/* zzekrd07.f -- translated by f2c (version 19980913).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* Table of constant values */

static integer c__1 = 1;

/* $Procedure   ZZEKRD07 ( EK, read class 7 column entry ) */
/* Subroutine */ int zzekrd07_(integer *handle, integer *segdsc, integer *
	coldsc, integer *recptr, integer *ival, logical *isnull)
{
    /* System generated locals */
    integer i__1, i__2;

    /* Local variables */
    integer mdat[2], nrec;
    extern integer zzekrp2n_(integer *, integer *, integer *);
    integer unit;
    char cflag[1];
    integer q, r__;
    extern /* Subroutine */ int chkin_(char *, ftnlen);
    integer recno, ncols, addrss, colidx, datbas, metloc, nflbas, offset;
    logical nullok;
    extern /* Subroutine */ int dashlu_(integer *, integer *), setmsg_(char *,
	     ftnlen), errint_(char *, integer *, ftnlen), errfnm_(char *, 
	    integer *, ftnlen), sigerr_(char *, ftnlen), chkout_(char *, 
	    ftnlen), dasrdi_(integer *, integer *, integer *, integer *), 
	    dasrdc_(integer *, integer *, integer *, integer *, integer *, 
	    char *, ftnlen);

/* $ Abstract */

/*     Read a column entry from a specified record in a class 7 column. */
/*     Class 7 columns contain fixed-count, scalar integer values. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     EK */

/* $ Keywords */

/*     EK */
/*     PRIVATE */

/* $ Declarations */
/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Boolean Enumerated Type */


/*        ekbool.inc Version 1   21-DEC-1994 (NJB) */


/*     Within the EK system, boolean values sometimes must be */
/*     represented by integer or character codes.  The codes and their */
/*     meanings are listed below. */

/*     Integer code indicating `true': */


/*     Integer code indicating `false': */


/*     Character code indicating `true': */


/*     Character code indicating `false': */


/*     End Include Section:  EK Boolean Enumerated Type */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Column Class 7 Parameters */

/*        ekclas07.inc  Version 1    07-NOV-1995 (NJB) */


/*     The following parameters give the offsets of items in the */
/*     class 7 integer metadata array. */

/*     Data array base address: */


/*     Null flag array base address: */


/*     Size of class 7 metadata array: */


/*     End Include Section:  EK Column Class 7 Parameters */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Column Descriptor Parameters */

/*        ekcoldsc.inc Version 6    23-AUG-1995 (NJB) */


/*     Note:  The column descriptor size parameter CDSCSZ  is */
/*     declared separately in the include section CDSIZE$INC.FOR. */

/*     Offset of column descriptors, relative to start of segment */
/*     integer address range.  This number, when added to the last */
/*     integer address preceding the segment, yields the DAS integer */
/*     base address of the first column descriptor.  Currently, this */
/*     offset is exactly the size of a segment descriptor.  The */
/*     parameter SDSCSZ, which defines the size of a segment descriptor, */
/*     is declared in the include file eksegdsc.inc. */


/*     Size of column descriptor */


/*     Indices of various pieces of column descriptors: */


/*     CLSIDX is the index of the column's class code.  (We use the */
/*     word `class' to distinguish this item from the column's data */
/*     type.) */


/*     TYPIDX is the index of the column's data type code (CHR, INT, DP, */
/*     or TIME).  The type is actually implied by the class, but it */
/*     will frequently be convenient to look up the type directly. */



/*     LENIDX is the index of the column's string length value, if the */
/*     column has character type.  A value of IFALSE in this element of */
/*     the descriptor indicates that the strings have variable length. */


/*     SIZIDX is the index of the column's element size value.  This */
/*     descriptor element is meaningful for columns with fixed-size */
/*     entries.  For variable-sized columns, this value is IFALSE. */


/*     NAMIDX is the index of the base address of the column's name. */


/*     IXTIDX is the data type of the column's index.  IXTIDX */
/*     contains a type value only if the column is indexed. For columns */
/*     that are not indexed, the location IXTIDX contains the boolean */
/*     value IFALSE. */


