FNMLEN,
                         fnames,  sizes,   nlflgs,        rcptrs,  wkindx );

              ekacld_c ( handle,  segno,   "order_date",  ets,
                         sizes,   nlflgs,  rcptrs,        wkindx );

              ekacld_c ( handle,  segno,   "cost",        costs,
                         sizes,   nlflgs,  rcptrs,        wkindx );

              /.
              Complete the segment.  The rcptrs array is that
              returned by ekifld_c.
              ./
              ekffld_c ( handle, segno, rcptrs );

              /.
              At this point, the second segment could be
              created by an analogous process.  In fact, the
              second segment could be created at any time; it is
              not necessary to populate the first segment with
              data before starting the second segment.

              The file must be closed by a call to ekcls_c.
              ./
              ekcls_c ( handle );
           }

#### Restrictions

       1)  Only one segment can be created at a time using the fast
           write routines.

       2)  No other EK operation may interrupt a fast write.  For
           example, it is not valid to issue a query while a fast write
           is in progress.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman   (JPL)

#### Version

       -CSPICE Version 1.2.2, 14-AUG-2006   (EDW)

          Replace mention of ldpool_c with furnsh_c.

       -CSPICE Version 1.2.1, 09-JAN-2002 (NJB)

          Documentation change:  instances of the phrase "fast load"
          were replaced with "fast write."

          Const-qualified input array cvals.

       -CSPICE Version 1.1.0, 12-JUL-1998 (NJB)

           Bug fix:  now counts elements rather than rows for vector-valued
           columns.

           Bug fix:  now uses dynamically allocated array of type logical
           to interface with underlying f2c'd function ekaclc_.

           Now maps segno from C to Fortran range.

           Added "undef" of masking macro.  Changed input pointer types
           to pointers to const objects.

           Replaced eksdsc_ call with ekssum_c call.  This removes unsightly
           references to segment descriptor alignments.

           Fixed some chkout_c calls which referenced ekifld_c.

       -CSPICE Version 1.0.0, 25-FEB-1999 (NJB)

          Based on SPICELIB Version 1.0.0, 08-NOV-1995 (NJB)

#### Index_Entries

       write entire character column to EK segment

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

    Wed Apr  5 17:54:33 2017