/*     IXPIDX is a pointer to the column's index.  IXTPDX contains a */
/*     meaningful value only if the column is indexed.  The */
/*     interpretation of the pointer depends on the data type of the */
/*     index. */


/*     NFLIDX is the index of a flag indicating whether nulls are */
/*     permitted in the column.  The value at location NFLIDX is */
/*     ITRUE if nulls are permitted and IFALSE otherwise. */


/*     ORDIDX is the index of the column's ordinal position in the */
/*     list of columns belonging to the column's parent segment. */


/*     METIDX is the index of the column's integer metadata pointer. */
/*     This pointer is a DAS integer address. */


/*     The last position in the column descriptor is reserved.  No */
/*     parameter is defined to point to this location. */


/*     End Include Section:  EK Column Descriptor Parameters */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Data Page Parameters */

/*        ekfilpar.inc  Version 1  03-APR-1995 (NJB) */

/*     These parameters apply to EK files using architecture 4. */
/*     These files use a paged DAS file as their underlying file */
/*     structure. */

/*     In paged DAS EK files, data pages are structured:  they contain */
/*     metadata as well as data.  The metadata is located in the last */
/*     few addresses of each page, so as to interfere as little as */
/*     possible with calculation of data addresses. */

/*     Each data page belongs to exactly one segment.  Some bookkeeping */
/*     information, such as record pointers, is also stored in data */
/*     pages. */

/*     Each page contains a forward pointer that allows rapid lookup */
/*     of data items that span multiple pages.  Each page also keeps */
/*     track of the current number of links from its parent segment */
/*     to the page.  Link counts enable pages to `know' when they */
/*     are no longer in use by a segment; unused pages are deallocated */
/*     and returned to the free list. */

/*     The parameters in this include file depend on the parameters */
/*     declared in the include file ekpage.inc.  If those parameters */
/*     change, this file must be updated.  The specified parameter */
/*     declarations we need from that file are: */

/*        INTEGER               PGSIZC */
/*        PARAMETER           ( PGSIZC = 1024 ) */

/*        INTEGER               PGSIZD */
/*        PARAMETER           ( PGSIZD = 128 ) */

/*        INTEGER               PGSIZI */
/*        PARAMETER           ( PGSIZI = 256 ) */



/*     Character pages use an encoding mechanism to represent integer */
/*     metadata.  Each integer is encoded in five consecutive */
/*     characters. */


/*     Character data page parameters: */


/*     Size of encoded integer: */


/*     Usable page size: */


/*     Location of character forward pointer: */


/*     Location of character link count: */


/*     Double precision data page parameters: */

/*     Usable page size: */


/*     Location of d.p. forward pointer: */


/*     Location of d.p. link count: */


/*     Integer data page parameters: */

/*     Usable page size: */


/*     Location of integer forward pointer: */


/*     Location of integer link count: */


/*     End Include Section:  EK Data Page Parameters */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Das Paging Parameters */

/*        ekpage.inc  Version 4    25-AUG-1995 (NJB) */



/*     The EK DAS paging system makes use of the integer portion */
/*     of an EK file's DAS address space to store the few numbers */
/*     required to describe the system's state.  The allocation */
/*     of DAS integer addresses is shown below. */


/*                       DAS integer array */

/*        +--------------------------------------------+ */
/*        |            EK architecture code            |  Address = 1 */
/*        +--------------------------------------------+ */
/*        |      Character page size (in DAS words)    | */
/*        +--------------------------------------------+ */
/*        |        Character page base address         | */
/*        +--------------------------------------------+ */
/*        |      Number of character pages in file     | */
/*        +--------------------------------------------+ */
/*        |   Number of character pages on free list   | */
/*        +--------------------------------------------+ */
/*        |      Character free list head pointer      |  Address = 6 */
/*        +--------------------------------------------+ */
/*        |                                            |  Addresses = */
/*        |           Metadata for d.p. pages          |    7--11 */
/*        |                                            | */
/*        +--------------------------------------------+ */
/*        |                                            |  Addresses = */
/*        |         Metadata for integer pages         |    12--16 */
/*        |                                            | */
/*        +--------------------------------------------+ */
/*                              . */
/*                              . */
/*                              . */
/*        +--------------------------------------------+ */
/*        |                                            |  End Address = */
/*        |                Unused space                |  integer page */
/*        |                                            |  end */
/*        +--------------------------------------------+ */
/*        |                                            |  Start Address = */
/*        |             First integer page             |  integer page */
/*        |                                            |  base */
/*        +--------------------------------------------+ */
/*                              . */
/*                              . */
/*                              . */
/*        +--------------------------------------------+ */
/*        |                                            | */
/*        |              Last integer page             | */
/*        |                                            | */
/*        +--------------------------------------------+ */

/*     The following parameters indicate positions of elements in the */
/*     paging system metadata array: */



/*     Number of metadata items per data type: */


/*     Character metadata indices: */


/*     Double precision metadata indices: */


/*     Integer metadata indices: */


/*     Size of metadata area: */


/*     Page sizes, in units of DAS words of the appropriate type: */


/*     Default page base addresses: */


/*     End Include Section:  EK Das Paging Parameters */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Segment Descriptor Parameters */

/*        eksegdsc.inc  Version 8  06-NOV-1995 (NJB) */


/*     All `base addresses' referred to below are the addresses */
/*     *preceding* the item the base applies to.  This convention */
/*     enables simplied address calculations in many cases. */

/*     Size of segment descriptor.  Note:  the include file ekcoldsc.inc */
/*     must be updated if this parameter is changed.  The parameter */
/*     CDOFF in that file should be kept equal to SDSCSZ. */


/*     Index of the segment type code: */


/*     Index of the segment's number.  This number is the segment's */
/*     index in the list of segments contained in the EK to which */
/*     the segment belongs. */


/*     Index of the DAS integer base address of the segment's integer */
/*     meta-data: */


/*     Index of the DAS character base address of the table name: */


/*     Index of the segment's column count: */


/*     Index of the segment's record count: */


/*     Index of the root page number of the record tree: */


/*     Index of the root page number of the character data page tree: */


/*     Index of the root page number of the double precision data page */
/*     tree: */


/*     Index of the root page number of the integer data page tree: */


/*     Index of the `modified' flag: */


/*     Index of the `initialized' flag: */


/*     Index of the shadowing flag: */


/*     Index of the companion file handle: */


/*     Index of the companion segment number: */


/*     The next three items are, respectively, the page numbers of the */
/*     last character, d.p., and integer data pages allocated by the */
/*     segment: */


/*     The next three items are, respectively, the page-relative */
/*     indices of the last DAS word in use in the segment's */
/*     last character, d.p., and integer data pages: */


/*     Index of the DAS character base address of the column name list: */


/*     The last descriptor element is reserved for future use.  No */
/*     parameter is defined to point to this location. */


/*     End Include Section:  EK Segment Descriptor Parameters */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Data Types */

/*        ektype.inc Version 1  27-DEC-1994 (NJB) */


/*     Within the EK system, data types of EK column contents are */
/*     represented by integer codes.  The codes and their meanings */
/*     are listed below. */

/*     Integer codes are also used within the DAS system to indicate */
/*     data types; the EK system makes no assumptions about compatibility */
/*     between the codes used here and those used in the DAS system. */


/*     Character type: */


/*     Double precision type: */


/*     Integer type: */


/*     `Time' type: */

/*     Within the EK system, time values are represented as ephemeris */
/*     seconds past J2000 (TDB), and double precision numbers are used */
/*     to store these values.  However, since time values require special */
/*     treatment both on input and output, and since the `TIME' column */
/*     has a special role in the EK specification and code, time values */
/*     are identified as a type distinct from double precision numbers. */


/*     End Include Section:  EK Data Types */

/* $ Brief_I/O */

/*     Variable  I/O  Description */
/*     --------  ---  -------------------------------------------------- */
/*     HANDLE     I   Handle attached to EK file. */
/*     SEGDSC     I   Segment descriptor. */
/*     COLDSC     I   Column descriptor. */
/*     RECPTR     I   Record pointer. */
/*     IVAL       O   Integer value in column entry. */
/*     ISNULL     O   Flag indicating whether column entry is null. */

/* $ Detailed_Input */

/*     HANDLE         is an EK file handle. */

/*     SEGDSC         is the descriptor of the segment from which data is */
/*                    to be read. */

/*     COLDSC         is the descriptor of the column from which data is */
/*                    to be read. */

/*     RECPTR         is a pointer to the record containing the column */
/*                    entry to be written.  For class 7 columns, record */
/*                    pointers are identical to record numbers. */

/* $ Detailed_Output */

/*     IVAL           is the value read from the specified column entry. */

/*     ISNULL         is a logical flag indicating whether the column */
/*                    entry is null. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

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

/*     2)  If the ordinal position of the column specified by COLDSC */
/*         is out of range, the error SPICE(INVALIDINDEX) is signalled. */

/*     3)  If an I/O error occurs while reading the indicated file, */
/*         the error will be diagnosed by routines called by this */
/*         routine. */

/* $ Files */

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

/* $ Particulars */

/*     This routine is a utility for reading data from class 7 columns. */

/* $ Examples */

/*     See EKRCEI. */

/* $ Restrictions */

/*     None. */

/* $ Literature_References */

/*     None. */

/* $ Author_and_Institution */

/*     N.J. Bachman   (JPL) */

/* $ Version */

/* -    Beta Version 1.0.0, 09-NOV-1995 (NJB) */

/* -& */

/*     Non-SPICELIB functions */


/*     Local variables */


/*     Use discovery check-in. */


/*     Make sure the column exists. */

    ncols = segdsc[4];
    colidx = coldsc[8];
    metloc = coldsc[9];
    nullok = coldsc[7] == 1;
    if (colidx < 1 || colidx > ncols) {
	recno = zzekrp2n_(handle, &segdsc[1], recptr);
	dashlu_(handle, &unit);
	chkin_("ZZEKRD07", (ftnlen)8);
	setmsg_("Column index = #; valid range is 1:#.SEGNO = #; RECNO = #; "
		"EK = #", (ftnlen)65);
	errint_("#", &colidx, (ftnlen)1);
	errint_("#", &nrec, (ftnlen)1);
	errint_("#", &segdsc[1], (ftnlen)1);
	errint_("#", &recno, (ftnlen)1);
	errfnm_("#", &unit, (ftnlen)1);
	sigerr_("SPICE(INVALIDINDEX)", (ftnlen)19);
	chkout_("ZZEKRD07", (ftnlen)8);
	return 0;
    }

/*     Read the metadata block.  There are two items in the block: */

/*        1) The base address of the first page of the data */
/*        2) The base address of the null flag array, if nulls are */
/*           permitted. */

    i__1 = metloc + 1;
    i__2 = metloc + 2;
    dasrdi_(handle, &i__1, &i__2, mdat);
    datbas = mdat[0];
    nflbas = mdat[1];

/*     If null values are permitted, the first step is to get */
/*     the null flag for the value of interest.  Compute the */
/*     address of this flag. */

/*     There are CPSIZE null flags per page, and each page has size */
/*     PGSIZC.  The null flags start at the beginning of the page. */

    if (nullok) {
	q = (*recptr - 1) / 1014;
	r__ = *recptr - q * 1014;
	offset = r__ + (q << 10);
	addrss = nflbas + offset;
	dasrdc_(handle, &addrss, &addrss, &c__1, &c__1, cflag, (ftnlen)1);
	*isnull = *(unsigned char *)cflag == 'T';
	if (*isnull) {
	    return 0;
	}
    }

/*     If we're still here, we'll read the data value. */

    *isnull = FALSE_;

/*     The address calculation for the value is analogous to that */
/*     for the null flag. */

    q = (*recptr - 1) / 254;
    r__ = *recptr - q * 254;
    offset = r__ + (q << 8);
    addrss = datbas + offset;
    dasrdi_(handle, &addrss, &addrss, ival);
    return 0;
} /* zzekrd07_ */

